146 Documents
  • Robert B. Hufnagel , Michael A. Walter, Gavin Arno
    Am J Med Genet Part C. 2020; 184C: 535– 537
    No abstract available.
  • Kari Branham, Dana Schlegel, Abigail T. Fahim, K. Thiran Jayasundera
    Am J Med Genet Part C. 2020; 184C: 571– 577
    No abstract available.
  • Chang Sup Lee, MD; Monique Leys, MD
    Ophthalmic Surgery, Lasers and Imaging Retina. 2020;51(6):354-362
    No abstract available.
  • Bojana Radojevic, Kaylie Jones, Martin Klein, Margarita Mauro-Herrera, Ronald Kingsley, David G. Birch & Lea D. Bennet
    Ophthalmic Genetics
    PMID: DOI: 10.1080/13816810.2020.1832532
    No abstract available.
  • R. Scott Lowery, John R. Dehnel, G. Bradley Schaefer & Sami H. Uwaydat
    Ophthalmic Genetics, 41:3, 271-274
    PMID: DOI: 10.1080/13816810.2020.1759107
    No abstract available.
  • Katharina G. Foote; Jessica J. Wong; Alexandra E. Boehm; Ethan Bensinger; Travis C. Porco; Austin Roorda; Jacque L. Duncan
    Investigative Ophthalmology & Visual Science April 2020, Vol.61, 42.
    PMID: doi:
    No abstract available.
  • Gabrielle Wheway, Andrew Douglas, Diana Baralle, Elsa Guillot
    Experimental Eye Research, Volume 192, March 2020, 107950
    No abstract available.
  • Roser Gonzàlez-Duarte, Marta de Castro-Miró, Miquel Tuson, Valeria Ramírez-Castañeda, Rebeca Valero Gils, Gemma Marfany
    Retinal Degenerative Diseases. Advances in Experimental Medicine and Biology, vol 1185. Springer, Cham
    No abstract available.
  • Zou J., Li R., Wang Z., Yang J.
    Retinal Degenerative Diseases. Advances in Experimental Medicine and Biology, vol 1185. Springer, Cham
    No abstract available.
  • Edwin H. Yau; Robert T. Taggart; Mohammed Zuber; Alexandria J. Trujillo; Zahra S. Fayazi; Mark C. Butler; Lowell G. Sheflin; Jennifer B. Breen; Dian Yu; Jack M. Sullivan
    Translational Vision Science & Technology December 2019, Vol.8, 28
    PMID: doi:
    No abstract available.
  • Katharina G. Foote; Nicholas Rinella; Janette Tang; Nicolas Bensaid; Hao Zhou; Qinqin Zhang; Ruikang K. Wang; Travis C. Porco; Austin Roorda; Jacque L. Duncan
    Investigative Ophthalmology & Visual Science November 2019, Vol.60, 4931-4942.
    PMID: doi:
    No abstract available.
  • Harini V. Gudiseva, Jesse L. Berry, Ashley Polski, Santa J. Tummina and Joan M. O’Brien
    Genes 2019, 10(12), 1032
    No abstract available.
  • Irena Tsui, Brian J. Song, Chyuan-Sheng Lin, Stephen H. Tsang
    Tsui I., Song B.J., Lin CS., Tsang S.H. (2018) A Practical Approach to Retinal Dystrophies. In: Tsang S., Sharma T. (eds) Atlas of Inherited Retinal Diseases. Advances in Experimental Medicine and Biology, vol 1085. Springer, Cham
    No abstract available.
  • Peter Y. Zhao, Maria Fernanda Abalem, Daniel Nadelman, Cynthia X. Qian, Kari Branham, Dana Schlegel, Naheed Khan, John R. Heckenlively, Thiran Jayasundera
    American Journal of Ophthalmology, Vol. 188, pgs. 104-110
    No abstract available.
  • Vivek Navale, Michelle Ji, Evan McCreedy, Tsega Gebremichael, Alison Garcia, Leonie Misquitta, Ching-Heng Lin, Yang Fann, Matthew McAuliffe
    bioRxiv 259465; doi:
    This article is a preprint and has not been peer-reviewed
    PMID: doi:
    No abstract available.
  • Simon M. Petersen-Jones, Laurence M. Occelli, Paige A. Winkler, Winston Lee, Janet R. Sparrow, Mai Tsukikawa, Sanford L. Boye, Vince Chiodo, Jenina E. Capasso, Elvir Becirovic, Christian Schön, Mathias W. Seeliger, Alex V. Levin, Stylianos Michalakis, William W. Hauswirth, Stephen H. Tsang
    J Clin Invest. 2018;128(1):190-206.
    No abstract available.
  • JZ Kartchner, ME Hartnett
    American Journal of Ophthalmology Case , 2017.
    No abstract available.
  • Sun LW, Johnson RD, Williams V, Summerfelt P, Dubra A, Weinberg DV, Stepien KE, Fishman GA, Carroll J
    PLoS One. 2016 Dec 9;11(12):e0167526. doi: 10.1371/journal.pone.0167526. eCollection 2016.
    PMID: 27936069

    PURPOSE: Choroideremia is a progressive X-linked recessive dystrophy, characterized by degeneration of the retinal pigment epithelium (RPE), choroid, choriocapillaris, and photoreceptors. We examined photoreceptor structure in a series of subjects with choroideremia with particular attention to areas bordering atrophic lesions. METHODS: Twelve males with clinically-diagnosed choroideremia and confirmed hemizygous mutations in the CHM gene were examined. High-resolution images of the retina were obtained using spectral domain optical coherence tomography (SD-OCT) and both confocal and non-confocal split-detector adaptive optics scanning light ophthalmoscope (AOSLO) techniques. RESULTS: Eleven CHM gene mutations (3 novel) were identified; three subjects had the same mutation and one subject had two mutations. SD-OCT findings included interdigitation zone (IZ) attenuation or loss in 10/12 subjects, often in areas with intact ellipsoid zones; RPE thinning in all subjects; interlaminar bridges in the imaged areas of 10/12 subjects; and outer retinal tubulations (ORTs) in 10/12 subjects. Only split-detector AOSLO could reliably resolve cones near lesion borders, and such cones were abnormally heterogeneous in morphology, diameter and density. On split-detector imaging, the cone mosaic terminated sharply at lesion borders in 5/5 cases examined. Split-detector imaging detected remnant cone inner segments within ORTs, which were generally contiguous with a central patch of preserved retina. CONCLUSIONS: Early IZ dropout and RPE thinning on SD-OCT are consistent with previously published results. Evidence of remnant cone inner segments within ORTs and the continuity of the ORTs with preserved retina suggests that these may represent an intermediate state of retinal degeneration prior to complete atrophy. Taken together, these results supports a model of choroideremia in which the RPE degenerates before photoreceptors. 

  • Zhong Z, Yan M, Sun W, Wu Z, Han L, Zhou Z, Zheng F, Chen J
    Sci Rep. 2016 Nov 25;6:37840. doi: 10.1038/srep37840.
    PMID: 27886254

    Retinitis pigmentosa (RP) is a heterogeneous set of hereditary eye diseases, characterized by selective death of photoreceptor cells in the retina, resulting in progressive visual impairment. Approximately 20-40% of RP cases are autosomal dominant RP (ADRP). In this study, a Chinese ADRP family previously localized to the region between D1S2819 and D1S2635 was sequenced via whole-exome sequencing and a variant c.1345C > G (p.R449G) was identified in PRPF3. The Sanger sequencing was performed in probands of additional 95 Chinese ADRP families to investigate the contribution of PRPF3 to ADRP in Chinese population and another variant c.1532A > C (p.H511P) was detected in one family. These two variants, co-segregate with RP in two families respectively and both variants are predicted to be pathological. This is the first report about the spectrum of PRPF3 mutations in Chinese population, leading to the identification of two novel PRPF3 mutations. Only three clustered mutations in PRPF3 have been identified so far in several populations and all are in exon 11. Our study expands the spectrum of PRPF3 mutations in RP. We also demonstrate that PRPF3 mutations are responsible for 2.08% of ADRP families in this cohort indicating that PRPF3 mutations might be relatively rare in Chinese ADRP patients. 

  • Arno G, Agrawal SA, Eblimit A, Bellingham J, Xu M, Wang F, Chakarova C, Parfitt DA, Lane A, Burgoyne T, Hull S, Carss KJ, Fiorentino A, Hayes MJ, Munro PM, Nicols R, Pontikos N, Holder GE, Asomugha C, Raymond FL, Moore AT, Plagnol V, Michaelides M, Hardcastle AJ, Li Y, Cukras C, Webster AR, Cheetham ME, Chen R
    Am J Hum Genet. 2016 Nov 17. pii: S0002-9297(16)30444-X. doi: 10.1016/j.ajhg.2016.10.008.
    PMID: 27889058

    Retinitis pigmentosa (RP) is a heterogeneous set of hereditary eye diseases, characterized by selective death of photoreceptor cells in the retina, resulting in progressive visual impairment. Approximately 20-40% of RP cases are autosomal dominant RP (ADRP). In this study, a Chinese ADRP family previously localized to the region between D1S2819 and D1S2635 was sequenced via whole-exome sequencing and a variant c.1345C > G (p.R449G) was identified in PRPF3. The Sanger sequencing was performed in probands of additional 95 Chinese ADRP families to investigate the contribution of PRPF3 to ADRP in Chinese population and another variant c.1532A > C (p.H511P) was detected in one family. These two variants, co-segregate with RP in two families respectively and both variants are predicted to be pathological. This is the first report about the spectrum of PRPF3 mutations in Chinese population, leading to the identification of two novel PRPF3 mutations. Only three clustered mutations in PRPF3 have been identified so far in several populations and all are in exon 11. Our study expands the spectrum of PRPF3 mutations in RP. We also demonstrate that PRPF3 mutations are responsible for 2.08% of ADRP families in this cohort indicating that PRPF3 mutations might be relatively rare in Chinese ADRP patients. 

  • Barnes RO, Shea KE, Watson PH
    Biopreserv Biobank. 2016 Oct 14.
    PMID: 27740852

    As health research increasingly relies on biospecimens and associated data, new demands have emerged for biorepositories to provide assurances of the quality of their overall operations, not just assurances of the quality of the biospecimens and data that they hold. The biobanking community has responded in various ways, including the creation of two different programs to disseminate biobanking best practices. This article describes in detail the Canadian Tissue Repository Network (CTRNet) Biobank Certification Program and the College of American Pathologists (CAP) Biorepository Accreditation Program. Despite differences in their approaches, these programs share one key element-assessment of biobanking practices by an external organization. In the absence of a single internationally endorsed biobanking best practices dissemination program, the CTRNet and CAP programs provide two different solutions, each contributing to the pursuit of enhanced quality in biobanking. 

  • Thomas AS, Branham K, Van Gelder RN, Daiger SP, Sullivan LS, Bowne SJ, Heckenlively JR, Pennesi ME
    Ophthalmic Surg Lasers Imaging Retina. 2016 Jun 1;47(6):574-9. doi: 10.3928/23258160-20160601-10.
    PMID: 27327288

    Wagner syndrome is a rare vitreoretinopathy described in a limited number of families. Here the authors describe four cases of suspected Wagner syndrome. All four cases had depressed rod and cone function on electroretinography, outer retinal disruption on spectral-domain optical coherence tomography, and constricted central visual fields with smaller isopter testing. Fundus autofluorescence performed in one patient highlighted a perivascular pattern to chorioretinal atrophy. Two patients had a history of uveitis with active cystoid macular edema. The diagnosis of Wagner syndrome was supported in three cases with genetic testing for VCAN mutations, whereas the other case harbored a variation of unknown significance in VCAN that may have been nonpathogenic. [Ophthalmic Surg Lasers Imaging Retina. 2016;47:574-579.]. 

  • Collins DW, Gudiseva HV, Trachtman B, Bowman AS, Sagaser A, Sankar P, Miller-Ellis E, Lehman A, Addis V, O'Brien JM
    Mol Vis. 2016 May 16;22:454-71. eCollection 2016.
    PMID: 27217714

    PURPOSE: To estimate the population frequencies of all common mitochondrial variants and ancestral haplogroups among 1,999 subjects recruited for the Primary Open-Angle African American Glaucoma Genetics (POAAGG) Study, including 1,217 primary open-angle glaucoma (POAG) cases and 782 controls, and to identify ancestral subpopulations and mitochondrial mutations as potential risk factors for POAG susceptibility. METHODS: Subject classification by characteristic glaucomatous optic nerve findings and corresponding visual field defects, as defined by enrolling glaucoma specialists, stereo disc photography, phlebotomy, extraction of total DNA from peripheral blood or saliva, DNA quantification and normalization, PCR amplification of whole mitochondrial genomes, Ion Torrent deep semiconductor DNA sequencing on DNA pools ("Pool-seq"), Sanger sequencing of 3,479 individual mitochondrial DNAs, and bioinformatic analysis. RESULTS: The distribution of common African haplogroups within the POAAGG study population was broadly similar to prior surveys of African Americans. However, the POAG case population was found to be enriched in L1c2 haplogroups, which are defined in part by missense mutations m.6150G>A (Val83Ile, odds ratio [OR] 1.8, p=0.01), m.6253C>T (Met117Thr, rs200165736, OR 1.6, p=0.04), and m.6480G>A (Val193Ile, rs199476128, OR 4.6, p=0.04) in the cytochrome c oxidase subunit 1 (MT-CO1) gene and by a variant, m.2220A>G (OR 2.0, p=0.01), in MT-RNR2, which encodes the mitochondrial ribosomal 16s RNA gene. L2 haplogroups were predicted to be overrepresented in the POAG case population by Pool-seq, and the difference was confirmed to be significant with Sanger sequencing, that targeted the L2-associated variants m.2416T>C (rs28358580, OR 1.2, p=0.02) and m.2332C>T (OR 1.2, p=.02) in MT-RNR2. Another variant within MT-RNR2, m.3010G>A (rs3928306), previously implicated in sensitivity to the optic neuropathy-associated antibiotic linezolid, and arising on D4 and J1 lineages, associated with Leber hereditary optic neuropathy (LHON) severity, was confirmed to be common (>5%) but was not significantly enriched in the POAG cases. Two variants linked to the composition of the gut microbiome, m.15784T>C (rs527236194, haplogroup L2a1) and m.16390G>A (rs41378955, L2 haplogroups), were also enriched in the case DNA pools. CONCLUSIONS: These results implicate African mtDNA haplogroups L1c2, L1c2b, and L2 as risk factors for POAG. Approximately one in four African Americans have these mitochondrial ancestries, which may contribute to their elevated glaucoma risk. These haplogroups are defined in part by ancestral variants in the MT-RNR2 and/or MT-CO1 genes, several of which have prior disease associations, such as MT-CO1 missense variants that have been implicated in prostate cancer. 

  • Rao KN, Zhang W, Li L, Ronquillo C, Baehr W, Khanna H
    Hum Mol Genet. 2016 May 15;25(10):2005-2012. Epub 2016 Mar 2.
    PMID: 26936822

    Mutations in RPGR (retinitis pigmentosa GTPase regulator) are the most common cause of X-linked RP, a severe blindness disorder. RPGR mutations result in clinically variable disease with early- to late-onset phenotypic presentation. Molecular mechanisms underlying such heterogeneity are unclear. Here we show that phenotypic expression of Rpgr-loss in mice is influenced genetically by the loss of Cep290, a human ciliopathy gene. We found that Rpgrko/Y mice with a heterozygous hypomorphic allele of Cep290 (Cep290rd16/+) but not of a heterozygous null allele of Cep290 (Cep290null/+) or of other ciliopathy genes, Rpgrip1, Nphp1, Nphp4 and Nphp5, exhibit relatively early onset (by 3 months of age) retinal degeneration and dysfunction when compared with the onset at approximately 7 months of age in the Rpgrko/Y mice. We also observed disorganized photoreceptor outer-segment morphology and defective trafficking of opsins in the Rpgrko/Y::Cep290rd16/+ mice. Together with a physical interaction between RPGR and the C-terminal domain of CEP290, our data suggest that RPGR and CEP290 genetically interact and highlight the involvement of hypomorphic alleles of genes as potential modifiers of heterogeneous retinal ciliopathies. 

  • Sun LW, Johnson RD, Langlo CS, Cooper RF, Razeen MM, Russillo MC, Dubra A, Connor TB Jr, Han DP, Pennesi ME, Kay CN, Weinberg DV, Stepien KE, Carroll J
    Invest Ophthalmol Vis Sci. 2016 May 1;57(6):2428-42. doi: 10.1167/iovs.15-18246.
    PMID: 27145477

    PURPOSE: The purpose of this study was to examine cone photoreceptor structure in retinitis pigmentosa (RP) and Usher syndrome using confocal and nonconfocal split-detector adaptive optics scanning light ophthalmoscopy (AOSLO). METHODS: Nineteen subjects (11 RP, 8 Usher syndrome) underwent ophthalmic and genetic testing, spectral-domain optical coherence tomography (SD-OCT), and AOSLO imaging. Split-detector images obtained in 11 subjects (7 RP, 4 Usher syndrome) were used to assess remnant cone structure in areas of altered cone reflectivity on confocal AOSLO. RESULTS: Despite normal interdigitation zone and ellipsoid zone appearance on OCT, foveal and parafoveal cone densities derived from confocal AOSLO images were significantly lower in Usher syndrome compared with RP. This was due in large part to an increased prevalence of non-waveguiding cones in the Usher syndrome retina. Although significantly correlated to best-corrected visual acuity and foveal sensitivity, cone density can decrease by nearly 38% before visual acuity becomes abnormal. Aberrantly waveguiding cones were noted within the transition zone of all eyes and corresponded to intact inner segment structures. These remnant cones decreased in density and increased in diameter across the transition zone and disappeared with external limiting membrane collapse. CONCLUSIONS: Foveal cone density can be decreased in RP and Usher syndrome before visible changes on OCT or a decline in visual function. Thus, AOSLO imaging may allow more sensitive monitoring of disease than current methods. However, confocal AOSLO is limited by dependence on cone waveguiding, whereas split-detector AOSLO offers unambiguous and quantifiable visualization of remnant cone inner segment structure. Confocal and split-detector thus offer complementary insights into retinal pathology. 

  • Gudiseva HV, Hansen M, Gutierrez L, Collins DW, He J, Verkuil LD, Danford ID, Sagaser A, Bowman AS, Salowe R, Sankar PS, Miller-Ellis E, Lehman A, O'Brien JM
    BMC Med Genomics. 2016 Apr 7;9:17. doi: 10.1186/s12920-016-0172-y.
    PMID: 27052975

    BACKGROUND: The question of whether DNA obtained from saliva is an acceptable alternative to DNA from blood is a topic of considerable interest for large genetics studies. We compared the yields, quality and performance of DNAs from saliva and blood from a mostly elderly study population. METHODS: Two thousand nine hundred ten DNAs from primarily elderly subjects (mean age +/- standard deviation (SD): 65 +/- 12 years), collected for the Primary Open-Angle African-American Glaucoma Genetics (POAAGG) study, were evaluated by fluorometry and/or spectroscopy. These included 566 DNAs from blood and 2344 from saliva. Subsets of these were evaluated by Sanger sequencing (n = 1555), and by microarray SNP genotyping (n = 94) on an Illumina OmniExpress bead chip platform. RESULTS: The mean age of subjects was 65, and 68 % were female in both the blood and saliva groups. The mean +/- SD of DNA yield per ml of requested specimen was significantly higher for saliva (17.6 +/- 17.8 mug/ml) than blood (13.2 +/- 8.5 mug/ml), but the mean +/- SD of total DNA yield obtained per saliva specimen (35 +/- 36 mug from 2 ml maximum specimen volume) was approximately three-fold lower than from blood (106 +/- 68 mug from 8 ml maximum specimen volume). The average genotyping call rates were >99 % for 43 of 44 saliva DNAs and >99 % for 50 of 50 for blood DNAs. For 22 of 23 paired blood and saliva samples from the same individuals, the average genotyping concordance rate was 99.996 %. High quality PCR Sanger sequencing was obtained from >/= 98 % of blood (n = 297) and saliva (n = 1258) DNAs. DNA concentrations >/=10 ng/mul, corresponding to total yields >/= 2 mug, were obtained for 94 % of the saliva specimens (n = 2344). CONCLUSIONS: In spite of inferior purity, the performance of saliva DNAs for microarray genotyping was excellent. Our results agree with other studies concluding that saliva collection is a viable alternative to blood. The potential to boost study enrollments and reduce subject discomfort is not necessarily offset by a reduction in genotyping efficiency. Saliva DNAs performed comparably to blood DNAs for PCR Sanger sequencing. 

  • Freund PR, Sergeev YV, MacDonald IM
    Mol Genet Genomic Med. 2016 Feb 28;4(3):344-58. doi: 10.1002/mgg3.208. eCollection 2016 May.
    PMID: 27247961

    BACKGROUND: Choroideremia (CHM) is an X-linked degeneration of the retinal pigment epithelium, photoreceptors, and choroid, which causes nyctalopia and progressive constriction of visual fields leading to blindness. The CHM gene encodes Rab escort protein 1 (REP-1). In this work, we reviewed the phenotypes and genotypes of affected males with the purpose of understanding the functional effects of CHM mutations and their relationship with the phenotypes. METHODS: A retrospective review of 128 affected males was performed analyzing the onset of symptoms, visual acuity, and visual fields with respect to their mutations in the CHM gene. RESULTS: In rank order, reflecting data from this report, the most common mutations found in the CHM gene were nonsense mutations (41%), exon deletions (37%), and splice sites (14%) associated with a loss of functional protein. In the pool of 106 CHM mutations, we discovered four novel missense mutations (c.238C>T; p.L80F, c.819G>T; p.Q273H, c.1327A>G; p.M443V, and c.1370C>T; p.L457P) predicted to be severe changes affecting protein stability and folding with the effect similar to that of other types of mutations. No significant genotype-phenotype correlation was found with respect to the onset of nyctalopia, the onset of other visual symptoms, visual acuity, or width of visual fields. CONCLUSION: There is no evidence to support exclusion of CHM patients from clinical trials based on their genotypes or any potential genotype-phenotype correlations. 

  • Parrish RS, Garafalo AV, Ndifor V, Goetz KE, Reeves MJ, Yim A, Cooper RC, Iano-Fletcher J, Wang X, Tumminia SJ
    Biopreserv Biobank. 2016 Feb 18.
    PMID: 26891080

    Quality assurance and quality control (QA/QC) procedures are vital to good biorepository management. The National Eye Institute (NEI) core CLIA-certified laboratory of the eyeGENE(R) Network receives blood from individuals with inherited eye conditions and isolates DNA for clinical genetic diagnostic testing and research. Clinical genetic test results are returned to the affected individuals, making it imperative that sample integrity is preserved throughout laboratory processing. A clinically validated, short tandem repeat (STR)-based approach, termed Sample Confirmation Testing (SCT), was developed to ensure that no significant laboratory errors occurred during processing. SCT uses modified protocols from commercial kits to create and compare STR profiles for each participant's original blood and derived DNA. This QA/QC procedure has been performed on 47% of the more than 6000 participants in the eyeGENE Biorepository and has identified significant laboratory errors in 0.4% of samples tested. SCT improves the quality of the data returned to affected individuals and the data distributed to researchers using eyeGENE samples by ensuring the integrity of the samples and aiding in curation of the biorepository. This approach serves as a model for other repositories to improve sample quality and management procedures. 

  • Ku CA, Hariprasad SM, Pennesi ME
    Ophthalmic Surg Lasers Imaging Retina. 2016 Jan 1;47(1):6-12. doi: 10.3928/23258160-20151214-01.
    PMID: 26731203
    No abstract available.
  • Ge Z, Bowles K, Goetz K, Scholl HP, Wang F, Wang X, Xu S, Wang K, Wang H, Chen R
    Sci Rep. 2015 Dec 15;5:18287. doi: 10.1038/srep18287.
    PMID: 26667666

    The National Ophthalmic Disease Genotyping and Phenotyping Network (eyeGENE(R)) was established in an effort to facilitate basic and clinical research of human inherited eye disease. In order to provide high quality genetic testing to eyeGENE(R)'s enrolled patients which potentially aids clinical diagnosis and disease treatment, we carried out a pilot study and performed Next-generation sequencing (NGS) based molecular diagnosis for 105 Retinitis Pigmentosa (RP) patients randomly selected from the network. A custom capture panel was designed, which incorporated 195 known retinal disease genes, including 61 known RP genes. As a result, disease-causing mutations were identified in 52 out of 105 probands (solving rate of 49.5%). A total of 82 mutations were identified, and 48 of them were novel. Interestingly, for three probands the molecular diagnosis was inconsistent with the initial clinical diagnosis, while for five probands the molecular information suggested a different inheritance model other than that assigned by the physician. In conclusion, our study demonstrated that NGS target sequencing is efficient and sufficiently precise for molecular diagnosis of a highly heterogeneous patient cohort from eyeGENE(R). 

  • Strauss RW, Munoz B, Wolfson Y, Sophie R, Fletcher E, Bittencourt MG, Scholl HP
    Br J Ophthalmol. 2015 Nov 14. pii: bjophthalmol-2015-307035. doi: 10.1136/bjophthalmol-2015-307035.
    PMID: 26568636

    AIMS: To estimate disease progression based on analysis of macular volume measured by spectral-domain optical coherence tomography (SD-OCT) in patients affected by Stargardt macular dystrophy (STGD1) and to evaluate the influence of software errors on these measurements. METHODS: 58 eyes of 29 STGD1 patients were included. Numbers and types of algorithm errors were recorded and manually corrected. In a subgroup of 36 eyes of 18 patients with at least two examinations over time, total macular volume (TMV) and volumes of all nine Early Treatment of Diabetic Retinopathy Study (ETDRS) subfields were obtained. Random effects models were used to estimate the rate of change per year for the population, and empirical Bayes slopes were used to estimate yearly decline in TMV for individual eyes. RESULTS: 6958 single B-scans from 190 macular cube scans were analysed. 2360 (33.9%) showed algorithm errors. Mean observation period for follow-up data was 15 months (range 3-40). The median (IQR) change in TMV using the empirical Bayes estimates for the individual eyes was -0.103 (-0.145, -0.059) mm3 per year. The mean (+/-SD) TMV was 6.321+/-1.000 mm3 at baseline, and rate of decline was -0.118 mm3 per year (p=0.003). Yearly mean volume change was -0.004 mm3 in the central subfield (mean baseline=0.128 mm3), -0.032 mm3 in the inner (mean baseline=1.484 mm3) and -0.079 mm3 in the outer ETDRS subfields (mean baseline=5.206 mm3). CONCLUSIONS: SD-OCT measurements allow monitoring the decline in retinal volume in STGD1; however, they require significant manual correction of software errors. 

  • Xu M, Yang L, Wang F, Li H, Wang X, Wang W, Ge Z, Wang K, Zhao L, Li H, Li Y, Sui R, Chen R
    Hum Genet. 2015 Oct;134(10):1069-78. doi: 10.1007/s00439-015-1586-x. Epub 2015 Jul 28.
    PMID: 26216056

    Leber congenital amaurosis (LCA) and retinitis pigmentosa (RP) are two genetically heterogeneous retinal degenerative disorders. Despite the identification of a number of genes involved in LCA and RP, the genetic etiology remains unknown in many patients. In this study, we aimed to identify novel disease-causing genes of LCA and RP. Retinal capture sequencing was initially performed to screen mutations in known disease-causing genes in different cohorts of LCA and RP patients. For patients with negative results, we performed whole exome sequencing and applied a series of variant filtering strategies. Sanger sequencing was done to validate candidate causative IFT140 variants. Exome sequencing data analysis led to the identification of IFT140 variants in multiple unrelated non-syndromic LCA and RP cases. All the variants are extremely rare and predicted to be damaging. All the variants passed Sanger validation and segregation tests provided that the family members' DNA was available. The results expand the phenotype spectrum of IFT140 mutations to non-syndromic retinal degeneration, thus extending our understanding of intraflagellar transport and primary cilia biology in the retina. This work also improves the molecular diagnosis of retinal degenerative disease. 

  • Zayit-Soudry S, Sippl-Swezey N, Porco TC, Lynch SK, Syed R, Ratnam K, Menghini M, Roorda AJ, Duncan JL
    Invest Ophthalmol Vis Sci. 2015 Sep 1;56(10):6179-89. doi: 10.1167/iovs.15-17010.
    PMID: 26416092

    PURPOSE: To determine short-term variability of adaptive optics scanning laser ophthalmoscopy (AOSLO)-derived cone spacing measures in eyes with inherited retinal degenerations (IRD) and in normal eyes. METHODS: Twenty IRD patients and 10 visually normal subjects underwent AOSLO imaging at two visits separated by no more than 1 month (NCT00254605). Cone spacing was measured in multiple macular regions in each image by three independent graders. Variability of cone spacing measures between visits, between graders, and between eyes was determined and correlated with standard clinical measures. RESULTS: Cone spacing was measured in 2905 regions. Interobserver agreement was high both in normal eyes and eyes with IRD (mean intraclass correlation coefficient [ICC] = 0.838 for normal and 0.892 for eyes with IRD). Cone spacing measures were closely correlated between visits (ICC > 0.869 for both study groups). Mean relative intervisit spacing difference (absolute difference in measures divided by the mean at each region) was 4.0% for normal eyes and 4.9% for eyes with IRD. Cone spacing measures from fellow eyes of the same subject showed strong agreement for all subjects (ICC > 0.85 for both study groups). CONCLUSIONS: Adaptive optics scanning laser ophthalmoscopy-derived macular cone spacing measures were correlated between observers, visits, and fellow eyes of the same subject in normal eyes and in eyes with IRD. This information may help establish the role of cone spacing measures derived from images of the cone mosaic obtained with AOSLO as a sensitive biomarker for longitudinal tracking of photoreceptor loss during disease progression and in response to treatment. ( number, NCT00254605.). 

  • Wu Z, Hiriyanna S, Qian H, Mookherjee S, Campos MM, Gao C, Fariss R, Sieving PA, Li T, Colosi P, Swaroop A
    Hum Mol Genet. 2015 Jul 15;24(14):3956-70. doi: 10.1093/hmg/ddv134. Epub 2015 Apr 15.
    PMID: 25877300

    Mutations in the retinitis pigmentosa GTPase regulator (RPGR) gene account for >70% of X-linked retinitis pigmentosa (XLRP) and 15-20% of all inherited retinal degeneration. Gene replacement therapy for RPGR-XLRP was hampered by the relatively slow disease progression in mouse models and by difficulties in cloning the full-length RPGR-ORF15 cDNA that includes a purine-rich 3'-coding region; however, its effectiveness has recently been demonstrated in four dogs with RPGR mutations. To advance the therapy to clinical stage, we generated new stable vectors in AAV8 or AAV9 carrying mouse and human full-length RPGR-ORF15-coding sequence and conducted a comprehensive long-term dose-efficacy study in Rpgr-knockout mice. After validating their ability to produce full-length proteins that localize to photoreceptor connecting cilia, we evaluated various vector doses in mice during a 2-year study. We demonstrate that eyes treated with a single injection of mouse or human RPGR-ORF15 vector at an optimal dose maintained the expression of RPGR-ORF15 throughout the study duration and exhibited higher electroretinogram amplitude, thicker photoreceptor layer and better targeting of opsins to outer segments compared with sham-treated eyes. Furthermore, mice that received treatment at an advanced age also showed remarkable preservation of retinal structure and function. Retinal toxicity was observed at high vector doses, highlighting the importance of careful dose optimization in future clinical experiments. Our long-term dose-efficacy study should facilitate the design of human trials with human RPGR-ORF15 vector as a clinical candidate. 

  • Mackay DS, Bennett TM, Shiels A
    PLoS One. 2015 Jul 10;10(7):e0132529. doi: 10.1371/journal.pone.0132529. eCollection 2015.
    PMID: 26162006

    Primary open-angle glaucoma (POAG) is a clinically important and genetically heterogeneous cause of progressive vision loss as a result of retinal ganglion cell death. Here we have utilized trio-based, whole-exome sequencing to identify the genetic defect underlying an autosomal dominant form of adult-onset POAG segregating in an African-American family. Exome sequencing identified a novel missense variant (c.418C>T, p.Arg140Trp) in exon-5 of the gene coding for epidermal growth factor (EGF) containing fibulin-like extracellular matrix protein 1 (EFEMP1) that co-segregated with disease in the family. Linkage and haplotype analyses with microsatellite markers indicated that the disease interval overlapped a known POAG locus (GLC1H) on chromosome 2p. The p.Arg140Trp substitution was predicted in silico to have damaging effects on protein function and transient expression studies in cultured cells revealed that the Trp140-mutant protein exhibited increased intracellular accumulation compared with wild-type EFEMP1. In situ hybridization of the mouse eye with oligonucleotide probes detected the highest levels of EFEMP1 transcripts in the ciliary body, cornea, inner nuclear layer of the retina, and the optic nerve head. The recent finding that a common variant near EFEMP1 was associated with optic nerve-head morphology supports the possibility that the EFEMP1 variant identified in this POAG family may be pathogenic. 

  • Yoon CK, Kim NK, Joung JG, Shin JY, Park JH, Eum HH, Lee HO, Park WY, Yu HG
    BMC Genomics. 2015 Jul 9;16:515. doi: 10.1186/s12864-015-1723-x.
    PMID: 26155838

    BACKGROUND: Identification of the causative genes of retinitis pigmentosa (RP) is important for the clinical care of patients with RP. However, a comprehensive genetic study has not been performed in Korean RP patients. Moreover, the genetic heterogeneity found in sensorineural genetic disorders makes identification of pathogenic mutations challenging. Therefore, high throughput genetic testing using massively parallel sequencing is needed. RESULTS: Sixty-two Korean patients with nonsyndromic RP (46 patients from 18 families and 16 simplex cases) who consented to molecular genetic testing were recruited in this study and targeted exome sequencing was applied on 53 RP-related genes. Causal variants were characterised by selecting exonic and splicing variants, selecting variants with low allele frequency (below 1 %), and discarding the remaining variants with quality below 20. The variants were additionally confirmed by an inheritance pattern and cosegregation test of the families, and the rest of the variants were prioritised using in-silico prediction tools. Finally, causal variants were detected from 10 of 18 familial cases (55.5 %) and 7 of 16 simplex cases (43.7 %) in total. Novel variants were detected in 13 of 20 (65 %) candidate variants. Compound heterozygous variants were found in four of 7 simplex cases. CONCLUSION: Panel-based targeted re-sequencing can be used as an effective molecular diagnostic tool for RP. 

  • Rao KN, Li L, Anand M, Khanna H
    Sci Rep. 2015 Jun 11;5:11137. doi: 10.1038/srep11137.
    PMID: 26068394

    Cilia regulate several developmental and homeostatic pathways that are critical to survival. Sensory cilia of photoreceptors regulate phototransduction cascade for visual processing. Mutations in the ciliary protein RPGR (retinitis pigmentosa GTPase regulator) are a prominent cause of severe blindness disorders due to degeneration of mature photoreceptors. However, precise function of RPGR is still unclear. Here we studied the involvement of RPGR in ciliary trafficking by analyzing the composition of photoreceptor sensory cilia (PSC) in Rpgr(ko) retina. Using tandem mass spectrometry analysis followed by immunoblotting, we detected few alterations in levels of proteins involved in proteasomal function and vesicular trafficking in Rpgr(ko) PSC, prior to onset of degeneration. We also found alterations in the levels of high molecular weight soluble proteins in Rpgr(ko) PSC. Our data indicate RPGR regulates entry or retention of soluble proteins in photoreceptor cilia but spares the trafficking of key structural and phototransduction-associated proteins. Given a frequent occurrence of RPGR mutations in severe photoreceptor degeneration due to ciliary disorders, our results provide insights into pathways resulting in altered mature cilia function in ciliopathies. 

  • Xu M, Gelowani V, Eblimit A, Wang F, Young MP, Sawyer BL, Zhao L, Jenkins G, Creel DJ, Wang K, Ge Z, Wang H, Li Y, Hartnett ME, Chen R
    Invest Ophthalmol Vis Sci. 2015 Jun;56(6):3889-95. doi: 10.1167/iovs.15-16778.
    PMID: 26070061

    PURPOSE: Photoreceptor degeneration (PRD) is a genetically heterogeneous retinal disorder. Although a number of genes involved in PRD have been identified, their genetic basis remains unknown in a significant number of patients. In this study, we aimed to identify novel disease-causing genes of PRD. METHODS: Comprehensive ocular examinations were performed in a 2-year-old patient diagnosed with early onset PRD. Retinal capture sequencing was performed to screen causative mutations in known retinal disease-causing loci. Whole-exome sequencing (WES) and a series of variant-filtering strategies were applied for identifying novel disease-causing genes. Retina ATF6 expression was confirmed by immunohistochemistry. RT-PCR was performed to identify ATF6 mRNA in the patient. RESULTS: The patient showed typical PRD features, with macular involvement and ellipsoid zone irregularities. Results of retinal capture sequencing were negative. WES data led to identification of biallelic loss-of-function mutations in the ATF6 gene. The first variant generates a premature stop codon (NCBI accession no. NM_007348: c.1126C>T, p.R376*) and the second variant affects a splicing donor site (NM_007348: c.1533+1G>C). Sanger sequencing confirmed the 2 alleles are from 1 parent each. Both of the variants are extremely rare in the population. The splicing variant causes either intron inclusion or exon skipping in the patient, thus severely disrupting ATF6 functional domains. ATF6 is expressed in three neuronal cell layers of mouse retina. CONCLUSIONS: Our results support ATF6 as a novel disease-causing gene for PRD and suggest that disrupted protein quality control mechanisms may be a novel pathological mechanism underlying human retinal degeneration. 

  • Jacobson SG, Cideciyan AV, Aguirre GD, Roman AJ, Sumaroka A, Hauswirth WW, Palczewski K
    Expert Opin Orphan Drugs. 2015 May 4;3(5):563-575.
    PMID: 26246977

    Introduction: Inherited retinal degenerations (IRDs) have long been considered untreatable and incurable. Recently, one form of early-onset autosomal recessive IRD, Leber congenital amaurosis (LCA) caused by mutations in RPE65 (retinal pigment epithelium-specific protein 65 kDa) gene, has responded with some improvement of vision to gene augmentation therapy and oral retinoid administration. This early success now requires refinement of such therapeutics to fully realize the impact of these major scientific and clinical advances. Areas covered: Progress toward human therapy for RPE65-LCA is detailed from the understanding of molecular mechanisms to preclinical proof-of-concept research to clinical trials. Unexpected positive and complicating results in the patients receiving treatment are explained. Logical next steps to advance the clinical value of the therapeutics are suggested. Expert opinion: The first molecularly based early-phase therapies for an IRD are remarkably successful in that vision has improved and adverse events are mainly associated with surgical delivery to the subretinal space. Yet, there are features of the gene augmentation therapeutic response, such as slowed kinetics of night vision, lack of foveal cone function improvement and relentlessly progressive retinal degeneration despite therapy, that still require research attention. 

  • Yang HJ, Ratnapriya R, Cogliati T, Kim JW, Swaroop A
    Prog Retin Eye Res. 2015 May;46:1-30. doi: 10.1016/j.preteyeres.2015.01.005. Epub 2015 Feb 7.
    PMID: 25668385

    Genomics and genetics have invaded all aspects of biology and medicine, opening uncharted territory for scientific exploration. The definition of "gene" itself has become ambiguous, and the central dogma is continuously being revised and expanded. Computational biology and computational medicine are no longer intellectual domains of the chosen few. Next generation sequencing (NGS) technology, together with novel methods of pattern recognition and network analyses, has revolutionized the way we think about fundamental biological mechanisms and cellular pathways. In this review, we discuss NGS-based genome-wide approaches that can provide deeper insights into retinal development, aging and disease pathogenesis. We first focus on gene regulatory networks (GRNs) that govern the differentiation of retinal photoreceptors and modulate adaptive response during aging. Then, we discuss NGS technology in the context of retinal disease and develop a vision for therapies based on network biology. We should emphasize that basic strategies for network construction and analyses can be transported to any tissue or cell type. We believe that specific and uniform guidelines are required for generation of genome, transcriptome and epigenome data to facilitate comparative analysis and integration of multi-dimensional data sets, and for constructing networks underlying complex biological processes. As cellular homeostasis and organismal survival are dependent on gene-gene and gene-environment interactions, we believe that network-based biology will provide the foundation for deciphering disease mechanisms and discovering novel drug targets for retinal neurodegenerative diseases. 

  • Lee K, Garg S
    Genet Med. 2015 Apr;17(4):245-52. doi: 10.1038/gim.2015.15. Epub 2015 Mar 19.
    PMID: 25790163

    Inherited eye disorders are a significant cause of vision loss. Genetic testing can be particularly helpful for patients with inherited retinal dystrophies because of genetic heterogeneity and overlapping phenotypes. The need to identify a molecular diagnosis for retinal dystrophies is particularly important in the era of developing novel gene therapy-based treatments, such as the RPE65 gene-based clinical trials and others on the horizon, as well as recent advances in reproductive options. The introduction of massively parallel sequencing technologies has significantly advanced the identification of novel gene candidates and has expanded the landscape of genetic testing. In a relatively short time clinical medicine has progressed from limited testing options to a plethora of choices ranging from single-gene testing to whole-exome sequencing. This article outlines currently available genetic testing and factors to consider when selecting appropriate testing for patients with inherited retinal dystrophies. 

  • Thompson DA, Ali RR, Banin E, Branham KE, Flannery JG, Gamm DM, Hauswirth WW, Heckenlively JR, Iannaccone A, Jayasundera KT, Khan NW, Molday RS, Pennesi ME, Reh TA, Weleber RG, Zacks DN
    Invest Ophthalmol Vis Sci. 2015 Feb 9;56(2):918-31. doi: 10.1167/iovs.14-16049.
    PMID: 25667399

    Although rare in the general population, retinal dystrophies occupy a central position in current efforts to develop innovative therapies for blinding diseases. This status derives, in part, from the unique biology, accessibility, and function of the retina, as well as from the synergy between molecular discoveries and transformative advances in functional assessment and retinal imaging. The combination of these factors has fueled remarkable progress in the field, while at the same time creating complex challenges for organizing collective efforts aimed at advancing translational research. The present position paper outlines recent progress in gene therapy and cell therapy for this group of disorders, and presents a set of recommendations for addressing the challenges remaining for the coming decade. It is hoped that the formulation of these recommendations will stimulate discussions among researchers, funding agencies, industry, and policy makers that will accelerate the development of safe and effective treatments for retinal dystrophies and related diseases. 

  • Weiss JS, Moller HU, Aldave AJ, Seitz B, Bredrup C, Kivela T, Munier FL, Rapuano CJ, Nischal KK, Kim EK, Sutphin J, Busin M, Labbe A, Kenyon KR, Kinoshita S, Lisch W
    Cornea. 2015 Feb;34(2):117-59. doi: 10.1097/ICO.0000000000000307.
    PMID: 25564336

    PURPOSE: To update the 2008 International Classification of Corneal Dystrophies (IC3D) incorporating new clinical, histopathologic, and genetic information. METHODS: The IC3D reviewed worldwide peer-reviewed articles for new information on corneal dystrophies published between 2008 and 2014. Using this information, corneal dystrophy templates and anatomic classification were updated. New clinical, histopathologic, and confocal photographs were added. RESULTS: On the basis of revisiting the cellular origin of corneal dystrophy, a modified anatomic classification is proposed consisting of (1) epithelial and subepithelial dystrophies, (2) epithelial-stromal TGFBI dystrophies, (3) stromal dystrophies, and (4) endothelial dystrophies. Most of the dystrophy templates are updated. The entity "Epithelial recurrent erosion dystrophies" actually includes a number of potentially distinct epithelial dystrophies (Franceschetti corneal dystrophy, Dystrophia Smolandiensis, and Dystrophia Helsinglandica) but must be differentiated from dystrophies such as TGFBI-induced dystrophies, which are also often associated with recurrent epithelial erosions. The chromosome locus of Thiel-Behnke corneal dystrophy is only located on 5q31. The entity previously designated as a variant of Thiel-Behnke corneal dystrophy on chromosome 10q24 may represent a novel corneal dystrophy. Congenital hereditary endothelial dystrophy (CHED, formerly CHED2) is most likely only an autosomal recessive disorder. The so-called autosomal dominant inherited CHED (formerly CHED1) is insufficiently distinct to continue to be considered a unique corneal dystrophy. On review of almost all of the published cases, the description appeared most similar to a type of posterior polymorphous corneal dystrophy linked to the same chromosome 20 locus (PPCD1). Confocal microscopy also has emerged as a helpful tool to reveal in vivo features of several corneal dystrophies that previously required histopathologic examination to definitively diagnose. CONCLUSIONS: This revision of the IC3D classification includes an updated anatomic classification of corneal dystrophies more accurately classifying TGFBI dystrophies that affect multiple layers rather than are confined to one corneal layer. Typical histopathologic and confocal images have been added to the corneal dystrophy templates. 

  • Schwarz N, Carr AJ, Lane A, Moeller F, Chen LL, Aguila M, Nommiste B, Muthiah MN, Kanuga N, Wolfrum U, Nagel-Wolfrum K, da Cruz L, Coffey PJ, Cheetham ME, Hardcastle AJ
    Hum Mol Genet. 2015 Feb 15;24(4):972-86. doi: 10.1093/hmg/ddu509. Epub 2014 Oct 6.
    PMID: 25292197

    Mutations in the RP2 gene lead to a severe form of X-linked retinitis pigmentosa. RP2 patients frequently present with nonsense mutations and no treatments are currently available to restore RP2 function. In this study, we reprogrammed fibroblasts from an RP2 patient carrying the nonsense mutation c.519C>T (p.R120X) into induced pluripotent stem cells (iPSC), and differentiated these cells into retinal pigment epithelial cells (RPE) to study the mechanisms of disease and test potential therapies. RP2 protein was undetectable in the RP2 R120X patient cells, suggesting a disease mechanism caused by complete lack of RP2 protein. The RP2 patient fibroblasts and iPSC-derived RPE cells showed phenotypic defects in IFT20 localization, Golgi cohesion and Gbeta1 trafficking. These phenotypes were corrected by over-expressing GFP-tagged RP2. Using the translational read-through inducing drugs (TRIDs) G418 and PTC124 (Ataluren), we were able to restore up to 20% of endogenous, full-length RP2 protein in R120X cells. This level of restored RP2 was sufficient to reverse the cellular phenotypic defects observed in both the R120X patient fibroblasts and iPSC-RPE cells. This is the first proof-of-concept study to demonstrate successful read-through and restoration of RP2 function for the R120X nonsense mutation. The ability of the restored RP2 protein level to reverse the observed cellular phenotypes in cells lacking RP2 indicates that translational read-through could be clinically beneficial for patients. 

  • Saffra N, Reinherz B
    BMJ Case Rep. 2015 Jan 16;2015. pii: bcr2014203737. doi: 10.1136/bcr-2014-203737.
    PMID: 25596286

    22q11.2 Deletion syndrome is one of the most common microdeletional syndromes, with an incidence of 1:4000 live-births, and potentially affects every organ in the body. More than 180 associated clinical features have been reported and not one phenotypic feature is present in 100% of cases. Ocular manifestations reported based on early childhood examinations include eyelid hooding, strabismus, posterior embryotoxon, retinal vessel tortuosity and refractive errors. Keratoconus has been reported once before in association with 22q11.2 deletion syndrome in a young adult. We report the second case of keratoconus in association with 22q11.2 deletion syndrome. 

  • Choquet R, Maaroufi M, de Carrara A, Messiaen C, Luigi E, Landais P
    J Am Med Inform Assoc. 2015 Jan;22(1):76-85. doi: 10.1136/amiajnl-2014-002794. Epub 2014 Jul 18.
    PMID: 25038198

    BACKGROUND: Although rare disease patients make up approximately 6-8% of all patients in Europe, it is often difficult to find the necessary expertise for diagnosis and care and the patient numbers needed for rare disease research. The second French National Plan for Rare Diseases highlighted the necessity for better care coordination and epidemiology for rare diseases. A clinical data standard for normalization and exchange of rare disease patient data was proposed. The original methodology used to build the French national minimum data set (F-MDS-RD) common to the 131 expert rare disease centers is presented. METHODS: To encourage consensus at a national level for homogeneous data collection at the point of care for rare disease patients, we first identified four national expert groups. We reviewed the scientific literature for rare disease common data elements (CDEs) in order to build the first version of the F-MDS-RD. The French rare disease expert centers validated the data elements (DEs). The resulting F-MDS-RD was reviewed and approved by the National Plan Strategic Committee. It was then represented in an HL7 electronic format to maximize interoperability with electronic health records. RESULTS: The F-MDS-RD is composed of 58 DEs in six categories: patient, family history, encounter, condition, medication, and questionnaire. It is HL7 compatible and can use various ontologies for diagnosis or sign encoding. The F-MDS-RD was aligned with other CDE initiatives for rare diseases, thus facilitating potential interconnections between rare disease registries. CONCLUSIONS: The French F-MDS-RD was defined through national consensus. It can foster better care coordination and facilitate determining rare disease patients' eligibility for research studies, trials, or cohorts. Since other countries will need to develop their own standards for rare disease data collection, they might benefit from the methods presented here. 

  • E Reichel, AJ Aldave, DA Schaumberg
    Expert Review of Ophthalmology , 2015.
    No abstract available.
  • Daiger SP, Bowne SJ, Sullivan LS
    Cold Spring Harb Perspect Med. 2014 Oct 10;5(10). pii: a017129. doi: 10.1101/cshperspect.a017129.
    PMID: 25304133

    Retinitis pigmentosa (RP) has a prevalence of approximately one in 4000; 25%-30% of these cases are autosomal dominant retinitis pigmentosa (adRP). Like other forms of inherited retinal disease, adRP is exceptionally heterogeneous. Mutations in more than 25 genes are known to cause adRP, more than 1000 mutations have been reported in these genes, clinical findings are highly variable, and there is considerable overlap with other types of inherited disease. Currently, it is possible to detect disease-causing mutations in 50%-75% of adRP families in select populations. Genetic diagnosis of adRP has advantages over other forms of RP because segregation of disease in families is a useful tool for identifying and confirming potentially pathogenic variants, but there are disadvantages too. In addition to identifying the cause of disease in the remaining 25% of adRP families, a central challenge is reconciling clinical diagnosis, family history, and molecular findings in patients and families. 

  • Farkas MH, Lew DS, Sousa ME, Bujakowska K, Chatagnon J, Bhattacharya SS, Pierce EA, Nandrot EF
    Am J Pathol. 2014 Oct;184(10):2641-52. doi: 10.1016/j.ajpath.2014.06.026. Epub 2014 Aug 8.
    PMID: 25111227

    Mutations in the ubiquitously expressed pre-mRNA processing factors 3, 8, and 31 (PRPF3, PRPF8, and PRPF31) cause nonsyndromic dominant retinitis pigmentosa in humans, an inherited retinal degeneration. It is unclear what mechanisms, or which cell types of the retina, are affected. Transgenic mice with the human mutations in these genes display late-onset morphological changes in the retinal pigment epithelium (RPE). To determine whether the observed morphological changes are preceded by abnormal RPE function, we investigated its phagocytic function in Prpf3(T494M/T494M), Prpf8(H2309P/H2309P), and Prpf31(+/-) mice. We observe decreased phagocytosis in primary RPE cultures from mutant mice, and this is replicated by shRNA-mediated knockdown of PRPF31 in human ARPE-19 cells. The diurnal rhythmicity of phagocytosis is almost lost, indicated by the marked attenuation of the phagocytic burst 2 hours after light onset. The strength of adhesion between RPE apical microvilli and photoreceptor outer segments also declined during peak adhesion in all mutants. In all models, at least one of the receptors involved in binding and internalization of shed photoreceptor outer segments was subjected to changes in localization. Although the mechanism underlying these changes in RPE function is yet to be elucidated, these data are consistent with the mouse RPE being the primary cell affected by mutations in the RNA splicing factors, and these changes occur at an early age. 

  • Sullivan LS, Koboldt DC, Bowne SJ, Lang S, Blanton SH, Cadena E, Avery CE, Lewis RA, Webb-Jones K, Wheaton DH, Birch DG, Coussa R, Ren H, Lopez I, Chakarova C, Koenekoop RK, Garcia CA, Fulton RS, Wilson RK, Weinstock GM, Daiger SP
    Invest Ophthalmol Vis Sci. 2014 Sep 4;55(11):7147-58. doi: 10.1167/iovs.14-15419.
    PMID: 25190649

    PURPOSE: To identify the cause of retinitis pigmentosa (RP) in UTAD003, a large, six-generation Louisiana family with autosomal dominant retinitis pigmentosa (adRP). METHODS: A series of strategies, including candidate gene screening, linkage exclusion, genome-wide linkage mapping, and whole-exome next-generation sequencing, was used to identify a mutation in a novel disease gene on chromosome 10q22.1. Probands from an additional 404 retinal degeneration families were subsequently screened for mutations in this gene. RESULTS: Exome sequencing in UTAD003 led to identification of a single, novel coding variant (c.2539G>A, p.Glu847Lys) in hexokinase 1 (HK1) present in all affected individuals and absent from normal controls. One affected family member carries two copies of the mutation and has an unusually severe form of disease, consistent with homozygosity for this mutation. Screening of additional adRP probands identified four other families (American, Canadian, and Sicilian) with the same mutation and a similar range of phenotypes. The families share a rare 450-kilobase haplotype containing the mutation, suggesting a founder mutation among otherwise unrelated families. CONCLUSIONS: We identified an HK1 mutation in five adRP families. Hexokinase 1 catalyzes phosphorylation of glucose to glucose-6-phosphate. HK1 is expressed in retina, with two abundant isoforms expressed at similar levels. The Glu847Lys mutation is located at a highly conserved position in the protein, outside the catalytic domains. We hypothesize that the effect of this mutation is limited to the retina, as no systemic abnormalities in glycolysis were detected. Prevalence of the HK1 mutation in our cohort of RP families is 1%. 

  • Capasso JE
    Curr Opin Ophthalmol. 2014 Sep;25(5):394-9. doi: 10.1097/ICU.0000000000000085.
    PMID: 25010001

    PURPOSE OF REVIEW: To facilitate ophthalmologists' understanding on the cost of genetic testing in ocular disease, the complexities of insurance coverage and its impact on the availability of testing. RECENT FINDINGS: Many insurance carriers address coverage for genetic testing in written clinical policies. They provide criteria for medically necessary testing. These policies mostly cover testing for individuals who are symptomatic and in whom testing will have a direct impact on medical treatment. In cases in which no treatments are currently available, other than research trials, patients may have difficulty in getting insurance coverage for genetic testing. SUMMARY: Genetic testing for inherited eye diseases can be costly but has many benefits to patient care, including confirmation of a diagnosis, insight into prognostic information, and identification of associated health risks, inheritance patterns, and possible current and future treatments. As gene therapy advances progress, the availability for treatment in ocular diseases, coverage for genetic testing by third-party payers could increase on the basis of current clinical policies. 

  • Parekh M, Montanini L, Crafa P, Salvalaio G, Ruzza A, Aaspollu A, Mora P, Orsoni J, Ponzin D, Ferrari S
    Biopreserv Biobank. 2014 Aug;12(4):255-8. doi: 10.1089/bio.2014.0018.
    PMID: 25162462

    Research studies on pathologies affecting the posterior segment of the eye are usually carried out either in animal models or cell lines of human origin that mimic the molecular patterns occurring in the human retina-pigment epithelium-choroid (RPC) complex in vivo. As this is not always the case, we were prompted to validate a biorepository of RPC tissues for research purposes. A PubMed literature search on "retina," "choroid," "bio-bank," or "biorepository" as keywords did not lead to any publication describing the collection and banking of samples from the RPC complex for research purposes. The possibility to obtain access to a validated collection of high quality human RPC tissues as starting material is likely to lead to more appropriate findings and treatments, which eventually may improve human ocular health. Here we show that when tissues are harvested (T <25 hours from donor death) and stored appropriately, RNAs are not degraded (RNA Integrity Number Values >8.0) and express specific genes and molecular/biochemical pathways occurring in the RPC complex. These quality controlled tissues/RNAs comprising the biorepository could therefore be used for gene expression studies by research scientists and clinicians interested in testing their hypotheses in a more appropriate setting, thus replacing studies performed on less relevant animal models and cells in vitro, and directly extrapolating the findings to human pathophysiology. 

  • Alapati A, Goetz K, Suk J, Navani M, Al-Tarouti A, Jayasundera T, Tumminia SJ, Lee P, Ayyagari R
    Invest Ophthalmol Vis Sci. 2014 Jul 31;55(9):5510-21. doi: 10.1167/iovs.14-14359.
    PMID: 25082885

    PURPOSE: To analyze the genetic test results of probands referred to eyeGENE with a diagnosis of hereditary maculopathy. METHODS: Patients with Best macular dystrophy (BMD), Doyne honeycomb retinal dystrophy (DHRD), Sorsby fundus dystrophy (SFD), or late-onset retinal degeneration (LORD) were screened for mutations in BEST1, EFEMP1, TIMP3, and CTRP5, respectively. Patients with pattern dystrophy (PD) were screened for mutations in PRPH2, BEST1, ELOVL4, CTRP5, and ABCA4; patients with cone-rod dystrophy (CRD) were screened for mutations in CRX, ABCA4, PRPH2, ELOVL4, and the c.2513G>A p.Arg838His variant in GUCY2D. Mutation analysis was performed by dideoxy sequencing. Impact of novel variants was evaluated using the computational tool PolyPhen. RESULTS: Among the 213 unrelated patients, 38 had BMD, 26 DHRD, 74 PD, 8 SFD, 6 LORD, and 54 CRD; six had both PD and BMD, and one had no specific clinical diagnosis. BEST1 variants were identified in 25 BMD patients, five with novel variants of unknown significance (VUS). Among the five patients with VUS, one was diagnosed with both BMD and PD. A novel EFEMP1 variant was identified in one DHRD patient. TIMP3 novel variants were found in two SFD patients, PRPH2 variants in 14 PD patients, ABCA4 variants in four PD patients, and p.Arg838His GUCY2D mutation in six patients diagnosed with dominant CRD; one patient additionally had a CRX VUS. ABCA4 mutations were identified in 15 patients with recessive CRD. CONCLUSIONS: Of the 213 samples, 55 patients (26%) had known causative mutations, and 13 (6%) patients had a VUS that was possibly pathogenic. Overall, selective screening for mutations in BEST1, PRPH2, and ABCA4 would likely yield the highest success rate in identifying the genetic basis for macular dystrophy phenotypes. Because of the overlap in phenotypes between BMD and PD, it would be beneficial to screen genes associated with both diseases. 

  • Pan X, Chen X, Liu X, Gao X, Kang X, Xu Q, Chen X, Zhao K, Zhang X, Chu Q, Wang X, Zhao C
    Mol Vis. 2014 Jun 2;20:770-9. eCollection 2014.
    PMID: 24940031

    PURPOSE: Seven genes involved in precursor mRNA (pre-mRNA) splicing have been implicated in autosomal dominant retinitis pigmentosa (adRP). We sought to detect mutations in all seven genes in Chinese families with RP, to characterize the relevant phenotypes, and to evaluate the prevalence of mutations in splicing genes in patients with adRP. METHODS: Six unrelated families from our adRP cohort (42 families) and two additional families with RP with uncertain inheritance mode were clinically characterized in the present study. Targeted sequence capture with next-generation massively parallel sequencing (NGS) was performed to screen mutations in 189 genes including all seven pre-mRNA splicing genes associated with adRP. Variants detected with NGS were filtered with bioinformatics analyses, validated with Sanger sequencing, and prioritized with pathogenicity analysis. RESULTS: Mutations in pre-mRNA splicing genes were identified in three individual families including one novel frameshift mutation in PRPF31 (p.Leu366fs*1) and two known mutations in SNRNP200 (p.Arg681His and p.Ser1087Leu). The patients carrying SNRNP200 p.R681H showed rapid disease progression, and the family carrying p.S1087L presented earlier onset ages and more severe phenotypes compared to another previously reported family with p.S1087L. In five other families, we identified mutations in other RP-related genes, including RP1 p. Ser781* (novel), RP2 p.Gln65* (novel) and p.Ile137del (novel), IMPDH1 p.Asp311Asn (recurrent), and RHO p.Pro347Leu (recurrent). CONCLUSIONS: Mutations in splicing genes identified in the present and our previous study account for 9.5% in our adRP cohort, indicating the important role of pre-mRNA splicing deficiency in the etiology of adRP. Mutations in the same splicing gene, or even the same mutation, could correlate with different phenotypic severities, complicating the genotype-phenotype correlation and clinical prognosis. 

  • Miraldi Utz V, Coussa RG, Marino MJ, Chappelow AV, Pauer GJ, Hagstrom SA, Traboulsi EI
    Br J Ophthalmol. 2014 Apr;98(4):513-8. doi: 10.1136/bjophthalmol-2013-304270. Epub 2014 Jan 23.
    PMID: 24457364

    PURPOSE: To assess the genotypic diversity in patients with Stargardt disease and to characterise epidemiological and genotypic predictors of phenotype. METHODS: Retrospective, cross-sectional study of 112 patients with Stargardt disease. We evaluated the correlation between age at presentation, best-corrected visual acuity (BCVA), and ABCA4 genotypes. RESULTS: Mean age at presentation was 30 +/- 16 years (range 6-78 years) for the 112 patients of 104 families. 98 of 90 families had a probable molecular diagnosis. We found that BCVA is not related to age of presentation in a linear or polynomial manner; that BCVA of patients presenting in the first decade was significantly worse than those presenting in later decades (p=0.04); that patients who harboured two or more mutations presented earlier and had worse BCVA than those with no or 1 mutation identified by any method of testing (n=112, p=3.29 x 10(-6)) or by full sequencing (n=32, p=0.02); that 16 patients with c.5882G>A allele demonstrated better BCVA than the remaining patients (p=0.01); and that 10 patients with the c.5461-10T>C mutation presented earlier (p=0.02 x 10(-5)) and had more severe disease. CONCLUSIONS: Epidemiological and genotypical findings portend visual prognosis in patients with Stargardt disease. Select sequence variations in ABCA4 may confer a specific phenotype. The present data will help in assessing patients for emerging therapies. 

  • Khan MI, Azam M, Ajmal M, Collin RW, den Hollander AI, Cremers FP, Qamar R
    Genes (Basel). 2014 Mar 11;5(1):176-95. doi: 10.3390/genes5010176.
    PMID: 24705292

    The customary consanguineous nuptials in Pakistan underlie the frequent occurrence of autosomal recessive inherited disorders, including retinal dystrophy (RD). In many studies, homozygosity mapping has been shown to be successful in mapping susceptibility loci for autosomal recessive inherited disease. RDs are the most frequent cause of inherited blindness worldwide. To date there is no comprehensive genetic overview of different RDs in Pakistan. In this review, genetic data of syndromic and non-syndromic RD families from Pakistan has been collected. Out of the 132 genes known to be involved in non-syndromic RD, 35 different genes have been reported to be mutated in families of Pakistani origin. In the Pakistani RD families 90% of the mutations causing non-syndromic RD and all mutations causing syndromic forms of the disease have not been reported in other populations. Based on the current inventory of all Pakistani RD-associated gene defects, a cost-efficient allele-specific analysis of 11 RD-associated variants is proposed, which may capture up to 35% of the genetic causes of retinal dystrophy in Pakistan. 

  • Huynh N, Jeffrey BG, Turriff A, Sieving PA, Cukras CA
    Ophthalmic Genet. 2014 Mar;35(1):51-6. doi: 10.3109/13816810.2013.865762. Epub 2014 Jan 7.
    PMID: 24397708

    BACKGROUND: Inherited retinal diseases are uncommon, and the likelihood of having more than one hereditary disorder is rare. Here, we report a case of Stargardt disease and congenital stationary night blindness (CSNB) in the same patient, and the identification of two novel in-frame deletions in the GRM6 gene. MATERIALS AND METHODS: The patient underwent an ophthalmic exam and visual function testing including: visual acuity, color vision, Goldmann visual field, and electroretinography (ERG). Imaging of the retina included fundus photography, spectral-domain optical coherence tomography (OCT), and fundus autofluorescence. Genomic DNA was PCR-amplified for analysis of all coding exons and flanking splice sites of both the ABCA4 and GRM6 genes. RESULTS: A 46-year-old woman presented with recently reduced central vision and clinical findings of characteristic yellow flecks consistent with Stargardt disease. However, ERG testing revealed an ERG phenotype unusual for Stargardt disease but consistent with CSNB1. Genetic testing revealed two previously reported mutations in the ABCA4 gene and two novel deletions in the GRM6 gene. CONCLUSIONS: Diagnosis of concurrent Stargardt disease and CSNB was made on the ophthalmic history, clinical examination, ERG, and genetic testing. This case highlights that clinical tests need to be taken in context, and that co-existing retinal dystrophies and degenerations should be considered when clinical impressions and objective data do not correlate. 

  • Charles M. Wormington, PhD, OD, FAAO
    No abstract available.
  • Cordovez JA, Capasso J, Lingao MD, Sadagopan KA, Spaeth GL, Wasserman BN, Levin AV
    Ophthalmology. 2014 Jan;121(1):392-8. doi: 10.1016/j.ophtha.2013.06.040. Epub 2013 Aug 21.
    PMID: 23972321

    PURPOSE: To report a new ocular manifestation of the dup22q11 syndrome and explore involved genes that may offer insight to mechanisms of pathogenesis. DESIGN: Case series. PARTICIPANTS: Two male patients with this syndrome diagnosed with dup22q11.2. METHODS: Medical records were reviewed. Duplication was detected in the oligo-single nucleotide polymorphism chromosomal microarray and duplicated genes within the segment where determined by literature and database review. Potential associations between the ophthalmologic manifestations and their physiopathology were investigated. MAIN OUTCOME MEASURES: Microarray results and identification of candidate genes within the duplicated segment. RESULTS: Our patients demonstrate previously unreported findings of dup22q11.2, including Marcus Gunn jaw winking, Duane's retraction syndrome, and other abnormal eye movements consistent with a congenital cranial dysinnervation disorder (CCDD), retinal vascular tortuosity, and primary infantile glaucoma. The duplicated segment in case 1 includes SNAP29, which could be linked with the development of retinal vascular tortuosity, and MAPK1, which seems to play a role in axonal development through the semaphorin pathway, which may serve as a candidate gene for CCDD. In case 2, the CLDN5 gene is within the duplicated segment. CLDN5 could be involved in the pathophysiology of glaucoma. CONCLUSIONS: Our cases expand the ocular phenotype for duplication of 22q11 and serve to identify potential candidate genes for the development of CCDD, retinal vascular tortuosity, and glaucoma. 

  • JE Roger, A Swaroop
    Vertebrate Photoreceptors, 2014.
    No abstract available.
  • PR Freund
    No abstract available.
  • Chan S, Freund PR, MacDonald I
    Curr Opin Pediatr. 2013 Dec;25(6):645-52. doi: 10.1097/MOP.0000000000000026.
    PMID: 24126856

    PURPOSE OF REVIEW: An update on heritable eye disease will allow informed patient counseling and improved patient care. RECENT FINDINGS: New loci and genes have been associated with identifiable heritable ocular traits. Molecular genetic analysis is available for many of these genes either as part of research or for clinical testing. The advent of gene array technologies has enabled screening of samples for known mutations in genes linked to various disorders. Exomic sequencing has proven to be particularly successful in research protocols in identifying the genetic causation of rare genetic traits by pooling patient resources and discovering new genes. Further, genetic analysis has led improvement in patient care and counselling, as exemplified by the continued advances in our treatment of retinoblastoma. SUMMARY: Patients and families are commonly eager to participate in either research or clinical testing to improve their understanding of the cause and heritability of an ocular condition. Many patients hope that testing will then lead to appropriate treatments or cures. The success of gene therapy in the RPE65 form of Leber congenital amaurosis has provided a brilliant example of this hope; that a similar trial may become available to other patients and families burdened by genetic disease. 

  • Utz VM, Chappelow AV, Marino MJ, Beight CD, Sturgill-Short GM, Pauer GJ, Crowe S, Hagstrom SA, Traboulsi EI
    Am J Ophthalmol. 2013 Dec;156(6):1220-1227.e2. doi: 10.1016/j.ajo.2013.07.008. Epub 2013 Sep 4.
    PMID: 24011517

    PURPOSE: To describe the clinical and molecular findings in ten unrelated African American patients with Stargardt disease. DESIGN: Retrospective, observational case series. METHODS: We reviewed the clinical histories, examinations, and genotypes of 85 patients with molecular diagnoses of Stargardt disease. Three ABCA4 sequence variations identified exclusively in African Americans were evaluated in 300 African American controls and by in silico analysis. RESULTS: ABCA4 sequence changes were identified in 85 patients from 80 families, of which 11 patients identified themselves as African American. Of these 11 patients, 10 unrelated patients shared 1 of 3 ABCA4 sequence variations: c.3602T>G (p.L1201R); c.3899G>A (p.R1300Q); or c.6320G>A (p.R2107H). The minor allele frequencies in the African American control population for each variation were 7.5%, 6.3%, and 2%, respectively. This is comparable to the allele frequency in African Americans in the Exome Variant Server. In contrast, the allele frequency of all three of these variations was less than or equal to 0.05% in European Americans. Although both c.3602T>G and c.3899G>A have been reported as likely disease-causing variations, one of our control patients was homozygous for each variant, suggesting that these are nonpathogenic. In contrast, the absence of c.6320G>A in the control population in the homozygous state, combined with the results of bioinformatics analysis, support its pathogenicity. CONCLUSIONS: Three ABCA4 sequence variations were identified exclusively in 10 unrelated African American patients: p.L1201R and p.R1300Q likely represent nonpathogenic sequence variants, whereas the p.R2107H substitution appears to be pathogenic. Characterization of population-specific disease alleles may have important implications for the development of genetic screening algorithms. 

  • Utz VM, Beight CD, Marino MJ, Hagstrom SA, Traboulsi EI
    Ophthalmic Genet. 2013 Dec;34(4):183-8. doi: 10.3109/13816810.2012.762932. Epub 2013 Jan 23.
    PMID: 23343310

    Several forms of autosomal dominant retinitis pigmentosa (adRP) are caused by mutations in genes encoding proteins that are ubiquitously expressed and involved in the pre-mRNA spliceosome such as PRPF31. This paper provides an overview of the molecular genetics, pathophysiology, and mechanism for incomplete penetrance and retina-specific disease in pedigrees of families who harbor mutations in PRPF31 (RP11). The molecular and clinical features of a family with a novel 3-base insertion, c.914_915insTGT (p.Val305_Asp306insVal) in exon 9 of PRPF31 are described to illustrate the salient clinical features of mutations in this gene. 

  • Bowne SJ, Sullivan LS, Avery CE, Sasser EM, Roorda A, Duncan JL, Wheaton DH, Birch DG, Branham KE, Heckenlively JR, Sieving PA, Daiger SP
    Mol Vis. 2013 Nov 24;19:2407-17. eCollection 2013.
    PMID: 24319334

    PURPOSE: The purpose of this project was to determine the spectrum and frequency of mutations in the small nuclear riboprotein 200 kDa gene (SNRNP200) that cause autosomal dominant retinitis pigmentosa (adRP). METHODS: A well-characterized adRP cohort of 251 families was tested for mutations in the exons and intron/exon junctions of SNRNP200 using fluorescent dideoxy sequencing. An additional 21 adRP families from the eyeGENE(R) Network were tested for possible mutations. Bioinformatic and segregation analysis was performed on novel variants. RESULTS: SNRNP200 mutations were identified in seven of the families tested. Two previously reported mutations, p.Arg681Cys and p.Ser1087Leu, were found in two families each. One family had the previously reported p.Arg681His mutation. Two novel SNRNP200 variants, p.Pro682Ser and p.Ala542Val, were also identified in one family each. Bioinformatic and segregation analyses suggested that these novel variants are likely to be pathogenic. Clinical examination of patients with SNRNP200 mutations showed a wide range of clinical symptoms and severity, including one instance of non-penetrance. CONCLUSIONS: Mutations in SNRNP200 caused 1.6% of disease in our adRP cohort. Pathogenic mutations were found primarily in exons 16 and 25, but the novel p.Ala542Val mutation in exon 13 suggests that variation in other genetic regions is also responsible for causing dominant disease. SNRNP200 mutations were associated with a wide range of clinical symptoms similar to those of individuals with other splice-factor gene mutations. 

  • D'Souza L, Cukras C, Antolik C, Craig C, Lee JY, He H, Li S, Smaoui N, Hejtmancik JF, Sieving PA, Wang X
    Mol Vis. 2013 Nov 7;19:2209-16. eCollection 2013.
    PMID: 24227916

    PURPOSE: X-linked juvenile retinoschisis (XLRS) is a vitreoretinal dystrophy characterized by schisis (splitting) of the inner layers of the neuroretina. Mutations within the retinoschisis (RS1) gene are responsible for this disease. The mutation spectrum consists of amino acid substitutions, splice site variations, small indels, and larger genomic deletions. Clinically, genomic deletions are rarely reported. Here, we characterize two novel full exonic deletions: one encompassing exon 1 and the other spanning exons 4-5 of the RS1 gene. We also report the clinical findings in these patients with XLRS with two different exonic deletions. METHODS: Unrelated XLRS men and boys and their mothers (if available) were enrolled for molecular genetics evaluation. The patients also underwent ophthalmologic examination and in some cases electroretinogram (ERG) recording. All the exons and the flanking intronic regions of the RS1 gene were analyzed with direct sequencing. Two patients with exonic deletions were further evaluated with array comparative genomic hybridization to define the scope of the genomic aberrations. After the deleted genomic region was identified, primer walking followed by direct sequencing was used to determine the exact breakpoints. RESULTS: Two novel exonic deletions of the RS1 gene were identified: one including exon 1 and the other spanning exons 4 and 5. The exon 1 deletion extends from the 5' region of the RS1 gene (including the promoter) through intron 1 (c.(-35)-1723_c.51+2664del4472). The exon 4-5 deletion spans introns 3 to intron 5 (c.185-1020_c.522+1844del5764). CONCLUSIONS: Here we report two novel exonic deletions within the RS1 gene locus. We have also described the clinical presentations and hypothesized the genomic mechanisms underlying these schisis phenotypes. 

  • Ratnapriya R, Swaroop A
    Genome Med. 2013 Oct 11;5(10):84. doi: 10.1186/gm488. eCollection 2013.
    PMID: 24112618

    Inherited retinal degenerative diseases (RDDs) display wide variation in their mode of inheritance, underlying genetic defects, age of onset, and phenotypic severity. Molecular mechanisms have not been delineated for many retinal diseases, and treatment options are limited. In most instances, genotype-phenotype correlations have not been elucidated because of extensive clinical and genetic heterogeneity. Next-generation sequencing (NGS) methods, including exome, genome, transcriptome and epigenome sequencing, provide novel avenues towards achieving comprehensive understanding of the genetic architecture of RDDs. Whole-exome sequencing (WES) has already revealed several new RDD genes, whereas RNA-Seq and ChIP-Seq analyses are expected to uncover novel aspects of gene regulation and biological networks that are involved in retinal development, aging and disease. In this review, we focus on the genetic characterization of retinal and macular degeneration using NGS technology and discuss the basic framework for further investigations. We also examine the challenges of NGS application in clinical diagnosis and management. 

  • Collins DW, Gudiseva HV, Trachtman BT, Jerrehian M, Gorry T, Merritt WT 3rd, Rhodes AL, Sankar PS, Regina M, Miller-Ellis E, O'Brien JM
    PLoS One. 2013 Oct 1;8(10):e76627. doi: 10.1371/journal.pone.0076627. eCollection 2013.
    PMID: 24146900

    Primary open-angle glaucoma (POAG) is a major cause of blindness and results from irreversible retinal ganglion cell damage and optic nerve degeneration. In the United States, POAG is most prevalent in African-Americans. Mitochondrial genetics and dysfunction have been implicated in POAG, and potentially pathogenic sequence variations, in particular novel transversional base substitutions, are reportedly common in mitochondrial genomes (mtDNA) from POAG patient blood. The purpose of this study was to ascertain the spectrum of sequence variation in mtDNA from African-American POAG patients and determine whether novel nonsynonymous, transversional or other potentially pathogenic sequence variations are observed more commonly in POAG cases than controls. mtDNA from African-American POAG cases (n = 22) and age-matched controls (n = 22) was analyzed by deep sequencing of a single 16,487 base pair PCR amplicon by Ion Torrent, and candidate novel variants were validated by Sanger sequencing. Sequence variants were classified and interpreted using the MITOMAP compendium of polymorphisms. 99.8% of the observed variations had been previously reported. The ratio of novel variants to POAG cases was 7-fold lower than a prior estimate. Novel mtDNA variants were present in 3 of 22 cases, novel nonsynonymous changes in 1 of 22 cases and novel transversions in 0 of 22 cases; these proportions are significantly lower (p<.0005, p<.0004, p<.0001) than estimated previously for POAG, and did not differ significantly from controls. Although it is possible that mitochondrial genetics play a role in African-Americans' high susceptibility to POAG, it is unlikely that any mitochondrial respiratory dysfunction is due to an abnormally high incidence of novel mutations that can be detected in mtDNA from peripheral blood. 

  • Sullivan LS, Bowne SJ, Reeves MJ, Blain D, Goetz K, Ndifor V, Vitez S, Wang X, Tumminia SJ, Daiger SP
    Invest Ophthalmol Vis Sci. 2013 Sep 19;54(9):6255-61. doi: 10.1167/iovs.13-12605.
    PMID: 23950152

    PURPOSE: To screen samples from patients with presumed autosomal dominant retinitis pigmentosa (adRP) for mutations in 12 disease genes as a contribution to the research and treatment goals of the National Ophthalmic Disease Genotyping and Phenotyping Network (eyeGENE). METHODS: DNA samples were obtained from eyeGENE. A total of 170 probands with an intake diagnosis of adRP were tested through enrollment in eyeGENE. The 10 most common genes causing adRP (IMPDH1, KLHL7, NR2E3, PRPF3/RP18, PRPF31/RP11, PRPF8/RP13, PRPH2/RDS, RHO, RP1, and TOPORS) were chosen for PCR-based dideoxy sequencing, along with the two X-linked RP genes, RPGR and RP2. RHO, PRPH2, PRPF31, RPGR, and RP2 were completely sequenced, while only mutation hotspots in the other genes were analyzed. RESULTS: Disease-causing mutations were identified in 52% of the probands. The frequencies of disease-causing mutations in the 12 genes were consistent with previous studies. CONCLUSIONS: The Laboratory for Molecular Diagnosis of Inherited Eye Disease at the University of Texas in Houston has thus far received DNA samples from 170 families with a diagnosis of adRP from the eyeGENE Network. Disease-causing mutations in autosomal genes were identified in 48% (81/170) of these families while mutations in X-linked genes accounted for an additional 4% (7/170). Of the 55 distinct mutations detected, 19 (33%) have not been previously reported. All diagnostic results were returned by eyeGENE to participating patients via their referring clinician. These genotyped samples along with their corresponding phenotypic information are also available to researchers who may request access to them for further study of these ophthalmic disorders. ( number, NCT00378742.). 

  • Willett K, Bennett J
    Front Immunol. 2013 Aug 30;4:261. doi: 10.3389/fimmu.2013.00261. eCollection 2013.
    PMID: 24009613

    The eye has been at the forefront of translational gene therapy largely owing to suitable disease targets, anatomic accessibility, and well-studied immunologic privilege. These advantages have fostered research culminating in several clinical trials and adeno-associated virus (AAV) has emerged as the vector of choice for many ocular therapies. Pre-clinical and clinical investigations have assessed the humoral and cellular immune responses to a variety of naturally occurring and engineered AAV serotypes as well as their delivered transgenes and these data have been correlated to potential clinical sequelae. Encouragingly, AAV appears safe and effective with clinical follow-up surpassing 5 years in some studies. As disease targets continue to expand for AAV in the eye, thorough and deliberate assessment of immunologic safety is critical. With careful study, the development of these technologies should concurrently inform the biology of the ocular immune response. 

  • Blain D, Goetz KE, Ayyagari R, Tumminia SJ
    Clin Genet. 2013 Aug;84(2):190-7. doi: 10.1111/cge.12193. Epub 2013 Jun 5.
    PMID: 23662816

    Molecular genetics and genomics are revolutionizing the study and treatment of inherited eye diseases. In recognition of the impact of molecular genetics on vision and ophthalmology, the National Eye Institute established the National Ophthalmic Disease Genotyping and Phenotyping Network (eyeGENE(R)) as a multidirectional research initiative whereby a clinical component for patients diagnosed with inherited eye disease fosters research into the causes and mechanisms of these ophthalmic diseases. This is accomplished by broadening access to genetic diagnostic testing and maintaining a repository of DNA samples from clinically characterized individuals and their families to allow investigations of the causes, interventions, and management of genetic eye disorders. The eyeGENE(R) Network currently includes Clinical Laboratory Improvement Amendments (CLIA)-certified diagnostic laboratory partners, over 270 registered clinical organizations with 500 registered users from around the United States and Canada, and is now testing approximately 100 genes representing 35 inherited eye diseases. To date, the Network has received 4400 samples from individuals with rare inherited eye diseases, which are available for access by the vision research community. eyeGENE(R) is a model partnership between the U.S. federal government, eye health care providers, CLIA-approved molecular diagnostic laboratories, private industry, and scientists who represent a broad research constituency. 

  • Branham K, Yashar BM
    Clin Genet. 2013 Aug;84(2):183-9. doi: 10.1111/cge.12192. Epub 2013 Jun 5.
    PMID: 23662791

    The diagnosis of an inherited retinal dystrophy can have a significant impact on both the physical and emotional lives of patients and their families. In order to optimize the health and quality of life for these individuals, a comprehensive approach to clinical care starting at the time of diagnosis and continuing throughout their lifespan is critical. A multidisciplinary team approach integrating ophthalmic and genetic counseling services can optimize the diagnostic process and long-term management of these patients. When vision loss is first appreciated, the diagnostic specificity of an ophthalmic evaluation can be enhanced by a detailed genetic work-up. This evaluation can help confirm the diagnosis and allow for accurate risk counseling of the patient and their family. Genetic counseling is critical at the time of diagnosis and is an opportunity to provide education about the diagnosis, discuss low-vision rehabilitation, and explore impacts on academics and employment. In addition, counseling can help patients deal with the current psychological aspects of their vision loss, prepare for the lifelong impact of their diagnosis and over time adjust to the impact of progressive vision loss. 

  • Natarajan S
    Indian J Ophthalmol. 2013 Mar;61(3):91-4. doi: 10.4103/0301-4738.109372.
    PMID: 23514641
    No abstract available.
  • Zahid S, Jayasundera T, Rhoades W, Branham K, Khan N, Niziol LM, Musch DC, Heckenlively JR
    Am J Ophthalmol. 2013 Mar;155(3):465-473.e3. doi: 10.1016/j.ajo.2012.09.011. Epub 2012 Dec 5.
    PMID: 23219216

    PURPOSE: To investigate the relationships between clinical and full-field electroretinographic (ERG) findings and progressive loss of visual function in Stargardt disease. DESIGN: Retrospective cohort study. METHODS: We performed a retrospective review of data from 198 patients with Stargardt disease. Measures of visual function over time, including visual acuity, quantified Goldmann visual fields, and full-field ERG data were recorded. Data were analyzed using SAS statistical software. Subgroup analyses were performed on 148 patients with ERG phenotypic data, 46 patients with longitudinal visual field data, and 92 patients with identified ABCA4 mutations (46 with 1 mutation, and 47 with 2 or more mutations). RESULTS: Of 46 patients with longitudinal visual field data, 8 patients with faster central scotoma progression rates had significantly worse scotopic B-wave amplitudes at their initial assessment than 20 patients with stable scotomata (P = .014) and were more likely to have atrophy beyond the arcades (P = .047). Overall, 47.3% of patients exhibited abnormal ERG results, with rod-cone dysfunction in 14.2% of patients, cone-rod dysfunction in 17.6% of patients, and isolated cone dysfunction in 15.5% of patients. Abnormal values in certain ERG parameters were associated significantly with (maximum-stimulation A- and B-wave amplitudes) or tended toward (photopic and scotopic B-wave amplitudes) a higher mean rate of central scotoma progression compared with those patients with normal ERG values. Scotoma size and ERG parameters differed significantly between those with a single mutation versus those with multiple mutations. CONCLUSIONS: Full-field ERG examination provides clinically relevant information regarding the severity of Stargardt disease, likelihood of central scotoma expansion, and visual acuity deterioration. Patients also may exhibit an isolated cone dystrophy on ERG examination. 

  • Schoenberger SD, Agarwal A
    Retina. 2013 Feb;33(2):429-35. doi: 10.1097/IAE.0b013e318263d3b4.
    PMID: 23023527

    PURPOSE: To report a novel mutation occurring in the N-terminal domain of the tissue inhibitor of metalloproteinase 3 (TIMP3) gene in Sorsby fundus dystrophy. METHODS: Retrospective review of medical records of two patients who had clinical features consistent with Sorsby fundus dystrophy. Genetic testing confirmed a mutation in the TIMP3 gene in both patients. RESULTS: Both patients had findings of drusenlike deposits, retinal pigment epithelial and photoreceptor atrophy, and bilateral, recurrent choroidal neovascularization. A strong family history of early onset macular degeneration was present in both. The patients developed choroidal neovascularization at the age of 45 and 48 years, and both had multiple recurrences in both eyes. Genetic testing in both patients confirmed a heterozygous nucleotide change of C113G, causing a Ser38Cys change in Exon 1 of the N-terminal domain of the TIMP3 gene. CONCLUSION: All previously reported mutations in Sorsby fundus dystrophy occur at Exon 5 in the C-terminal domain. We report 2 patients with novel mutations in Exon 1 of the N-terminal domain. Although the mutation occurs at a different location on the TIMP3 gene, the clinical features are similar to other reported patients with Sorsby fundus dystrophy. This finding assists in understanding the pathogenesis of this disorder. 

  • Goetz KE, Reeves MJ, Tumminia SJ, Brooks BP
    Curr Opin Ophthalmol. 2012 Sep;23(5):355-63. doi: 10.1097/ICU.0b013e32835715c9.
    PMID: 22847030

    PURPOSE OF REVIEW: Molecular genetics is revolutionizing the diagnosis and treatment of inherited eye diseases. The National Eye Institute of the National Institutes of Health (NIH), in an effort to facilitate future basic and clinical research in inherited eye disease, created The National Ophthalmic Disease Genotyping and Phenotyping Network (eyeGENE). This review describes the process and utility of the eyeGENE program as it relates to ophthalmic clinical practice. RECENT FINDINGS: Over the last few years, genetic testing of specific genes associated with inherited eye conditions is becoming the standard practice. Vision research and human clinical trials relying on molecular genetic testing of individuals with inherited eye conditions are becoming more common. Eye healthcare professionals must consider the options to assist patients in obtaining genetic testing results and locating trials or studies that may have benefit. SUMMARY: eyeGENE is a DNA repository and patient registry for inherited eye diseases coupled to phenotypic descriptors and molecular genetic information. Through eyeGENE, healthcare professionals throughout the United States and Canada can obtain Clinical Laboratory Improvement Amendments-certified clinical molecular genetic results on their patients. Researchers may request access to a de-identified database of phenotype and genotype information about eyeGENE participants and DNA aliquots for their research studies. eyeGENE also offers participants the option of being included in a patient registry, whereby they may be re-contacted if an approved clinical study for which they might qualify is offered. 

  • Huang AS, Kim LA, Fawzi AA
    Arch Ophthalmol. 2012 Sep;130(9):1184-9. doi: 10.1001/archophthalmol.2012.1117.
    PMID: 22965595

    OBJECTIVE: To describe a large family with a novel mutation in CHM. METHODS: Family members were characterized using clinical examination, wide-field fundus photography, wide-field autofluorescence, and spectral domain optical coherence tomography. The CHM mutation was identified with the National Institutes of Health-sponsored eyeGene program. RESULTS: A novel nonsense CHM mutation (T1194G), resulting in a premature stop (Y398X) and loss of the final one-third C-terminal portion of the protein, was identified. A large pedigree was generated from information provided by the twice-married proband. Seven men (aged 27-39 years) and 7 women (aged 22-89 years) were evaluated. Affected men showed characteristic peripheral chorioretinal atrophy with islands of macular sparing. Female carriers exhibited a wide range of variability, from mild pigmentary alterations to significant chorioretinal atrophy with severe vision loss. Older women tended to have a more severe phenotype. Autofluorescence demonstrating subfoveal loss or absence of retinal pigment epithelium correlated with vision loss in both sexes. Spectral domain optical coherence tomography demonstrated dynamic changes and remodeling of the outer retina over time, including focal thickening, drusenlike deposits, and disruption to photoreceptor inner segment and outer segment junctions in young female carriers. CONCLUSIONS: CHM (T1194G) is a novel mutation that manifests a wide range of phenotypic variability in a single family with a trend toward more severe phenotypes in older female carriers. Our findings emphasize the importance of considering X-linked diseases by carefully evaluating pedigrees in women with severe manifestations of disease. CLINICAL RELEVANCE: These findings demonstrate a novel CHM mutation that emphasizes severe posterior pole carrier phenotypes, age-related changes, and early choroideremia disease. 

  • Hadziahmetovic M, Kumar U, Song Y, Grieco S, Song D, Li Y, Tobias JW, Dunaief JL
    Invest Ophthalmol Vis Sci. 2012 Aug 7;53(9):5231-41. doi: 10.1167/iovs.12-10204.
    PMID: 22736611

    PURPOSE: The purpose of this study was to investigate light damage-induced transcript changes within neurosensory retina (NSR) and isolated retinal pigment epithelium (RPE). Similar studies have been conducted previously, but were usually limited to the NSR and only a portion of the transcriptome. Herein most of the transcriptome, not just in the NSR but also in isolated RPE, was queried. METHODS: Mice were exposed to 10,000 lux cool white fluorescent light for 18 hours and euthanized 4 hours after photic injury. NSR and isolated RPE were collected, and RNA was isolated. DNA microarray hybridization was conducted as described in the Affymetrix GeneChip Expression Analysis Technical Manual. Microarray analysis was performed using probe intensity data derived from the Mouse Gene 1.0 ST Array. For the genes of interest, confirmation of gene expression was done using quantitative real-time PCR. Immunofluorescence assessed protein levels and localization. RESULTS: Numerous iron regulatory genes were significantly changed in the light-exposed NSR and RPE. Several of these gene expression changes favored an iron-overloaded state. For example, the transferrin receptor was upregulated in both light-exposed NSR and RPE. Consistent with this, there was stronger transferrin receptor immunoreactivity in the light-exposed retinas. Significant changes in gene expression following light damage were also observed in oxidative stress and complement system genes. CONCLUSIONS: The concept of a photooxidative stress-induced vicious cycle of increased iron uptake leading to further oxidative stress was introduced. 

  • Tumminia SJ
    Invest Ophthalmol Vis Sci. 2012 May 4;53(5):2515-21. doi: 10.1167/iovs.12-9483q.
    PMID: 22562854
    No abstract available.
  • Sachdeva UM, O'Brien JM
    J Clin Invest. 2012 Feb;122(2):425-34. doi: 10.1172/JCI57114. Epub 2012 Feb 1.
    PMID: 22293180

    Retinoblastoma is a pediatric retinal tumor initiated by biallelic inactivation of the retinoblastoma gene (RB1). RB1 was the first identified tumor suppressor gene and has defined roles in the regulation of cell cycle progression, DNA replication, and terminal differentiation. However, despite the abundance of work demonstrating the molecular function and identifying binding partners of pRb, the challenge facing molecular biologists and clinical oncologists is how to integrate this vast body of molecular knowledge into the development of targeted therapies for treatment of retinoblastoma. We propose that a more thorough genetic understanding of retinoblastoma would inform targeted treatment decisions and could improve outcomes and quality of life in children affected by this disease. 

  • Strunnikova N, Zein WM, Silvin C, MacDonald IM
    Adv Exp Med Biol. 2012;723:381-7. doi: 10.1007/978-1-4614-0631-0_49.
    PMID: 22183356
    No abstract available.
  • Bejjani A, Choi MR, Cassidy L, Collins DW, O'Brien JM, Murray T, Ksander BR, Seigel GM
    Mol Vis. 2012;18:2805-13. Epub 2012 Nov 29.
    PMID: 23233783

    PURPOSE: Retinoblastoma (RB), an intraocular tumor of childhood, is commonly associated with mutations in the RB1 gene. RB116 is a novel, early passage RB cell line that has not been previously characterized. In this study, we examined RB116 for the expression of RB1 and tested the hypothesis that RB116 cells would express stem cell markers as well as retinal progenitor cell markers. We compared RB116 cells with other well known RB cell lines, including Y79 and WERI-RB27. METHODS: We evaluated expression of RB1 in RB116 cells by sequencing, multiplex ligation-dependent probe amplification, quantitative reverse transcriptase polymerase chain reaction (qRT-PCR), western immunoblot, and immunocytochemistry. Next, RB116 cells, along with Y79 and WERI-RB27 cells, were examined for expression of stem cell markers (ABCG2, Nanog, Oct3/4, ALDH1A1) and retinal progenitor markers (PAX6, CHX10) by quantitative immunocytochemistry. Immunocytochemical findings were accompanied by PCR analysis. RESULTS: RB116 cells expressed RB1 at the mRNA and protein levels, with no mutations detected by either sequencing analysis, or gene dosage abnormalities detected by multiplex ligation-dependent probe amplification. The RB1 protein was immunoreactive in RB116 cells with an atypical perinuclear localization. RB116 cells also expressed stem cell markers, with 3%-5% of cells immunopositive for ABCG2, Oct3/4 and ALDH1A1, with at least 18% of cells immunoreactive to Nanog. These findings were confirmed by RT-PCR. Small percentages of RB116 cells also exhibited immunoreactivity to retinal progenitor markers PAX6 (9.8%) and CHX10 (1.2%). Expression of mRNAs for these markers was confirmed by qRT-PCR. CONCLUSIONS: RB116 cells demonstrate RB1 expression accompanied by atypical perinuclear localization. RB116 cells also express primitive stem cell and retinal progenitor cell markers. Further studies on the phenotypes of both RB1-positive and RB1-negative human RB cells may be important in assessing differentiation potential of these cells, as well as designing targeted differentiation therapies. 

  • Duncan JL, Ratnam K, Birch DG, Sundquist SM, Lucero AS, Zhang Y, Meltzer M, Smaoui N, Roorda A
    Invest Ophthalmol Vis Sci. 2011 Dec 20;52(13):9614-23. doi: 10.1167/iovs.11-8600.
    PMID: 22110067

    PURPOSE: To evaluate macular cone structure in patients with X-linked retinoschisis (XLRS) caused by mutations in exon 6 of the RS1 gene. METHODS: High-resolution macular images were obtained with adaptive optics scanning laser ophthalmoscopy (AOSLO) and spectral domain optical coherence tomography (SD-OCT) in two patients with XLRS and 27 age-similar healthy subjects. Retinal structure was correlated with best-corrected visual acuity, kinetic and static perimetry, fundus-guided microperimetry, full-field electroretinography (ERG), and multifocal ERG. The six coding exons and the flanking intronic regions of the RS1 gene were sequenced in each patient. RESULTS: Two unrelated males, ages 14 and 29, with visual acuity ranging from 20/32 to 20/63, had macular schisis with small relative central scotomas in each eye. The mixed scotopic ERG b-wave was reduced more than the a-wave. SD-OCT showed schisis cavities in the outer and inner nuclear and plexiform layers. Cone spacing was increased within the largest foveal schisis cavities but was normal elsewhere. In each patient, a mutation in exon 6 of the RS1 gene was identified and was predicted to change the amino acid sequence in the discoidin domain of the retinoschisin protein. CONCLUSIONS: AOSLO images of two patients with molecularly characterized XLRS revealed increased cone spacing and abnormal packing in the macula of each patient, but cone coverage and function were near normal outside the central foveal schisis cavities. Although cone density is reduced, the preservation of wave-guiding cones at the fovea and eccentric macular regions has prognostic and therapeutic implications for XLRS patients with foveal schisis. (Clinical number, NCT00254605.). 

  • Song J, Smaoui N, Ayyagari R, Stiles D, Benhamed S, MacDonald IM, Daiger SP, Tumminia SJ, Hejtmancik F, Wang X
    Invest Ophthalmol Vis Sci. 2011 Nov 25;52(12):9053-60. doi: 10.1167/iovs.11-7978.
    PMID: 22025579

    PURPOSE: Retinal dystrophy (RD) is a broad group of hereditary disorders with heterogeneous genotypes and phenotypes. Current available genetic testing for these diseases is complicated, time consuming, and expensive. This study was conducted to develop and apply a microarray-based, high-throughput resequencing system to detect sequence alterations in genes related to inherited RD. METHODS: A customized 300-kb resequencing chip, Retina-Array, was developed to detect sequence alterations of 267,550 bases of both sense and antisense sequence in 1470 exons spanning 93 genes involved in inherited RD. Retina-Array was evaluated in 19 patient samples with inherited RD provided by the eyeGENE repository and four Centre d'Etudes du Polymorphisme Humaine reference samples through a high-throughput experimental approach that included an automated PCR assay setup and quantification, efficient post-quantification data processing, optimized pooling and fragmentation, and standardized chip processing. RESULTS: The performance of the chips demonstrated that the average base pair call rate and accuracy were 93.56% and 99.86%, respectively. In total, 304 candidate variations were identified using a series of customized screening filters. Among 174 selected variations, 123 (70.7%) were further confirmed by dideoxy sequencing. Analysis of patient samples using Retina-Array resulted in the identification of 10 known mutations and 12 novel variations with high probability of deleterious effects. CONCLUSIONS: This study suggests that Retina-Array might be a valuable tool for the detection of disease-causing mutations and disease severity modifiers in a single experiment. Retinal-Array may provide a powerful and feasible approach through which to study genetic heterogeneity in retinal diseases. 

  • Gregory A, Hayflick SJ
    Curr Neurol Neurosci Rep. 2011 Jun;11(3):254-61. doi: 10.1007/s11910-011-0181-3.
    PMID: 21286947

    The condition originally called Hallervorden-Spatz syndrome is a collection of related disorders involving abnormal iron accumulation in the basal ganglia, usually manifesting with a movement disorder. To date, mutations in the following genes have been associated with neurodegeneration with brain iron accumulation (NBIA) phenotypes: PANK2, PLA2G6, FA2H, ATP13A2, C2orf37, CP, and FTL. This collection, now classified under the umbrella term NBIA, continues to evolve as new genes and associated phenotypes are recognized. As this body of information continues to grow, better approaches to diagnosis and treatment have become available. Continued investigations of the underlying pathogenesis of disease, with a focus on lipid, iron, and energy metabolism, will lead to the identification of new therapeutic targets. 

  • Chen Y, Ratnam K, Sundquist SM, Lujan B, Ayyagari R, Gudiseva VH, Roorda A, Duncan JL
    Invest Ophthalmol Vis Sci. 2011 May 17;52(6):3281-92. doi: 10.1167/iovs.10-6538.
    PMID: 21296825

    PURPOSE. To study the relationship between macular cone structure, fundus autofluorescence (AF), and visual function in patients with Stargardt disease (STGD). METHODS. High-resolution images of the macula were obtained with adaptive optics scanning laser ophthalmoscopy (AOSLO) and spectral domain optical coherence tomography in 12 patients with STGD and 27 age-matched healthy subjects. Measures of retinal structure and AF were correlated with visual function, including best-corrected visual acuity, color vision, kinetic and static perimetry, fundus-guided microperimetry, and full-field electroretinography. Mutation analysis of the ABCA4 gene was completed in all patients. RESULTS. Patients were 15 to 55 years old, and visual acuity ranged from 20/25-20/320. Central scotomas were present in all patients, although the fovea was spared in three patients. The earliest cone spacing abnormalities were observed in regions of homogeneous AF, normal visual function, and normal outer retinal structure. Outer retinal structure and AF were most normal near the optic disc. Longitudinal studies showed progressive increases in AF followed by reduced AF associated with losses of visual sensitivity, outer retinal layers, and cones. At least one disease-causing mutation in the ABCA4 gene was identified in 11 of 12 patients studied; 1 of 12 patients showed no disease-causing ABCA4 mutations. CONCLUSIONS. AOSLO imaging demonstrated abnormal cone spacing in regions of abnormal fundus AF and reduced visual function. These findings provide support for a model of disease progression in which lipofuscin accumulation results in homogeneously increased AF with cone spacing abnormalities, followed by heterogeneously increased AF with cone loss, then reduced AF with cone and RPE cell death. 

  • Williams MA, Carson R, Passmore P, Silvestri G, Craig D
    Optometry. 2011 Feb;82(2):83-91. doi: 10.1016/j.optm.2010.01.014. Epub 2010 Oct 13.
    PMID: 20947437

    Genetic epidemiology is of topical and increasingly practical relevance. The subject attempts to answer 2 questions: (1) is there a genetic component to a disease, and (2) what genes are involved? This article summarizes genetic epidemiologic methods, describing family- and population-based methods used to locate and identify genes and the advantages and disadvantages of each approach. Health care professionals are faced with more and more genetic information, both from interested patients and from the media, and understanding the principles underlying genetic studies allows such information to be placed in context. 

  • Gabriel LA, Traboulsi EI
    Middle East Afr J Ophthalmol. 2011 Jan;18(1):24-9. doi: 10.4103/0974-9233.75881.
    PMID: 21572730

    Accurate molecular diagnosis of genetic eye diseases has proven to be of great importance because of the prognostic and therapeutic value of an accurate ascertainment of the underlying genetic mutation. Efforts continue in diagnostic laboratories to develop strategies that allow the discovery of responsible gene/mutations in the individual patient using the least number of assays and economizing on the expenses and time involved in the process. Once the ophthalmologist has made the best possible clinical diagnosis, blood samples are obtained for genetic testing. In this paper we will review the basic laboratory methods utilized to identify the chromosomal or mutational etiology of genetic diseases that affect the eye. 

  • Weiss JS
    Invest Ophthalmol Vis Sci. 2010 Nov;51(11):5391-402. doi: 10.1167/iovs.09-4746.
    PMID: 20980701
    No abstract available.
  • Rubinstein YR, Groft SC, Bartek R, Brown K, Christensen RA, Collier E, Farber A, Farmer J, Ferguson JH, Forrest CB, Lockhart NC, McCurdy KR, Moore H, Pollen GB, Richesson R, Miller VR, Hull S, Vaught J
    Contemp Clin Trials. 2010 Sep;31(5):394-404. doi: 10.1016/j.cct.2010.06.007. Epub 2010 Jul 8.
    PMID: 20609392

    A movement to create a global patient registry for as many as 7,000 rare diseases was launched at a workshop, "Advancing Rare Disease Research: The Intersection of Patient Registries, Biospecimen Repositories, and Clinical Data." The workshop was sponsored by the Office of Rare Diseases Research (ORDR). The focus was the building of an infrastructure for an internet-based global registry linking to biorepositories. Such a registry would serve the patients, investigators, and drug companies. To aid researchers the participants suggested the creation of a centralized database of biorepositories for rare biospecimens (RD-HUB) that could be linked to the registry. Over two days of presentations and breakout sessions, several hundred attendees discussed government rules and regulations concerning privacy and patients' rights and the nature and scope of data to be entered into a central registry as well as concerns about how to validate patient and clinician-entered data to ensure data accuracy. Mechanisms for aggregating data from existing registries were also discussed. The attendees identified registry best practices, model coding systems, international systems for recruiting patients into clinical trials and novel ways of using the internet directly to invite participation in research. They also speculated about who would bear ultimate responsibility for the informatics in the registry and who would have access to the information. Hurdles associated with biospecimen collection and how to overcome them were detailed. The development of the recommendations was, in itself, an indication of the commitment of the rare disease community as never before. 

  • Sieving PA
    Am J Ophthalmol. 2010 Feb;149(2):179-81. doi: 10.1016/j.ajo.2009.10.016.
    PMID: 20103048
    No abstract available.
  • Drack AV, Lambert SR, Stone EM
    Am J Ophthalmol. 2010 Jan;149(1):10-17. doi: 10.1016/j.ajo.2009.08.038.
    PMID: 20103038

    PURPOSE: To review the current state of molecular genetic testing as it relates to pediatric ophthalmology and to discuss its uses. DESIGN: Review and evaluation of available molecular genetic testing. METHODS: Literature review and discussion of testing in practice based on the authors' clinical and laboratory experience. RESULTS: Fee-for-service testing for many genetic eye diseases now is available. A report is always generated for fee-for-service testing. Detection of DNA variants in genes known to cause eye disease must be interpreted taking into account the variability of the human genome, the presence of benign variants (polymorphisms), and the carrier frequency of recessive alleles. Negative results in genetic testing are helpful in some disorders for which most of the causative genes are known and many disease-causing variants have already been reported, but are less helpful in those that currently have many undiscovered causative genes or novel mutations. Research-based testing also is available, but does not always yield a result. Patients with RPE65-associated Leber congenital amaurosis may be eligible for the current gene therapy trial. Patients with a variety of disorders may benefit from improved surveillance if their genetic diagnosis is known. CONCLUSIONS: Entry into the genetic testing system often is via the patient's ophthalmologist. Collaboration with geneticists and genetic counselors, use of web sites to keep up with the ever-changing availability and detection rates, and knowledge of clinical trials, when combined with excellent clinical diagnosis, can improve diagnosis and allow eligible patients to participate in treatment trials. 

  • JL Wiggs
    Archives of ophthalmology, 2010.
    No abstract available.
  • Strunnikova NV, Barb J, Sergeev YV, Thiagarajasubramanian A, Silvin C, Munson PJ, Macdonald IM
    PLoS One. 2009 Dec 22;4(12):e8402. doi: 10.1371/journal.pone.0008402.
    PMID: 20027300

    BACKGROUND: Choroideremia (CHM) is a progressive X-linked retinopathy caused by mutations in the CHM gene, which encodes Rab escort protein-1 (REP-1), an escort protein involved in the prenylation of Rabs. Under-prenylation of certain Rabs, as a result of loss of function mutations in REP-1, could affect vesicular trafficking, exocytosis and secretion in peripheral cells of CHM patients. METHODOLOGY/PRINCIPAL FINDINGS: To evaluate this hypothesis, intracellular vesicle transport, lysosomal acidification and rates of proteolytic degradation were studied in monocytes (CD14+ fraction) and primary skin fibroblasts from the nine age-matched controls and thirteen CHM patients carrying 10 different loss-of-function mutations. With the use of pHrodo BioParticles conjugated with E. coli, collagen I coated FluoSpheres beads and fluorescent DQ ovalbumin with BODYPY FL dye, we demonstrated for the first time that lysosomal pH was increased in monocytes of CHM patients and, as a consequence, the rates of proteolytic degradation were slowed. Microarray analysis of gene expression revealed that some genes involved in the immune response, small GTPase regulation, transcription, cell adhesion and the regulation of exocytosis were significantly up and down regulated in cells from CHM patients compared to controls. Finally, CHM fibroblasts secreted significantly lower levels of cytokine/growth factors such as macrophage chemoattractant protein-1 (MCP-1), pigment epithelial derived factor (PEDF), tumor necrosis factor (TNF) alpha, fibroblast growth factor (FGF) beta and interleukin (lL)-8. CONCLUSIONS/SIGNIFICANCE: We demonstrated for the first time that peripheral cells of CHM patients had increased pH levels in lysosomes, reduced rates of proteolytic degradation and altered secretion of cytokines. Peripheral cells from CHM patients expose characteristics that were not previously recognized and could used as an alternative models to study the effects of different mutations in the REP-1 gene on mechanism of CHM development in human population. 

  • Shintani K, Shechtman DL, Gurwood AS
    Optometry. 2009 Jul;80(7):384-401. doi: 10.1016/j.optm.2008.01.026.
    PMID: 19545852

    BACKGROUND: Retinitis pigmentosa (RP) is a heterogeneous group of inherited retinal disorders characterized by progressive photoreceptor apoptosis. It is the leading cause of inherited retinal degeneration-associated blindness. RP has a unique set of clinical characteristics that make it a complex disease associated with distinct inheritance patterns. An understanding of the pathogenesis is essential in the process of the differential diagnosis and the development of treatment options. Recent developments in research are likely to expand the various therapeutic modalities to include gene therapy, pharmacologic treatment, cell transplantation, and neuro-prosthetic devices. METHODS: A literature search was performed to comprehensively review RP diagnosis, pathophysiology, and treatment. CONCLUSION: Advances in the understanding of the pathophysiology of RP are creating new opportunities for the treatment of this often visually debilitating eye condition. Optometrists, as primary eye care practitioners, should be aware of the inheritance, pathophysiology, and current treatment options for RP as well as treatments in development so that they can best care for their patients with inherited retinal disorders. 

  • Founti P, Topouzis F, van Koolwijk L, Traverso CE, Pfeiffer N, Viswanathan AC
    Br J Ophthalmol. 2009 May;93(5):577-81. doi: 10.1136/bjo.2008.156273. Epub 2009 Feb 24.
    PMID: 19244267

    BACKGROUND: Dissecting complex diseases has become an attainable goal through large-scale collaborative projects under the term "biobanks." However, large sample size alone is no guarantee of a reliable genetic association study, and the genetic epidemiology of complex diseases still has many challenges to face. Among these, issues such as genotyping errors and population stratification have been previously highlighted. However, comparatively little attention has been given to accurate phenotyping. Study procedures of existing large-scale biobanks are usually restricted to very basic physical measurements and non-standardised phenotyping, based on routine medical records and health registry systems. DISCUSSION: Study procedures of existing large-scale biobanks are usually restricted. Considering that the objective of an association study is to establish genotype-phenotype correlations, it is doubtful how easily this could be achieved in the absence of accurate and reliable phenotype description. The use of non-specific or poorly defined phenotypes may partly explain the limited progress so far in glaucoma complex genetics. This report examines the European Glaucoma Society GlaucoGENE project, which is the only large multicentre glaucoma-specific biobank. Unlike previous biorepositories, this initiative focuses on detailed and standardised phenotyping and is expected to become a major resource for future studies on glaucoma. 

  • Kaput J, Cotton RG, Hardman L, Watson M, Al Aqeel AI, Al-Aama JY, Al-Mulla F, Alonso S, Aretz S, Auerbach AD, Bapat B, Bernstein IT, Bhak J, Bleoo SL, Blocker H, Brenner SE, Burn J, Bustamante M, Calzone R, Cambon-Thomsen A, Cargill M, Carrera P, Cavedon L, Cho YS, Chung YJ, Claustres M, Cutting G, Dalgleish R, den Dunnen JT, Diaz C, Dobrowolski S, dos Santos MR, Ekong R, Flanagan SB, Flicek P, Furukawa Y, Genuardi M, Ghang H, Golubenko MV, Greenblatt MS, Hamosh A, Hancock JM, Hardison R, Harrison TM, Hoffmann R, Horaitis R, Howard HJ, Barash CI, Izagirre N, Jung J, Kojima T, Laradi S, Lee YS, Lee JY, Gil-da-Silva-Lopes VL, Macrae FA, Maglott D, Marafie MJ, Marsh SG, Matsubara Y, Messiaen LM, Moslein G, Netea MG, Norton ML, Oefner PJ, Oetting WS, O'Leary JC, de Ramirez AM, Paalman MH, Parboosingh J, Patrinos GP, Perozzi G, Phillips IR, Povey S, Prasad S, Qi M, Quin DJ, Ramesar RS, Richards CS, Savige J, Scheible DG, Scott RJ, Seminara D, Shephard EA, Sijmons RH, Smith TD, Sobrido MJ, Tanaka T, Tavtigian SV, Taylor GR, Teague J, Topel T, Ullman-Cullere M, Utsunomiya J, van Kranen HJ, Vihinen M, Webb E, Weber TK, Yeager M, Yeom YI, Yim SH, Yoo HS
    Hum Mutat. 2009 Apr;30(4):496-510. doi: 10.1002/humu.20972.
    PMID: 19306394

    The remarkable progress in characterizing the human genome sequence, exemplified by the Human Genome Project and the HapMap Consortium, has led to the perception that knowledge and the tools (e.g., microarrays) are sufficient for many if not most biomedical research efforts. A large amount of data from diverse studies proves this perception inaccurate at best, and at worst, an impediment for further efforts to characterize the variation in the human genome. Because variation in genotype and environment are the fundamental basis to understand phenotypic variability and heritability at the population level, identifying the range of human genetic variation is crucial to the development of personalized nutrition and medicine. The Human Variome Project (HVP; was proposed initially to systematically collect mutations that cause human disease and create a cyber infrastructure to link locus specific databases (LSDB). We report here the discussions and recommendations from the 2008 HVP planning meeting held in San Feliu de Guixols, Spain, in May 2008. 

  • Griggs RC, Batshaw M, Dunkle M, Gopal-Srivastava R, Kaye E, Krischer J, Nguyen T, Paulus K, Merkel PA
    Mol Genet Metab. 2009 Jan;96(1):20-6. doi: 10.1016/j.ymgme.2008.10.003. Epub 2008 Nov 13.
    PMID: 19013090

    Over 7000 rare diseases, each <200,000 US residents, affect nearly 30 million people in the United States. Furthermore, for the 10% of people with a rare disease and for their families, these disorders no longer seem rare. Molecular genetics have characterized the cause of many rare diseases and provide unprecedented opportunities for identifying patients, determining phenotypes, and devising treatments to prevent, stabilize, or improve each disease. Rare disease research poses challenges to investigators requiring specific approaches to: (1) the design of clinical studies; (2) the funding of research programs; (3) the discovery, testing, and approval of new treatments, and (4) the training of clinical scientists. Rigorous, statistically-valid, natural history-controlled, cross-over, and n-of-1 trials can establish efficacy and support regulatory approval of new treatments for rare diseases. The U.S. Orphan Drug Act of the U.S. FDA has stimulated industry investment in clinical trials to develop treatments for rare diseases. For trainees interested in finding a treatment for a rare disease, a commitment to longitudinal care of patients provides a base for the characterization of phenotype and natural history, a stimulus for innovation, a target population for research and helps fund training and research. The scientific methodology, financial resources, and logistics of clinical research for rare diseases have changed dramatically in the past two decades resulting in increased understanding of the pathophysiology of these disorders and direct benefit to patients. 

  • AP Seyed
    The 12th Annual Bio-Ontologies, 2009.
    No abstract available.
  • W Ceusters
    ICBO, 2009.
    No abstract available.
  • [Anonymous]
    Insight (American Society of Ophthalmic Registered Nurses). 2009;34(2):27-27.
    No abstract available.
  • Wiggs JL
    Arch Ophthalmol. 2008 Mar;126(3):422-3. doi: 10.1001/archopht.126.3.422.
    PMID: 18332327
    No abstract available.
  • Brooks BP, Macdonald IM, Tumminia SJ, Smaoui N, Blain D, Nezhuvingal AA, Sieving PA
    Arch Ophthalmol. 2008 Mar;126(3):424-5. doi: 10.1001/archopht.126.3.424.
    PMID: 18332328
    No abstract available.
  • P Goodwin
    Current opinion in ophthalmology, 2008.
    No abstract available.
  • MacDonald IM, Brooks BP, Sieving PA
    Science. 2007 Nov 16;318(5853):1068.
    PMID: 18006726
    No abstract available.
  • Zhao XC, Nakamura H, Subramanyam S, Stock LE, Gillette TE, Yoshikawa S, Ma X, Yee RW
    Ophthalmology. 2007 Nov;114(11):e39-46.
    PMID: 17980739

    PURPOSE: Bowman's layer corneal dystrophies (CDBs) include 2 distinct types: CDB1, or Reis-Bucklers (RBCD), and CDB2, or Thiel-Behnke (TBCD). We studied the genetic basis of 2 cases of apparent spontaneous CDB mutations and attempted to determine if these are sporadic and inheritable mutations. DESIGN: Retrospective molecular genetic study and case report. PARTICIPANTS: Twelve patients were recruited from 2 unrelated families for this study, including 2 affected individuals from one family (family A) and 1 affected individual from another (family B). METHODS: Slit-lamp examination was performed for each patient to determine the disease phenotype. Histological analysis of affected cornea specimens was used for identification of pathogenic corneal opacities in 2 affected patients from family A. MAIN OUTCOME MEASURES: Genomic DNA was isolated from the blood samples and used for mutation screening of the TGFBI/BIGH3 gene. Sixteen polymorphic DNA markers from 9 different chromosomes were used to establish the maternity and paternity of the 2 probands. RESULTS: The 2 families were confirmed to be unrelated. The age onset of ocular symptoms was <2 years for all 3 affected patients. Clinical diagnoses of CDB1 (RBCD) and CDB2 (TBCD) were made for probands A and B, respectively. The affected corneas showed epithelial haze with diffuse, irregular, patchy opacities in a honeycomb and geographic pattern. Subepithelial plaques, increased trichome staining of anterior stroma, and irregular Bowman's layer were observed. An R555Q mutation was found in TGFBI/BIGH3 in the 2 probands but not in their parents. The son of proband A was also affected and apparently inherited his disease allele from his father. CONCLUSION: The R555Q mutation occurred spontaneously and independently in the 2 unrelated CDB families and was confirmed to be transmitted to the next generation in 1 of the 2 families. These findings strongly support the notion that a genetic diagnosis should be determined for CDB and other dystrophies associated with mutations in TGFBI/BIGH3. The discovery of a spontaneous mutation should alert clinicians to be aware of the existence of genetic alterations for their patients without apparent family history of the disease.

  • Guymer RH
    Clin Experiment Ophthalmol. 2007 Jul;35(5):403-8.
    PMID: 17651243
    No abstract available.
  • Sieving PA, Collins FS
    JAMA. 2007 Feb 21;297(7):733-6.
    PMID: 17315303
    No abstract available.
  • Daiger SP, Bowne SJ, Sullivan LS
    Arch Ophthalmol. 2007 Feb;125(2):151-8.
    PMID: 17296890

    Exceptional progress has been made during the past two decades in identifying genes causing inherited retinal diseases such as retinitis pigmentosa. An inescapable consequence is that the relationship between genes, mutations, and clinical findings has become very complex. Success in identifying the causes of inherited retinal diseases has many implications, including a better understanding of the biological basis of vision and insights into the processes involved in retinal pathology. From a clinical point of view, there are two important questions arising from these developments: where do we stand today in finding disease-causing mutations in affected individuals, and what are the implications of this information for clinical practice? This perspective addresses these questions specifically for retinitis pigmentosa, but the observations apply generally to other forms of inherited eye disease. 

  • No Authors
    No abstract available.
  • No Authors
    No abstract available.
  • No Authors
    No abstract available.
  • Vaness Caceres
    No abstract available.
  • No Authors
    No abstract available.
  • No Authors
    No abstract available.
  • No Authors
    No abstract available.
  • No Authors
    No abstract available.
  • No Authors
    No abstract available.
  • Shahrokh Khani, Airaj Fasiuddin
    No abstract available.
  • MacDonald, Ian; Brooks, Brian
    No abstract available.
  • D Clarkson
    No abstract available.
  • No Authors
    No abstract available.
  • Sieving, PA, Ziccardi L

    Juvenile Retinoschisis 

  • No Authors
    No abstract available.
  • No Authors
    No abstract available.