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Huang D, Thompson JA, Chen SC, Adams A, Pitout I, Lima A, Zhang D, Jeffery RCH, Attia MS, McLaren TL, Lamey TM, De Roach JN, McLenachan S, Aung-Htut MT, Fletcher S, Wilton SD, Chen FK. Characterising splicing defects of ABCA4 variants within exons 13-50 in patient-derived fibroblasts. Exp Eye Res 2022; 225:109276. [PMID: 36209838 DOI: 10.1016/j.exer.2022.109276] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/12/2022] [Revised: 09/12/2022] [Accepted: 09/28/2022] [Indexed: 12/29/2022]
Abstract
The ATP-binding cassette subfamily A member 4 gene (ABCA4)-associated retinopathy, Stargardt disease, is the most common monogenic inherited retinal disease. Given the pathogenicity of numerous ABCA4 variants is yet to be examined and a significant proportion (more than 15%) of ABCA4 variants are categorized as splice variants in silico, we therefore established a fibroblast-based splice assay to analyze ABCA4 variants in an Australian Stargardt disease cohort and characterize the pathogenic mechanisms of ABCA4 variants. A cohort of 67 patients clinically diagnosed with Stargardt disease was recruited. Genomic DNA was analysed using a commercial panel for ABCA4 variant detection and the consequences of ABCA4 variants were predicted in silico. Dermal fibroblasts were propagated from skin biopsies, total RNA was extracted and the ABCA4 transcript was amplified by RT-PCR. Our analysis identified a total of 67 unique alleles carrying 74 unique variants. The most prevalent splice-affecting complex allele c.[5461-10T>C; 5603A>T] was carried by 10% of patients in a compound heterozygous state. ABCA4 transcripts from exon 13 to exon 50 were readily detected in fibroblasts. In this region, aberrant splicing was evident in 10 out of 57 variant transcripts (18%), carried by 19 patients (28%). Patient-derived fibroblasts provide a feasible platform for identification of ABCA4 splice variants located within exons 13-50. Experimental evidence of aberrant splicing contributes to the pathogenic classification for ABCA4 variants. Moreover, identification of variants that affect splicing processes provides opportunities for intervention, in particular antisense oligonucleotide-mediated splice correction.
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Affiliation(s)
- Di Huang
- Centre for Molecular Medicine and Innovative Therapeutics, Health Futures Institute, Murdoch University, Western Australia, Australia; Ocular Tissue Engineering Laboratory, Lions Eye Institute, Nedlands, Western Australia, Australia
| | - Jennifer A Thompson
- Australian Inherited Retinal Disease Registry and DNA Bank, Department of Medical Technology and Physics, Sir Charles Gairdner Hospital, Nedlands, Western Australia, Australia
| | - Shang-Chih Chen
- Ocular Tissue Engineering Laboratory, Lions Eye Institute, Nedlands, Western Australia, Australia
| | - Abbie Adams
- Centre for Molecular Medicine and Innovative Therapeutics, Health Futures Institute, Murdoch University, Western Australia, Australia
| | - Ianthe Pitout
- Centre for Molecular Medicine and Innovative Therapeutics, Health Futures Institute, Murdoch University, Western Australia, Australia
| | - Alanis Lima
- Centre for Molecular Medicine and Innovative Therapeutics, Health Futures Institute, Murdoch University, Western Australia, Australia
| | - Dan Zhang
- Ocular Tissue Engineering Laboratory, Lions Eye Institute, Nedlands, Western Australia, Australia
| | - Rachael C Heath Jeffery
- Ocular Tissue Engineering Laboratory, Lions Eye Institute, Nedlands, Western Australia, Australia; Centre for Ophthalmology and Visual Sciences, The University of Western Australia, Nedlands, Western Australia, Australia; Royal Victorian Eye and Ear Hospital, Centre for Eye Research Australia, East Melbourne, Victoria, Australia
| | - Mary S Attia
- Ocular Tissue Engineering Laboratory, Lions Eye Institute, Nedlands, Western Australia, Australia
| | - Terri L McLaren
- Australian Inherited Retinal Disease Registry and DNA Bank, Department of Medical Technology and Physics, Sir Charles Gairdner Hospital, Nedlands, Western Australia, Australia; Centre for Ophthalmology and Visual Sciences, The University of Western Australia, Nedlands, Western Australia, Australia
| | - Tina M Lamey
- Australian Inherited Retinal Disease Registry and DNA Bank, Department of Medical Technology and Physics, Sir Charles Gairdner Hospital, Nedlands, Western Australia, Australia; Centre for Ophthalmology and Visual Sciences, The University of Western Australia, Nedlands, Western Australia, Australia
| | - John N De Roach
- Australian Inherited Retinal Disease Registry and DNA Bank, Department of Medical Technology and Physics, Sir Charles Gairdner Hospital, Nedlands, Western Australia, Australia; Centre for Ophthalmology and Visual Sciences, The University of Western Australia, Nedlands, Western Australia, Australia
| | - Samuel McLenachan
- Ocular Tissue Engineering Laboratory, Lions Eye Institute, Nedlands, Western Australia, Australia; Centre for Ophthalmology and Visual Sciences, The University of Western Australia, Nedlands, Western Australia, Australia
| | - May Thandar Aung-Htut
- Centre for Molecular Medicine and Innovative Therapeutics, Health Futures Institute, Murdoch University, Western Australia, Australia; Perron Institute for Neurological and Translational Science, Centre for Neuromuscular and Neurological Disorders, The University of Western Australia, Australia
| | - Sue Fletcher
- Centre for Molecular Medicine and Innovative Therapeutics, Health Futures Institute, Murdoch University, Western Australia, Australia; Perron Institute for Neurological and Translational Science, Centre for Neuromuscular and Neurological Disorders, The University of Western Australia, Australia; PYC Therapeutics, Harry Perkins Institute of Medical Research, Verdun St, Nedlands, Western Australia, Australia
| | - Steve D Wilton
- Centre for Molecular Medicine and Innovative Therapeutics, Health Futures Institute, Murdoch University, Western Australia, Australia; Perron Institute for Neurological and Translational Science, Centre for Neuromuscular and Neurological Disorders, The University of Western Australia, Australia
| | - Fred K Chen
- Centre for Molecular Medicine and Innovative Therapeutics, Health Futures Institute, Murdoch University, Western Australia, Australia; Australian Inherited Retinal Disease Registry and DNA Bank, Department of Medical Technology and Physics, Sir Charles Gairdner Hospital, Nedlands, Western Australia, Australia; Centre for Ophthalmology and Visual Sciences, The University of Western Australia, Nedlands, Western Australia, Australia; Department of Ophthalmology, Royal Perth Hospital, Perth, Western Australia, Australia; Ophthalmology, Department of Surgery, University of Melbourne, East Melbourne, Victoria, Australia; Royal Victorian Eye and Ear Hospital, Centre for Eye Research Australia, East Melbourne, Victoria, Australia.
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Lugo-Merly A, Molina Thurin LJ, Izquierdo-Encarnacion NJ, Casillas-Murphy SM, Oliver-Cruz A. Stargardt Disease Due to an Intronic Mutation in the ABCA4: A Case Report. Int Med Case Rep J 2022; 15:693-698. [DOI: 10.2147/imcrj.s391001] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/23/2022] [Accepted: 11/23/2022] [Indexed: 11/30/2022] Open
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Al-Khuzaei S, Broadgate S, Foster CR, Shah M, Yu J, Downes SM, Halford S. An Overview of the Genetics of ABCA4 Retinopathies, an Evolving Story. Genes (Basel) 2021; 12:1241. [PMID: 34440414 PMCID: PMC8392661 DOI: 10.3390/genes12081241] [Citation(s) in RCA: 19] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/01/2021] [Revised: 08/09/2021] [Accepted: 08/10/2021] [Indexed: 11/16/2022] Open
Abstract
Stargardt disease (STGD1) and ABCA4 retinopathies (ABCA4R) are caused by pathogenic variants in the ABCA4 gene inherited in an autosomal recessive manner. The gene encodes an importer flippase protein that prevents the build-up of vitamin A derivatives that are toxic to the RPE. Diagnosing ABCA4R is complex due to its phenotypic variability and the presence of other inherited retinal dystrophy phenocopies. ABCA4 is a large gene, comprising 50 exons; to date > 2000 variants have been described. These include missense, nonsense, splicing, structural, and deep intronic variants. Missense variants account for the majority of variants in ABCA4. However, in a significant proportion of patients with an ABCA4R phenotype, a second variant in ABCA4 is not identified. This could be due to the presence of yet unknown variants, or hypomorphic alleles being incorrectly classified as benign, or the possibility that the disease is caused by a variant in another gene. This underlines the importance of accurate genetic testing. The pathogenicity of novel variants can be predicted using in silico programs, but these rely on databases that are not ethnically diverse, thus highlighting the need for studies in differing populations. Functional studies in vitro are useful towards assessing protein function but do not directly measure the flippase activity. Obtaining an accurate molecular diagnosis is becoming increasingly more important as targeted therapeutic options become available; these include pharmacological, gene-based, and cell replacement-based therapies. The aim of this review is to provide an update on the current status of genotyping in ABCA4 and the status of the therapeutic approaches being investigated.
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Affiliation(s)
- Saoud Al-Khuzaei
- Oxford Eye Hospital, John Radcliffe Hospital, Oxford University Hospitals NHS Foundation Trust, Oxford OX3 9DU, UK; (S.A.-K.); (M.S.)
- Nuffield Laboratory of Ophthalmology, Nuffield Department of Clinical Neuroscience, University of Oxford, Level 6 John Radcliffe Hospital, Headley Way, Oxford OX3 9DU, UK; (S.B.); (J.Y.)
| | - Suzanne Broadgate
- Nuffield Laboratory of Ophthalmology, Nuffield Department of Clinical Neuroscience, University of Oxford, Level 6 John Radcliffe Hospital, Headley Way, Oxford OX3 9DU, UK; (S.B.); (J.Y.)
| | | | - Mital Shah
- Oxford Eye Hospital, John Radcliffe Hospital, Oxford University Hospitals NHS Foundation Trust, Oxford OX3 9DU, UK; (S.A.-K.); (M.S.)
| | - Jing Yu
- Nuffield Laboratory of Ophthalmology, Nuffield Department of Clinical Neuroscience, University of Oxford, Level 6 John Radcliffe Hospital, Headley Way, Oxford OX3 9DU, UK; (S.B.); (J.Y.)
| | - Susan M. Downes
- Oxford Eye Hospital, John Radcliffe Hospital, Oxford University Hospitals NHS Foundation Trust, Oxford OX3 9DU, UK; (S.A.-K.); (M.S.)
- Nuffield Laboratory of Ophthalmology, Nuffield Department of Clinical Neuroscience, University of Oxford, Level 6 John Radcliffe Hospital, Headley Way, Oxford OX3 9DU, UK; (S.B.); (J.Y.)
| | - Stephanie Halford
- Nuffield Laboratory of Ophthalmology, Nuffield Department of Clinical Neuroscience, University of Oxford, Level 6 John Radcliffe Hospital, Headley Way, Oxford OX3 9DU, UK; (S.B.); (J.Y.)
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Al-Khuzaei S, Shah M, Foster CR, Yu J, Broadgate S, Halford S, Downes SM. The role of multimodal imaging and vision function testing in ABCA4-related retinopathies and their relevance to future therapeutic interventions. Ther Adv Ophthalmol 2021; 13:25158414211056384. [PMID: 34988368 PMCID: PMC8721514 DOI: 10.1177/25158414211056384] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/19/2021] [Accepted: 10/08/2021] [Indexed: 11/16/2022] Open
Abstract
The aim of this review article is to describe the specific features of Stargardt disease and ABCA4 retinopathies (ABCA4R) using multimodal imaging and functional testing and to highlight their relevance to potential therapeutic interventions. Standardised measures of tissue loss, tissue function and rate of change over time using formal structured deep phenotyping in Stargardt disease and ABCA4R are key in diagnosis, and prognosis as well as when selecting cohorts for therapeutic intervention. In addition, a meticulous documentation of natural history will be invaluable in the future to compare treated with untreated retinas. Despite the familiarity with the term Stargardt disease, this eponymous classification alone is unhelpful when evaluating ABCA4R, as the ABCA4 gene is associated with a number of phenotypes, and a range of severity. Multimodal imaging, psychophysical and electrophysiologic measurements are necessary in diagnosing and characterising these differing retinopathies. A wide range of retinal dystrophy phenotypes are seen in association with ABCA4 mutations. In this article, these will be referred to as ABCA4R. These different phenotypes and the existence of phenocopies present a significant challenge to the clinician. Careful phenotypic characterisation coupled with the genotype enables the clinician to provide an accurate diagnosis, associated inheritance pattern and information regarding prognosis and management. This is particularly relevant now for recruiting to therapeutic trials, and in the future when therapies become available. The importance of accurate genotype-phenotype correlation studies cannot be overemphasised. This approach together with segregation studies can be vital in the identification of causal mutations when variants in more than one gene are being considered as possible. In this article, we give an overview of the current imaging, psychophysical and electrophysiological investigations, as well as current therapeutic research trials for retinopathies associated with the ABCA4 gene.
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Affiliation(s)
- Saoud Al-Khuzaei
- Oxford Eye Hospital, John Radcliffe Hospital, Oxford University Hospitals NHS Foundation Trust, Oxford, UK
- Nuffield Laboratory of Ophthalmology, Nuffield Department of Clinical Neurosciences, University of Oxford, Oxford, UK
| | - Mital Shah
- Oxford Eye Hospital, John Radcliffe Hospital, Oxford University Hospitals NHS Foundation Trust, Oxford, UK
| | | | | | | | - Stephanie Halford
- Nuffield Laboratory of Ophthalmology, Nuffield Department of Clinical Neurosciences, University of Oxford, Oxford, UK
| | - Susan M. Downes
- Nuffield Laboratory of Ophthalmology, Nuffield Department of Clinical Neurosciences, University of Oxford, Level 6 John Radcliffe Hospital, Headley Way, Oxford OX3 9DU, UK
- Oxford Eye Hospital, John Radcliffe Hospital, Oxford University Hospitals NHS Foundation Trust, Oxford, UK
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Tracewska AM, Kocyła-Karczmarewicz B, Rafalska A, Murawska J, Jakubaszko-Jablonska J, Rydzanicz M, Stawiński P, Ciara E, Khan MI, Henkes A, Hoischen A, Gilissen C, van de Vorst M, Cremers FPM, Płoski R, Chrzanowska KH. Genetic Spectrum of ABCA4-Associated Retinal Degeneration in Poland. Genes (Basel) 2019; 10:E959. [PMID: 31766579 PMCID: PMC6947411 DOI: 10.3390/genes10120959] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/22/2019] [Revised: 11/05/2019] [Accepted: 11/19/2019] [Indexed: 12/03/2022] Open
Abstract
Mutations in retina-specific ATP-binding cassette transporter 4 (ABCA4) are responsible for over 95% of cases of Stargardt disease (STGD), as well as a minor proportion of retinitis pigmentosa (RP) and cone-rod dystrophy cases (CRD). Since the knowledge of the genetic causes of inherited retinal diseases (IRDs) in Poland is still scarce, the purpose of this study was to identify pathogenic ABCA4 variants in a subgroup of Polish IRD patients. We recruited 67 families with IRDs as a part of a larger study. The patients were screened with next generation sequencing using a molecular inversion probes (MIPs)-based technique targeting 108 genes involved in the pathogenesis of IRDs. All identified mutations were validated and their familial segregation was tested using Sanger sequencing. In the case of the most frequent complex allele, consisting of two variants in exon 12 and 21, familial segregation was tested using restriction fragment length polymorphism (RFLP). The most prevalent variant, a complex change c.[1622T>C;3113C>T], p.[Leu541Pro;Ala1038Val], was found in this cohort in 54% of all solved ABCA4-associated disorder cases, which is the highest frequency reported thus far. Additionally, we identified nine families displaying a pseudo-dominant mode of inheritance, indicating a high frequency of pathogenic variants within this population.
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Affiliation(s)
- Anna M. Tracewska
- DNA Analysis Unit, ŁUKASIEWICZ Research Network–PORT Polish Center for Technology Development, 54-066 Wrocław, Poland
| | | | - Agnieszka Rafalska
- Department of Ophthalmology, Wrocław Medical University, 50-556 Wrocław, Poland; (A.R.); (J.J.-J.)
| | - Joanna Murawska
- Department of Ophthalmology, University Clinical Centre, 80-214 Gdańsk, Poland;
| | - Joanna Jakubaszko-Jablonska
- Department of Ophthalmology, Wrocław Medical University, 50-556 Wrocław, Poland; (A.R.); (J.J.-J.)
- Department of Paediatric Traumatology and Emergency Medicine, Wrocław Medical University, 50-345 Wrocław, Poland
- SPEKTRUM Ophthalmology Clinic, 53-334 Wrocław, Poland
| | - Małgorzata Rydzanicz
- Department of Medical Genetics, Medical University of Warsaw, 02-106 Warsaw, Poland; (M.R.); (P.S.); (R.P.)
| | - Piotr Stawiński
- Department of Medical Genetics, Medical University of Warsaw, 02-106 Warsaw, Poland; (M.R.); (P.S.); (R.P.)
| | - Elżbieta Ciara
- Children’s Memorial Health Institute, 04-730 Warsaw, Poland; (B.K.-K.); (E.C.)
| | - Muhammad Imran Khan
- Department of Human Genetics, Radboud university medical center, PO Box 9101, 6500 HB Nijmegen, The Netherland; (M.I.K.); (A.H.); (A.H.); (M.v.d.V.); (F.P.M.C.)
- Donders Institute for Brain, Cognition and Behavior, Radboud University Medical Center, PO Box 9104, 6500 HE Nijmegen, The Netherlands;
| | - Arjen Henkes
- Department of Human Genetics, Radboud university medical center, PO Box 9101, 6500 HB Nijmegen, The Netherland; (M.I.K.); (A.H.); (A.H.); (M.v.d.V.); (F.P.M.C.)
- Donders Institute for Brain, Cognition and Behavior, Radboud University Medical Center, PO Box 9104, 6500 HE Nijmegen, The Netherlands;
| | - Alexander Hoischen
- Department of Human Genetics, Radboud university medical center, PO Box 9101, 6500 HB Nijmegen, The Netherland; (M.I.K.); (A.H.); (A.H.); (M.v.d.V.); (F.P.M.C.)
- Department of Internal Medicine and Radboud Center for Infectious Diseases (RCI), Radboud University Medical Center, P.O. Box 9101, 6500 HB Nijmegen, The Netherlands
| | - Christian Gilissen
- Donders Institute for Brain, Cognition and Behavior, Radboud University Medical Center, PO Box 9104, 6500 HE Nijmegen, The Netherlands;
- Department of Internal Medicine and Radboud Center for Infectious Diseases (RCI), Radboud University Medical Center, P.O. Box 9101, 6500 HB Nijmegen, The Netherlands
| | - Maartje van de Vorst
- Department of Human Genetics, Radboud university medical center, PO Box 9101, 6500 HB Nijmegen, The Netherland; (M.I.K.); (A.H.); (A.H.); (M.v.d.V.); (F.P.M.C.)
- Donders Institute for Brain, Cognition and Behavior, Radboud University Medical Center, PO Box 9104, 6500 HE Nijmegen, The Netherlands;
| | - Frans P. M. Cremers
- Department of Human Genetics, Radboud university medical center, PO Box 9101, 6500 HB Nijmegen, The Netherland; (M.I.K.); (A.H.); (A.H.); (M.v.d.V.); (F.P.M.C.)
- Donders Institute for Brain, Cognition and Behavior, Radboud University Medical Center, PO Box 9104, 6500 HE Nijmegen, The Netherlands;
| | - Rafał Płoski
- Department of Medical Genetics, Medical University of Warsaw, 02-106 Warsaw, Poland; (M.R.); (P.S.); (R.P.)
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Hu FY, Li JK, Gao FJ, Qi YH, Xu P, Zhang YJ, Wang DD, Wang LS, Li W, Wang M, Chen F, Shen SM, Xu GZ, Zhang SH, Chang Q, Wu JH. ABCA4 Gene Screening in a Chinese Cohort With Stargardt Disease: Identification of 37 Novel Variants. Front Genet 2019; 10:773. [PMID: 31543898 PMCID: PMC6739639 DOI: 10.3389/fgene.2019.00773] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/27/2019] [Accepted: 07/22/2019] [Indexed: 11/13/2022] Open
Abstract
Purpose: To clarify the mutation spectrum and frequency of ABCA4 in a Chinese cohort with Stargardt disease (STGD1). Methods: A total of 153 subjects, comprising 25 families (25 probands and their family members) and 71 sporadic cases, were recruited for the analysis of ABCA4 variants. All probands with STGD1 underwent a comprehensive ophthalmologic examination. Overall, 792 genes involved in common inherited eye diseases were screened for variants by panel-based next-generation sequencing (NGS). Variants were filtered and analyzed to evaluate possible pathogenicity. Results: The total variant detection rate of at least one ABCA4 mutant allele was 84.3% (129/153): two or three disease-associated variants in 86 subjects (56.2%), one mutant allele in 43 subjects (28.1%), and no variants in 24 subjects (15.7%). Ninety-six variants were identified in the total cohort, which included 62 missense (64%), 15 splicing (16%), 11 frameshift (12%), 6 nonsense (6%), and 2 small insertion or deletion (2%) variants. Thirty-seven novel variants were found, including a de novo variant, c.4561delA. The most prevalent variant was c.101_106delCTTTAT (10.5%), followed by c.2894A > G (6.5%) and c.6563T > C (4.6%), in STGD1 patients from eastern China. Conclusion: Thirty-seven novel variants were detected using panel-based NGS, including one de novo variant, further extending the mutation spectrum of ABCA4. The common variants in a population from eastern China with STGD1 were also identified.
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Affiliation(s)
- Fang-Yuan Hu
- Eye Institute, Eye and ENT Hospital, College of Medicine, Fudan University, Shanghai, China.,State Key Laboratory of Medical Neurobiology, Institutes of Brain Science and Collaborative Innovation Center for Brain Science, Shanghai Medical College, Fudan University, Shanghai, China.,Shanghai Key Laboratory of Visual Impairment and Restoration, Science and Technology Commission of Shanghai Municipality, Shanghai, China.,Key Laboratory of Myopia (Fudan University), Chinese Academy of Medical Sciences, National Health Commission, Shanghai, China
| | - Jian-Kang Li
- BGI-Shenzhen, Shenzhen, China.,Department of Computer Science, City University of Hong Kong, Kowloon, Hong Kong
| | - Feng-Juan Gao
- Eye Institute, Eye and ENT Hospital, College of Medicine, Fudan University, Shanghai, China.,State Key Laboratory of Medical Neurobiology, Institutes of Brain Science and Collaborative Innovation Center for Brain Science, Shanghai Medical College, Fudan University, Shanghai, China.,Shanghai Key Laboratory of Visual Impairment and Restoration, Science and Technology Commission of Shanghai Municipality, Shanghai, China.,Key Laboratory of Myopia (Fudan University), Chinese Academy of Medical Sciences, National Health Commission, Shanghai, China
| | - Yu-He Qi
- Eye Institute, Eye and ENT Hospital, College of Medicine, Fudan University, Shanghai, China.,State Key Laboratory of Medical Neurobiology, Institutes of Brain Science and Collaborative Innovation Center for Brain Science, Shanghai Medical College, Fudan University, Shanghai, China.,Shanghai Key Laboratory of Visual Impairment and Restoration, Science and Technology Commission of Shanghai Municipality, Shanghai, China.,Key Laboratory of Myopia (Fudan University), Chinese Academy of Medical Sciences, National Health Commission, Shanghai, China
| | - Ping Xu
- Eye Institute, Eye and ENT Hospital, College of Medicine, Fudan University, Shanghai, China.,State Key Laboratory of Medical Neurobiology, Institutes of Brain Science and Collaborative Innovation Center for Brain Science, Shanghai Medical College, Fudan University, Shanghai, China.,Shanghai Key Laboratory of Visual Impairment and Restoration, Science and Technology Commission of Shanghai Municipality, Shanghai, China.,Key Laboratory of Myopia (Fudan University), Chinese Academy of Medical Sciences, National Health Commission, Shanghai, China
| | - Yong-Jin Zhang
- Eye Institute, Eye and ENT Hospital, College of Medicine, Fudan University, Shanghai, China.,State Key Laboratory of Medical Neurobiology, Institutes of Brain Science and Collaborative Innovation Center for Brain Science, Shanghai Medical College, Fudan University, Shanghai, China.,Shanghai Key Laboratory of Visual Impairment and Restoration, Science and Technology Commission of Shanghai Municipality, Shanghai, China.,Key Laboratory of Myopia (Fudan University), Chinese Academy of Medical Sciences, National Health Commission, Shanghai, China
| | - Dan-Dan Wang
- Eye Institute, Eye and ENT Hospital, College of Medicine, Fudan University, Shanghai, China.,State Key Laboratory of Medical Neurobiology, Institutes of Brain Science and Collaborative Innovation Center for Brain Science, Shanghai Medical College, Fudan University, Shanghai, China.,Shanghai Key Laboratory of Visual Impairment and Restoration, Science and Technology Commission of Shanghai Municipality, Shanghai, China.,Key Laboratory of Myopia (Fudan University), Chinese Academy of Medical Sciences, National Health Commission, Shanghai, China
| | - Lu-Sheng Wang
- Department of Computer Science, City University of Hong Kong, Kowloon, Hong Kong
| | - Wei Li
- BGI-Shenzhen, Shenzhen, China.,BGI Education Center, University of Chinese Academy of Sciences, Shenzhen, China
| | - Min Wang
- Eye Institute, Eye and ENT Hospital, College of Medicine, Fudan University, Shanghai, China.,State Key Laboratory of Medical Neurobiology, Institutes of Brain Science and Collaborative Innovation Center for Brain Science, Shanghai Medical College, Fudan University, Shanghai, China.,Shanghai Key Laboratory of Visual Impairment and Restoration, Science and Technology Commission of Shanghai Municipality, Shanghai, China.,Key Laboratory of Myopia (Fudan University), Chinese Academy of Medical Sciences, National Health Commission, Shanghai, China
| | - Fang Chen
- BGI-Shenzhen, Shenzhen, China.,Laboratory of Genomics and Molecular Biomedicine, Department of Biology, University of Copenhagen, Copenhagen, Denmark.,Shenzhen Engineering Laboratory for Birth Defects Screening, BGI-Shenzhen, Shenzhen, China
| | | | - Ge-Zhi Xu
- Eye Institute, Eye and ENT Hospital, College of Medicine, Fudan University, Shanghai, China.,State Key Laboratory of Medical Neurobiology, Institutes of Brain Science and Collaborative Innovation Center for Brain Science, Shanghai Medical College, Fudan University, Shanghai, China.,Shanghai Key Laboratory of Visual Impairment and Restoration, Science and Technology Commission of Shanghai Municipality, Shanghai, China.,Key Laboratory of Myopia (Fudan University), Chinese Academy of Medical Sciences, National Health Commission, Shanghai, China
| | - Sheng-Hai Zhang
- Eye Institute, Eye and ENT Hospital, College of Medicine, Fudan University, Shanghai, China.,State Key Laboratory of Medical Neurobiology, Institutes of Brain Science and Collaborative Innovation Center for Brain Science, Shanghai Medical College, Fudan University, Shanghai, China.,Shanghai Key Laboratory of Visual Impairment and Restoration, Science and Technology Commission of Shanghai Municipality, Shanghai, China.,Key Laboratory of Myopia (Fudan University), Chinese Academy of Medical Sciences, National Health Commission, Shanghai, China
| | - Qing Chang
- Eye Institute, Eye and ENT Hospital, College of Medicine, Fudan University, Shanghai, China.,State Key Laboratory of Medical Neurobiology, Institutes of Brain Science and Collaborative Innovation Center for Brain Science, Shanghai Medical College, Fudan University, Shanghai, China.,Shanghai Key Laboratory of Visual Impairment and Restoration, Science and Technology Commission of Shanghai Municipality, Shanghai, China.,Key Laboratory of Myopia (Fudan University), Chinese Academy of Medical Sciences, National Health Commission, Shanghai, China
| | - Ji-Hong Wu
- Eye Institute, Eye and ENT Hospital, College of Medicine, Fudan University, Shanghai, China.,State Key Laboratory of Medical Neurobiology, Institutes of Brain Science and Collaborative Innovation Center for Brain Science, Shanghai Medical College, Fudan University, Shanghai, China.,Shanghai Key Laboratory of Visual Impairment and Restoration, Science and Technology Commission of Shanghai Municipality, Shanghai, China.,Key Laboratory of Myopia (Fudan University), Chinese Academy of Medical Sciences, National Health Commission, Shanghai, China
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7
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Kim MS, Joo K, Seong MW, Kim MJ, Park KH, Park SS, Woo SJ. Genetic Mutation Profiles in Korean Patients with Inherited Retinal Diseases. J Korean Med Sci 2019; 34:e161. [PMID: 31144483 PMCID: PMC6543061 DOI: 10.3346/jkms.2019.34.e161] [Citation(s) in RCA: 41] [Impact Index Per Article: 8.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/24/2019] [Accepted: 05/13/2019] [Indexed: 01/17/2023] Open
Abstract
BACKGROUND Because of genetically and phenotypically heterogenous features, identification of causative genes for inherited retinal diseases (IRD) is essential for diagnosis and treatment in coming gene therapy era. To date, there are no large-scale data of the genes responsible for IRD in Korea. The aim of this study was to identify the distribution of genetic defects in IRD patients in Korea. METHODS Medical records and DNA samples from 86 clinically diagnosed IRD patients were consecutively collected between July 2011 and May 2015. We applied the next-generation sequencing strategy (gene panel) for screening 204 known pathogenic genes associated with IRD. RESULTS Molecular diagnoses were made in 38/86 (44.2%) IRD patients: 18/44 (40.9%) retinitis pigmentosa (RP), 8/22 (36.4%) cone dystrophy, 6/7 (85.7%) Stargardt disease, 1/1 (100%) Best disease, 1/1 (100%) Bardet-Biedl syndrome, 1/1 (100%) congenital stationary night blindness, 1/1 (100%) choroideremia, and 2/8 (25%) other macular dystrophies. ABCA4 was the most common causative gene associated with IRD and was responsible for causing Stargardt disease (n = 6), RP (n = 1), and cone dystrophy (n = 1). In particular, mutations in EYS were found in 4 of 14 autosomal recessive RP (29%). All cases of Stargardt disease had a mutation in the ABCA4 gene with an autosomal recessive trait. CONCLUSION This study provided the distribution of genetic mutations responsible for causing IRD in the Korean patients. This data will serve as a reference for future genetic screening and treatment for Korean IRD patients.
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Affiliation(s)
- Min Seok Kim
- Department of Ophthalmology, Seoul National University Bundang Hospital, Seoul National University College of Medicine, Seongnam, Korea
| | - Kwangsic Joo
- Department of Ophthalmology, Seoul National University Bundang Hospital, Seoul National University College of Medicine, Seongnam, Korea
| | - Moon Woo Seong
- Department of Laboratory Medicine, Seoul National University Hospital, Seoul National University College of Medicine, Seoul, Korea
| | - Man Jin Kim
- Department of Laboratory Medicine, Seoul National University Hospital, Seoul National University College of Medicine, Seoul, Korea
| | - Kyu Hyung Park
- Department of Ophthalmology, Seoul National University Bundang Hospital, Seoul National University College of Medicine, Seongnam, Korea
| | - Sung Sup Park
- Department of Laboratory Medicine, Seoul National University Hospital, Seoul National University College of Medicine, Seoul, Korea.
| | - Se Joon Woo
- Department of Ophthalmology, Seoul National University Bundang Hospital, Seoul National University College of Medicine, Seongnam, Korea.
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Mutation Spectrum of the ABCA4 Gene in a Greek Cohort with Stargardt Disease: Identification of Novel Mutations and Evidence of Three Prevalent Mutated Alleles. J Ophthalmol 2018; 2018:5706142. [PMID: 29854428 PMCID: PMC5952432 DOI: 10.1155/2018/5706142] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/14/2017] [Accepted: 02/15/2018] [Indexed: 11/18/2022] Open
Abstract
Aim To evaluate the frequency and pattern of disease-associated mutations of ABCA4 gene among Greek patients with presumed Stargardt disease (STGD1). Materials and Methods A total of 59 patients were analyzed for ABCA4 mutations using the ABCR400 microarray and PCR-based sequencing of all coding exons and flanking intronic regions. MLPA analysis as well as sequencing of two regions in introns 30 and 36 reported earlier to harbor deep intronic disease-associated variants was used in 4 selected cases. Results An overall detection rate of at least one mutant allele was achieved in 52 of the 59 patients (88.1%). Direct sequencing improved significantly the complete characterization rate, that is, identification of two mutations compared to the microarray analysis (93.1% versus 50%). In total, 40 distinct potentially disease-causing variants of the ABCA4 gene were detected, including six previously unreported potentially pathogenic variants. Among the disease-causing variants, in this cohort, the most frequent was c.5714+5G>A representing 16.1%, while p.Gly1961Glu and p.Leu541Pro represented 15.2% and 8.5%, respectively. Conclusions By using a combination of methods, we completely molecularly diagnosed 48 of the 59 patients studied. In addition, we identified six previously unreported, potentially pathogenic ABCA4 mutations.
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Sheremet NL, Zhorzholadze NV, Ronzina IA, Grushke IG, Kurbatov SA, Chukhrova AL, Loginova AN, Shcherbakova PO, Tanas AS, Polyakov AV, Strel'nikov VV. [Molecular genetic diagnosis of Stargardt disease]. Vestn Oftalmol 2018; 133:4-11. [PMID: 28980559 DOI: 10.17116/oftalma201713344-11] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Abstract
AIM To comparatively evaluate the efficacy of genetic screening in patients with Stargardt disease (SD) by using an express panel of 5 most common ABCA4 mutations and performing massive parallel sequencing of all coding regions of the ABCA4, ELOVL4, PROM1, and CNGB3 genes. MATERIAL AND METHODS MLPA analysis for 5 ABCA4 mutations, namely p.G863A, p.L541P, p.A1038V, p.G1961E, and p.P1380L, was done in 54 patients with SD. In 25 patients, massive parallel sequencing of coding regions (exons) and neighboring introns of the ABCA4, ELOVL4, PROM1, and CNGB3 genes was also performed. RESULTS Gene testing for 5 ABCA4 mutations showed that 50% of patients (27 patients) harbored one mutation and 13% - two mutations. At massive parallel sequencing (25 patients), two pathogenic alleles were found in 21 patients (84%), one mutation - in 23 patients (91.7%). The majority of mutations was accounted for by the ABCA4 gene (83% of all mutation-positive patients). CONCLUSION Sequencing of exons and neighboring introns of the ABCA4, ELOVL4, PROM1, and CNGB3 genes with the new molecular genetic diagnostic system enabled confirmation of the diagnosis of SD in 84% of patients. High prevalence of p.L541P, p.A1038V, and p.G1961E mutations of the ABCA4 gene has been established.
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Affiliation(s)
- N L Sheremet
- Research Institute of Eye Diseases, 11 A, B, Rossolimo St., Moscow, Russia, 119021
| | - N V Zhorzholadze
- Research Institute of Eye Diseases, 11 A, B, Rossolimo St., Moscow, Russia, 119021
| | - I A Ronzina
- Research Institute of Eye Diseases, 11 A, B, Rossolimo St., Moscow, Russia, 119021
| | - I G Grushke
- Research Institute of Eye Diseases, 11 A, B, Rossolimo St., Moscow, Russia, 119021
| | - S A Kurbatov
- Voronezh Regional Clinical Consultative and Diagnostic Center, 5a Lenina Sq., Voronezh, Russia, 394018
| | - A L Chukhrova
- Research Centre of Medical Genetics, 1 Moskvorech'e St., Moscow, Russia, 115478
| | - A N Loginova
- Research Centre of Medical Genetics, 1 Moskvorech'e St., Moscow, Russia, 115478
| | - P O Shcherbakova
- Pirogov Russian National Research Medical University, 1 Ostrovityanova St., Moscow, Russia, 117997
| | - A S Tanas
- Research Centre of Medical Genetics, 1 Moskvorech'e St., Moscow, Russia, 115478
| | - A V Polyakov
- Research Centre of Medical Genetics, 1 Moskvorech'e St., Moscow, Russia, 115478
| | - V V Strel'nikov
- Research Centre of Medical Genetics, 1 Moskvorech'e St., Moscow, Russia, 115478
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Zolnikova IV, Strelnikov VV, Skvortsova NA, Tanas AS, Barh D, Rogatina EV, Egorova IV, Levina DV, Demenkova ON, Prikaziuk EG, Ivanova ME. Stargardt disease-associated mutation spectrum of a Russian Federation cohort. Eur J Med Genet 2016; 60:140-147. [PMID: 27939946 DOI: 10.1016/j.ejmg.2016.12.002] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/20/2016] [Revised: 11/26/2016] [Accepted: 12/01/2016] [Indexed: 12/24/2022]
Abstract
ABCA4-associated mutation screening is extensively performed in European, African, American and several other populations for various retinopathies. However, it has not been well studied in a Russian cohort. Using next-generation (325 genes inherited disease panel) and Sanger sequencing technologies for the first time we documented the spectrum of genetic variations in a Russian retinopathy cohort of 51 patients from 10 ethnic groups. We found ABCA4 variations in 70.5% cases and one case with BEST1 variation. Multiple ABCA4 variations, ABCA4 + RDH12, and ABCA4 + BEST1 variations are also observed and the disease severity is found proportionate to the variation burden. Ten novel ABCA4 variations are detected of which 8 belongs to non-Slavonian population. Most of the detected known variations are found in European and American Stargardt disease populations. No retinopathy causing variation is detected in 14 (27%) cases suggesting that in this Russian retinopathies cohort the causal variants could be in genes that are not covered by our 325 gene panel. Therefore, whole genome/exome analysis is required to identify novel retinopathy associated genes and provide better disease management for this heterogeneous cohort.
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Affiliation(s)
- Inna V Zolnikova
- Moscow Helmholtz Research Institute of Eye Diseases, Sadovaya Chernogryazskaya Str. 14/19, Moscow 105062, Russia
| | | | - Natalia A Skvortsova
- Posterior Eye Segment Diagnostics and Surgery Centre, 2nd Vladimirskaya Str. b.2, 4th Floor, Moscow 111123, Russia
| | - Alexander S Tanas
- Research Centre for Medical Genetics, Moskvorechie Str. 1, Moscow 15478, Russia
| | - Debmalya Barh
- Centre for Genomics and Applied Gene Technology, Institute of Integrative Omics and Applied Biotechnology (IIOAB), Nonakuri, Purba Medinipur, WB 721172, India; Xcode Life Sciences, 3D Eldorado, 112 Nungambakkam High Road, Nungambakkam, Chennai, Tamil Nadu 600034, India.
| | - Elena V Rogatina
- Moscow Helmholtz Research Institute of Eye Diseases, Sadovaya Chernogryazskaya Str. 14/19, Moscow 105062, Russia
| | - Irina V Egorova
- Moscow Helmholtz Research Institute of Eye Diseases, Sadovaya Chernogryazskaya Str. 14/19, Moscow 105062, Russia
| | - Darja V Levina
- Moscow Helmholtz Research Institute of Eye Diseases, Sadovaya Chernogryazskaya Str. 14/19, Moscow 105062, Russia
| | - Olga N Demenkova
- Moscow Helmholtz Research Institute of Eye Diseases, Sadovaya Chernogryazskaya Str. 14/19, Moscow 105062, Russia
| | - Egor G Prikaziuk
- Bioinformatics Institute, Kantemirovskaya Str. b.2a, Saint Petersburg 197342, Russia
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11
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Ścieżyńska A, Oziębło D, Ambroziak AM, Korwin M, Szulborski K, Krawczyński M, Stawiński P, Szaflik J, Szaflik JP, Płoski R, Ołdak M. Next-generation sequencing of ABCA4: High frequency of complex alleles and novel mutations in patients with retinal dystrophies from Central Europe. Exp Eye Res 2015; 145:93-99. [PMID: 26593885 DOI: 10.1016/j.exer.2015.11.011] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/21/2015] [Revised: 09/04/2015] [Accepted: 11/11/2015] [Indexed: 10/22/2022]
Abstract
Variation in the ABCA4 locus has emerged as the most prevalent cause of monogenic retinal diseases. The study aimed to discover causative ABCA4 mutations in a large but not previously investigated cohort with ABCA4-related diseases originating from Central Europe and to refine the genetic relevance of all identified variants based on population evidence. Comprehensive clinical studies were performed to identify patients with Stargardt disease (STGD, n = 76) and cone-rod dystrophy (CRD, n = 16). Next-generation sequencing targeting ABCA4 was applied for a widespread screening of the gene. The results were analyzed in the context of exome data from a corresponding population (n = 594) and other large genomic databases. Our data disprove the pathogenic status of p.V552I and provide more evidence against a causal role of four further ABCA4 variants as drivers of the phenotype under a recessive paradigm. The study identifies 12 novel potentially pathogenic mutations (four of them recurrent) and a novel complex allele p.[(R152*; V2050L)]. In one third (31/92) of our cohort we detected the p.[(L541P; A1038V)] complex allele, which represents an unusually high level of genetic homogeneity for ABCA4-related diseases. Causative ABCA4 mutations account for 79% of STGD and 31% of CRD cases. A combination of p.[(L541P; A1038V)] and/or a truncating ABCA4 mutation always resulted in an early disease onset. Identification of ABCA4 retinopathies provides a specific molecular diagnosis and justifies a prompt introduction of simple precautions that may slow disease progression. The comprehensive, population-specific study expands our knowledge on the genetic landscape of retinal diseases.
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Affiliation(s)
- Aneta Ścieżyńska
- Department of Histology and Embryology, Medical University of Warsaw, Warsaw, Poland
| | - Dominika Oziębło
- Department of Genetics, Institute of Physiology and Pathology of Hearing, Warsaw/Kajetany, Poland
| | - Anna M Ambroziak
- Department of Ophthalmology, Medical University of Warsaw, Warsaw, Poland; Faculty of Physics, University of Warsaw, Warsaw, Poland
| | - Magdalena Korwin
- Department of Ophthalmology, Medical University of Warsaw, Warsaw, Poland
| | - Kamil Szulborski
- Department of Ophthalmology, Medical University of Warsaw, Warsaw, Poland
| | - Maciej Krawczyński
- Department of Medical Genetics, Poznan University of Medical Sciences, Poznan, Poland; Center for Medical Genetics GENESIS, Poznan, Poland
| | - Piotr Stawiński
- Department of Genetics, Institute of Physiology and Pathology of Hearing, Warsaw/Kajetany, Poland
| | - Jerzy Szaflik
- Department of Ophthalmology, Medical University of Warsaw, Warsaw, Poland
| | - Jacek P Szaflik
- Department of Ophthalmology, Medical University of Warsaw, Warsaw, Poland
| | - Rafał Płoski
- Department of Medical Genetics, Medical University of Warsaw, Warsaw, Poland.
| | - Monika Ołdak
- Department of Histology and Embryology, Medical University of Warsaw, Warsaw, Poland; Department of Genetics, Institute of Physiology and Pathology of Hearing, Warsaw/Kajetany, Poland.
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12
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Xin W, Xiao X, Li S, Jia X, Guo X, Zhang Q. Identification of Genetic Defects in 33 Probands with Stargardt Disease by WES-Based Bioinformatics Gene Panel Analysis. PLoS One 2015; 10:e0132635. [PMID: 26161775 PMCID: PMC4498695 DOI: 10.1371/journal.pone.0132635] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/31/2014] [Accepted: 06/16/2015] [Indexed: 11/19/2022] Open
Abstract
Stargardt disease (STGD) is the most common hereditary macular degeneration in juveniles, with loss of central vision occurring in the first or second decade of life. The aim of this study is to identify the genetic defects in 33 probands with Stargardt disease. Clinical data and genomic DNA were collected from 33 probands from unrelated families with STGD. Variants in coding genes were initially screened by whole exome sequencing. Candidate variants were selected from all known genes associated with hereditary retinal dystrophy and then confirmed by Sanger sequencing. Putative pathogenic variants were further validated in available family members and controls. Potential pathogenic mutations were identified in 19 of the 33 probands (57.6%). These mutations were all present in ABCA4, but not in the other four STGD-associated genes or in genes responsible for other retinal dystrophies. Of the 19 probands, ABCA4 mutations were homozygous in one proband and compound heterozygous in 18 probands, involving 28 variants (13 novel and 15 known). Analysis of normal controls and available family members in 12 of the 19 families further support the pathogenicity of these variants. Clinical manifestation of all probands met the diagnostic criteria of STGD. This study provides an overview of a genetic basis for STGD in Chinese patients. Mutations in ABCA4 are the most common cause of STGD in this cohort. Genetic defects in approximately 42.4% of STGD patients await identification in future studies.
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Affiliation(s)
- Wei Xin
- State Key Laboratory of Ophthalmology, Zhongshan Ophthalmic Center, Sun Yat-sen University, Guangzhou, China
| | - Xueshan Xiao
- State Key Laboratory of Ophthalmology, Zhongshan Ophthalmic Center, Sun Yat-sen University, Guangzhou, China
| | - Shiqiang Li
- State Key Laboratory of Ophthalmology, Zhongshan Ophthalmic Center, Sun Yat-sen University, Guangzhou, China
| | - Xiaoyun Jia
- State Key Laboratory of Ophthalmology, Zhongshan Ophthalmic Center, Sun Yat-sen University, Guangzhou, China
| | - Xiangming Guo
- State Key Laboratory of Ophthalmology, Zhongshan Ophthalmic Center, Sun Yat-sen University, Guangzhou, China
| | - Qingjiong Zhang
- State Key Laboratory of Ophthalmology, Zhongshan Ophthalmic Center, Sun Yat-sen University, Guangzhou, China
- * E-mail:
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13
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Homozygous c.1937+1G>A splice-site variant of the ABCA4 gene is associated with Stargardt disease. Eur J Ophthalmol 2014; 24:814-7. [PMID: 24585425 DOI: 10.5301/ejo.5000458] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 02/12/2014] [Indexed: 11/20/2022]
Abstract
PURPOSE To report the phenotype of homozygous ABCA4 c.1937+1G>A splice-site variant associated with Stargardt disease. METHODS Two siblings, a 10-year-old boy and a 32-year-old woman, born from consanguineous parents, presented with central vision loss and macular pigmentary atrophic changes suggestive of Stargardt disease. After genetic counselling, ABCA4 gene analysis was performed. RESULTS The 2 siblings affected were shown to be homozygous for the c.1937+1G>A splice junction variant of the ABCA4 gene. Both parents were heterozygous for the same mutation; they were asymptomatic and the fundus examination revealed a normal appearance. CONCLUSIONS Thus far, ABCA4 c.1937+1G>A splice-site variant was shown to cause retinitis pigmentosa when in hemizygosity and Stargardt disease when present on one allele. In this family two sibs homozygous for the ABCA4 c.1937+1G>A splice-site variant have a less severe phenotype of Stargardt disease. This observation provides useful information for the diagnosis and counseling of patients with this ABCA4 variant.
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14
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Utz VM, Chappelow AV, Marino MJ, Beight CD, Sturgill-Short GM, Pauer GJT, Crowe S, Hagstrom SA, Traboulsi EI. Identification of three ABCA4 sequence variations exclusive to African American patients in a cohort of patients with Stargardt disease. Am J Ophthalmol 2013; 156:1220-1227.e2. [PMID: 24011517 DOI: 10.1016/j.ajo.2013.07.008] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/20/2012] [Revised: 07/10/2013] [Accepted: 07/11/2013] [Indexed: 11/18/2022]
Abstract
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.
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15
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Chacón-Camacho OF, Granillo-Alvarez M, Ayala-Ramírez R, Zenteno JC. ABCA4 mutational spectrum in Mexican patients with Stargardt disease: Identification of 12 novel mutations and evidence of a founder effect for the common p.A1773V mutation. Exp Eye Res 2013; 109:77-82. [PMID: 23419329 DOI: 10.1016/j.exer.2013.02.006] [Citation(s) in RCA: 33] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/01/2012] [Revised: 01/16/2013] [Accepted: 02/04/2013] [Indexed: 01/10/2023]
Abstract
The aim of this study was to assess the mutational spectrum of the ABCA4 gene in a cohort of patients with Stargardt disease from Mexico, a previously uncharacterized population. Clinical diagnosis in each patient was supported by a complete ophthalmological assessment that included visual acuity measurement, a slit lamp examination, a fundus examination and photography, electroretinography, fluorescein angiography, and computerized visual fields testing. Molecular analysis was performed by PCR amplification and direct nucleotide sequence of the 50 exons of the ABCA4 gene in genomic DNA. A total of 31 unrelated subjects with the disease were enrolled in the study. Molecular analysis in the total group of 62 alleles allowed the identification of 46 mutant ABCA4 alleles carrying 29 different pathogenic disease-associated mutations. Two ABCA4 mutant alleles were detected in 20 of the 31 patients (64.5%), a single disease allele was identified in six (19.4%), and no mutant alleles were detected in five of the cases (16.1%). Most patients with two ABCA4 mutations (11/20, 55%) were compound heterozygotes. Twelve variants were novel ABCA4 mutations. Nucleotide substitutions were the most frequent type of variation, occurring in 26 out of 29 (89.7%) different mutations. The two most common mutations in our study were the missense changes p.A1773V and p.G818E, which were identified in eight (17%) and seven (15%) of the total 46 disease-associated alleles, respectively. Haplotype analyses of intragenic SNPs in four subjects carrying the p.A1773V mutation supported a common origin for this mutation. In conclusion, this is the first report of ABCA4 molecular screening in Latin American Stargardt disease patients. Our results expand the mutational spectrum of the disease by adding 12 novel ABCA4 pathogenic variants and support the occurrence of a founder effect for the p.A1773V mutation in the Mexican population. The identification of recurrent mutations in our cohort will direct future ABCA4 molecular screening in patients from this ethnic group.
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Affiliation(s)
- Oscar F Chacón-Camacho
- Department of Genetics-Research Unit, Institute of Ophthalmology Conde de Valenciana, Mexico City, Mexico
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16
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Cuevas P, Outeiriño LA, Angulo J, Giménez-Gallego G. Treatment of Stargardt disease with dobesilate. BMJ Case Rep 2012; 2012:bcr-2012-007128. [PMID: 23076703 DOI: 10.1136/bcr-2012-007128] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022] Open
Abstract
Stargardt disease is a common inherited macular degeneration characterised by a significant loss in the central vision during the first or second decade of the life. Bilateral atrophic changes in the central retina are associated with degeneration of photoreceptors and underlying retinal pigment epithelium, and yellow flecks are extending from the macula. We present a patient with Stargardt disease treated with an intravitreal injection of dobesilate, showing an improvement of visual acuity 4 weeks after treatment.
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Affiliation(s)
- Pedro Cuevas
- Departamento de Investigación, IRYCIS, Hospital Universitario Ramón y Cajal, Madrid, Spain.
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17
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Strom SP, Gao YQ, Martinez A, Ortube C, Chen Z, Nelson SF, Nusinowitz S, Farber DB, Gorin MB. Molecular diagnosis of putative Stargardt Disease probands by exome sequencing. BMC MEDICAL GENETICS 2012; 13:67. [PMID: 22863181 PMCID: PMC3459799 DOI: 10.1186/1471-2350-13-67] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 04/11/2012] [Accepted: 07/25/2012] [Indexed: 12/22/2022]
Abstract
BACKGROUND The commonest genetic form of juvenile or early adult onset macular degeneration is Stargardt Disease (STGD) caused by recessive mutations in the gene ABCA4. However, high phenotypic and allelic heterogeneity and a small but non-trivial amount of locus heterogeneity currently impede conclusive molecular diagnosis in a significant proportion of cases. METHODS We performed whole exome sequencing (WES) of nine putative Stargardt Disease probands and searched for potentially disease-causing genetic variants in previously identified retinal or macular dystrophy genes. Follow-up dideoxy sequencing was performed for confirmation and to screen for mutations in an additional set of affected individuals lacking a definitive molecular diagnosis. RESULTS Whole exome sequencing revealed seven likely disease-causing variants across four genes, providing a confident genetic diagnosis in six previously uncharacterized participants. We identified four previously missed mutations in ABCA4 across three individuals. Likely disease-causing mutations in RDS/PRPH2, ELOVL, and CRB1 were also identified. CONCLUSIONS Our findings highlight the enormous potential of whole exome sequencing in Stargardt Disease molecular diagnosis and research. WES adequately assayed all coding sequences and canonical splice sites of ABCA4 in this study. Additionally, WES enables the identification of disease-related alleles in other genes. This work highlights the importance of collecting parental genetic material for WES testing as the current knowledge of human genome variation limits the determination of causality between identified variants and disease. While larger sample sizes are required to establish the precision and accuracy of this type of testing, this study supports WES for inherited early onset macular degeneration disorders as an alternative to standard mutation screening techniques.
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Affiliation(s)
- Samuel P Strom
- Jules Stein Eye Institute, University of California Los Angeles, 200 Stein Plaza, Los Angeles, CA 90095, USA.
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Burke TR, Fishman GA, Zernant J, Schubert C, Tsang SH, Smith RT, Ayyagari R, Koenekoop RK, Umfress A, Ciccarelli ML, Baldi A, Iannaccone A, Cremers FPM, Klaver CCW, Allikmets R. Retinal phenotypes in patients homozygous for the G1961E mutation in the ABCA4 gene. Invest Ophthalmol Vis Sci 2012; 53:4458-67. [PMID: 22661473 DOI: 10.1167/iovs.11-9166] [Citation(s) in RCA: 71] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022] Open
Abstract
PURPOSE We evaluated the pathogenicity of the G1961E mutation in the ABCA4 gene, and present the range of retinal phenotypes associated with this mutation in homozygosity in a patient cohort with ABCA4-associated phenotypes. METHODS Patients were enrolled from the ABCA4 disease database at Columbia University or by inquiry from collaborating physicians. Only patients homozygous for the G1961E mutation were enrolled. The entire ABCA4 gene open reading frame, including all exons and flanking intronic sequences, was sequenced in all patients. Phenotype data were obtained from clinical history and examination, fundus photography, infrared imaging, fundus autofluorescence, fluorescein angiography, and spectral domain-optical coherence tomography. Additional functional data were obtained using the full-field electroretinogram, and static or kinetic perimetry. RESULTS We evaluated 12 patients homozygous for the G1961E mutation. All patients had evidence of retinal pathology consistent with the range of phenotypes observed in ABCA4 disease. The latest age of onset was recorded at 64 years, in a patient diagnosed initially with age-related macular degeneration (AMD). Of 6 patients in whom severe structural (with/without functional) fundus changes were detected, 5 had additional, heterozygous or homozygous, variants detected in the ABCA4 gene. CONCLUSIONS Homozygous G1961E mutation in ABCA4 results in a range of retinal pathology. The phenotype usually is at the milder end of the disease spectrum, with severe phenotypes linked to the presence of additional ABCA4 variants. Our report also highlights that milder, late-onset Stargardt disease may be confused with AMD.
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Affiliation(s)
- Tomas R Burke
- Department of Ophthalmology, Columbia University, New York, New York 10032, USA
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Abstract
Since the discovery of the ABCA4 gene as the cause of autosomal recessive Stargardt disease/fundus flavimaculatus much has been written of the phenotypic variability in ABCA4 retinopathy. In this review the authors discuss the findings seen on examination and the disease features detected using various clinical tests. Important differential diagnoses are presented and unusual presentations of ABCA4 disease highlighted.
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Affiliation(s)
- Tomas R Burke
- Department of Ophthalmology, Edward S. Harkness Eye Institute, Columbia University, 160 Fort Washington Avenue, New York, NY, 10032, USA
| | - Stephen H Tsang
- Department of Ophthalmology, Edward S. Harkness Eye Institute, Columbia University, 160 Fort Washington Avenue, New York, NY, 10032, USA
- Department of Pathology and Cell Biology, Bernard and Shirlee Brown Glaucoma Laboratory, Edward S. Harkness Eye Institute, Columbia University, 160 Fort Washington Avenue, New York, NY, 10032, USA
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Tátrai E, Ranganathan S, Ferencz M, DeBuc DC, Somfai GM. Comparison of retinal thickness by Fourier-domain optical coherence tomography and OCT retinal image analysis software segmentation analysis derived from Stratus optical coherence tomography images. JOURNAL OF BIOMEDICAL OPTICS 2011; 16:056004. [PMID: 21639572 PMCID: PMC3104045 DOI: 10.1117/1.3573817] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/03/2023]
Abstract
PURPOSE To compare thickness measurements between Fourier-domain optical coherence tomography (FD-OCT) and time-domain OCT images analyzed with a custom-built OCT retinal image analysis software (OCTRIMA). METHODS Macular mapping (MM) by StratusOCT and MM5 and MM6 scanning protocols by an RTVue-100 FD-OCT device are performed on 11 subjects with no retinal pathology. Retinal thickness (RT) and the thickness of the ganglion cell complex (GCC) obtained with the MM6 protocol are compared for each early treatment diabetic retinopathy study (ETDRS)-like region with corresponding results obtained with OCTRIMA. RT results are compared by analysis of variance with Dunnett post hoc test, while GCC results are compared by paired t-test. RESULTS A high correlation is obtained for the RT between OCTRIMA and MM5 and MM6 protocols. In all regions, the StratusOCT provide the lowest RT values (mean difference 43 ± 8 μm compared to OCTRIMA, and 42 ± 14 μm compared to RTVue MM6). All RTVue GCC measurements were significantly thicker (mean difference between 6 and 12 μm) than the GCC measurements of OCTRIMA. CONCLUSION High correspondence of RT measurements is obtained not only for RT but also for the segmentation of intraretinal layers between FD-OCT and StratusOCT-derived OCTRIMA analysis. However, a correction factor is required to compensate for OCT-specific differences to make measurements more comparable to any available OCT device.
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Affiliation(s)
- Erika Tátrai
- Faculty of Medicine, Department of Ophthalmology, Semmelweis University, Mária Street 39, Budapest 1085, Hungary
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21
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Burke TR, Allikmets R, Smith RT, Gouras P, Tsang SH. Loss of peripapillary sparing in non-group I Stargardt disease. Exp Eye Res 2010; 91:592-600. [PMID: 20696155 PMCID: PMC2962723 DOI: 10.1016/j.exer.2010.07.018] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/16/2010] [Revised: 07/26/2010] [Accepted: 07/28/2010] [Indexed: 11/26/2022]
Abstract
The aim of this study was to assess peripapillary sparing in patients with non-group I Stargardt disease. We suggest this as a useful clinical sign for formulating disease severity. Patients with a diagnosis of Stargardt disease were grouped by electroretinogram (ERG). Fundus autofluorescence was used to assess the peripapillary area for involvement in the Stargardt disease process. From a cohort of 32 patients (64 eyes), 17 patients (33 eyes) demonstrated loss of peripapillary sparing. One of 15 patients in Group I, six of 7 patients in group II and 9 of 10 patients in group III demonstrated peripapillary atrophy. One patient in group II had peripapillary flecks. All patients had at least one mutation detected in the ABCA4 gene. Both mutations were detected in 21 patients. Patients in groups II and III had the earliest ages of onset and the poorest visual acuities. Two novel disease causing mutation in the ABCA4 gene were detected. Our data supports the observation that peripapillary sparing is not universal finding for Stargardt disease and peripapillary atrophy is a useful clinical sign for identifying patients with Stargardt disease who fall into the more severe ERG groups, i.e. groups II and III. The presence of atrophy suggests a continuum of disease between groups II and III. Loss of peripapillary sparing is likely associated with the more deleterious mutations of the ABCA4 gene.
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Affiliation(s)
- Tomas R Burke
- Department of Ophthalmology, Bernard and Shirlee Brown Glaucoma Laboratory, Edward S. Harkness Eye Institute, Columbia University, 160 Fort Washington Avenue, New York, NY, 10032, USA
| | - Rando Allikmets
- Department of Ophthalmology, Bernard and Shirlee Brown Glaucoma Laboratory, Edward S. Harkness Eye Institute, Columbia University, 160 Fort Washington Avenue, New York, NY, 10032, USA
- Department of Pathology and Cell Biology, Bernard and Shirlee Brown Glaucoma Laboratory, Edward S. Harkness Eye Institute, Columbia University, 160 Fort Washington Avenue, New York, NY 10032, USA
| | - R. Theodore Smith
- Department of Ophthalmology, Bernard and Shirlee Brown Glaucoma Laboratory, Edward S. Harkness Eye Institute, Columbia University, 160 Fort Washington Avenue, New York, NY, 10032, USA
- Department of Biomedical Engineering, Columbia University, 160 Fort Washington Avenue, New York, NY 10032, USA
| | - Peter Gouras
- Department of Ophthalmology, Bernard and Shirlee Brown Glaucoma Laboratory, Edward S. Harkness Eye Institute, Columbia University, 160 Fort Washington Avenue, New York, NY, 10032, USA
| | - Stephen H Tsang
- Department of Ophthalmology, Bernard and Shirlee Brown Glaucoma Laboratory, Edward S. Harkness Eye Institute, Columbia University, 160 Fort Washington Avenue, New York, NY, 10032, USA
- Department of Pathology and Cell Biology, Bernard and Shirlee Brown Glaucoma Laboratory, Edward S. Harkness Eye Institute, Columbia University, 160 Fort Washington Avenue, New York, NY 10032, USA
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22
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Querques G, Benlian P, Chanu B, Leveziel N, Coscas G, Soubrane G, Souied EH. DHA supplementation for late onset Stargardt disease: NAT-3 study. Clin Ophthalmol 2010; 4:575-80. [PMID: 20668719 PMCID: PMC2909886 DOI: 10.2147/opth.s10049] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/24/2010] [Indexed: 11/23/2022] Open
Abstract
Background: We analyzed the effects of a docosahexaenoic acid (DHA) supplementation in patients affected with late onset Stargardt disease (STGD). Methods: DHA (840 mg/day) was given to 20 STGD patients for six months. A complete ophthalmologic examination, including best-corrected visual acuity (BCVA) and multifocal electroretinogram (mfERG), was performed at inclusion day 0 (D0) and at month 6 (M6). Results: Overall, no statistical differences have been observed at M6 vs D0 as regards BCVA and mfERG (P > 0.05). Mild Improvement of BCVA and improvement of mfERG was noted in seven/40 eyes of four/20 patients. In the first patient, the peak of the a wave increased from 66 nV/deg2 to 75.4 nV/deg2 in the right eye (RE) and 24.5 nV/deg2 to 49.1 nV/deg2 in the left eye (LE). The peak of the b wave improved from 122 nV/deg2 to 157 nV/deg2 in the RE, and 102 nV/deg2 to 149 nV/deg2 in the LE. In the second patient peaks of the a and b waves respectively increased from 11.8 nV/deg2 to 72.1 nV/deg2 and 53 nV/deg2 to 185 nV/deg2 in the RE. In the third patient the peak of the a wave increased from 37 nV/deg2 to 43 nV/deg2 in the RE, and from 31 nV/deg2 to 45 nV/deg2 in the LE; the peak of the b wave improved from 70 nV/deg2 to 89 nV/deg2 in the RE, and from 101 nV/deg2 to 108 nV/deg2 in the LE. In the fourth patient, the peak of the a wave increased from 39 nV/deg2 to 42 nV/deg2 in the RE, and from 40 nV/deg2 to 43 nV/deg2 in the LE; the peak of the b wave improved from 86 nV/deg2 to 94 nV/deg2 in the RE, and from 87 nV/deg2 to 107 nV/deg2 in the LE. Conclusion: DHA seems to influence some functional parameters in patients affected with STGD. However, no short-term benefit should be expected from DHA supplementation.
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Affiliation(s)
- Giuseppe Querques
- Department of Ophthalmology, University of Paris XII, Centre Hospitalier Intercommunal de Creteil, Creteil, France.
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Cella W, Greenstein VC, Zernant-Rajang J, Smith TR, Barile G, Allikmets R, Tsang SH. G1961E mutant allele in the Stargardt disease gene ABCA4 causes bull's eye maculopathy. Exp Eye Res 2009; 89:16-24. [PMID: 19217903 PMCID: PMC2742677 DOI: 10.1016/j.exer.2009.02.001] [Citation(s) in RCA: 81] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/15/2008] [Revised: 12/16/2008] [Accepted: 02/04/2009] [Indexed: 02/08/2023]
Abstract
The aim of this study was to characterize the pathological and functional consequences of the G1961E mutant allele in the Stargardt disease gene ABCA4. Data from 15 patients were retrospectively reviewed and all the patients had at least one G1961E mutation. Comprehensive ophthalmic examination, full-field and pattern electroretinograms, and fundus autofluorescence (FAF) imaging were performed on all patients. Microperimetry, spectral-domain optical coherence tomography (OCT), and fluorescein angiography were performed in selected cases. Genetic screening was performed using the ABCR400 micro-array that currently detects 496 distinct ABCA4 variants. All patients had normal full-field scotopic and photopic electroretinograms (ERGs) and abnormal pattern electroretinograms (PERGs) performed on both eyes, and all the fundi had bull's eye maculopathy without retinal flecks on FAF. On OCT, 1 patient had disorganization of photoreceptor outer segment, 2 had outer nuclear layer (ONL) thinning likely due to photoreceptor atrophy proximal to the foveal center, and 3 had additional retinal pigment epithelium (RPE) atrophy. On microperimetry, 6 patients had eccentric superior fixation and amongst this group, 5 had an absolute scotoma in the foveal area. DNA analysis revealed that 3 patients were homozygous G1961E/G1961E and the rest were compound heterozygotes for G1961E and other ABCA4 mutations. The G1961E allele in either homozygosity or heterozygosity is associated with anatomical and functional pathologies limited to the parafoveal region and a trend to delayed onset of symptoms, relative to other manifestations of ABCA4 mutations. Our observations support the hypothesis that the G1961E allele contributes to localized macular changes rather than generalized retinal dysfunction, and is a cause of bull's eye maculopathy in either the homozygosity or heterozygosity state. In addition, genetic testing provides precise diagnosis of the underlying maculopathy, and current non-invasive imaging techniques could be used to detect photoreceptor damage at the earliest clinical onset of the disease.
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Affiliation(s)
- Wener Cella
- Department of Ophthalmology, Columbia University, 160 Fort Washington Avenue, New York, NY, 10032, USA
| | - Vivienne C. Greenstein
- Department of Ophthalmology, Columbia University, 160 Fort Washington Avenue, New York, NY, 10032, USA
- Department of Ophthalmology, School of Medicine, New York University, NYU Langone Medical Center, 550 First Avenue, New York, NY 10016, USA
| | - Jana Zernant-Rajang
- Department of Ophthalmology, Columbia University, 160 Fort Washington Avenue, New York, NY, 10032, USA
| | - Theodore R. Smith
- Department of Ophthalmology, Columbia University, 160 Fort Washington Avenue, New York, NY, 10032, USA
| | - Gaetano Barile
- Department of Ophthalmology, Columbia University, 160 Fort Washington Avenue, New York, NY, 10032, USA
| | - Rando Allikmets
- Department of Ophthalmology, Columbia University, 160 Fort Washington Avenue, New York, NY, 10032, USA
- Department of Pathology & Cell Biology, Columbia University, 160 Fort Washington Avenue, New York, NY, 10032, USA
| | - Stephen H. Tsang
- Department of Ophthalmology, Columbia University, 160 Fort Washington Avenue, New York, NY, 10032, USA
- Department of Pathology & Cell Biology, Columbia University, 160 Fort Washington Avenue, New York, NY, 10032, USA
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Passerini I, Sodi A, Giambene B, Mariottini A, Menchini U, Torricelli F. Novel mutations in of the ABCR gene in Italian patients with Stargardt disease. Eye (Lond) 2009; 24:158-64. [PMID: 19265867 DOI: 10.1038/eye.2009.35] [Citation(s) in RCA: 34] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022] Open
Abstract
PURPOSE Stargardt disease (STGD) is the most prevalent juvenile macular dystrophy, and it has been associated with mutations in the ABCR gene, encoding a photoreceptor-specific transport protein. In this study, we determined the mutation spectrum in the ABCR gene in a group of Italian STGD patients. METHODS The DNA samples of 71 Italian patients (from 62 independent pedigrees), affected with autosomal recessive STGD, were analysed for mutations in all 50 exons of the ABCR gene by the DHPLC approach (with optimization of the DHPLC conditions for mutation analysis) and direct sequencing techniques. RESULTS In our group of STGD patients, 71 mutations were identified in 68 patients with a detection rate of 95.7%. Forty-three mutations had been already reported in the literature, whereas 28 mutations had not been previously described and were not detected in 150 unaffected control individuals of Italian origin. Missense mutations represented the most frequent finding (59.2%); G1961E was the most common mutation and it was associated with phenotypes in various degrees of severity. CONCLUSIONS Some novel mutations in the ABCR gene were reported in a group of Italian STGD patients confirming the extensive allelic heterogeneity of this gene-probably related to the vast number of exons that favours rearrangements in the DNA sequence.
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Affiliation(s)
- I Passerini
- Department of Genetic Diagnosis, Careggi Universitary Hospital, Florence, Italy.
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Shah SN, Koozekanani DD, Kim JE. Phenotypic Heterogeneity and Lesion Size Measurements in Stargardt Macular Dystrophy. Ophthalmic Surg Lasers Imaging Retina 2009; 40:506-12. [DOI: 10.3928/15428877-20090901-14] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 09/17/2008] [Indexed: 11/20/2022]
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Stenirri S, Alaimo G, Manitto MP, Brancato R, Ferrari M, Cremonesi L. Are microarrays useful in the screening of ABCA4 mutations in Italian patients affected by macular degenerations? Clin Chem Lab Med 2008; 46:1250-5. [PMID: 18652558 DOI: 10.1515/cclm.2008.248] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
Abstract
BACKGROUND Recessive Stargardt disease is due to mutation in the retina-specific ABC transporter gene. Established strategies for molecular characterization of this gene include direct detection by a microarray interrogating approximately 500 DNA variations and a scanning denaturing HPLC methodology. METHODS Because 11 mutations were recorded to account for approximately 50% of molecular defects in the Italian population, we evaluated an alternative open microchip-based assay for a fast and simplified level 1 screening for these mutations. RESULTS This approach allowed the characterization of both mutated alleles in 4% and one mutated allele in 43% of cases when applied to a cohort of 47 Stargardt patients. In the same patients, further investigation by denaturing HPLC for complete characterization identified both mutated allele in 51% and one mutated allele in 19% of cases, allowing the detection of 38 different mutations, five of which had never been described. Notably, new mutations account for a high proportion (13%) of molecular defects in our patient cohort. CONCLUSION The findings raises the question about the choice of the optimal diagnostic strategy for complete genotyping of the ABCA4 gene, as new mutations could not be identified by any direct detection technology, irrespective of the total number of variations screened.
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Affiliation(s)
- Stefania Stenirri
- Genomic Unit for the Diagnosis of Human Pathologies, San Raffaele Scientific Institute, Milan, Italy
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Evaluation of macular abnormalities in Stargardt's disease using optical coherence tomography and scanning laser ophthalmoscope microperimetry. Graefes Arch Clin Exp Ophthalmol 2008; 247:303-9. [PMID: 18941768 DOI: 10.1007/s00417-008-0963-8] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/08/2008] [Revised: 09/09/2008] [Accepted: 09/24/2008] [Indexed: 10/21/2022] Open
Abstract
BACKGROUND The purpose of this study is to evaluate the diagnostic value of optical coherence tomography (Stratus OCT) and scanning laser ophthalmoscope (SLO) microperimetry in patients with Stargardt's disease (STGD), and the correlation between macular morphology and visual function in these patients. METHODS Twenty-two patients with STGD (mean age 44 years, range 11 to 71 years) and 20 age-matched healthy control subjects were included in the study. OCT imaging was performed using six radial line scans manually centered on the fovea. SLO microperimetry was used to assess central scotoma and fixation behavior in patients with STGD. RESULTS Mean best corrected Snellen visual acuity (BCVA) was 20/80, range 20/25 to 20/300 (log MAR 0.6, range 0.1 to 1.2) in the STGD group and 20/20 (log MAR 0.0) in the control group. Foveal thickness was significantly reduced in patients with STGD (119.0 +/- 19.6 microm) compared to controls (210.7 +/- 19.6 microm, P < 0.0001). A significant correlation between foveal thickness and BCVA was observed within the STGD group (R(2) = 0.62, P < 0.0001). Photoreceptor loss in the macular area and a corresponding central scotoma were observed in all STGD patients. CONCLUSIONS OCT findings, particularly reduced foveomacular thickness and photoreceptor loss in the macular area may be useful in the diagnosis of STGD. Furthermore, a strong correlation between foveal thickness and visual function was observed in our patients. Assessment of central visual function using SLO microperimetry provides additional useful information, important in the management of STGD.
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Querques G, Prato R, Iaculli C, Voigt M, Delle Noci N, Coscas G, Soubrane G, Souied EH. Correlation of visual function impairment and OCT findings in patients with Stargardt disease and fundus flavimaculatus. Eur J Ophthalmol 2008; 18:239-47. [PMID: 18320517 DOI: 10.1177/112067210801800212] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
Abstract
PURPOSE To investigate the relationship between morphologic lesions of the retina and functional abnormalities in patients with Stargardt disease (STGD) and fundus flavimaculatus (FFM). DESIGN. Case-controlled, prospective, comparative observational study. METHODS A complete ophthalmologic examination, including best-corrected visual acuity (BCVA) and optical coherence tomography (OCT), was performed in 61 eyes of 32 consecutive patients with STGD/FFM and in 60 eyes of 30 matched healthy control subjects. Furthermore, fundus-related perimetry was performed in 12 of the affected eyes. RESULTS The age ranged from 21 to 71 years in STGD/FFM patients and from 21 to 72 years in controls. BCVA ranged from 20/20 to 20/400 and from 20/20 to 20/32, respectively, in STGD/FFM patients and in controls. A foveal thinning was found by OCT Stratus in almost all cases (average 160 microm) compared with controls (average 210 microm) (p<0.001). BCVA impairment significantly correlated to the degree of foveal thinning (r2=0.16; p=0.0014). Moreover, in STGD/FFM patients the authors observed two types of hyperreflective deposits which were not correlated with BCVA impairment or foveal thinning. In addition, fundus-related perimetry revealed a stable fixation in 8/12 eyes, that was predominantly central in only 4 of these eyes. A smaller degree of foveal thinning correlated to a more stable fixation (p=0.0108), even if not predominantly central (p=0.0218). CONCLUSIONS In this series, lower visual acuity and unstable fixation correlated with a greater transverse foveal thinning. OCT and fundus-related perimetry may be useful tools in STGD/FFM patients.
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Affiliation(s)
- G Querques
- Department of Ophthalmology, Hopital Intercommunal de Creteil, University Paris XII, Paris, France.
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Mizota A, Sakuma T, Miyauchi O, Honda M, Tanaka M. Measurement of retinal thickness from three-dimensional images obtained from C scan images from the optical coherence tomography ophthalmoscope. Clin Exp Ophthalmol 2007; 35:220-4. [PMID: 17430507 DOI: 10.1111/j.1442-9071.2007.01456.x] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
BACKGROUND One of the unique features of the optical coherence tomography (OCT) ophthalmoscope is that it can record C scan images of the retina. The purpose of this study was to determine the best recording time to measure the retinal thickness with the OCT ophthalmoscope. In addition, the accuracy of the measurements was examined by comparing the values obtained by the OCT ophthalmoscope with those obtained with the Stratus OCT Model 3000 (OCT III) assuming that the OCT III gives an accurate measurement of retinal thickness. METHODS The topography mode of the OCT ophthalmoscope was used. First, the average retinal thickness recorded with 2-s scans was compared with that recorded with 4-s scans for a recording area of 15 degreesx15 degrees. Next, the average retinal thickness recorded by the OCT ophthalmoscope was compared with that obtained by the Fast Macular Thickness program of the OCT III in patients with macular oedema. RESULTS The mean retinal thickness of the central area was 208.1 microm for both 2 and 4 s recording times. The average retinal thickness obtained by the OCT ophthalmoscope was highly correlated and not significantly different from the values obtained by the OCT III. The largest differences obtained by the two instruments were seen in the parts of the retina with accumulation of hard exudates. CONCLUSIONS Accurate measurements of retinal thickness can be obtained with the OCT ophthalmoscope by 2-s scans, and thus, the OCT ophthalmoscope can be a valuable instrument for clinical assessments of retinal thickness.
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Affiliation(s)
- Atsushi Mizota
- Department of Ophthalmology, Juntendo University Urayasu Hospital, Tomioka, Urayasu, Japan.
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Stur M, Hermann B, Ergun E, Unterhuber A, Wirtitsch M, Sattmann H, Drexler W. Optische Kohärenztomographie der Photorezeptorschicht im gesunden Auge und bei hereditärer Makuladystrophie. SPEKTRUM DER AUGENHEILKUNDE 2007. [DOI: 10.1007/s00717-006-0170-0] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
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