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Ibrahim M, Jaffal L, Assi A, Helou C, El Shamieh S. ABCA4-related retinopathies in Lebanon. Heliyon 2024; 10:e30304. [PMID: 38694055 PMCID: PMC11061736 DOI: 10.1016/j.heliyon.2024.e30304] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/15/2023] [Revised: 04/20/2024] [Accepted: 04/23/2024] [Indexed: 05/03/2024] Open
Abstract
Variants in ATP-binding cassette transporter type A4 (ABCA4) have been linked to several forms of inherited retinal diseases (IRDs) besides the classically defined Stargardt disease (STGD), known collectively as ABCA4 retinopathies. ABCA4 is a sizable locus harboring 50 exons; thus, its analysis has revealed over 2,400 variants described, of which more than 2,000 are causal. Due to the clinical and genetic heterogeneity, diagnosing ABCA4 retinopathies is challenging. To date, no ABCA4-related retinopathy has been detected in Lebanon. Using next-generation sequencing, we analyzed our IRDs' cohort retrospectively (61 families) and identified five with ABCA4-related retinopathies, making it a relatively abundant cause of IRDs (about 8 %). Three families were diagnosed with rod-cone dystrophy (RCD), two with STGD, and one with cone-rod dystrophy (CRD). In conclusion, our study showed the presence of ABCA4 variants with a high degree of heterogeneity in Lebanon.
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Affiliation(s)
- Mariam Ibrahim
- Molecular Testing Laboratory, Department of Medical Laboratory Technology, Faculty of Health Sciences, Beirut Arab University, Beirut, Lebanon
- Rammal Hassan Rammal Research Laboratory, PhyToxE Research Group, Faculty of Sciences, Lebanese University, Nabatieh, Lebanon
| | - Lama Jaffal
- Department of Biological and Chemical Sciences, School of Arts and Sciences, Lebanese International University, Beirut, Lebanon
| | | | - Charles Helou
- Retinal Service, Beirut Eye & ENT Specialist Hospital, Beirut, Lebanon
| | - Said El Shamieh
- Molecular Testing Laboratory, Department of Medical Laboratory Technology, Faculty of Health Sciences, Beirut Arab University, Beirut, Lebanon
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Kamenarova K, Mihova K, Veleva N, Mermeklieva E, Mihaylova B, Dimitrova G, Oscar A, Shandurkov I, Cherninkova S, Kaneva R. Panel-based next-generation sequencing identifies novel mutations in Bulgarian patients with inherited retinal dystrophies. Mol Genet Genomic Med 2022; 10:e1997. [PMID: 35656873 PMCID: PMC9356554 DOI: 10.1002/mgg3.1997] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/29/2021] [Revised: 04/07/2022] [Accepted: 05/13/2022] [Indexed: 11/05/2022] Open
Abstract
BACKGROUND Next-generation sequencing (NGS)-based method is being used broadly for genetic testing especially for clinically and genetically heterogeneous disorders, such as inherited retinal degenerations (IRDs) but still not routinely used for molecular diagnostics in Bulgaria. Consequently, the purpose of this study was to evaluate the effectiveness of a molecular diagnostic approach, based on targeted NGS for the identification of the disease-causing mutations in 16 Bulgarian patients with different IRDs. METHODS We applied a customized NGS panel, including 125 genes associated with retinal and other eye diseases to the patients with hereditary retinopathies. RESULTS Systematic filtering approach coupled with copy number variation analysis and segregation study lead to the identification of 16 pathogenic and likely pathogenic variants in 12/16 (75%) of IRD patients, 2 of which novel (12.5%): ABCA4-c.668delA (p.K223Rfs18) and RР1-c.2015dupA (p.K673Efs*25). Mutations in the ABCA4, PRPH2, USH2A, BEST1, RР1, CDHR1, and RHO genes were detected reaching a diagnostic yield between 42.9% for Retinitis pigmentosa cases and 100% for macular degeneration, Usher syndrome, and cone-rod dystrophy patients. CONCLUSION Our results confirm the usefulness of targeted NGS approach based on frequently mutated genes as a comprehensive and successful genetic diagnostic tool for IRDs with significant impact on patients counseling.
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Affiliation(s)
- Kunka Kamenarova
- Molecular Medicine Center, Department of Medical Chemistry and Biochemistry, Medical Faculty, Medical University of Sofia, Sofia, Bulgaria.,Laboratory of Genomic Diagnostics, Department of Medical Chemistry and Biochemistry, Medical Faculty, Medical University of Sofia, Sofia, Bulgaria
| | - Kalina Mihova
- Molecular Medicine Center, Department of Medical Chemistry and Biochemistry, Medical Faculty, Medical University of Sofia, Sofia, Bulgaria.,Laboratory of Genomic Diagnostics, Department of Medical Chemistry and Biochemistry, Medical Faculty, Medical University of Sofia, Sofia, Bulgaria
| | - Nevyana Veleva
- Department of Ophthalmology, University Hospital "Alexandrovska", Medical University of Sofia, Sofia, Bulgaria
| | - Elena Mermeklieva
- Clinic of Ophthalmology, University Hospital "Lozenetz", Medical Faculty, Sofia University "St. Kliment Ohridski", Sofia, Bulgaria
| | | | - Galina Dimitrova
- Department of Ophthalmology, University Hospital "Alexandrovska", Medical University of Sofia, Sofia, Bulgaria
| | - Alexander Oscar
- Department of Ophthalmology, University Hospital "Alexandrovska", Medical University of Sofia, Sofia, Bulgaria
| | | | - Sylvia Cherninkova
- Department of Neurology, University hospital "Alexandrovska", Medical University of Sofia, Sofia, Bulgaria
| | - Radka Kaneva
- Molecular Medicine Center, Department of Medical Chemistry and Biochemistry, Medical Faculty, Medical University of Sofia, Sofia, Bulgaria.,Laboratory of Genomic Diagnostics, Department of Medical Chemistry and Biochemistry, Medical Faculty, Medical University of Sofia, Sofia, Bulgaria
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3
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Genetic characteristics of 234 Italian patients with macular and cone/cone-rod dystrophy. Sci Rep 2022; 12:3774. [PMID: 35260635 PMCID: PMC8904500 DOI: 10.1038/s41598-022-07618-1] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/22/2021] [Accepted: 02/16/2022] [Indexed: 01/09/2023] Open
Abstract
Two-hundred and thirty-four Italian patients with a clinical diagnosis of macular, cone and cone-rod dystrophies (MD, CD, and CRD) were examined using next-generation sequencing (NGS) and gene sequencing panels targeting a specific set of genes, Sanger sequencing and—when necessary—multiplex ligation-dependent probe amplification (MLPA) to diagnose the molecular cause of the aforementioned diseases. When possible, segregation analysis was performed in order to confirm unsolved cases. Each patient’s retinal phenotypic characteristics were determined using focal and full-field ERGs, perimetry, spectral domain optical coherence tomography and fundus autofluorescence. We identified 236 potentially causative variants in 136 patients representing the 58.1% of the total cohort, 43 of which were unpublished. After stratifying the patients according to their clinical suspicion, the diagnostic yield was 62.5% and 53.8% for patients with MD and for those with CD/CRD, respectively. The mode of inheritance of all cases confirmed by genetic analysis was 70% autosomal recessive, 26% dominant, and 4% X-linked. The main cause (59%) of both MD and CD/CRD cases was the presence of variants in the ABCA4 gene, followed by variants in PRPH2 (9%) and BEST1 (6%). A careful morpho-functional evaluation of the phenotype, together with genetic counselling, resulted in an acceptable diagnostic yield in a large cohort of Italian patients. Our study emphasizes the role of targeted NGS to diagnose MDs, CDs, and CRDs, as well as the clinical usefulness of segregation analysis for patients with unsolved diagnosis.
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Mucciolo DP, Giorgio D, Lippera M, Dattilo V, Passerini I, Pelo E, Sodi A, Virgili G, Giansanti F, Murro V. Choroidal Caverns in Stargardt Disease. Invest Ophthalmol Vis Sci 2022; 63:25. [PMID: 35156991 PMCID: PMC8857610 DOI: 10.1167/iovs.63.2.25] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022] Open
Abstract
Purpose To report choroidal caverns in patients affected by recessive Stargardt disease (STGD1) and to investigate its clinical features. Methods Retrospective analysis of STGD1 patients recruited at the Regional Reference Center for Hereditary Retinal Degenerations at the Eye Clinic in Florence from 2012 to 2017. Patients included in the study underwent a complete ophthalmic examination including best-corrected visual acuity, color fundus photography, fundus autofluorescence, optical coherence tomography (OCT) and OCT angiography. Results Eighty-six patients (172 eyes) were included in the study. Twenty-three eyes (13.3%) of 21 patients presented choroidal caverns. The total number of detected choroidal caverns was 63. Choroidal caverns were only present in patients with stage III and IV STGD. Interestingly, patients with choroidal caverns presented larger macular atrophy (20.53 ± 16.9 mm2 vs. 18.11 ± 20.39 mm2), worse visual acuity (1.03 ± 0.29 vs. 0.83 ± 0.26), and a thinner choroidal thickness (245.9 ± 88.7 vs. 266.0 ± 110.5 µm). Conclusions Choroidal caverns are present only in the advanced stage of STGD1, and a possible degenerative origin of the finding has been hypothesized.
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Affiliation(s)
- Dario Pasquale Mucciolo
- Department of Neuroscience, Psychology, Drug Research and Child Health, University of Florence, Florence, Italy.,Ophthalmology Unit, San Jacopo Hospital, Pistoia, Italy
| | - Dario Giorgio
- Department of Neuroscience, Psychology, Drug Research and Child Health, University of Florence, Florence, Italy
| | - Myrta Lippera
- Department of Neuroscience, Psychology, Drug Research and Child Health, University of Florence, Florence, Italy
| | - Valeria Dattilo
- Department of Neuroscience, Psychology, Drug Research and Child Health, University of Florence, Florence, Italy
| | - Ilaria Passerini
- Department of Genetic Diagnosis, Careggi Teaching Hospital, Florence, Italy
| | - Elisabetta Pelo
- Department of Genetic Diagnosis, Careggi Teaching Hospital, Florence, Italy
| | - Andrea Sodi
- Department of Neuroscience, Psychology, Drug Research and Child Health, University of Florence, Florence, Italy
| | - Gianni Virgili
- Department of Neuroscience, Psychology, Drug Research and Child Health, University of Florence, Florence, Italy.,Fondazione GB Bietti, Roma, Italy
| | - Fabrizio Giansanti
- Department of Neuroscience, Psychology, Drug Research and Child Health, University of Florence, Florence, Italy
| | - Vittoria Murro
- Department of Neuroscience, Psychology, Drug Research and Child Health, University of Florence, Florence, Italy
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Molday RS, Garces FA, Scortecci JF, Molday LL. Structure and function of ABCA4 and its role in the visual cycle and Stargardt macular degeneration. Prog Retin Eye Res 2021; 89:101036. [PMID: 34954332 DOI: 10.1016/j.preteyeres.2021.101036] [Citation(s) in RCA: 26] [Impact Index Per Article: 8.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/24/2021] [Revised: 12/07/2021] [Accepted: 12/13/2021] [Indexed: 12/17/2022]
Abstract
ABCA4 is a member of the superfamily of ATP-binding cassette (ABC) transporters that is preferentially localized along the rim region of rod and cone photoreceptor outer segment disc membranes. It uses the energy from ATP binding and hydrolysis to transport N-retinylidene-phosphatidylethanolamine (N-Ret-PE), the Schiff base adduct of retinal and phosphatidylethanolamine, from the lumen to the cytoplasmic leaflet of disc membranes. This ensures that all-trans-retinal and excess 11-cis-retinal are efficiently cleared from photoreceptor cells thereby preventing the accumulation of toxic retinoid compounds. Loss-of-function mutations in the gene encoding ABCA4 cause autosomal recessive Stargardt macular degeneration, also known as Stargardt disease (STGD1), and related autosomal recessive retinopathies characterized by impaired central vision and an accumulation of lipofuscin and bis-retinoid compounds. High resolution structures of ABCA4 in its substrate and nucleotide free state and containing bound N-Ret-PE or ATP have been determined by cryo-electron microscopy providing insight into the molecular architecture of ABCA4 and mechanisms underlying substrate recognition and conformational changes induced by ATP binding. The expression and functional characterization of a large number of disease-causing missense ABCA4 variants have been determined. These studies have shed light into the molecular mechanisms underlying Stargardt disease and a classification that reliably predicts the effect of a specific missense mutation on the severity of the disease. They also provide a framework for developing rational therapeutic treatments for ABCA4-associated diseases.
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Affiliation(s)
- Robert S Molday
- Department of Biochemistry & Molecular Biology, University of British Columbia, Vancouver, B.C., Canada; Department of Ophthalmology & Visual Sciences, University of British Columbia, Vancouver, B.C., Canada.
| | - Fabian A Garces
- Department of Biochemistry & Molecular Biology, University of British Columbia, Vancouver, B.C., Canada
| | | | - Laurie L Molday
- Department of Biochemistry & Molecular Biology, University of British Columbia, Vancouver, B.C., Canada
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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: 26] [Impact Index Per Article: 8.7] [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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Duzkale N, Arslan U. Investigation of genotype-phenotype relationship in Turkish patients with inherited retinal disease by next generation sequencing. Ophthalmic Genet 2021; 42:674-684. [PMID: 34315337 DOI: 10.1080/13816810.2021.1952616] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/20/2022]
Abstract
BACKGROUND Inherited retinal dystrophies (IRDs) are a group of retinal diseases genetically and clinically highly heterogeneous and associated with more than 300 genes. This study aims to investigate the genetic basis of Turkish patients with IRDs. MATERIALS AND METHODS In the study, genes related to retinal diseases in 86 IRDs patients were analyzed using the Next Generations Sequencing method (NGS). RESULTS The mean age of 86 patients was 35 and the mean age at diagnosis was 18. There was consanguinity between the parents of 62% of these patients. Fifty-six retinal disease-associated genes of 46 patients and 230 retinal disease-associated genes of 40 patients were examined. Genetic analysis provides a molecular diagnosis in a total of 53 (61.6%) patients. The genes responsible for the IRDs phenotype were frequently identified as ABCA4 (25%), EYS (11%), and RDH12 (9%). There was no significant difference between those with and without a molecular diagnosis in terms of demographic characteristics and family history. CONCLUSIONS Determination of genetic cause by NGS method in IRDs subgroups that are difficult to define by ophthalmic examination ensures that patients receive accurate diagnosis, treatment and counseling. This study contributed to the understanding of the genotype-phenotype relationship of Turkish patients with IRDs.
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Affiliation(s)
- Neslihan Duzkale
- Department of Medical Genetic, Diskapi Yildirim Beyazit Training and Research Hospital, Ankara, Turkey
| | - Umut Arslan
- Department of Bioretina, Ankara University Technopolis, Ankara, Turkey
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9
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Mena MD, Moresco AA, Vidal SH, Aguilar-Cortes D, Obregon MG, Fandiño AC, Sendoya JM, Llera AS, Podhajcer OL. Clinical and Genetic Spectrum of Stargardt Disease in Argentinean Patients. Front Genet 2021; 12:646058. [PMID: 33841504 PMCID: PMC8033171 DOI: 10.3389/fgene.2021.646058] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/24/2020] [Accepted: 03/05/2021] [Indexed: 12/11/2022] Open
Abstract
Purpose To describe the clinical and molecular spectrum of Stargardt disease (STGD) in a cohort of Argentinean patients. Methods This retrospective study included 132 subjects comprising 95 probands clinically diagnosed with STGD and relatives from 16 of them. Targeted next-generation sequencing of the coding and splicing regions of ABCA4 and other phenocopying genes (ELOVL4, PROM1, and CNGB3) was performed in 97 STGD patients. Results We found two or more disease-causing variants in the ABCA4 gene in 69/95 (73%) probands, a single ABCA4 variant in 9/95 (9.5%) probands, and no ABCA4 variants in 17/95 (18%) probands. The final analysis identified 173 variants in ABCA4. Seventy-nine ABCA4 variants were unique, of which nine were novel. No significant findings were seen in the other evaluated genes. Conclusion This study describes the phenotypic and genetic features of STGD1 in an Argentinean cohort. The mutations p.(Gly1961Glu) and p.(Arg1129Leu) were the most frequent, representing almost 20% of the mutated alleles. We also expanded the ABCA4 mutational spectrum with nine novel disease-causing variants, of which eight might be associated with South American natives.
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Affiliation(s)
- Marcela D Mena
- Laboratorio de Terapia Molecular y Celular (Genocan), Fundación Instituto Leloir, CONICET, Buenos Aires, Argentina
| | - Angélica A Moresco
- Servicio de Genética, Hospital de Pediatría Prof. Dr. Juan P. Garrahan, Buenos Aires, Argentina
| | - Sofía H Vidal
- Servicio de Oftalmología, Hospital de Pediatría Prof. Dr. Juan P. Garrahan, Buenos Aires, Argentina
| | - Diana Aguilar-Cortes
- Laboratorio de Terapia Molecular y Celular (Genocan), Fundación Instituto Leloir, CONICET, Buenos Aires, Argentina
| | - María G Obregon
- Servicio de Genética, Hospital de Pediatría Prof. Dr. Juan P. Garrahan, Buenos Aires, Argentina
| | - Adriana C Fandiño
- Servicio de Oftalmología, Hospital de Pediatría Prof. Dr. Juan P. Garrahan, Buenos Aires, Argentina
| | - Juan M Sendoya
- Laboratorio de Terapia Molecular y Celular (Genocan), Fundación Instituto Leloir, CONICET, Buenos Aires, Argentina
| | - Andrea S Llera
- Laboratorio de Terapia Molecular y Celular (Genocan), Fundación Instituto Leloir, CONICET, Buenos Aires, Argentina
| | - Osvaldo L Podhajcer
- Laboratorio de Terapia Molecular y Celular (Genocan), Fundación Instituto Leloir, CONICET, Buenos Aires, Argentina
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Maggi J, Koller S, Bähr L, Feil S, Kivrak Pfiffner F, Hanson JVM, Maspoli A, Gerth-Kahlert C, Berger W. Long-Range PCR-Based NGS Applications to Diagnose Mendelian Retinal Diseases. Int J Mol Sci 2021; 22:ijms22041508. [PMID: 33546218 PMCID: PMC7913364 DOI: 10.3390/ijms22041508] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/04/2021] [Revised: 01/27/2021] [Accepted: 01/28/2021] [Indexed: 12/27/2022] Open
Abstract
The purpose of this study was to develop a flexible, cost-efficient, next-generation sequencing (NGS) protocol for genetic testing. Long-range polymerase chain reaction (PCR) amplicons of up to 20 kb in size were designed to amplify entire genomic regions for a panel (n = 35) of inherited retinal disease (IRD)-associated loci. Amplicons were pooled and sequenced by NGS. The analysis was applied to 227 probands diagnosed with IRD: (A) 108 previously molecularly diagnosed, (B) 94 without previous genetic testing, and (C) 25 undiagnosed after whole-exome sequencing (WES). The method was validated with 100% sensitivity on cohort A. Long-range PCR-based sequencing revealed likely causative variant(s) in 51% and 24% of proband from cohorts B and C, respectively. Breakpoints of 3 copy number variants (CNVs) could be characterized. Long-range PCR libraries spike-in extended coverage of WES. Read phasing confirmed compound heterozygosity in 5 probands. The proposed sequencing protocol provided deep coverage of the entire gene, including intronic and promoter regions. Our method can be used (i) as a first-tier assay to reduce genetic testing costs, (ii) to elucidate missing heritability cases, (iii) to characterize breakpoints of CNVs at nucleotide resolution, (iv) to extend WES data to non-coding regions by spiking-in long-range PCR libraries, and (v) to help with phasing of candidate variants.
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Affiliation(s)
- Jordi Maggi
- Institute of Medical Molecular Genetics, University of Zurich, 8952 Schlieren, Switzerland; (J.M.); (S.K.); (L.B.); (S.F.); (F.K.P.); (A.M.)
| | - Samuel Koller
- Institute of Medical Molecular Genetics, University of Zurich, 8952 Schlieren, Switzerland; (J.M.); (S.K.); (L.B.); (S.F.); (F.K.P.); (A.M.)
| | - Luzy Bähr
- Institute of Medical Molecular Genetics, University of Zurich, 8952 Schlieren, Switzerland; (J.M.); (S.K.); (L.B.); (S.F.); (F.K.P.); (A.M.)
| | - Silke Feil
- Institute of Medical Molecular Genetics, University of Zurich, 8952 Schlieren, Switzerland; (J.M.); (S.K.); (L.B.); (S.F.); (F.K.P.); (A.M.)
| | - Fatma Kivrak Pfiffner
- Institute of Medical Molecular Genetics, University of Zurich, 8952 Schlieren, Switzerland; (J.M.); (S.K.); (L.B.); (S.F.); (F.K.P.); (A.M.)
| | - James V. M. Hanson
- Department of Ophthalmology, University Hospital Zurich and University of Zurich, 8091 Zurich, Switzerland; (J.V.M.H.); (C.G.-K.)
| | - Alessandro Maspoli
- Institute of Medical Molecular Genetics, University of Zurich, 8952 Schlieren, Switzerland; (J.M.); (S.K.); (L.B.); (S.F.); (F.K.P.); (A.M.)
| | - Christina Gerth-Kahlert
- Department of Ophthalmology, University Hospital Zurich and University of Zurich, 8091 Zurich, Switzerland; (J.V.M.H.); (C.G.-K.)
| | - Wolfgang Berger
- Institute of Medical Molecular Genetics, University of Zurich, 8952 Schlieren, Switzerland; (J.M.); (S.K.); (L.B.); (S.F.); (F.K.P.); (A.M.)
- Zurich Center for Integrative Human Physiology (ZIHP), University of Zurich, 8057 Zurich, Switzerland
- Neuroscience Center Zurich (ZNZ), University and ETH Zurich, 8057 Zurich, Switzerland
- Correspondence: ; Tel.: +41-44-556-33-50
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Perea-Romero I, Gordo G, Iancu IF, Del Pozo-Valero M, Almoguera B, Blanco-Kelly F, Carreño E, Jimenez-Rolando B, Lopez-Rodriguez R, Lorda-Sanchez I, Martin-Merida I, Pérez de Ayala L, Riveiro-Alvarez R, Rodriguez-Pinilla E, Tahsin-Swafiri S, Trujillo-Tiebas MJ, Garcia-Sandoval B, Minguez P, Avila-Fernandez A, Corton M, Ayuso C. Genetic landscape of 6089 inherited retinal dystrophies affected cases in Spain and their therapeutic and extended epidemiological implications. Sci Rep 2021; 11:1526. [PMID: 33452396 PMCID: PMC7810997 DOI: 10.1038/s41598-021-81093-y] [Citation(s) in RCA: 68] [Impact Index Per Article: 22.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/28/2020] [Accepted: 12/31/2020] [Indexed: 02/08/2023] Open
Abstract
Inherited retinal diseases (IRDs), defined by dysfunction or progressive loss of photoreceptors, are disorders characterized by elevated heterogeneity, both at the clinical and genetic levels. Our main goal was to address the genetic landscape of IRD in the largest cohort of Spanish patients reported to date. A retrospective hospital-based cross-sectional study was carried out on 6089 IRD affected individuals (from 4403 unrelated families), referred for genetic testing from all the Spanish autonomous communities. Clinical, demographic and familiar data were collected from each patient, including family pedigree, age of appearance of visual symptoms, presence of any systemic findings and geographical origin. Genetic studies were performed to the 3951 families with available DNA using different molecular techniques. Overall, 53.2% (2100/3951) of the studied families were genetically characterized, and 1549 different likely causative variants in 142 genes were identified. The most common phenotype encountered is retinitis pigmentosa (RP) (55.6% of families, 2447/4403). The most recurrently mutated genes were PRPH2, ABCA4 and RS1 in autosomal dominant (AD), autosomal recessive (AR) and X-linked (XL) NON-RP cases, respectively; RHO, USH2A and RPGR in AD, AR and XL for non-syndromic RP; and USH2A and MYO7A in syndromic IRD. Pathogenic variants c.3386G > T (p.Arg1129Leu) in ABCA4 and c.2276G > T (p.Cys759Phe) in USH2A were the most frequent variants identified. Our study provides the general landscape for IRD in Spain, reporting the largest cohort ever presented. Our results have important implications for genetic diagnosis, counselling and new therapeutic strategies to both the Spanish population and other related populations.
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Affiliation(s)
- Irene Perea-Romero
- Department of Genetics, Health Research Institute-Fundación Jiménez Díaz University Hospital, Universidad Autónoma de Madrid (IIS-FJD, UAM), Madrid, Spain.,Center for Biomedical Network Research on Rare Diseases (CIBERER), Instituto de Salud Carlos III, Madrid, Spain
| | - Gema Gordo
- Department of Genetics, Health Research Institute-Fundación Jiménez Díaz University Hospital, Universidad Autónoma de Madrid (IIS-FJD, UAM), Madrid, Spain
| | - Ionut F Iancu
- Department of Genetics, Health Research Institute-Fundación Jiménez Díaz University Hospital, Universidad Autónoma de Madrid (IIS-FJD, UAM), Madrid, Spain.,Center for Biomedical Network Research on Rare Diseases (CIBERER), Instituto de Salud Carlos III, Madrid, Spain
| | - Marta Del Pozo-Valero
- Department of Genetics, Health Research Institute-Fundación Jiménez Díaz University Hospital, Universidad Autónoma de Madrid (IIS-FJD, UAM), Madrid, Spain.,Center for Biomedical Network Research on Rare Diseases (CIBERER), Instituto de Salud Carlos III, Madrid, Spain
| | - Berta Almoguera
- Department of Genetics, Health Research Institute-Fundación Jiménez Díaz University Hospital, Universidad Autónoma de Madrid (IIS-FJD, UAM), Madrid, Spain.,Center for Biomedical Network Research on Rare Diseases (CIBERER), Instituto de Salud Carlos III, Madrid, Spain
| | - Fiona Blanco-Kelly
- Department of Genetics, Health Research Institute-Fundación Jiménez Díaz University Hospital, Universidad Autónoma de Madrid (IIS-FJD, UAM), Madrid, Spain.,Center for Biomedical Network Research on Rare Diseases (CIBERER), Instituto de Salud Carlos III, Madrid, Spain
| | - Ester Carreño
- Department of Ophthalmology, Health Research Institute-Fundación Jiménez Díaz University Hospital, Universidad Autónoma de Madrid (IIS-FJD, UAM), Madrid, Spain
| | - Belen Jimenez-Rolando
- Department of Ophthalmology, Health Research Institute-Fundación Jiménez Díaz University Hospital, Universidad Autónoma de Madrid (IIS-FJD, UAM), Madrid, Spain
| | - Rosario Lopez-Rodriguez
- Department of Genetics, Health Research Institute-Fundación Jiménez Díaz University Hospital, Universidad Autónoma de Madrid (IIS-FJD, UAM), Madrid, Spain
| | - Isabel Lorda-Sanchez
- Department of Genetics, Health Research Institute-Fundación Jiménez Díaz University Hospital, Universidad Autónoma de Madrid (IIS-FJD, UAM), Madrid, Spain.,Center for Biomedical Network Research on Rare Diseases (CIBERER), Instituto de Salud Carlos III, Madrid, Spain
| | - Inmaculada Martin-Merida
- Department of Genetics, Health Research Institute-Fundación Jiménez Díaz University Hospital, Universidad Autónoma de Madrid (IIS-FJD, UAM), Madrid, Spain.,Center for Biomedical Network Research on Rare Diseases (CIBERER), Instituto de Salud Carlos III, Madrid, Spain
| | - Lucia Pérez de Ayala
- Department of Genetics, Health Research Institute-Fundación Jiménez Díaz University Hospital, Universidad Autónoma de Madrid (IIS-FJD, UAM), Madrid, Spain
| | - Rosa Riveiro-Alvarez
- Department of Genetics, Health Research Institute-Fundación Jiménez Díaz University Hospital, Universidad Autónoma de Madrid (IIS-FJD, UAM), Madrid, Spain.,Center for Biomedical Network Research on Rare Diseases (CIBERER), Instituto de Salud Carlos III, Madrid, Spain
| | - Elvira Rodriguez-Pinilla
- Department of Genetics, Health Research Institute-Fundación Jiménez Díaz University Hospital, Universidad Autónoma de Madrid (IIS-FJD, UAM), Madrid, Spain
| | - Saoud Tahsin-Swafiri
- Department of Genetics, Health Research Institute-Fundación Jiménez Díaz University Hospital, Universidad Autónoma de Madrid (IIS-FJD, UAM), Madrid, Spain.,Center for Biomedical Network Research on Rare Diseases (CIBERER), Instituto de Salud Carlos III, Madrid, Spain
| | - Maria J Trujillo-Tiebas
- Department of Genetics, Health Research Institute-Fundación Jiménez Díaz University Hospital, Universidad Autónoma de Madrid (IIS-FJD, UAM), Madrid, Spain.,Center for Biomedical Network Research on Rare Diseases (CIBERER), Instituto de Salud Carlos III, Madrid, Spain
| | | | | | | | - Blanca Garcia-Sandoval
- Center for Biomedical Network Research on Rare Diseases (CIBERER), Instituto de Salud Carlos III, Madrid, Spain.,Department of Ophthalmology, Health Research Institute-Fundación Jiménez Díaz University Hospital, Universidad Autónoma de Madrid (IIS-FJD, UAM), Madrid, Spain
| | - Pablo Minguez
- Department of Genetics, Health Research Institute-Fundación Jiménez Díaz University Hospital, Universidad Autónoma de Madrid (IIS-FJD, UAM), Madrid, Spain.,Center for Biomedical Network Research on Rare Diseases (CIBERER), Instituto de Salud Carlos III, Madrid, Spain
| | - Almudena Avila-Fernandez
- Department of Genetics, Health Research Institute-Fundación Jiménez Díaz University Hospital, Universidad Autónoma de Madrid (IIS-FJD, UAM), Madrid, Spain.,Center for Biomedical Network Research on Rare Diseases (CIBERER), Instituto de Salud Carlos III, Madrid, Spain
| | - Marta Corton
- Department of Genetics, Health Research Institute-Fundación Jiménez Díaz University Hospital, Universidad Autónoma de Madrid (IIS-FJD, UAM), Madrid, Spain. .,Center for Biomedical Network Research on Rare Diseases (CIBERER), Instituto de Salud Carlos III, Madrid, Spain.
| | - Carmen Ayuso
- Department of Genetics, Health Research Institute-Fundación Jiménez Díaz University Hospital, Universidad Autónoma de Madrid (IIS-FJD, UAM), Madrid, Spain. .,Center for Biomedical Network Research on Rare Diseases (CIBERER), Instituto de Salud Carlos III, Madrid, Spain.
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12
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Cremers FPM, Lee W, Collin RWJ, Allikmets R. Clinical spectrum, genetic complexity and therapeutic approaches for retinal disease caused by ABCA4 mutations. Prog Retin Eye Res 2020; 79:100861. [PMID: 32278709 PMCID: PMC7544654 DOI: 10.1016/j.preteyeres.2020.100861] [Citation(s) in RCA: 162] [Impact Index Per Article: 40.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/06/2019] [Revised: 03/13/2020] [Accepted: 03/18/2020] [Indexed: 12/18/2022]
Abstract
The ABCA4 protein (then called a “rim protein”) was first
identified in 1978 in the rims and incisures of rod photoreceptors. The
corresponding gene, ABCA4, was cloned in 1997, and variants
were identified as the cause of autosomal recessive Stargardt disease (STGD1).
Over the next two decades, variation in ABCA4 has been
attributed to phenotypes other than the classically defined STGD1 or fundus
flavimaculatus, ranging from early onset and fast progressing cone-rod dystrophy
and retinitis pigmentosa-like phenotypes to very late onset cases of mostly mild
disease sometimes resembling, and confused with, age-related macular
degeneration. Similarly, analysis of the ABCA4 locus uncovered
a trove of genetic information, including >1200 disease-causing mutations
of varying severity, and of all types – missense, nonsense, small
deletions/insertions, and splicing affecting variants, of which many are located
deep-intronic. Altogether, this has greatly expanded our understanding of
complexity not only of the diseases caused by ABCA4 mutations,
but of all Mendelian diseases in general. This review provides an in depth
assessment of the cumulative knowledge of ABCA4-associated retinopathy –
clinical manifestations, genetic complexity, pathophysiology as well as current
and proposed therapeutic approaches.
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Affiliation(s)
- Frans P M Cremers
- Department of Human Genetics, Radboud University Medical Center, PO Box 9101, 6500 HB, Nijmegen, the Netherlands; Donders Institute for Brain, Cognition and Behaviour, Radboud University Medical Center, PO Box 9104, 6500 HE, Nijmegen, the Netherlands.
| | - Winston Lee
- Department of Ophthalmology, Columbia University, New York, NY, 10032, USA; Department of Genetics & Development, Columbia University, New York, NY, 10032, USA
| | - Rob W J Collin
- Department of Human Genetics, Radboud University Medical Center, PO Box 9101, 6500 HB, Nijmegen, the Netherlands; Donders Institute for Brain, Cognition and Behaviour, Radboud University Medical Center, PO Box 9104, 6500 HE, Nijmegen, the Netherlands
| | - Rando Allikmets
- Department of Ophthalmology, Columbia University, New York, NY, 10032, USA; Department of Pathology & Cell Biology, Columbia University, New York, NY, 10032, USA.
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13
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Raj RK, Dhoble P, Anjanamurthy R, Chermakani P, Kumaran M, Devarajan B, Sundaresan P. Genetic characterization of Stargardt clinical phenotype in South Indian patients using sanger and targeted sequencing. EYE AND VISION 2020; 7:3. [PMID: 31934596 PMCID: PMC6950877 DOI: 10.1186/s40662-019-0168-8] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 06/04/2019] [Accepted: 12/07/2019] [Indexed: 11/10/2022]
Abstract
Background Stargardt disease 1 (STGD1; MIM 248200) is a monogenic form of autosomal recessive genetic disease caused by mutation in ABCA4. This gene has a major role in hydrolyzing N-retinylidene-phosphatidylethanolamine to all-trans-retinal and phosphatidylethanolamine. The purpose of this study is to identify the frequency of putative disease-causing mutations associated with Stargardt disease in a South Indian population. Methods A total of 28 clinically diagnosed Stargardt-like phenotype patients were recruited from south India. Ophthalmic examination of all patients was carefully carried out by a retina specialist based on the stages of fundus imaging and ERG grouping. Genetic analysis of ABCA4 was performed for all patients using Sanger sequencing and clinical exome sequencing. Results This study identified disease-causing mutations in ABCA4 in 75% (21/28) of patients, 7% (2/28) exhibited benign variants and 18% (5/28) were negative for the disease-causing mutation. Conclusion This is the first study describing the genetic association of ABCA4 disease-causing mutation in South Indian Stargardt 1 patients (STGD1). Our findings highlighted the presence of two novel missense mutations and an (in/del, single base pair deletion & splice variant) in ABCA4. However, genetic heterogeneity in ABCA4 mutants requires a larger sample size to establish a true correlation with clinical phenotype.
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Affiliation(s)
- Rajendran Kadarkarai Raj
- 1Department of Genetics, Aravind Medical Research Foundation-Madurai, No.1 Anna Nagar, Madurai, Tamil Nadu 625 020 India
| | - Pankaja Dhoble
- 2Retina Consultant, Department of Vitreo Retinal services, Aravind Eye Hospital-Pondicherry, Puducherry, India
| | - Rupa Anjanamurthy
- 3Department of Paediatrics and Adult strabismus, Aravind Eye Hospital-Madurai, Madurai, Tamil Nadu India
| | - Prakash Chermakani
- 1Department of Genetics, Aravind Medical Research Foundation-Madurai, No.1 Anna Nagar, Madurai, Tamil Nadu 625 020 India
| | - Manojkumar Kumaran
- 4Department of Bioinformatics, Aravind Medical Research Foundation-Madurai, Madurai, Tamil Nadu India
| | - Bharanidharan Devarajan
- 4Department of Bioinformatics, Aravind Medical Research Foundation-Madurai, Madurai, Tamil Nadu India
| | - Periasamy Sundaresan
- 1Department of Genetics, Aravind Medical Research Foundation-Madurai, No.1 Anna Nagar, Madurai, Tamil Nadu 625 020 India
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14
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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: 46] [Impact Index Per Article: 9.2] [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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15
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Sodi A, Passerini I, Bacherini D, Boni L, Palchetti S, Murro V, Caporossi O, Mucciolo DP, Franco F, Vannozzi L, Torricelli F, Pelo E, Rizzo S, Virgili G. CFH Y402H polymorphism in Italian patients with age-related macular degeneration, retinitis pigmentosa, and Stargardt disease. Ophthalmic Genet 2018; 39:699-705. [PMID: 30285522 DOI: 10.1080/13816810.2018.1525753] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/28/2022]
Abstract
BACKGROUND The complement system has been implicated in the pathogenesis of age-related macular degeneration (AMD) and the CFH Y402H polymorphism has been suggested as a major risk factor for AMD. Recent evidences supported the role of inflammation in the pathogenesis of some retinal dystrophies. Aim of this study was to evaluate the prevalence of CFHY402H polymorphism in a group of Italian patients affected by atrophic AMD, Stargardt disease (STGD), or retinitis pigmentosa(RP). MATERIALS AND METHODS Our case-control association study included 116 patients with atrophic AMD, 77 with RP, 86 with STGD, and 100 healthy controls. All the patients were evaluated by a standard ophthalmologic examination and OCT. ERG was performed on STGD and RP patients. All the subjects underwent a blood drawing for genetic testing and the CFHY402H polymorphism was genotyped with the TaqMan real-time polymerase chain reaction single nucleotide polymorphism assay. RESULTS The prevalence of the risk genotype C/C was higher in the AMD group than in controls (p < 0.001). The risk allele C was more frequent in the AMD group than in controls (p < 0.001). The prevalence of the risk genotype was higher in the RP patients than in controls (p < 0.001) and similarly the risk allele C was more frequent in the RP group (p = 0.008). The CFHY402H genotype distribution was not different between patients with STGD and the controls, for the biallelic (p = 0.531) and for the monoallelic (p = 0.318) evaluation. CONCLUSIONS In our series of Italian patients, the CFHY402H genotype is associated with atrophic AMD and RP, but not with STGD. This result may support the hypothesis of a complement system dysregulation in the pathogenesis of AMD and RP.
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Affiliation(s)
- Andrea Sodi
- a Department of Surgery and Translational Medicine, Eye Clinic , Careggi Teaching Hospital, University of Florence , Florence , Italy
| | - Ilaria Passerini
- b Department of Genetic Diagnosis , Careggi Teaching Hospital , Florence , Italy
| | - Daniela Bacherini
- a Department of Surgery and Translational Medicine, Eye Clinic , Careggi Teaching Hospital, University of Florence , Florence , Italy
| | - Luca Boni
- c Clinical Trials Coordinating Center , Careggi Teaching Hospital , Florence , Italy
| | - Simona Palchetti
- b Department of Genetic Diagnosis , Careggi Teaching Hospital , Florence , Italy
| | - Vittoria Murro
- a Department of Surgery and Translational Medicine, Eye Clinic , Careggi Teaching Hospital, University of Florence , Florence , Italy
| | - Orsola Caporossi
- a Department of Surgery and Translational Medicine, Eye Clinic , Careggi Teaching Hospital, University of Florence , Florence , Italy
| | - Dario Pasquale Mucciolo
- a Department of Surgery and Translational Medicine, Eye Clinic , Careggi Teaching Hospital, University of Florence , Florence , Italy
| | - Fabrizio Franco
- a Department of Surgery and Translational Medicine, Eye Clinic , Careggi Teaching Hospital, University of Florence , Florence , Italy
| | - Lorenzo Vannozzi
- a Department of Surgery and Translational Medicine, Eye Clinic , Careggi Teaching Hospital, University of Florence , Florence , Italy
| | - Francesca Torricelli
- b Department of Genetic Diagnosis , Careggi Teaching Hospital , Florence , Italy
| | - Elisabetta Pelo
- b Department of Genetic Diagnosis , Careggi Teaching Hospital , Florence , Italy
| | - Stanislao Rizzo
- a Department of Surgery and Translational Medicine, Eye Clinic , Careggi Teaching Hospital, University of Florence , Florence , Italy
| | - Gianni Virgili
- a Department of Surgery and Translational Medicine, Eye Clinic , Careggi Teaching Hospital, University of Florence , Florence , Italy
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16
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González-Del Pozo M, Martín-Sánchez M, Bravo-Gil N, Méndez-Vidal C, Chimenea Á, Rodríguez-de la Rúa E, Borrego S, Antiñolo G. Searching the second hit in patients with inherited retinal dystrophies and monoallelic variants in ABCA4, USH2A and CEP290 by whole-gene targeted sequencing. Sci Rep 2018; 8:13312. [PMID: 30190494 PMCID: PMC6127285 DOI: 10.1038/s41598-018-31511-5] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/11/2018] [Accepted: 08/20/2018] [Indexed: 12/19/2022] Open
Abstract
Inherited Retinal Dystrophies are clinically and genetically heterogeneous disorders affecting the photoreceptors. Although NGS has shown to be helpful for the molecular diagnosis of these conditions, some cases remain unsolved. Among these, several individuals harboured monoallelic variants in a recessive gene, suggesting that a comprehensive screening could improve the overall diagnosis. In order to assess the contribution of non-coding variations in a cohort of 29 patients, 25 of them with monoallelic mutations, we performed targeted NGS. The design comprised the entire genomic sequence of three genes (USH2A, ABCA4 and CEP290), the coding exons of 76 genes and two disease-associated intronic regions in OFD1 and PRPF31. As a result, likely causative mutations (8 novel) were identified in 17 probands (diagnostic rate: 58.62%), including two copy-number variations in USH2A (one deletion of exons 22-55 and one duplication of exons 46-47). Possibly damaging deep-intronic mutations were identified in one family, and another with a monoallelic variant harboured causal mutations in a different locus. In conclusion, due to the high prevalence of carriers of IRD mutations and the results obtained here, sequencing entire genes do not seem to be the approach of choice for detecting the second hit in IRD patients with monoallelic variants.
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Affiliation(s)
- María González-Del Pozo
- Department of Maternofetal Medicine, Genetics and Reproduction, Institute of Biomedicine of Seville, University Hospital Virgen del Rocío/CSIC/University of Seville, Seville, Spain
- Centro de Investigación Biomédica en Red de Enfermedades Raras (CIBERER), Seville, Spain
| | - Marta Martín-Sánchez
- Department of Maternofetal Medicine, Genetics and Reproduction, Institute of Biomedicine of Seville, University Hospital Virgen del Rocío/CSIC/University of Seville, Seville, Spain
| | - Nereida Bravo-Gil
- Department of Maternofetal Medicine, Genetics and Reproduction, Institute of Biomedicine of Seville, University Hospital Virgen del Rocío/CSIC/University of Seville, Seville, Spain
- Centro de Investigación Biomédica en Red de Enfermedades Raras (CIBERER), Seville, Spain
| | - Cristina Méndez-Vidal
- Department of Maternofetal Medicine, Genetics and Reproduction, Institute of Biomedicine of Seville, University Hospital Virgen del Rocío/CSIC/University of Seville, Seville, Spain
- Centro de Investigación Biomédica en Red de Enfermedades Raras (CIBERER), Seville, Spain
| | - Ángel Chimenea
- Department of Maternofetal Medicine, Genetics and Reproduction, Institute of Biomedicine of Seville, University Hospital Virgen del Rocío/CSIC/University of Seville, Seville, Spain
| | - Enrique Rodríguez-de la Rúa
- Department of Ophthalmology, University Hospital Virgen Macarena, Seville, Spain
- Retics Patologia Ocular. OFTARED. Instituto de Salud Carlos III, Madrid, Spain
| | - Salud Borrego
- Department of Maternofetal Medicine, Genetics and Reproduction, Institute of Biomedicine of Seville, University Hospital Virgen del Rocío/CSIC/University of Seville, Seville, Spain
- Centro de Investigación Biomédica en Red de Enfermedades Raras (CIBERER), Seville, Spain
| | - Guillermo Antiñolo
- Department of Maternofetal Medicine, Genetics and Reproduction, Institute of Biomedicine of Seville, University Hospital Virgen del Rocío/CSIC/University of Seville, Seville, Spain.
- Centro de Investigación Biomédica en Red de Enfermedades Raras (CIBERER), Seville, Spain.
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17
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Nassisi M, Mohand-Saïd S, Dhaenens CM, Boyard F, Démontant V, Andrieu C, Antonio A, Condroyer C, Foussard M, Méjécase C, Eandi CM, Sahel JA, Zeitz C, Audo I. Expanding the Mutation Spectrum in ABCA4: Sixty Novel Disease Causing Variants and Their Associated Phenotype in a Large French Stargardt Cohort. Int J Mol Sci 2018; 19:E2196. [PMID: 30060493 PMCID: PMC6121640 DOI: 10.3390/ijms19082196] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/21/2018] [Revised: 06/18/2018] [Accepted: 07/22/2018] [Indexed: 12/18/2022] Open
Abstract
Here we report novel mutations in ABCA4 with the underlying phenotype in a large French cohort with autosomal recessive Stargardt disease. The DNA samples of 397 index subjects were analyzed in exons and flanking intronic regions of ABCA4 (NM_000350.2) by microarray analysis and direct Sanger sequencing. At the end of the screening, at least two likely pathogenic mutations were found in 302 patients (76.1%) while 95 remained unsolved: 40 (10.1%) with no variants identified, 52 (13.1%) with one heterozygous mutation, and 3 (0.7%) with at least one variant of uncertain significance (VUS). Sixty-three novel variants were identified in the cohort. Three of them were variants of uncertain significance. The other 60 mutations were classified as likely pathogenic or pathogenic, and were identified in 61 patients (15.4%). The majority of those were missense (55%) followed by frameshift and nonsense (30%), intronic (11.7%) variants, and in-frame deletions (3.3%). Only patients with variants never reported in literature were further analyzed herein. Recruited subjects underwent complete ophthalmic examination including best corrected visual acuity, kinetic and static perimetry, color vision test, full-field and multifocal electroretinography, color fundus photography, short-wavelength and near-infrared fundus autofluorescence imaging, and spectral domain optical coherence tomography. Clinical evaluation of each subject confirms the tendency that truncating mutations lead to a more severe phenotype with electroretinogram (ERG) impairment (p = 0.002) and an earlier age of onset (p = 0.037). Our study further expands the mutation spectrum in the exonic and flanking regions of ABCA4 underlying Stargardt disease.
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Affiliation(s)
- Marco Nassisi
- Sorbonne Université, INSERM, CNRS, Institut de la Vision, F-75012 Paris, France.
- Department of Surgical Sciences, Eye Clinic, University of Turin, 10126 Turin, Italy.
| | - Saddek Mohand-Saïd
- Sorbonne Université, INSERM, CNRS, Institut de la Vision, F-75012 Paris, France.
- Centre Hospitalier National d'Ophtalmologie des Quinze-Vingts, DHU Sight Restore, INSERM-DHOS CIC 1423, F-75012 Paris, France.
| | - Claire-Marie Dhaenens
- Univ. Lille, Inserm UMR-S 1172, CHU Lille, Biochemistry and Molecular Biology Department-UF Génopathies, F-59000 Lille, France.
| | - Fiona Boyard
- Sorbonne Université, INSERM, CNRS, Institut de la Vision, F-75012 Paris, France.
| | - Vanessa Démontant
- Sorbonne Université, INSERM, CNRS, Institut de la Vision, F-75012 Paris, France.
| | - Camille Andrieu
- Centre Hospitalier National d'Ophtalmologie des Quinze-Vingts, DHU Sight Restore, INSERM-DHOS CIC 1423, F-75012 Paris, France.
| | - Aline Antonio
- Sorbonne Université, INSERM, CNRS, Institut de la Vision, F-75012 Paris, France.
| | - Christel Condroyer
- Sorbonne Université, INSERM, CNRS, Institut de la Vision, F-75012 Paris, France.
| | - Marine Foussard
- Sorbonne Université, INSERM, CNRS, Institut de la Vision, F-75012 Paris, France.
| | - Cécile Méjécase
- Sorbonne Université, INSERM, CNRS, Institut de la Vision, F-75012 Paris, France.
| | - Chiara Maria Eandi
- Department of Surgical Sciences, Eye Clinic, University of Turin, 10126 Turin, Italy.
| | - José-Alain Sahel
- Sorbonne Université, INSERM, CNRS, Institut de la Vision, F-75012 Paris, France.
- Centre Hospitalier National d'Ophtalmologie des Quinze-Vingts, DHU Sight Restore, INSERM-DHOS CIC 1423, F-75012 Paris, France.
- Fondation Ophtalmologique Adolphe de Rothschild, F-75019 Paris, France.
- Académie des Sciences-Institut de France, F-75006 Paris, France.
- Department of Ophthalmology, The University of Pittsburgh School of Medicine, Pittsburg, PA 15213, USA.
| | - Christina Zeitz
- Sorbonne Université, INSERM, CNRS, Institut de la Vision, F-75012 Paris, France.
| | - Isabelle Audo
- Sorbonne Université, INSERM, CNRS, Institut de la Vision, F-75012 Paris, France.
- Centre Hospitalier National d'Ophtalmologie des Quinze-Vingts, DHU Sight Restore, INSERM-DHOS CIC 1423, F-75012 Paris, France.
- Institute of Ophthalmology, University College of London, London EC1V 9EL, UK.
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18
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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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Sodi A, Bacherini D, Lenzetti C, Caporossi O, Murro V, Mucciolo DP, Cipollini F, Passerini I, Virgili G, Rizzo S. EDI OCT evaluation of choroidal thickness in Stargardt disease. PLoS One 2018; 13:e0190780. [PMID: 29304098 PMCID: PMC5755895 DOI: 10.1371/journal.pone.0190780] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/25/2017] [Accepted: 12/20/2017] [Indexed: 12/26/2022] Open
Abstract
Purpose Choroidal thickness (CT) evaluation with EDI-OCT in Stargardt Disease (STGD), considering its possible association with some clinical features of the disease. Methods CT was evaluated in 41 STGD patients and in 70 controls. Measurements were performed in the subfoveal position and at 1000 μm nasally and temporally. CT average values in STGD and in the control group were first compared by means of Student’s T test. Then, the possible association between CT and some clinical features was evaluated by means of linear regression analysis. Considered clinical parameters were: age, age on onset, duration of the disease, visual acuity, foveal thickness, Fishman clinical phenotype, visual field loss and ERG response. Results Average CT was not significantly different between controls and STGD patients. In the STGD group the correlation between CT and age (r = 0.22, p = 0.033) and age of onset (r = 0.05, p = 0.424) was modest, while that of CT with disease duration (r = 0.30, p<0.001) was moderate. CT and foveal thickness were also significantly but modestly correlated (r = 0.15, p = 0.033). Conclusion In our series average CT is not significantly changed in STGD in comparison with the controls. Nevertheless a choroidal thinning may be identified in the more advanced stages of the disease.
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Affiliation(s)
- Andrea Sodi
- Department of Surgery and Translational Medicine, Eye Clinic, Careggi Teaching Hospital, Florence, Italy
| | - Daniela Bacherini
- Department of Surgery and Translational Medicine, Eye Clinic, Careggi Teaching Hospital, Florence, Italy
| | - Chiara Lenzetti
- Department of Surgery and Translational Medicine, Eye Clinic, Careggi Teaching Hospital, Florence, Italy
- * E-mail:
| | - Orsola Caporossi
- Department of Surgery and Translational Medicine, Eye Clinic, Careggi Teaching Hospital, Florence, Italy
| | - Vittoria Murro
- Department of Surgery and Translational Medicine, Eye Clinic, Careggi Teaching Hospital, Florence, Italy
| | - Dario Pasquale Mucciolo
- Department of Surgery and Translational Medicine, Eye Clinic, Careggi Teaching Hospital, Florence, Italy
| | - Francesca Cipollini
- Department of Surgery and Translational Medicine, Eye Clinic, Careggi Teaching Hospital, Florence, Italy
| | - Ilaria Passerini
- Department of Genetic Diagnosis, Careggi Teaching Hospital, Florence, Italy
| | - Gianni Virgili
- Department of Surgery and Translational Medicine, Eye Clinic, Careggi Teaching Hospital, Florence, Italy
| | - Stanislao Rizzo
- Department of Surgery and Translational Medicine, Eye Clinic, Careggi Teaching Hospital, Florence, Italy
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20
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Abeshi A, Zulian A, Beccari T, Dundar M, D’Esposito F, Bertelli M. Genetic testing for Stargardt macular dystrophy. THE EUROBIOTECH JOURNAL 2017. [DOI: 10.24190/issn2564-615x/2017/s1.33] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022] Open
Abstract
Abstract
We studied the scientific literature and disease guidelines in order to summarize the clinical utility of genetic testing for Stargardt macular dystrophy (STGD). STGD is mostly inherited in an autosomal recessive manner and rarely in an autosomal dominant manner, with an overall prevalence of 1-5 per 10 000 live births. It is caused by variations in the ABCA4, CNGB3, ELOVL4, PRPH2 and PROM1 genes. Clinical diagnosis is based on ophthalmological examination, fluorescein angiography, electroretinography, visual field testing, optical coherence tomography and color testing. The genetic test is useful for confirming diagnosis, and for differential diagnosis, couple risk assessment and access to clinical trials.
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Affiliation(s)
- Andi Abeshi
- MAGI Balkans, Tirana , Albania
- MAGI’S Lab, Rovereto , Italy
| | | | - Tommaso Beccari
- Department of Pharmaceutical Sciences, University of Perugia, Perugia , Italy
| | - Munis Dundar
- Department of Medical Genetics, Erciyes University Medical School, Kayseri , Turkey
| | - Fabiana D’Esposito
- Head and Neck Department, School of Medicine and Surgery, University of Naples “Federico II”, Napoli , Italy
- ICORG (Imperial College Ophthalmology Research Group), Western Eye Hospital, London , UK
- MAGI Euregio, Bolzano , Italy
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Abstract
Purpose To study the reading performance of patients with Stargardt disease (STGD) and the relationship between clinical vision measurements and vision-related quality of life (VRQOL). Methods We studied both eyes of 16 patients with STGD. Each patient was examined for best-corrected visual acuity (Early Treatment Diabetic Retinopathy Study [ETDRS]), reading ability (MNREAD and REX charts), contrast sensitivity (Pelli-Robson charts), fixation study (MP1 microperimeter), and VRQOL (25-item National Eye Institute Visual Function Questionnaire [NEI VFQ-25]). The correlation pattern among these variables was examined and an exploratory factor analysis was used to investigate dimensionality of both visual function and VRQOL. Results Mean ETDRS visual acuity was about 20/160 (0.9 logMAR). All studied psychophysical measures were highly or moderately correlated with MNREAD reading speed (p<0.05 level). A similar correlation was found between psychophysical measures and VRQOL, which was higher for MNREAD measures of acuity (r = -0.75) and speed (r = 0.74). Accordingly, exploratory factor analysis suggested that a single latent dimension explained most of the variance of vision psychophysical measures as well as of VRQOL. Conclusions We propose that reading ability should be assessed in patients with STGD, since we found that both MNREAD reading speed and visual acuity are strong determinants of quality of life. The observed relation between reading ability and VRQOL in STGD suggests that in these patients appropriate low vision rehabilitation can improve both reading performance and consequently VRQOL. Finally, our data support the use of reading speed and visual acuity as important outcome measures for monitoring STGD progression.
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22
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Kaway CS, Adams MKM, Jenkins KS, Layton CJ. A Novel ABCA4 Mutation Associated with a Late-Onset Stargardt Disease Phenotype: A Hypomorphic Allele? Case Rep Ophthalmol 2017; 8:180-184. [PMID: 28611652 PMCID: PMC5465797 DOI: 10.1159/000464129] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/17/2016] [Accepted: 02/16/2017] [Indexed: 11/19/2022] Open
Abstract
BACKGROUND Stargardt disease (STGD) is the most common juvenile hereditary macular dystrophy. In the majority of cases, the diagnosis is made prior to 20 years of age and usually leads to loss of central vision. Late-onset STGD affects a smaller number of patients. Identifying genetic changes which could be associated with clinically important differences in severity or presentation of the disease is important for understanding the mechanisms of visual loss and for planning future therapeutic approaches. METHODS We report a patient with the classic phenotype of STGD with late-onset mild disease exhibiting a slow clinical progression over 14 months of follow-up. RESULTS A 37-year-old man presented with STGD and good vision of 6/24 in the right eye and of 6/6 in the left eye as well as typical electrophysiology findings. Objective and subjective visual deterioration was not noted over a period of 14 months. Macular genetic testing revealed a novel missense mutation in ABCA4 (Thr829Met) combined with Gly1961Glu, a classic STGD mutation usually associated with a moderately severe phenotype. CONCLUSIONS It is suggested that the Thr829Met mutation could give rise to a hypomorphic allele of the ABC transporter with a resultant phenotype of comparatively mild STGD.
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Affiliation(s)
| | - Madeleine K M Adams
- bGallipoli Medical Research Institute, Brisbane, Queensland, Australia.,cUniversity of Queensland School of Medicine, Herston, Queensland, Australia.,dGreenslopes Private Hospital Ophthalmology Department, Greenslopes Hospital, Brisbane, Queensland, Australia
| | - Kevin Sean Jenkins
- bGallipoli Medical Research Institute, Brisbane, Queensland, Australia.,cUniversity of Queensland School of Medicine, Herston, Queensland, Australia
| | - Christopher J Layton
- bGallipoli Medical Research Institute, Brisbane, Queensland, Australia.,cUniversity of Queensland School of Medicine, Herston, Queensland, Australia.,dGreenslopes Private Hospital Ophthalmology Department, Greenslopes Hospital, Brisbane, Queensland, Australia
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23
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Rizzo S, Mucciolo DP, Bacherini D, Murro V, Vannozzi L, Virgili G, Bani D, Sodi A. Macular hole in Stargardt disease: Clinical and ultra-structural observation. Ophthalmic Genet 2017; 38:486-489. [PMID: 28121212 DOI: 10.1080/13816810.2016.1266666] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/20/2022]
Abstract
PURPOSE To report for the first time a case report of a Stargardt disease patient who developed a macular hole (MH) which was treated with a surgical approach. METHOD Case report. RESULTS After vitrectomy a complete closure of the MH was obtained and the best-corrected visual acuity remained stable. No complications were reported after one year of follow-up. An ultra-structural examination of the removed internal limiting membrane (ILM) and epiretinal membrane (ERM) was carried out under electron microscopy. CONCLUSION Vitreo-retinal surgery could represent a therapeutic option to treat vitreo-retinal interface abnormalities associated with inherited retinal diseases.
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Affiliation(s)
- Stanislao Rizzo
- a Department of Translational Surgery and Medicine , Eye Clinic, University of Florence , Florence , Italy
| | - Dario Pasquale Mucciolo
- a Department of Translational Surgery and Medicine , Eye Clinic, University of Florence , Florence , Italy
| | - Daniela Bacherini
- a Department of Translational Surgery and Medicine , Eye Clinic, University of Florence , Florence , Italy
| | - Vittoria Murro
- a Department of Translational Surgery and Medicine , Eye Clinic, University of Florence , Florence , Italy
| | - Lorenzo Vannozzi
- a Department of Translational Surgery and Medicine , Eye Clinic, University of Florence , Florence , Italy
| | - Gianni Virgili
- a Department of Translational Surgery and Medicine , Eye Clinic, University of Florence , Florence , Italy
| | - Daniele Bani
- b Department of Experimental & Clinical Medicine , Research Unit of Histology & Embryology, University of Florence , Florence , Italy
| | - Andrea Sodi
- a Department of Translational Surgery and Medicine , Eye Clinic, University of Florence , Florence , Italy
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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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25
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Lin B, Cai XB, Zheng ZL, Huang XF, Liu XL, Qu J, Jin ZB. Clinical and genetic analyses reveal novel pathogenic ABCA4 mutations in Stargardt disease families. Sci Rep 2016; 6:35414. [PMID: 27739528 PMCID: PMC5064356 DOI: 10.1038/srep35414] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/23/2016] [Accepted: 09/27/2016] [Indexed: 12/28/2022] Open
Abstract
Stargardt disease (STGD1) is a juvenile macular degeneration predominantly inherited in an autosomal recessive pattern, characterized by decreased central vision in the first 2 decades of life. The condition has a genetic basis due to mutation in the ABCA4 gene, and arises from the deposition of lipofuscin-like substance in the retinal pigmented epithelium (RPE) with secondary photoreceptor cell death. In this study, we describe the clinical and genetic features of Stargardt patients from four unrelated Chinese cohorts. The targeted exome sequencing (TES) was carried out in four clinically confirmed patients and their family members using a gene panel comprising 164 known causative inherited retinal dystrophy (IRD) genes. Genetic analysis revealed eight ABCA4 mutations in all of the four pedigrees, including six mutations in coding exons and two mutations in adjacent intronic areas. All the affected individuals showed typical manifestations consistent with the disease phenotype. We disclose two novel ABCA4 mutations in Chinese patients with STGD disease, which will expand the existing spectrum of disease-causing variants and will further aid in the future mutation screening and genetic counseling, as well as in the understanding of phenotypic and genotypic correlations.
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Affiliation(s)
- Bing Lin
- The Eye Hospital of Wenzhou Medical University, The State Key Laboratory Cultivation Base and Key Laboratory of Vision Science, Ministry of Health, Wenzhou 325027, China
| | - Xue-Bi Cai
- The Eye Hospital of Wenzhou Medical University, The State Key Laboratory Cultivation Base and Key Laboratory of Vision Science, Ministry of Health, Wenzhou 325027, China
| | - Zhi-Li Zheng
- The Eye Hospital of Wenzhou Medical University, The State Key Laboratory Cultivation Base and Key Laboratory of Vision Science, Ministry of Health, Wenzhou 325027, China
| | - Xiu-Feng Huang
- The Eye Hospital of Wenzhou Medical University, The State Key Laboratory Cultivation Base and Key Laboratory of Vision Science, Ministry of Health, Wenzhou 325027, China
| | - Xiao-Ling Liu
- The Eye Hospital of Wenzhou Medical University, The State Key Laboratory Cultivation Base and Key Laboratory of Vision Science, Ministry of Health, Wenzhou 325027, China
| | - Jia Qu
- The Eye Hospital of Wenzhou Medical University, The State Key Laboratory Cultivation Base and Key Laboratory of Vision Science, Ministry of Health, Wenzhou 325027, China
| | - Zi-Bing Jin
- The Eye Hospital of Wenzhou Medical University, The State Key Laboratory Cultivation Base and Key Laboratory of Vision Science, Ministry of Health, Wenzhou 325027, China
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26
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Sofi F, Sodi A, Franco F, Murro V, Biagini D, Miele A, Abbruzzese G, Mucciolo DP, Virgili G, Menchini U, Casini A, Rizzo S. Dietary profile of patients with Stargardt's disease and Retinitis Pigmentosa: is there a role for a nutritional approach? BMC Ophthalmol 2016; 16:13. [PMID: 26801981 PMCID: PMC4722760 DOI: 10.1186/s12886-016-0187-3] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/16/2015] [Accepted: 01/08/2016] [Indexed: 12/19/2022] Open
Abstract
Background Stargardt’s disease (STGD) and Retinitis Pigmentosa (RP) are inherited retinal degenerations that may be affected, in opposite way, by diet. Methods Dietary profile was assessed in 24 patients with STGD and in 56 patients with RP. We documented in only 6 out of 24 (25 %) STGD patients a daily intake of vitamin A within the recommended range while 14/24 (58.3 %) reported a high daily intake and 4/24 (16.7 %) showed a low daily intake. With regard to RP, 4/56 (7.1 %) reported to be within the recommended range, 37/56 (66.1 %) reported high daily intake and 15/56 (26.8 %) showed low daily intake of vitamin A. Results Interestingly, STGD patients with low vitamin A intake (<600 µg RAE/day) showed significantly better visual acuity with respect to those introducing higher intake of vitamin A. Conclusion The present study suggests insuitable nutrient intakes among patients with STGD and RP, especially for daily intake of vitamin A. The results may be used to provide tailored nutritional interventions in these patients.
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Affiliation(s)
- Francesco Sofi
- Department of Experimental and Clinical Medicine, University of Florence, Florence, Italy.,Agency of Nutrition, University Hospital of Careggi, Florence, Italy.,Don Carlo Gnocchi Foundation Italy, Onlus IRCCS, Florence, Italy
| | - Andrea Sodi
- Department of Surgery and Translational Medicine, Eye Clinic, University of Florence, Florence, Italy.
| | - Fabrizio Franco
- Department of Surgery and Translational Medicine, Eye Clinic, University of Florence, Florence, Italy
| | - Vittoria Murro
- Department of Surgery and Translational Medicine, Eye Clinic, University of Florence, Florence, Italy
| | - Dania Biagini
- Agency of Nutrition, University Hospital of Careggi, Florence, Italy
| | - Alba Miele
- Department of Surgery and Translational Medicine, Eye Clinic, University of Florence, Florence, Italy
| | - Giacomo Abbruzzese
- Department of Surgery and Translational Medicine, Eye Clinic, University of Florence, Florence, Italy
| | | | - Gianni Virgili
- Department of Experimental and Clinical Medicine, University of Florence, Florence, Italy.,Don Carlo Gnocchi Foundation Italy, Onlus IRCCS, Florence, Italy
| | - Ugo Menchini
- Department of Surgery and Translational Medicine, Eye Clinic, University of Florence, Florence, Italy
| | - Alessandro Casini
- Department of Experimental and Clinical Medicine, University of Florence, Florence, Italy.,Agency of Nutrition, University Hospital of Careggi, Florence, Italy
| | - Stanislao Rizzo
- Department of Surgery and Translational Medicine, Eye Clinic, University of Florence, Florence, Italy
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Sodi A, Mucciolo DP, Cipollini F, Murro V, Caporossi O, Virgili G, Rizzo S. En face OCT in Stargardt disease. Graefes Arch Clin Exp Ophthalmol 2016; 254:1669-79. [PMID: 26743751 DOI: 10.1007/s00417-015-3254-1] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/06/2015] [Revised: 12/15/2015] [Accepted: 12/21/2015] [Indexed: 11/25/2022] Open
Abstract
PURPOSE To evaluate the structural features of the macular region by enface OCT imaging in patients with clinical diagnosis of Stargardt disease, confirmed by the detection of ABCA4 mutations. METHODS Thirty-two STGD patients were included in the study for a total of 64 eyes. All patients received a comprehensive ophthalmological examination, color fundus photography, fundus auto-fluorescence imaging and OCT. Five OCT scans were considered: ILM and RPE scans (both automatically obtained from the instrument), above-RPE slab, photoreceptor slab and sub-RPE slab (these last three manually obtained). RESULTS ILM scans showed evident radial folds on the retinal surface in 8/64 eyes (12.5 %). In 6 of the 7 patients, these vitreo-retinal interface abnormalities were unilateral. The photoreceptor slab showed some macular alterations ranging from dis-homogeneous, hypo-reflective abnormalities (7/64 eyes, 11 %) to a homogeneous, well-defined, roundish, hypo-reflective area (17/64 eyes, 27 %) in all the eyes. The sub-RPE slab showed a centrally evident, hyper-reflective abnormality in 58/64 eyes (90.6 %). Superimposing the sub-RPE slab over the images corresponding to the photoreceptor slab, the area of the photoreceptor atrophy sharply exceeded that of the RPE atrophy (44/46 eyes, 96 %). CONCLUSION Enface OCT proved to be a clinically useful tool for the management of STGD patients, illustrating in vivo the structural abnormalities of the different retinal layers.
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Affiliation(s)
- Andrea Sodi
- Careggi Teaching Hospital , Eye Clinic, University of Florence, Largo Brambilla 3, 50134, Florence, Italy
| | - Dario Pasquale Mucciolo
- Careggi Teaching Hospital , Eye Clinic, University of Florence, Largo Brambilla 3, 50134, Florence, Italy.
| | - Francesca Cipollini
- Careggi Teaching Hospital , Eye Clinic, University of Florence, Largo Brambilla 3, 50134, Florence, Italy
| | - Vittoria Murro
- Careggi Teaching Hospital , Eye Clinic, University of Florence, Largo Brambilla 3, 50134, Florence, Italy
| | - Orsola Caporossi
- Careggi Teaching Hospital , Eye Clinic, University of Florence, Largo Brambilla 3, 50134, Florence, Italy
| | - Gianni Virgili
- Careggi Teaching Hospital , Eye Clinic, University of Florence, Largo Brambilla 3, 50134, Florence, Italy
| | - Stanislao Rizzo
- Careggi Teaching Hospital , Eye Clinic, University of Florence, Largo Brambilla 3, 50134, Florence, Italy
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28
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Identification of Novel Mutations in ABCA4 Gene: Clinical and Genetic Analysis of Indian Patients with Stargardt Disease. BIOMED RESEARCH INTERNATIONAL 2015; 2015:940864. [PMID: 25922843 PMCID: PMC4398921 DOI: 10.1155/2015/940864] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 12/26/2014] [Revised: 02/13/2015] [Accepted: 03/09/2015] [Indexed: 11/17/2022]
Abstract
Stargardt disease (STGD) is the leading cause of juvenile macular degeneration associated with progressive central vision loss, photophobia, and colour vision abnormalities. In this study, we have described the clinical and genetic features of Stargardt patients from an Indian cohort. The next generation sequencing was carried out in five clinically confirmed unrelated patients and their family members using a gene panel comprising 184 retinal specific genes. Sequencing results were analyzed by read mapping and variant calling in genes of interest, followed by their verification and interpretation. Genetic analysis revealed ABCA4 mutations in all of the five unrelated patients. Among these, four patients were found with compound heterozygous mutations and another one had homozygous mutation. All the affected individuals showed signs and symptoms consistent with the disease phenotype. We report two novel ABCA4 mutations in Indian patients with STGD disease, which expands the existing spectrum of disease-causing variants and the understanding of phenotypic and genotypic correlations. Screening for causative mutations in patients with STGD using panel of targeted gene sequencing by NGS would be a cost effective tool, might be helpful in confirming the precise diagnosis, and contributes towards the genetic counselling of asymptomatic carriers and isolated patients.
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29
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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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30
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Yi J, Li S, Jia X, Xiao X, Wang P, Guo X, Zhang Q. Evaluation of the ELOVL4, PRPH2 and ABCA4 genes in patients with Stargardt macular degeneration. Mol Med Rep 2012; 6:1045-9. [PMID: 22948568 DOI: 10.3892/mmr.2012.1063] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/29/2012] [Accepted: 08/23/2012] [Indexed: 11/06/2022] Open
Abstract
Mutations in the ATP-binding cassette, subfamily A, member 4 (ABCA4), elongation of very long chain fatty acids 4 (ELOVL4) and peripherin-2 (PRPH2) genes have been identified in patients with Stargardt macular degeneration (STGD). The aim of this study was to investigate which of these genes is responsible for susceptibility in Chinese patients. A total of 41 probands with STGD or suspected STGD were enrolled in the study. The coding regions and adjacent intronic sequences of the ELOVL4 and PRPH2 genes and 3 coding exons of the ABCA4 gene were amplified by polymerase chain reaction (PCR). The nucleotide sequences of the amplicons were determined by Sanger sequencing. Three novel heterozygous missense mutations in the ABCA4 gene were identified: c:2633C>A (p:Ser878X), c:5646G>A (p:Met1882Ile) and c:6389T>A (p:Met2130Lys). These mutations were not present in 176 normal individuals and were predicted to be pathogenic. Two benign variations were found: a reported variation, c:5682G>C in ABCA4 and a novel variation, c:699G>A in ELOVL4. In addition, 5 single nucleotide polymorphisms (SNPs: rs3812153, rs7764439, rs390659, rs434102 and c:929G>A) were detected in ELOVL4 and PRPH2. The c:929G>A variation has not been previously reported. We conclude that no pathogenic variations in ELOVL4 and PRPH2 were detected in the Chinese STGD patients. Our results imply that ABCA4 is more likely to be significant in Chinese STGD patients.
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Affiliation(s)
- Junhui Yi
- Department of Ophthalmology, The Third Xiangya Hospital, Central-South University, Changsha, Hunan 410013, PR China
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31
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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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Verdina T, Tsang SH, Greenstein VC, Zernant J, Sodi A, Lima LH, Chang S, Allikmets R, Menchini U. Functional Analysis of Retinal Flecks in Stargardt Disease. JOURNAL OF CLINICAL & EXPERIMENTAL OPHTHALMOLOGY 2012; 3:10.4172/2155-9570.1000233. [PMID: 24409374 PMCID: PMC3882688 DOI: 10.4172/2155-9570.1000233] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
Abstract
PURPOSE To evaluate visual function of flecked areas in a series of patients with Stargardt disease (STGD) and compare them with adjacent non flecked areas. METHODS Twenty-seven patients with STGD, ABCA4 mutations and yellowish retinal flecks at fundus examination were recruited. Microperimetry with the Nidek MP-1 and fundus autofluorescence imaging (FAF) were performed in all the patients (27 eyes) while spectral-domain optical coherence tomography (SD-OCT) was performed in a subgroup of patients (20 eyes). Visual sensitivity (in dB) for each hyperfluorescent flecked area on FAF was compared with the value of the nearest adjacent non-flecked area in the MP-1 grid and at approximately the same distance from the fovea. Retinal structure in some of the flecked areas tested by microperimetry was analysed with SD-OCT. All patients were screened for mutations in the ABCA4 gene by APEX array and direct sequencing. RESULTS A total of 1836 locations (68 locations for each eye with the 10-2 program) were tested with the MP-1 and 97 corresponded to hyperautofluorescent flecks. A repeated measure, linear regression analysis was used to evaluate differences between visual sensitivity associated with the 97 flecked areas with those in the 97 neighbouring non-flecked areas. The difference was statistically significant (p<0.001) (flecked areas 12.89 +/- 3.86 dB vs. non-flecked areas 14.40 +/- 3.53 dB, respectively). SD-OCT in the flecked areas revealed the presence of hyperreflective dome-shaped lesions in the outer retina located at the level of the retinal pigment epithelium (RPE), with dislocation or disruption of the photoreceptor layer. CONCLUSIONS In STGD hyperfluorescent flecks on FAF are associated with decreased visual sensitivity compared to adjacent non-flecked areas and with an alteration of the photoreceptor layer on OCT. Flecks do not represent only a typical ophthalmoscopic feature but correspond, in some cases, to retinal damage that contributes to patients' visual loss.
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Affiliation(s)
- Tommaso Verdina
- Department of Specialized Surgical Sciences, Eye Clinic, University of Florence, Florence, Italy
| | - Stephen H. Tsang
- Department of Ophthalmology, Columbia University, New York, NY, USA
- Department of Pathology and Cell Biology, Columbia University, New York, NY, USA
| | | | - Jana Zernant
- Department of Ophthalmology, Columbia University, New York, NY, USA
| | - Andrea Sodi
- Department of Specialized Surgical Sciences, Eye Clinic, University of Florence, Florence, Italy
| | - Luiz H. Lima
- Department of Ophthalmology, Federal University of Sao Paulo, Sao Paulo, Brazil
| | - Stanley Chang
- Department of Ophthalmology, Columbia University, New York, NY, USA
| | - Rando Allikmets
- Department of Ophthalmology, Columbia University, New York, NY, USA
- Department of Pathology and Cell Biology, Columbia University, New York, NY, USA
| | - Ugo Menchini
- Department of Specialized Surgical Sciences, Eye Clinic, University of Florence, Florence, Italy
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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: 76] [Impact Index Per Article: 6.3] [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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Duno M, Schwartz M, Larsen PL, Rosenberg T. Phenotypic and genetic spectrum of Danish patients with ABCA4-related retinopathy. Ophthalmic Genet 2012; 33:225-31. [PMID: 22229821 DOI: 10.3109/13816810.2011.643441] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
Abstract
BACKGROUND Pathogenic variations in the ABCA4 gene were originally recognized as genetic background for the autosomal recessive disorders Stargardt disease and fundus flavimaculatus, but have expanded to embrace a diversity of retinal diseases, giving rise to the new diagnostic term, ABCA4-related retinopathy. Diagnostic genotyping of ABCA4 is complicated by the large size of the gene and the existence of approximately 600 known pathogenic variations, along with numerous rare polymorphisms. A commercial diagnostic array-based assay has been developed targeting known mutations, however a conclusive genetic diagnosis must rely on a comprehensive genetic screening as the mutation spectrum of ABCA4-related retinopathies continues to expand. MATERIAL AND METHODS Among 161 patients with a Stargardt-related phenotype previously assessed with the commercial ABCA4 mutation microarray, we analyzed the ABCA4 gene with High-resolution melting (HRM) in patients in whom the array analysis identified either a heterozygous mutation (n = 50) or no mutation (n = 30). RESULTS The HRM method detected each of the already known mutations and polymorphisms. We identified the second ABCA4 mutation in 31 of 50 heterozygous patients (62%). Several novel mutations were identified of which four were identified multiple times. The recurrent novel mutations were subsequently assessed among the 30 patients with possible ABCA4-related diseases, previously found to be negative for known ABCA4 mutations by array analysis. In total, 30 different mutations were identified of which 21 have not been described before. CONCLUSION Scandinavian patients with ABCA4-related retinopathy appear to have a distinct mutation spectrum, which can be identified in patients of diverse clinical phenotypes.
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Affiliation(s)
- Morten Duno
- Department of Clinical Genetics, Rigshospitalet, Copenhagen University Hospital, Denmark.
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Oldani M, Marchi S, Giani A, Cecchin S, Rigoni E, Persi A, Podavini D, Guerrini A, Nervegna A, Staurenghi G, Bertelli M. Clinical and molecular genetic study of 12 Italian families with autosomal recessive Stargardt disease. GENETICS AND MOLECULAR RESEARCH 2012; 11:4342-50. [DOI: 10.4238/2012.october.9.3] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022]
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