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Sung YC, Yang CH, Yang CM, Lin CW, Huang DS, Huang YS, Hu FR, Chen PL, Chen TC. Genotypes Predispose Phenotypes-Clinical Features and Genetic Spectrum of ABCA4-Associated Retinal Dystrophies. Genes (Basel) 2020; 11:genes11121421. [PMID: 33261146 PMCID: PMC7759801 DOI: 10.3390/genes11121421] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/20/2020] [Revised: 11/12/2020] [Accepted: 11/25/2020] [Indexed: 12/31/2022] Open
Abstract
The ABCA4 gene is one of the most common disease-causing genes of inherited retinal degeneration. In this study, we report different phenotypes of ABCA4-associated retinal dystrophies in the Taiwanese population, its clinical progression, and its relationship with genetic characteristics. Thirty-seven subjects were recruited and all patients underwent serial ophthalmic examinations at a single medical center. Fundus autofluorescence (FAF) images were quantified for clinical evaluation, and panel-based next-generation sequencing testing was performed for genetic diagnosis. Visual preservation, disease progression, and genotype–phenotype correlation were analyzed. In this cohort, ABCA4-associated retinal degeneration presented as Stargardt disease 1 (STGD1, 62.16%), retinitis pigmentosa (32.43%), and cone-rod dystrophy (5.41%). STGD1 could be further divided into central and dispersed types. In each phenotype, the lesion areas quantified by FAF increased with age (p < 0.01) and correlated with poorer visual acuity. However, three patients had the foveal sparing phenotype and had relatively preserved visual acuity. Forty-two ABCA4 variants were identified as disease-causing, with c.1804C>T (p.Arg602Trp) the most frequent (37.84%). Patients with a combination of severe/null variants could have more extensive phenotypes, such as arRP and dispersed STGD1. This is the first cohort study of ABCA4-associated retinal degeneration in Taiwan with wide spectrums of both genotypic and phenotypic characteristics. An extremely high prevalence of c.1804C>T, which has not been reported in East Asia before, was noted. The extensiveness of retinal involvement might be regarded as a spectrum of ABCA4-associated retinal dystrophies. Different types of genetic variations could lead to distinctive phenotypes, according to the coding impact of variants.
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Affiliation(s)
- Yu-Chi Sung
- Department of Medical Education, National Taiwan University Hospital, Taipei 100, Taiwan;
| | - Chang-Hao Yang
- Department of Ophthalmology, National Taiwan University Hospital, Taipei 100, Taiwan; (C.-H.Y.); (C.-M.Y.); (C.-W.L.); (D.-S.H.); (Y.-S.H.); (F.-R.H.)
- Department of Ophthalmology, College of Medicine, National Taiwan University, Taipei 100, Taiwan
| | - Chung-May Yang
- Department of Ophthalmology, National Taiwan University Hospital, Taipei 100, Taiwan; (C.-H.Y.); (C.-M.Y.); (C.-W.L.); (D.-S.H.); (Y.-S.H.); (F.-R.H.)
- Department of Ophthalmology, College of Medicine, National Taiwan University, Taipei 100, Taiwan
| | - Chao-Wen Lin
- Department of Ophthalmology, National Taiwan University Hospital, Taipei 100, Taiwan; (C.-H.Y.); (C.-M.Y.); (C.-W.L.); (D.-S.H.); (Y.-S.H.); (F.-R.H.)
| | - Ding-Siang Huang
- Department of Ophthalmology, National Taiwan University Hospital, Taipei 100, Taiwan; (C.-H.Y.); (C.-M.Y.); (C.-W.L.); (D.-S.H.); (Y.-S.H.); (F.-R.H.)
| | - Yu-Shu Huang
- Department of Ophthalmology, National Taiwan University Hospital, Taipei 100, Taiwan; (C.-H.Y.); (C.-M.Y.); (C.-W.L.); (D.-S.H.); (Y.-S.H.); (F.-R.H.)
| | - Fung-Rong Hu
- Department of Ophthalmology, National Taiwan University Hospital, Taipei 100, Taiwan; (C.-H.Y.); (C.-M.Y.); (C.-W.L.); (D.-S.H.); (Y.-S.H.); (F.-R.H.)
- Department of Ophthalmology, College of Medicine, National Taiwan University, Taipei 100, Taiwan
| | - Pei-Lung Chen
- Graduate Institute of Clinical Medicine, College of Medicine, National Taiwan University, Taipei 100, Taiwan
- Graduate Institute of Medical Genomics and Proteomics, College of Medicine, National Taiwan University, Taipei 100, Taiwan
- Department of Medical Genetics, National Taiwan University Hospital, Taipei 100, Taiwan
- Correspondence: (P.-L.C.); (T.-C.C.); Tel.: +886-2-23123456 (ext. 71942) (P.-L.C.); +886-2-23123456 (ext. 63783) (T.-C.C.); Fax: +886-2-23934420 (T.-C.C.)
| | - Ta-Ching Chen
- Department of Ophthalmology, National Taiwan University Hospital, Taipei 100, Taiwan; (C.-H.Y.); (C.-M.Y.); (C.-W.L.); (D.-S.H.); (Y.-S.H.); (F.-R.H.)
- Graduate Institute of Clinical Medicine, College of Medicine, National Taiwan University, Taipei 100, Taiwan
- Correspondence: (P.-L.C.); (T.-C.C.); Tel.: +886-2-23123456 (ext. 71942) (P.-L.C.); +886-2-23123456 (ext. 63783) (T.-C.C.); Fax: +886-2-23934420 (T.-C.C.)
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