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Thuma TBT, Procopio RA, Jimenez HJ, Gunton KB, Pulido JS. Hypomorphic variants in inherited retinal and ocular diseases: A review of the literature with clinical cases. Surv Ophthalmol 2024; 69:337-348. [PMID: 38036193 DOI: 10.1016/j.survophthal.2023.11.006] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/20/2022] [Revised: 11/17/2023] [Accepted: 11/20/2023] [Indexed: 12/02/2023]
Abstract
Hypomorphic variants decrease, but do not eliminate, gene function via a reduction in the amount of mRNA or protein product produced by a gene or by production of a gene product with reduced function. Many hypomorphic variants have been implicated in inherited retinal diseases (IRDs) and other genetic ocular conditions; however, there is heterogeneity in the use of the term "hypomorphic" in the scientific literature. We searched for all hypomorphic variants reported to cause IRDs and ocular disorders. We also discuss the presence of hypomorphic variants in the patient population of our ocular genetics department over the past decade. We propose that standardized criteria should be adopted for use of the term "hypomorphic" to describe gene variants to improve genetic counseling and patient care outcomes.
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Affiliation(s)
- Tobin B T Thuma
- Department of Pediatric Ophthalmology and Strabismus, Wills Eye Hospital, Philadelphia, PA, USA
| | | | - Hiram J Jimenez
- Vickie and Jack Farber Vision Research Center, Wills Eye Hospital, Philadelphia, PA, USA
| | - Kammi B Gunton
- Department of Pediatric Ophthalmology and Strabismus, Wills Eye Hospital, Philadelphia, PA, USA
| | - Jose S Pulido
- Vickie and Jack Farber Vision Research Center, Wills Eye Hospital, Philadelphia, PA, USA; Retina Service, Wills Eye Hospital, Philadelphia, PA, USA.
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2
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Otsuka Y, Imamura K, Oishi A, Asakawa K, Kondo T, Nakai R, Suga M, Inoue I, Sagara Y, Tsukita K, Teranaka K, Nishimura Y, Watanabe A, Umeyama K, Okushima N, Mitani K, Nagashima H, Kawakami K, Muguruma K, Tsujikawa A, Inoue H. Phototoxicity avoidance is a potential therapeutic approach for retinal dystrophy caused by EYS dysfunction. JCI Insight 2024; 9:e174179. [PMID: 38646933 PMCID: PMC11141876 DOI: 10.1172/jci.insight.174179] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/24/2023] [Accepted: 03/06/2024] [Indexed: 04/25/2024] Open
Abstract
Inherited retinal dystrophies (IRDs) are progressive diseases leading to vision loss. Mutation in the eyes shut homolog (EYS) gene is one of the most frequent causes of IRD. However, the mechanism of photoreceptor cell degeneration by mutant EYS has not been fully elucidated. Here, we generated retinal organoids from induced pluripotent stem cells (iPSCs) derived from patients with EYS-associated retinal dystrophy (EYS-RD). In photoreceptor cells of RD organoids, both EYS and G protein-coupled receptor kinase 7 (GRK7), one of the proteins handling phototoxicity, were not in the outer segment, where they are physiologically present. Furthermore, photoreceptor cells in RD organoids were vulnerable to light stimuli, and especially to blue light. Mislocalization of GRK7, which was also observed in eys-knockout zebrafish, was reversed by delivering control EYS into photoreceptor cells of RD organoids. These findings suggest that avoiding phototoxicity would be a potential therapeutic approach for EYS-RD.
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Affiliation(s)
- Yuki Otsuka
- iPSC-based Drug discovery and Development Team, RIKEN BioResource Research Center, Kyoto, Japan
- Center for iPS Cell Research and Application (CiRA), Kyoto University, Kyoto, Japan
- Department of Ophthalmology and Visual Sciences, Kyoto University Graduate School of Medicine, Kyoto, Japan
| | - Keiko Imamura
- iPSC-based Drug discovery and Development Team, RIKEN BioResource Research Center, Kyoto, Japan
- Center for iPS Cell Research and Application (CiRA), Kyoto University, Kyoto, Japan
- RIKEN Center for Advanced Intelligence Project (AIP), Kyoto, Japan
| | - Akio Oishi
- Department of Ophthalmology and Visual Sciences, Nagasaki University, Nagasaki, Japan
| | - Kazuhide Asakawa
- Division of Molecular and Developmental Biology, National Institute of Genetics, Mishima, Japan
| | - Takayuki Kondo
- iPSC-based Drug discovery and Development Team, RIKEN BioResource Research Center, Kyoto, Japan
- Center for iPS Cell Research and Application (CiRA), Kyoto University, Kyoto, Japan
- RIKEN Center for Advanced Intelligence Project (AIP), Kyoto, Japan
| | - Risako Nakai
- iPSC-based Drug discovery and Development Team, RIKEN BioResource Research Center, Kyoto, Japan
- Center for iPS Cell Research and Application (CiRA), Kyoto University, Kyoto, Japan
| | - Mika Suga
- iPSC-based Drug discovery and Development Team, RIKEN BioResource Research Center, Kyoto, Japan
- Center for iPS Cell Research and Application (CiRA), Kyoto University, Kyoto, Japan
| | - Ikuyo Inoue
- Center for iPS Cell Research and Application (CiRA), Kyoto University, Kyoto, Japan
- RIKEN Center for Advanced Intelligence Project (AIP), Kyoto, Japan
| | - Yukako Sagara
- iPSC-based Drug discovery and Development Team, RIKEN BioResource Research Center, Kyoto, Japan
| | - Kayoko Tsukita
- iPSC-based Drug discovery and Development Team, RIKEN BioResource Research Center, Kyoto, Japan
- Center for iPS Cell Research and Application (CiRA), Kyoto University, Kyoto, Japan
| | - Kaori Teranaka
- Graduate School of Medicine, Kyoto University, Kyoto, Japan
| | - Yu Nishimura
- Graduate School of Medicine, Kyoto University, Kyoto, Japan
| | - Akira Watanabe
- Graduate School of Medicine, Kyoto University, Kyoto, Japan
| | - Kazuhiro Umeyama
- Meiji University International Institute for Bio-Resource Research, Kawasaki, Japan
| | - Nanako Okushima
- Division of Systems Medicine and Gene Therapy, Faculty of Medicine, Saitama Medical University, Saitama, Japan
| | - Kohnosuke Mitani
- Division of Systems Medicine and Gene Therapy, Faculty of Medicine, Saitama Medical University, Saitama, Japan
| | - Hiroshi Nagashima
- Meiji University International Institute for Bio-Resource Research, Kawasaki, Japan
| | - Koichi Kawakami
- Division of Molecular and Developmental Biology, National Institute of Genetics, Mishima, Japan
| | - Keiko Muguruma
- Department of iPS Cell Applied Medicine, Graduate School of Medicine, Kansai Medical University, Hirakata, Osaka, Japan
| | - Akitaka Tsujikawa
- Department of Ophthalmology and Visual Sciences, Kyoto University Graduate School of Medicine, Kyoto, Japan
| | - Haruhisa Inoue
- iPSC-based Drug discovery and Development Team, RIKEN BioResource Research Center, Kyoto, Japan
- Center for iPS Cell Research and Application (CiRA), Kyoto University, Kyoto, Japan
- RIKEN Center for Advanced Intelligence Project (AIP), Kyoto, Japan
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Nwagbo U, Parvez S, Maschek JA, Bernstein PS. Elovl4b knockout zebrafish as a model for ocular very-long-chain PUFA deficiency. J Lipid Res 2024; 65:100518. [PMID: 38342437 PMCID: PMC10940177 DOI: 10.1016/j.jlr.2024.100518] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/02/2023] [Revised: 02/03/2024] [Accepted: 02/06/2024] [Indexed: 02/13/2024] Open
Abstract
Very-long-chain PUFAs (VLC-PUFAs) are a group of lipids with chain lengths >24 carbons, and the ELOVL4 (elongation of very-long-chain FA-4) enzyme is responsible for vertebrate VLC-PUFA biosynthesis. Studies on the role of VLC-PUFAs in vision have been hindered because of the need for adequate animal models to capture the global loss of VLC-PUFAs. Since homozygous Elovl4 ablation is lethal in neonatal mice because of catastrophic drying from the loss of their protective skin barrier, we established a zebrafish (Danio rerio) model of Elovl4 ablation. We generated Elovl4b KO zebrafish by creating a 56-bp deletion mutation in exon 2 of the Elovl4b gene using CRISPR-Cas9. We used GC-MS and LC-MS/MS to analyze the VLC-PUFA and lipid profiles from wild-type and Elovl4b KO fish eyes. We also performed histology and visual-behavioral tests. We found that heterozygous and homozygous Elovl4b KO zebrafish eyes had altered lipid profiles and a significantly lower C30 to C36 VLC-PUFA abundance than wild-type fish. Moreover, Elovl4b+/- and Elovl4b-/- KO larvae had significantly lower motor activity in response to light-dark cycles than their age-matched controls. Elovl4b-/- adult fish showed no obvious differences in gross retinal morphology and lamination compared with wild type, except for the presence of lipid droplets within the retinal pigment epithelial cell layer of Elovl4b-/- fish. Our data indicate that the loss of Elovl4b in zebrafish changes ocular lipid profiles and leads to visual abnormalities and subtle retinal changes. These findings highlight the use of zebrafish as a model for VLC-PUFA depletion and ELOVL4-related dysfunction.
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Affiliation(s)
- Uzoamaka Nwagbo
- Department of Ophthalmology and Visual Sciences, John A. Moran Eye Center, University of Utah, Salt Lake City, UT, USA; Department of Pharmacology and Toxicology, University of Utah, Salt Lake City, UT, USA
| | - Saba Parvez
- Department of Ophthalmology and Visual Sciences, John A. Moran Eye Center, University of Utah, Salt Lake City, UT, USA
| | - J Alan Maschek
- Metabolomics Core, University of Utah Health Sciences Center, Salt Lake City, UT, USA
| | - Paul S Bernstein
- Department of Ophthalmology and Visual Sciences, John A. Moran Eye Center, University of Utah, Salt Lake City, UT, USA; Department of Pharmacology and Toxicology, University of Utah, Salt Lake City, UT, USA.
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Dai C, Ren W, Wei Y, Xie C, Duan S, Li Q, Jiang L, Shi Y. A Novel Pair of Compound Heterozygous Mutation of EYS in a Han Chinese Family with Retinitis Pigmentosa. Genet Test Mol Biomarkers 2023; 27:258-266. [PMID: 37643323 DOI: 10.1089/gtmb.2023.0016] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 08/31/2023] Open
Abstract
Background: Retinitis pigmentosa (RP) is a complex inherited and progressive degenerative retinal disease. The eyes shut homolog (EYS) is frequently associated with RP is surprisingly high. Exploring the function of EYS is quite difficult due to the unique gene size and species specificity. Gene therapy may provide a breakthrough to treat this disease. Therefore, exploring and clarifying pathogenic mutations of EYS-associated RP has important guiding significance for clinical treatment. Methods: Clinical and molecular genetic data for EYS-associated RP were retrospectively analyzed. Sanger sequencing was applied to identify novel mutations in these patients. Candidate pathogenic variants were subsequently evaluated using bioinformatic tools. Results: A novel pair of compound heterozygous mutations was identified: a novel stop-gain mutation c.2439C>A (p.C813fsX) and a frameshift deletion mutation c.6714delT (p. P2238fsX) of the EYS gene in the RP family. Both of these mutations were rare or absent in the 1000 Genomes Project, dbSNP, and Genome Aggregation Database (gnomAD). These two mutations would result in a lack of multiple functionally important epidermal growth factor-like and Laminin G-like coding regions in EYS. Conclusions: A novel compound heterozygote of the EYS gene in a Chinese family with an autosomal inheritance pattern of RP was identified. Identifying more pathogenic mutations and expanding the mutation spectrum of the EYS gene will contribute to a more comprehensive understanding of the molecular pathogenesis of RP disease that could be gained in the future. It also could provide an important basis for the diagnosis, clinical management, and genetic counseling of the disease.
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Affiliation(s)
- Chao Dai
- Sichuan Provincial Key Laboratory for Human Disease Gene Study and Department of Laboratory Medicine, Sichuan Provincial People's Hospital, University of Electronic Science and Technology of China, Chengdu, China
- Research Unit for Blindness Prevention of Chinese Academy of Medical Sciences (2019RU026), Sichuan Academy of Medical Sciences & Sichuan Provincial People's Hospital, Chengdu, China
| | - Weiming Ren
- Sichuan Provincial Key Laboratory for Human Disease Gene Study and Department of Laboratory Medicine, Sichuan Provincial People's Hospital, University of Electronic Science and Technology of China, Chengdu, China
- Research Unit for Blindness Prevention of Chinese Academy of Medical Sciences (2019RU026), Sichuan Academy of Medical Sciences & Sichuan Provincial People's Hospital, Chengdu, China
| | - Yao Wei
- Sichuan Provincial Key Laboratory for Human Disease Gene Study and Department of Laboratory Medicine, Sichuan Provincial People's Hospital, University of Electronic Science and Technology of China, Chengdu, China
- Research Unit for Blindness Prevention of Chinese Academy of Medical Sciences (2019RU026), Sichuan Academy of Medical Sciences & Sichuan Provincial People's Hospital, Chengdu, China
| | - Chunbao Xie
- Sichuan Provincial Key Laboratory for Human Disease Gene Study and Department of Laboratory Medicine, Sichuan Provincial People's Hospital, University of Electronic Science and Technology of China, Chengdu, China
| | - Suyang Duan
- Sichuan Provincial Key Laboratory for Human Disease Gene Study and Department of Laboratory Medicine, Sichuan Provincial People's Hospital, University of Electronic Science and Technology of China, Chengdu, China
| | - Qi Li
- Sichuan Provincial Key Laboratory for Human Disease Gene Study and Department of Laboratory Medicine, Sichuan Provincial People's Hospital, University of Electronic Science and Technology of China, Chengdu, China
| | - Lingxi Jiang
- Sichuan Provincial Key Laboratory for Human Disease Gene Study and Department of Laboratory Medicine, Sichuan Provincial People's Hospital, University of Electronic Science and Technology of China, Chengdu, China
- Research Unit for Blindness Prevention of Chinese Academy of Medical Sciences (2019RU026), Sichuan Academy of Medical Sciences & Sichuan Provincial People's Hospital, Chengdu, China
| | - Yi Shi
- Sichuan Provincial Key Laboratory for Human Disease Gene Study and Department of Laboratory Medicine, Sichuan Provincial People's Hospital, University of Electronic Science and Technology of China, Chengdu, China
- Research Unit for Blindness Prevention of Chinese Academy of Medical Sciences (2019RU026), Sichuan Academy of Medical Sciences & Sichuan Provincial People's Hospital, Chengdu, China
- Health Management Center, Sichuan Provincial People's Hospital, University of Electronic Science and Technology of China, Chengdu, China
- Department of Ophthalmology, Sichuan Provincial People's Hospital, University of Electronic Science and Technology of China, Chengdu, China
- Department of Laboratory Medicine, Sichuan Provincial People's Hospital, University of Electronic Science and Technology of China, Chengdu, China
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Hussain HMJ, Wang M, Huang A, Schmidt R, Qian X, Yang P, Marra M, Li Y, Pennesi ME, Chen R. Novel Pathogenic Mutations Identified from Whole-Genome Sequencing in Unsolved Cases of Patients Affected with Inherited Retinal Diseases. Genes (Basel) 2023; 14:447. [PMID: 36833373 PMCID: PMC9956865 DOI: 10.3390/genes14020447] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/16/2023] [Revised: 01/31/2023] [Accepted: 02/03/2023] [Indexed: 02/12/2023] Open
Abstract
Inherited retinal diseases (IRDs) are a diverse set of visual disorders that collectively represent a major cause of early-onset blindness. With the reduction in sequencing costs in recent years, whole-genome sequencing (WGS) is being used more frequently, particularly when targeted gene panels and whole-exome sequencing (WES) fail to detect pathogenic mutations in patients. In this study, we performed mutation screens using WGS for a cohort of 311 IRD patients whose mutations were undetermined. A total of nine putative pathogenic mutations in six IRD patients were identified, including six novel mutations. Among them, four were deep intronic mutations that affected mRNA splicing, while the other five affected protein-coding sequences. Our results suggested that the rate of resolution of unsolved cases via targeted gene panels and WES can be further enhanced with WGS; however, the overall improvement may be limited.
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Affiliation(s)
- Hafiz Muhammad Jafar Hussain
- Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, TX 77030, USA
- Human Genome Sequencing Center, Baylor College of Medicine, Houston, TX 77030, USA
| | - Meng Wang
- Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, TX 77030, USA
- Human Genome Sequencing Center, Baylor College of Medicine, Houston, TX 77030, USA
| | - Austin Huang
- Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, TX 77030, USA
| | - Ryan Schmidt
- Department of Ophthalmology, Casey Eye Institute, Oregon Health & Science University, Portland, OR 97239, USA
| | - Xinye Qian
- Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, TX 77030, USA
| | - Paul Yang
- Department of Ophthalmology, Casey Eye Institute, Oregon Health & Science University, Portland, OR 97239, USA
| | - Molly Marra
- Department of Ophthalmology, Casey Eye Institute, Oregon Health & Science University, Portland, OR 97239, USA
| | - Yumei Li
- Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, TX 77030, USA
- Human Genome Sequencing Center, Baylor College of Medicine, Houston, TX 77030, USA
| | - Mark E. Pennesi
- Department of Ophthalmology, Casey Eye Institute, Oregon Health & Science University, Portland, OR 97239, USA
| | - Rui Chen
- Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, TX 77030, USA
- Human Genome Sequencing Center, Baylor College of Medicine, Houston, TX 77030, USA
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Sato K, Liu Y, Yamashita T, Ohuchi H. The medaka mutant deficient in eyes shut homolog exhibits opsin transport defects and enhanced autophagy in retinal photoreceptors. Cell Tissue Res 2023; 391:249-267. [PMID: 36418571 DOI: 10.1007/s00441-022-03702-0] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/05/2022] [Accepted: 11/03/2022] [Indexed: 11/27/2022]
Abstract
Eyes shut homolog (EYS) encodes a proteoglycan and the human mutation causes retinitis pigmentosa type 25 (RP25) with progressive retinal degeneration. RP25 most frequently affects autosomal recessive RP patients with many ethnic backgrounds. Although studies using RP models have facilitated the development of therapeutic medications, Eys has been lost in rodent model animals. Here we examined the roles for Eys in the maintenance of photoreceptor structure and function by generating eys-null medaka fish using the CRISPR-Cas9 system. Medaka EYS protein was present near the connecting cilium of wild-type photoreceptors, while it was absent from the eys-/- retina. The mutant larvae exhibited a reduced visual motor response compared with wild-type. In contrast to reported eys-deficient zebrafish at the similar stage, no retinal cell death was detected in the 8-month post-hatching (8-mph) medaka eys mutant. Immunohistochemistry showed a significant reduction in the length of cone outer segments (OSs), retention of OS proteins in the inner segments of photoreceptors, and abnormal filamentous actin network at the base of cone OSs in the mutant retina by 8 mph. Electron microscopy revealed aberrant structure of calyceal processes, numerous vesiculation and lamellar interruptions, and autophagosomes in the eys-mutant cone photoreceptors. In situ hybridization showed an autophagy component gene, gabarap, was ectopically expressed in the eys-null retina. These results suggest eys is required for regeneration of OS, especially of cone photoreceptors, and transport of OS proteins by regulating actin filaments. Enhanced autophagy may delay the progression of retinal degeneration when lacking EYS in the medaka retina.
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Affiliation(s)
- Keita Sato
- Department of Cytology and Histology, Faculty of Medicine, Dentistry, and Pharmaceutical Sciences, Okayama University, Okayama, 700-8558, Japan.
| | - Yang Liu
- Department of Cytology and Histology, Graduate School of Medicine, Dentistry, and Pharmaceutical Sciences, Okayama University, Okayama, 700-8558, Japan
| | - Takahiro Yamashita
- Department of Biophysics, Graduate School of Science, Kyoto University, Kyoto, 606-8502, Japan
| | - Hideyo Ohuchi
- Department of Cytology and Histology, Faculty of Medicine, Dentistry, and Pharmaceutical Sciences, Okayama University, Okayama, 700-8558, Japan.
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Deletion of POMT2 in Zebrafish Causes Degeneration of Photoreceptors. Int J Mol Sci 2022; 23:ijms232314809. [PMID: 36499139 PMCID: PMC9738688 DOI: 10.3390/ijms232314809] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/05/2022] [Revised: 11/22/2022] [Accepted: 11/24/2022] [Indexed: 12/03/2022] Open
Abstract
Mutations in the extracellular matrix protein eyes shut homolog (EYS) are a common cause of retinitis pigmentosa, a blinding disease characterized by photoreceptor degeneration. EYS binds to matriglycan, a carbohydrate modification on O-mannosyl glycan substitutions of the cell-surface glycoprotein α-dystroglycan. Patients with mutations in enzymes required for the biosynthesis of matriglycan exhibit syndromic retinal atrophy, along with brain malformations and congenital muscular dystrophy. Protein O-mannosyltransferase 2 (POMT2) is an enzyme required for the synthesis of O-mannosyl glycans. To evaluate the roles of O-mannosyl glycans in photoreceptor health, we generated protein O-mannosyltransferase 2 (pomt2) mutant zebrafish by CRISPR. pomt2 mutation resulted in a loss of matriglycan and abolished binding of EYS protein to α-dystroglycan. Mutant zebrafish presented with hydrocephalus and hypoplasia of the cerebellum, as well as muscular dystrophy. EYS protein was enriched near photoreceptor connecting cilia in the wild-type, but its presence and proper localization was significantly reduced in mutant animals. The mutant retina exhibited mis-localization of opsins and increased apoptosis in both rod and cone photoreceptors. Immunofluorescence intensity of G protein subunit alpha transducin 2 (GNAT2) antibody (a general cone marker) and 1D4 antibody (a long double cone marker) in mutant retinas did not differ from wild-type retinas at 1-month post fertilization, but was reduced at 6 months post fertilization, indicating significant cone degeneration. These data suggest that POMT2-mediated O-mannosyl glycosylation is required for EYS protein localization to the connecting cilium region and photoreceptor survival.
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Lo JE, Cheng CY, Yang CH, Yang CM, Chen YC, Huang YS, Chen PL, Chen TC. Genotypes Influence Clinical Progression in EYS-Associated Retinitis Pigmentosa. Transl Vis Sci Technol 2022; 11:6. [PMID: 35816039 PMCID: PMC9284463 DOI: 10.1167/tvst.11.7.6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/02/2022] Open
Abstract
Purpose The purpose of this study was to investigate the genetic and clinical characteristics of eyes shut homolog (EYS)-associated retinitis pigmentosa (RP). Methods This was a retrospective cross-sectional observational study of 36 patients with EYS-associated autosomal recessive RP (arRP). Results The gene sequencing results revealed that c.6416G>A (p.Cys2139Tyr) and c.7228+1G>A were the two most predominant variants in our cohort and that variants near the C-terminus, which contains alternating laminin and epidermal growth factor (EGF) domains, accounted for the majority of the allele counts (58 of a total of 72) and relative allele frequencies (81%). Over half of the patients presented with pericentral-type RP (n = 19, 60%), which frequently occurred in combination with macular lesions (n = 10, 52%). Patients having both variants within the alternating laminin and EGF domains near the C-terminus had a more severe disease progression (average 0.045 logMAR increase per year) than those having one variant in the N-terminus and the other in the C-terminus (average 0.001 logMAR increase per year). Conclusions Pericentral RP was the major phenotype in patients with EYS-associated arRP. There was also a statistically significant relationship between the location of the variants and the severity of the disease. Translational Relevance This study may aid patients with EYS-associated arRP to predict future vision acuity based on their genetic and clinical features.
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Affiliation(s)
- Jui-En Lo
- School of Medicine, National Taiwan University, Taipei, Taiwan
| | - Chia-Yi Cheng
- Department of Ophthalmology, National Taiwan University Hospital, Taipei, Taiwan
| | - Chang-Hao Yang
- Department of Ophthalmology, National Taiwan University Hospital, Taipei, Taiwan.,Department of Ophthalmology, College of Medicine, National Taiwan University, Taipei, Taiwan
| | - Chung-May Yang
- Department of Ophthalmology, National Taiwan University Hospital, Taipei, Taiwan.,Department of Ophthalmology, College of Medicine, National Taiwan University, Taipei, Taiwan
| | - Yi-Chieh Chen
- Department of Ophthalmology, National Taiwan University Hospital, Taipei, Taiwan
| | - Yu-Shu Huang
- Department of Ophthalmology, National Taiwan University Hospital, Taipei, Taiwan
| | - Pei-Lung Chen
- Graduate Institute of Clinical Medicine, College of Medicine, National Taiwan University, Taipei, Taiwan.,Graduate Institute of Medical Genomics and Proteomics, College of Medicine, National Taiwan University, Taipei, Taiwan.,Department of Medical Genetics, National Taiwan University Hospital, Taipei, Taiwan
| | - Ta-Ching Chen
- Department of Ophthalmology, National Taiwan University Hospital, Taipei, Taiwan.,Center of Frontier Medicine, National Taiwan University Hospital, Taipei, Taiwan
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Evaluation of outer nuclear layer overshadowed by retinal vessels in retinitis pigmentosa. Eye (Lond) 2022; 36:1042-1049. [PMID: 33976398 PMCID: PMC9046433 DOI: 10.1038/s41433-021-01578-y] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/28/2020] [Revised: 04/07/2021] [Accepted: 04/23/2021] [Indexed: 11/08/2022] Open
Abstract
OBJECTIVES We investigated in vivo light-induced photoreceptor damage in retinitis pigmentosa (RP) using spectral-domain optical coherence tomography (SD-OCT) images. METHODS We retrospectively reviewed patients with genetic diagnosis of EYS-associated RP. The outer nuclear layer (ONL) thickness under retinal vessels was measured on SD-OCT vertical scans. As a control, we measured adjacent ONL thickness 100 μm superior and inferior from the vessel. Same measurements were performed in healthy subjects. We calculated the ratio of ONL thickness under vessel divided by the average of adjacent ONL thickness and defined as ONL preservation ratio. In patients with RP, the length of ellipsoid zone (EZ) from the fovea was also measured with SD-OCT vertical scans. RESULTS Thirty EYS-associated RP patients and 25 healthy subjects were included. In both groups, ONL thickness overshadowed by retinal vessels was not significantly different from that of adjacent area. However, ONL preservation ratio of RP was larger than that of healthy control in both superior and inferior retina (1.03 vs 0.97; p < 0.01, 1.15 vs 0.95; p < 0.01, respectively). In RP, ONL preservation ratio was significantly larger in the inferior retina than superior retina (p < 0.01). Furthermore, in RP patients, the EZ length from the fovea was always shorter in the inferior than superior retina and there was a significant difference (p < 0.01). CONCLUSIONS Patients with EYS-associated RP exhibited inferior-dominant photoreceptor death and the relative ONL preservation under retinal vessels. These results suggest that longitudinal environment light exposure may be correlated with the photoreceptor death.
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Rai D, Iwanami M, Takahashi Y, Komuta Y, Aoi N, Umezawa A, Seko Y. Evaluation of photoreceptor-directed fibroblasts derived from retinitis pigmentosa patients with defects in the EYS gene: a possible cost-effective cellular model for mechanism-oriented drug. Stem Cell Res Ther 2022; 13:157. [PMID: 35410372 PMCID: PMC8996485 DOI: 10.1186/s13287-022-02827-x] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/27/2021] [Accepted: 03/14/2022] [Indexed: 12/15/2022] Open
Abstract
Background The most common gene responsible for autosomal recessive retinitis pigmentosa (RP) is EYS. The manner of decay of genetically defective EYS gene transcripts varies depending on the type of mutation using our cellular model, which consists of induced photoreceptor-directed fibroblasts from EYS-RP patients (EYS-RP cells). However, disease-specific profiles have not been clarified in EYS-RP cells. Herein we investigated comprehensive gene expression patterns and restoration of altered expression by low molecular weight molecules in EYS-RP cells.
Methods Using induced photoreceptor-like cells by CRX, RAX, NeuroD, and OTX2, we employed qRT-PCR and DNA microarray analysis to compare expression levels of disease-related genes in EYS-RP cells. We investigated the effect of antiapoptotic or anti-endoplasmic reticulum (ER) stress/antioxidant reagents on the restoration of altered gene expression. Results Expression levels of phototransduction-related genes (blue opsin, rhodopsin, S-antigen, GNAT1, GNAT2) were lower in EYS-RP cells. CRYGD was extracted by global gene expression analysis, as a downregulated, retina-related and apoptosis-, endoplasmic reticulum (ER) stress- or aging-related gene. Pathway enrichment analysis suggested that “complement and coagulation cascades,” “ECM-receptor interaction” and “PI3K-Akt signaling pathway” could be involved in EYS-RP-associated pathogenesis. Among the matching/overlapping genes involved in those pathways, F2R was suggested as an EYS-RP-associated gene. The downregulation of CRYGD and F2R was completely restored by additional 4-PBA, an inhibitor of ER stress, and partially restored by metformin or NAC. In addition, 4-PBA normalized the expression level of cleaved caspase-3. Conclusions Our cellular model may reflect the ER stress-mediated degenerative retina and serve as a pathogenesis-oriented cost-effective rescue strategy for RP patients. Supplementary Information The online version contains supplementary material available at 10.1186/s13287-022-02827-x.
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Affiliation(s)
- Dilip Rai
- Sensory Functions Section, Research Institute, National Rehabilitation Center for Persons With Disabilities, 4-1 Namiki, Tokorozawa, 359-8555, Japan
| | - Masaki Iwanami
- Department of Ophthalmology, Hospital, National Rehabilitation Center for Persons With Disabilities, 4-1 Namiki, Tokorozawa, 359-8555, Japan.,Iwanami Eye Clinic, 7-1-3, Tsuchihashi, Miyamae-ku Kawasaki, Tokyo, 216-0005, Japan
| | - Yoriko Takahashi
- Bioscience and Healthcare Engineering Division, Mitsui Knowledge Industry Co., Ltd., 2-7-14 Higashi-Nakano, Nakano-ku, Tokyo, 164-8555, Japan
| | - Yukari Komuta
- Sensory Functions Section, Research Institute, National Rehabilitation Center for Persons With Disabilities, 4-1 Namiki, Tokorozawa, 359-8555, Japan.,Division of Bioinformation and Therapeutic Systems, National Defense Medical College, 3 Namiki, Tokorozawa, 359-0042, Japan
| | - Noriyuki Aoi
- Department of Plastic, Oral and Maxillofacial Surgery, Teikyo University School of Medicine, 2-11-1 Kaga, Itabashi, Tokyo, 173-8605, Japan.,Miyamasuzaka Clinic, SK Aoyama Bldg. 5F, 1-6-5 Shibuya, Tokyo, 150-0002, Japan
| | - Akihiro Umezawa
- National Center for Child Health and Development, Research Institute, 2-10-1 Okura, Setagaya, 157-8535, Japan
| | - Yuko Seko
- Sensory Functions Section, Research Institute, National Rehabilitation Center for Persons With Disabilities, 4-1 Namiki, Tokorozawa, 359-8555, Japan.
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11
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Vision and sensorimotor defects associated with loss of Vps11 function in a zebrafish model of genetic leukoencephalopathy. Sci Rep 2022; 12:3511. [PMID: 35241734 PMCID: PMC8894412 DOI: 10.1038/s41598-022-07448-1] [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: 07/21/2021] [Accepted: 02/17/2022] [Indexed: 12/05/2022] Open
Abstract
Genetic Leukoencephalopathies (gLEs) are heritable white matter disorders that cause progressive neurological abnormalities. A founder mutation in the human endolysosomal trafficking protein VPS11 has been identified in Ashkenazi Jewish patients manifesting classic gLE symptoms of hypomyelination, developmental delay, motor and systemic deficits. In this study, we characterized the visual and sensorimotor function of two zebrafish vps11 mutant lines: the previously reported vps11(plt), and a new vps11(−/−) null mutant line, using behavioral analysis to track larval motor responses to visual and acoustic stimuli. We found that mutant larvae from both vps11(plt) and vps11(−/−) lines were able to visually distinguish light and dark, but showed a progressive loss of a normal sensorimotor response to visual stimuli from 5 days post fertilization (dpf) to 7dpf. Additionally, optokinetic response analysis performed at 5dpf indicated that the mutants were significantly visually impaired. Both mutant lines also displayed a progressively lower sensorimotor response to a singular acoustic stimulus from 5-7dpf. Next, we tested the habituation response of the mutant lines to series of acoustic taps. We found both mutant lines habituated faster than their siblings, and that vps11(plt) mutants habituated faster than the vps11(−/−) mutants. Together, these data suggest that loss of Vps11 function results in progressive visual and sensorimotor abnormalities in the zebrafish vps11(plt) and vps11(−/−) mutant lines. This is the first study to characterize behavioral deficits in a vertebrate model of Vps11-dependent gLE. The mutants and behavioral assays described here could be a valuable model system in which to test potential pharmacological interventions for gLE.
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12
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Perkins BD. Zebrafish models of inherited retinal dystrophies. JOURNAL OF TRANSLATIONAL GENETICS AND GENOMICS 2022; 6:95-110. [PMID: 35693295 PMCID: PMC9186516 DOI: 10.20517/jtgg.2021.47] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 04/18/2023]
Abstract
Inherited retinal degenerations (IRDs) cause permanent vision impairment or vision loss due to the death of rod and cone photoreceptors. Animal models of IRDs have been instrumental in providing knowledge of the pathological mechanisms that cause photoreceptor death and in developing successful approaches that could slow or prevent vision loss. Zebrafish models of IRDs represent an ideal model system to study IRDs in a cone-rich retina and to test strategies that exploit the natural ability to regenerate damaged neurons. This review highlights those zebrafish mutants and transgenic lines that exhibit adult-onset retinal degeneration and serve as models of retinitis pigmentosa, cone-rod dystrophy, and ciliopathies.
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Affiliation(s)
- Brian D. Perkins
- Department of Ophthalmic Research, Cole Eye Institute, Cleveland Clinic, OH 44195, USA
- Department of Ophthalmology, Cleveland Clinic Lerner College of Medicine, Case Western Reserve University, OH 44195, USA
- Department of Molecular Medicine, Cleveland Clinic Lerner College of Medicine, Case Western Reserve University, Cleveland, OH 44195, USA
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13
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Gao FJ, Wang DD, Hu FY, Xu P, Chang Q, Li JK, Liu W, Zhang SH, Xu GZ, Wu JH. Genotypic spectrum and phenotype correlations of EYS-associated disease in a Chinese cohort. Eye (Lond) 2021; 36:2122-2129. [PMID: 34689181 PMCID: PMC9581949 DOI: 10.1038/s41433-021-01794-6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/22/2021] [Revised: 09/09/2021] [Accepted: 09/24/2021] [Indexed: 12/02/2022] Open
Abstract
Background To date, certain efforts have been made to investigate the clinical and genetic characteristics of patients with EYS mutations. However, data for Chinese patients are limited. Objectives To perform a detailed phenotyping and genetic characterization of 55 Chinese patients with EYS-RD, and to identify risk factors for these clinical data. Methods A total of 55 patients with EYS-RD were recruited. Best-corrected visual acuity (BCVA), patient age, age at symptom onset, disease duration, and genetic information were collected. Results Thirty-six novel variants, three hot mutations of EYS (30.3%, c.6416G>A, c.6557G>A, c.7492G>C) and one hot region (49.06%, Laminin G domains) were identified. In all, 36.84% of the mutations occurred at base G site, and majority of mutations (56.56%) were missense. Late-truncating mutations are significantly more prevalent (41.30%). The mean age of onset was 15.65 ± 14.67 years old; it had no significant correlation with genotype. The average BCVA was 0.73 ± 0.93 LogMAR, and 61.8% of eyes had a BCVA better than 0.52 logMAR. BCVA was positively correlated with disease duration time. The mean MD was 23.18 ± 7.34 dB, MD showed a significant correlation with genotype and age. Cataract was present in 56.45% of patients, and 42.59% of patients showed an absence of pigmentation in the retina. Cataract and hyperpigmentation both showed a significant correlation with age. Conclusions EYS-RD is associated with a moderate phenotype with onset around adolescence, but great variability. Our study largely enhances the current knowledge of phenotypic and genotypic characteristics of EYS-RD, which could pave the way for better management of these patients.
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Affiliation(s)
- Feng-Juan Gao
- Eye Institute, Eye and ENT Hospital, College of Medicine, Fudan University, Shanghai, China.,Shanghai Key Laboratory of Visual Impairment and Restoration, Science and Technology Commission of Shanghai Municipality, Shanghai, China.,Key Laboratory of Myopia (Fudan University), Chinese Academy of Medical Sciences, National Health Commission, Shanghai, China
| | - Dan-Dan Wang
- Eye Institute, Eye and ENT Hospital, College of Medicine, Fudan University, Shanghai, China.,Shanghai Key Laboratory of Visual Impairment and Restoration, Science and Technology Commission of Shanghai Municipality, Shanghai, China.,Key Laboratory of Myopia (Fudan University), Chinese Academy of Medical Sciences, National Health Commission, Shanghai, China
| | - Fang-Yuan Hu
- Eye Institute, Eye and ENT Hospital, College of Medicine, Fudan University, Shanghai, China.,Shanghai Key Laboratory of Visual Impairment and Restoration, Science and Technology Commission of Shanghai Municipality, Shanghai, China.,Key Laboratory of Myopia (Fudan University), Chinese Academy of Medical Sciences, National Health Commission, Shanghai, China
| | - Ping Xu
- Eye Institute, Eye and ENT Hospital, College of Medicine, Fudan University, Shanghai, China.,Shanghai Key Laboratory of Visual Impairment and Restoration, Science and Technology Commission of Shanghai Municipality, Shanghai, China.,Key Laboratory of Myopia (Fudan University), Chinese Academy of Medical Sciences, National Health Commission, Shanghai, China
| | - Qing Chang
- Eye Institute, Eye and ENT Hospital, College of Medicine, Fudan University, Shanghai, China.,Shanghai Key Laboratory of Visual Impairment and Restoration, Science and Technology Commission of Shanghai Municipality, Shanghai, China.,Key Laboratory of Myopia (Fudan University), Chinese Academy of Medical Sciences, National Health Commission, Shanghai, China
| | - Jian-Kang Li
- BGI-Shenzhen, Shenzhen, Guangdong, China.,Department of Computer Science, City University of Hong Kong, Kowloon, Hong Kong
| | - Wei Liu
- Eye Institute, Eye and ENT Hospital, College of Medicine, Fudan University, Shanghai, China
| | - Sheng-Hai Zhang
- Eye Institute, Eye and ENT Hospital, College of Medicine, Fudan University, Shanghai, China.,Shanghai Key Laboratory of Visual Impairment and Restoration, Science and Technology Commission of Shanghai Municipality, Shanghai, China.,Key Laboratory of Myopia (Fudan University), Chinese Academy of Medical Sciences, National Health Commission, Shanghai, China
| | - Ge-Zhi Xu
- Eye Institute, Eye and ENT Hospital, College of Medicine, Fudan University, Shanghai, China. .,Shanghai Key Laboratory of Visual Impairment and Restoration, Science and Technology Commission of Shanghai Municipality, Shanghai, China. .,Key Laboratory of Myopia (Fudan University), Chinese Academy of Medical Sciences, National Health Commission, Shanghai, China.
| | - Ji-Hong Wu
- Eye Institute, Eye and ENT Hospital, College of Medicine, Fudan University, Shanghai, China. .,Shanghai Key Laboratory of Visual Impairment and Restoration, Science and Technology Commission of Shanghai Municipality, Shanghai, China. .,Key Laboratory of Myopia (Fudan University), Chinese Academy of Medical Sciences, National Health Commission, Shanghai, China.
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14
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Huang T, Yan T, Chen G, Zhang C. Development and Validation of a Gene Mutation-Associated Nomogram for Hepatocellular Carcinoma Patients From Four Countries. Front Genet 2021; 12:714639. [PMID: 34621291 PMCID: PMC8490742 DOI: 10.3389/fgene.2021.714639] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/25/2021] [Accepted: 09/03/2021] [Indexed: 01/07/2023] Open
Abstract
Background: Genomic alteration is the basis of occurrence and development of carcinoma. Specific gene mutation may be associated with the prognosis of hepatocellular carcinoma (HCC) patients without distant or lymphatic metastases. Hence, we developed a nomogram based on prognostic gene mutations that could predict the overall survival of HCC patients at early stage and provide reference for immunotherapy. Methods: HCC cohorts were obtained from The Cancer Genome Atlas (TCGA) and International Cancer Genome Consortium (ICGC) databases. The total patient was randomly assigned to training and validation sets. Univariate and multivariate cox analysis were used to select significant variables for construction of nomogram. The support vector machine (SVM) and principal component analysis (PCA) were used to assess the distinguished effect of significant genes. Besides, the nomogram model was evaluated by concordance index, time-dependent receiver operating characteristics (ROC) curve, calibration curve and decision curve analysis (DCA). Gene Set Enrichment Analysis (GSEA), CIBERSORT, Tumor Immune Dysfunction and Exclusion (TIDE) and Immunophenoscore (IPS) were utilized to explore the potential mechanism of immune-related process and immunotherapy. Results: A total of 695 HCC patients were selected in the process including 495 training patients and 200 validation patients. Nomogram was constructed based on T stage, age, country, mutation status of DOCK2, EYS, MACF1 and TP53. The assessment showed the nomogram has good discrimination and high consistence between predicted and actual data. Furthermore, we found T cell exclusion was the potential mechanism of malignant progression in high-risk group. Meanwhile, low-risk group might be sensitive to immunotherapy and benefit from CTLA-4 blocker treatment. Conclusion: Our research established a nomogram based on mutant genes and clinical parameters, and revealed the underlying association between these risk factors and immune-related process.
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Affiliation(s)
- Tingping Huang
- Department of Gastroenterology, Shandong Provincial Hospital, Cheeloo College of Medicine, Shandong University, Jinan, China
| | - Tao Yan
- Department of Thoracic Surgery, Shandong Provincial Hospital, Cheeloo College of Medicine, Shandong University, Jinan, China
| | - Gonghai Chen
- Department of Gastroenterology, Shandong Provincial Hospital, Cheeloo College of Medicine, Shandong University, Jinan, China
| | - Chunqing Zhang
- Department of Gastroenterology, Shandong Provincial Hospital, Cheeloo College of Medicine, Shandong University, Jinan, China
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15
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Schellens R, de Vrieze E, Graave P, Broekman S, Nagel-Wolfrum K, Peters T, Kremer H, Collin RWJ, van Wijk E. Zebrafish as a Model to Evaluate a CRISPR/Cas9-Based Exon Excision Approach as a Future Treatment Option for EYS-Associated Retinitis Pigmentosa. Int J Mol Sci 2021; 22:ijms22179154. [PMID: 34502064 PMCID: PMC8431288 DOI: 10.3390/ijms22179154] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/30/2021] [Revised: 08/18/2021] [Accepted: 08/18/2021] [Indexed: 12/26/2022] Open
Abstract
Retinitis pigmentosa (RP) is an inherited retinal disease (IRD) with an overall prevalence of 1 in 4000 individuals. Mutations in EYS (Eyes shut homolog) are among the most frequent causes of non-syndromic autosomal recessively inherited RP and act via a loss-of-function mechanism. In light of the recent successes for other IRDs, we investigated the therapeutic potential of exon skipping for EYS-associated RP. CRISPR/Cas9 was employed to generate zebrafish from which the region encompassing the orthologous exons 37-41 of human EYS (eys exons 40-44) was excised from the genome. The excision of these exons was predicted to maintain the open reading frame and to result in the removal of exactly one Laminin G and two EGF domains. Although the eysΔexon40-44 transcript was found at levels comparable to wild-type eys, and no unwanted off-target modifications were identified within the eys coding sequence after single-molecule sequencing, EysΔexon40-44 protein expression could not be detected. Visual motor response experiments revealed that eysΔexon40-44 larvae were visually impaired and histological analysis revealed a progressive degeneration of the retinal outer nuclear layer in these zebrafish. Altogether, the data obtained in our zebrafish model currently provide no indications for the skipping of EYS exons 37-41 as an effective future treatment strategy for EYS-associated RP.
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Affiliation(s)
- Renske Schellens
- Department of Otorhinolaryngology, Radboud University Medical Center, 6525 GA Nijmegen, The Netherlands; (R.S.); (E.d.V.); (S.B.); (T.P.); (H.K.)
- Donders Institute for Brain Cognition and Behaviour, 6500 GL Nijmegen, The Netherlands;
| | - Erik de Vrieze
- Department of Otorhinolaryngology, Radboud University Medical Center, 6525 GA Nijmegen, The Netherlands; (R.S.); (E.d.V.); (S.B.); (T.P.); (H.K.)
- Donders Institute for Brain Cognition and Behaviour, 6500 GL Nijmegen, The Netherlands;
| | - Pam Graave
- Department of Human Genetics, Radboud University Medical Center, 6525 GA Nijmegen, The Netherlands;
| | - Sanne Broekman
- Department of Otorhinolaryngology, Radboud University Medical Center, 6525 GA Nijmegen, The Netherlands; (R.S.); (E.d.V.); (S.B.); (T.P.); (H.K.)
| | - Kerstin Nagel-Wolfrum
- Institute for Molecular Physiology, Johannes Gutenberg-University Mainz, 55099 Mainz, Germany;
- Institute for Developmental Biology and Neurobiology, Johannes Gutenberg-University Mainz, 55099 Mainz, Germany
| | - Theo Peters
- Department of Otorhinolaryngology, Radboud University Medical Center, 6525 GA Nijmegen, The Netherlands; (R.S.); (E.d.V.); (S.B.); (T.P.); (H.K.)
| | - Hannie Kremer
- Department of Otorhinolaryngology, Radboud University Medical Center, 6525 GA Nijmegen, The Netherlands; (R.S.); (E.d.V.); (S.B.); (T.P.); (H.K.)
- Donders Institute for Brain Cognition and Behaviour, 6500 GL Nijmegen, The Netherlands;
- Department of Human Genetics, Radboud University Medical Center, 6525 GA Nijmegen, The Netherlands;
| | - Rob W. J. Collin
- Donders Institute for Brain Cognition and Behaviour, 6500 GL Nijmegen, The Netherlands;
- Department of Human Genetics, Radboud University Medical Center, 6525 GA Nijmegen, The Netherlands;
| | - Erwin van Wijk
- Department of Otorhinolaryngology, Radboud University Medical Center, 6525 GA Nijmegen, The Netherlands; (R.S.); (E.d.V.); (S.B.); (T.P.); (H.K.)
- Donders Institute for Brain Cognition and Behaviour, 6500 GL Nijmegen, The Netherlands;
- Correspondence:
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16
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Garcia-Delgado AB, Valdes-Sanchez L, Morillo-Sanchez MJ, Ponte-Zuñiga B, Diaz-Corrales FJ, de la Cerda B. Dissecting the role of EYS in retinal degeneration: clinical and molecular aspects and its implications for future therapy. Orphanet J Rare Dis 2021; 16:222. [PMID: 34001227 PMCID: PMC8127272 DOI: 10.1186/s13023-021-01843-z] [Citation(s) in RCA: 16] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/08/2021] [Accepted: 04/23/2021] [Indexed: 01/22/2023] Open
Abstract
Mutations in the EYS gene are one of the major causes of autosomal recessive retinitis pigmentosa. EYS-retinopathy presents a severe clinical phenotype, and patients currently have no therapeutic options. The progress in personalised medicine and gene and cell therapies hold promise for treating this degenerative disease. However, lack of understanding and incomplete comprehension of disease's mechanism and the role of EYS in the healthy retina are critical limitations for the translation of current technical advances into real therapeutic possibilities. This review recapitulates the present knowledge about EYS-retinopathies, their clinical presentations and proposed genotype–phenotype correlations. Molecular details of the gene and the protein, mainly based on animal model data, are analysed. The proposed cellular localisation and roles of this large multi-domain protein are detailed. Future therapeutic approaches for EYS-retinopathies are discussed.
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Affiliation(s)
- Ana B Garcia-Delgado
- Andalusian Center for Molecular Biology and Regenerative Medicine (CABIMER), Avda. Americo Vespucio 24, 41092, Seville, Spain
| | - Lourdes Valdes-Sanchez
- Andalusian Center for Molecular Biology and Regenerative Medicine (CABIMER), Avda. Americo Vespucio 24, 41092, Seville, Spain
| | | | - Beatriz Ponte-Zuñiga
- Department of Ophthalmology, University Hospital Virgen Macarena, Seville, Spain.,Retics Oftared, Institute of Health Carlos III, Madrid, Spain
| | - Francisco J Diaz-Corrales
- Andalusian Center for Molecular Biology and Regenerative Medicine (CABIMER), Avda. Americo Vespucio 24, 41092, Seville, Spain.
| | - Berta de la Cerda
- Andalusian Center for Molecular Biology and Regenerative Medicine (CABIMER), Avda. Americo Vespucio 24, 41092, Seville, Spain
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17
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Novel compound heterozygous EYS variants may be associated with arRP in a large Chinese pedigree. Biosci Rep 2021; 40:224912. [PMID: 32436957 PMCID: PMC7268256 DOI: 10.1042/bsr20193443] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/02/2019] [Revised: 04/22/2020] [Accepted: 04/29/2020] [Indexed: 12/11/2022] Open
Abstract
As a genetically heterogeneous ocular dystrophy, gene mutations with autosomal recessive retinitis pigmentosa (arRP) in patients have not been well described. We aimed to detect the disease-causing genes and variants in a Chinese arRP family. In the present study, a large Chinese pedigree consisting of 31 members including a proband and another two patients was recruited; clinical examinations were conducted; next-generation sequencing using a gene panel was used for identifying pathogenic genes, and Sanger sequencing was performed for verification of mutations. Novel compound heterozygous variants c.G2504A (p.C835Y) and c.G6557A (p.G2186E) for the EYS gene were identified, which co-segregated with the clinical RP phenotypes. Sequencing of 100 ethnically matched normal controls didn't found these mutations in EYS. Therefore, our study identified pathogenic variants in EYS that may cause arRP in this Chinese family. This is the first study to reveal the novel mutation in the EYS gene (c.G2504A, p.C835Y), extending its mutation spectrum. Thus, the EYS c.G2504A (p.C835Y) and c.G6557A (p.G2186E) variants may be the disease-causing missense mutations for RP in this large arRP family. These findings should be helpful for molecular diagnosis, genetic counseling and clinical management of arRP disease.
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18
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Neurodegeneration, Neuroprotection and Regeneration in the Zebrafish Retina. Cells 2021; 10:cells10030633. [PMID: 33809186 PMCID: PMC8000332 DOI: 10.3390/cells10030633] [Citation(s) in RCA: 20] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/31/2020] [Revised: 02/10/2021] [Accepted: 03/01/2021] [Indexed: 12/15/2022] Open
Abstract
Neurodegenerative retinal diseases, such as glaucoma and diabetic retinopathy, involve a gradual loss of neurons in the retina as the disease progresses. Central nervous system neurons are not able to regenerate in mammals, therefore, an often sought after course of treatment for neuronal loss follows a neuroprotective or regenerative strategy. Neuroprotection is the process of preserving the structure and function of the neurons that have survived a harmful insult; while regenerative approaches aim to replace or rewire the neurons and synaptic connections that were lost, or induce regrowth of damaged axons or dendrites. In order to test the neuroprotective effectiveness or the regenerative capacity of a particular agent, a robust experimental model of retinal neuronal damage is essential. Zebrafish are being used more often in this type of study because their eye structure and development is well-conserved between zebrafish and mammals. Zebrafish are robust genetic tools and are relatively inexpensive to maintain. The large array of functional and behavioral tests available in zebrafish makes them an attractive model for neuroprotection studies. Some common insults used to model retinal disease and study neuroprotection in zebrafish include intense light, chemical toxicity and mechanical damage. This review covers the existing retinal neuroprotection and regeneration literature in the zebrafish and highlights their potential for future studies.
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19
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A hypomorphic variant in EYS detected by genome-wide association study contributes toward retinitis pigmentosa. Commun Biol 2021; 4:140. [PMID: 33514863 PMCID: PMC7846782 DOI: 10.1038/s42003-021-01662-9] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/10/2020] [Accepted: 01/06/2021] [Indexed: 12/26/2022] Open
Abstract
The genetic basis of Japanese autosomal recessive retinitis pigmentosa (ARRP) remains largely unknown. Herein, we applied a 2-step genome-wide association study (GWAS) in 640 Japanese patients. Meta-GWAS identified three independent peaks at P < 5.0 × 10−8, all within the major ARRP gene EYS. Two of the three were each in linkage disequilibrium with a different low frequency variant (allele frequency < 0.05); a known founder Mendelian mutation (c.4957dupA, p.S1653Kfs*2) and a non-synonymous variant (c.2528 G > A, p.G843E) of unknown significance. mRNA harboring c.2528 G > A failed to restore rhodopsin mislocalization induced by morpholino-mediated knockdown of eys in zebrafish, consistent with the variant being pathogenic. c.2528 G > A solved an additional 7.0% of Japanese ARRP cases. The third peak was in linkage disequilibrium with a common non-synonymous variant (c.7666 A > T, p.S2556C), possibly representing an unreported disease-susceptibility signal. GWAS successfully unraveled genetic causes of a rare monogenic disorder and identified a high frequency variant potentially linked to development of local genome therapeutics. Koji Nishiguchi et al. identify three genetic variants within the EYS gene that are associated with retinitis pigmentosa using a genome-wide association study. They demonstrate that one of these variants (G843E) causes retinal dysfunction in zebrafish, suggesting a causal role for EYS in retinitis pigmentosa.
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20
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Noel NCL, MacDonald IM, Allison WT. Zebrafish Models of Photoreceptor Dysfunction and Degeneration. Biomolecules 2021; 11:78. [PMID: 33435268 PMCID: PMC7828047 DOI: 10.3390/biom11010078] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/19/2020] [Revised: 01/02/2021] [Accepted: 01/04/2021] [Indexed: 12/15/2022] Open
Abstract
Zebrafish are an instrumental system for the generation of photoreceptor degeneration models, which can be utilized to determine underlying causes of photoreceptor dysfunction and death, and for the analysis of potential therapeutic compounds, as well as the characterization of regenerative responses. We review the wealth of information from existing zebrafish models of photoreceptor disease, specifically as they relate to currently accepted taxonomic classes of human rod and cone disease. We also highlight that rich, detailed information can be derived from studying photoreceptor development, structure, and function, including behavioural assessments and in vivo imaging of zebrafish. Zebrafish models are available for a diversity of photoreceptor diseases, including cone dystrophies, which are challenging to recapitulate in nocturnal mammalian systems. Newly discovered models of photoreceptor disease and drusenoid deposit formation may not only provide important insights into pathogenesis of disease, but also potential therapeutic approaches. Zebrafish have already shown their use in providing pre-clinical data prior to testing genetic therapies in clinical trials, such as antisense oligonucleotide therapy for Usher syndrome.
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Affiliation(s)
- Nicole C. L. Noel
- Department of Medical Genetics, University of Alberta, Edmonton, AB T6G 2H7, Canada; (I.M.M.); (W.T.A.)
| | - Ian M. MacDonald
- Department of Medical Genetics, University of Alberta, Edmonton, AB T6G 2H7, Canada; (I.M.M.); (W.T.A.)
- Department of Ophthalmology and Visual Sciences, University of Alberta, Edmonton, AB T6G 2R7, Canada
| | - W. Ted Allison
- Department of Medical Genetics, University of Alberta, Edmonton, AB T6G 2H7, Canada; (I.M.M.); (W.T.A.)
- Department of Biological Sciences, University of Alberta, Edmonton, AB T6G 2E9, Canada
- Centre for Prions and Protein Folding Diseases, University of Alberta, Edmonton, AB T6G 2M8, Canada
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21
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Color as an important biological variable in zebrafish models: Implications for translational neurobehavioral research. Neurosci Biobehav Rev 2020; 124:1-15. [PMID: 33359096 DOI: 10.1016/j.neubiorev.2020.12.014] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/27/2020] [Revised: 07/05/2020] [Accepted: 12/15/2020] [Indexed: 01/03/2023]
Abstract
Color is an important environmental factor that in multiple ways affects human and animal behavior and physiology. Widely used in neuroscience research, various experimental (animal) models may help improve our understanding of how different colors impact brain and behavioral processes. Complementing laboratory rodents, the zebrafish (Danio rerio) is rapidly emerging as an important novel model species to explore complex neurobehavioral processes. The growing utility of zebrafish in biomedicine makes it timely to consider the role of colors in their behavioral and physiological responses. Here, we summarize mounting evidence implicating colors as a critical variable in zebrafish models and neurobehavioral traits, with a particular relevance to CNS disease modeling, genetic and pharmacological modulation, as well as environmental enrichment and animal welfare. We also discuss the growing value of zebrafish models to study color neurobiology and color-related neurobehavioral phenomics, and outline future directions of research in this field.
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22
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Takita S, Seko Y. eys +/- ; lrp5 +/- Zebrafish Reveals Lrp5 Can Be the Receptor of Retinol in the Visual Cycle. iScience 2020; 23:101762. [PMID: 33251495 PMCID: PMC7683268 DOI: 10.1016/j.isci.2020.101762] [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: 06/08/2020] [Revised: 09/17/2020] [Accepted: 10/30/2020] [Indexed: 12/04/2022] Open
Abstract
Vision is essential for vertebrates including humans. Sustained vision is accomplished by retinoid metabolism, the “visual cycle,” where all-trans retinol (atROL) is incorporated into the retinal pigment epithelium (RPE) from photoreceptors presumably through decade-long missing receptor(s). Here, we show that the LDL-related receptor-5 (Lrp5) protein is linked to the retinol binding protein 1a (Rbp1a), the transporter of atROL in the visual cycle, by generating and analyzing the digenic eyes shut homolog+/-; lrp5+/− zebrafish, the same form of gene defect detected in a human case of inherited retinal degeneration. Global gene expression analysis followed by genetic study clarified that rbp1a played a role downstream of lrp5. Rbp1a protein was colocalized with Lrp5 protein at microvilli of RPE cells. Furthermore, Rbp1a directly bound to the C-terminal intracellular region of Lrp5 in vitro. Collectively, these results strongly suggest that Lrp5 is a potent candidate of the receptor of atROL in the visual cycle. eys+/-; lrp5+/− zebrafish showed mild photoreceptor degeneration Microarray analysis identified dramatical decrease of rbp1a expression Rbp1a protein was colocalized with Lrp5 protein at the microvilli of the RPE Rbp1a directly bound to the C-terminal intracellular region of Lrp5 in vitro
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Affiliation(s)
- Shimpei Takita
- Visual Functions Section, Department of Rehabilitation for Sensory Functions, Research Institute, National Rehabilitation Center for Persons with Disabilities, 4-1 Namiki, Tokorozawa, Saitama 359-8555, Japan
| | - Yuko Seko
- Visual Functions Section, Department of Rehabilitation for Sensory Functions, Research Institute, National Rehabilitation Center for Persons with Disabilities, 4-1 Namiki, Tokorozawa, Saitama 359-8555, Japan
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23
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Liu Y, Yu M, Shang X, Nguyen MHH, Balakrishnan S, Sager R, Hu H. Eyes shut homolog (EYS) interacts with matriglycan of O-mannosyl glycans whose deficiency results in EYS mislocalization and degeneration of photoreceptors. Sci Rep 2020; 10:7795. [PMID: 32385361 PMCID: PMC7210881 DOI: 10.1038/s41598-020-64752-4] [Citation(s) in RCA: 16] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/28/2019] [Accepted: 04/21/2020] [Indexed: 12/12/2022] Open
Abstract
Mutations in eyes shut homolog (EYS), a secreted extracellular matrix protein containing multiple laminin globular (LG) domains, and in protein O-mannose β1, 2-N-acetylglucosaminyl transferase 1 (POMGnT1), an enzyme involved in O-mannosyl glycosylation, cause retinitis pigmentosa (RP), RP25 and RP76, respectively. How EYS and POMGnT1 regulate photoreceptor survival is poorly understood. Since some LG domain-containing proteins function by binding to the matriglycan moiety of O-mannosyl glycans, we hypothesized that EYS interacted with matriglycans as well. To test this hypothesis, we performed EYS Far-Western blotting assay and generated pomgnt1 mutant zebrafish. The results showed that EYS bound to matriglycans. Pomgnt1 mutation in zebrafish resulted in a loss of matriglycan, retention of synaptotagmin-1-positive EYS secretory vesicles within the outer nuclear layer, and diminished EYS protein near the connecting cilia. Photoreceptor density in 2-month old pomgnt1 mutant retina was similar to the wild-type animals but was significantly reduced at 6-months. These results indicate that EYS protein localization to the connecting cilia requires interaction with the matriglycan and that O-mannosyl glycosylation is required for photoreceptor survival in zebrafish. This study identified a novel interaction between EYS and matriglycan demonstrating that RP25 and RP76 are mechanistically linked in that O-mannosyl glycosylation controls targeting of EYS protein.
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Affiliation(s)
- Yu Liu
- Center for Vision Research, Departments of Neuroscience and Physiology and of Ophthalmology and Visual Sciences, Upstate Medical University, Syracuse, NY, 13210, USA
| | - Miao Yu
- Center for Vision Research, Departments of Neuroscience and Physiology and of Ophthalmology and Visual Sciences, Upstate Medical University, Syracuse, NY, 13210, USA
| | - Xuanze Shang
- Center for Vision Research, Departments of Neuroscience and Physiology and of Ophthalmology and Visual Sciences, Upstate Medical University, Syracuse, NY, 13210, USA
| | - My Hong Hoai Nguyen
- Center for Vision Research, Departments of Neuroscience and Physiology and of Ophthalmology and Visual Sciences, Upstate Medical University, Syracuse, NY, 13210, USA
- Department of Biological Sciences, State University of New York at Plattsburgh, 101 Broad St., Plattsburgh, New York, 12901, USA
| | - Shanmuganathan Balakrishnan
- Center for Vision Research, Departments of Neuroscience and Physiology and of Ophthalmology and Visual Sciences, Upstate Medical University, Syracuse, NY, 13210, USA
| | - Rachel Sager
- Center for Vision Research, Departments of Neuroscience and Physiology and of Ophthalmology and Visual Sciences, Upstate Medical University, Syracuse, NY, 13210, USA
| | - Huaiyu Hu
- Center for Vision Research, Departments of Neuroscience and Physiology and of Ophthalmology and Visual Sciences, Upstate Medical University, Syracuse, NY, 13210, USA.
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24
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Application of CRISPR Tools for Variant Interpretation and Disease Modeling in Inherited Retinal Dystrophies. Genes (Basel) 2020; 11:genes11050473. [PMID: 32349249 PMCID: PMC7290804 DOI: 10.3390/genes11050473] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/04/2020] [Revised: 04/23/2020] [Accepted: 04/23/2020] [Indexed: 12/27/2022] Open
Abstract
Inherited retinal dystrophies are an assorted group of rare diseases that collectively account for the major cause of visual impairment of genetic origin worldwide. Besides clinically, these vision loss disorders present a high genetic and allelic heterogeneity. To date, over 250 genes have been associated to retinal dystrophies with reported causative variants of every nature (nonsense, missense, frameshift, splice-site, large rearrangements, and so forth). Except for a fistful of mutations, most of them are private and affect one or few families, making it a challenge to ratify the newly identified candidate genes or the pathogenicity of dubious variants in disease-associated loci. A recurrent option involves altering the gene in in vitro or in vivo systems to contrast the resulting phenotype and molecular imprint. To validate specific mutations, the process must rely on simulating the precise genetic change, which, until recently, proved to be a difficult endeavor. The rise of the CRISPR/Cas9 technology and its adaptation for genetic engineering now offers a resourceful suite of tools to alleviate the process of functional studies. Here we review the implementation of these RNA-programmable Cas9 nucleases in culture-based and animal models to elucidate the role of novel genes and variants in retinal dystrophies.
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25
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Karjosukarso DW, Ali Z, Peters TA, Zhang JQC, Hoogendoorn ADM, Garanto A, van Wijk E, Jensen LD, Collin RWJ. Modeling ZNF408-Associated FEVR in Zebrafish Results in Abnormal Retinal Vasculature. Invest Ophthalmol Vis Sci 2020; 61:39. [PMID: 32097476 PMCID: PMC7329629 DOI: 10.1167/iovs.61.2.39] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022] Open
Abstract
Purpose Familial exudative vitreoretinopathy (FEVR) is an inherited retinal disease in which the retinal vasculature is affected. Patients with FEVR typically lack or have abnormal vasculature in the peripheral retina, the outcome of which can range from mild visual impairment to complete blindness. A missense mutation (p.His455Tyr) in ZNF408 was identified in an autosomal dominant FEVR family. Little, however, is known about the molecular role of ZNF408 and how its defect leads to the clinical features of FEVR. Methods Using CRISPR/Cas9 technology, two homozygous mutant zebrafish models with truncated znf408 were generated, as well as one heterozygous and one homozygous missense znf408 model in which the human p.His455Tyr mutation is mimicked. Results Intriguingly, all three znf408-mutant zebrafish strains demonstrated progressive retinal vascular pathology, initially characterized by a deficient hyaloid vessel development at 5 days postfertilization (dpf) leading to vascular insufficiency in the retina. The generation of stable mutant lines allowed long-term follow up studies, which showed ectopic retinal vascular hyper-sprouting at 90 dpf and extensive vascular leakage at 180 dpf. Conclusions Together, our data demonstrate an important role for znf408 in the development and maintenance of the vascular system within the retina.
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Genetic Spectrum of EYS-associated Retinal Disease in a Large Japanese Cohort: Identification of Disease-associated Variants with Relatively High Allele Frequency. Sci Rep 2020; 10:5497. [PMID: 32218477 PMCID: PMC7099090 DOI: 10.1038/s41598-020-62119-3] [Citation(s) in RCA: 19] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/29/2019] [Accepted: 03/04/2020] [Indexed: 11/10/2022] Open
Abstract
Biallelic variants in the EYS gene are a major cause of autosomal recessive inherited retinal disease (IRD), with a high prevalence in the Asian population. The purpose of this study was to identify pathogenic EYS variants, to determine the clinical/genetic spectrum of EYS-associated retinal disease (EYS-RD), and to discover disease-associated variants with relatively high allele frequency (1%-10%) in a nationwide Japanese cohort. Sixty-six affected subjects from 61 families with biallelic or multiple pathogenic/disease-associated EYS variants were ascertained by whole-exome sequencing. Three phenotype groups were identified in EYS-RD: retinitis pigmentosa (RP; 85.94%), cone-rod dystrophy (CORD; 10.94%), and Leber congenital amaurosis (LCA; 3.12%). Twenty-six pathogenic/disease-associated EYS variants were identified, including seven novel variants. The two most prevalent variants, p.(Gly843Glu) and p.(Thr2465Ser) were found in 26 and twelve families (42.6%, 19.7%), respectively, for which the allele frequency (AF) in the Japanese population was 2.2% and 3.0%, respectively. These results expand the phenotypic and genotypic spectrum of EYS-RD, accounting for a high proportion of EYS-RD both in autosomal recessive RP (23.4%) and autosomal recessive CORD (9.9%) in the Japanese population. The presence of EYS variants with relatively high AF highlights the importance of considering the pathogenicity of non-rare variants in relatively prevalent Mendelian disorders.
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27
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Whelan L, Dockery A, Wynne N, Zhu J, Stephenson K, Silvestri G, Turner J, O’Byrne JJ, Carrigan M, Humphries P, Keegan D, Kenna PF, Farrar GJ. Findings from a Genotyping Study of Over 1000 People with Inherited Retinal Disorders in Ireland. Genes (Basel) 2020; 11:E105. [PMID: 31963381 PMCID: PMC7016747 DOI: 10.3390/genes11010105] [Citation(s) in RCA: 34] [Impact Index Per Article: 8.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/16/2019] [Revised: 12/13/2019] [Accepted: 01/13/2020] [Indexed: 12/15/2022] Open
Abstract
The Irish national registry for inherited retinal degenerations (Target 5000) is a clinical and scientific program to identify individuals in Ireland with inherited retinal disorders and to attempt to ascertain the genetic cause underlying the disease pathology. Potential participants first undergo a clinical assessment, which includes clinical history and analysis with multimodal retinal imaging, electrophysiology, and visual field testing. If suitable for recruitment, a sample is taken and used for genetic analysis. Genetic analysis is conducted by use of a retinal gene panel target capture sequencing approach. With over 1000 participants from 710 pedigrees now screened, there is a positive candidate variant detection rate of approximately 70% (495/710). Where an autosomal recessive inheritance pattern is observed, an additional 9% (64/710) of probands have tested positive for a single candidate variant. Many novel variants have also been detected as part of this endeavor. The target capture approach is an economic and effective means of screening patients with inherited retinal disorders. Despite the advances in sequencing technology and the ever-decreasing associated processing costs, target capture remains an attractive option as the data produced is easily processed, analyzed, and stored compared to more comprehensive methods. However, with decreasing costs of whole genome and whole exome sequencing, the focus will likely move towards these methods for more comprehensive data generation.
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Affiliation(s)
- Laura Whelan
- The School of Genetics & Microbiology, Trinity College Dublin, D02 VF25 Dublin, Ireland; (A.D.); (M.C.); (P.H.); (P.F.K.); (G.J.F.)
| | - Adrian Dockery
- The School of Genetics & Microbiology, Trinity College Dublin, D02 VF25 Dublin, Ireland; (A.D.); (M.C.); (P.H.); (P.F.K.); (G.J.F.)
| | - Niamh Wynne
- The Research Foundation, Royal Victoria Eye and Ear Hospital, D02 XK51 Dublin, Ireland;
| | - Julia Zhu
- Clinical Genetics Centre for Ophthalmology, The Mater Misericordiae University Hospital, D07 R2WY Dublin, Ireland; (J.Z.); (K.S.); (J.T.); (J.J.O.); (D.K.)
| | - Kirk Stephenson
- Clinical Genetics Centre for Ophthalmology, The Mater Misericordiae University Hospital, D07 R2WY Dublin, Ireland; (J.Z.); (K.S.); (J.T.); (J.J.O.); (D.K.)
| | - Giuliana Silvestri
- Department of Ophthalmology, The Royal Victoria Hospital, Belfast BT12 6BA, Northern Ireland, UK;
- Centre for Experimental Medicine, Queen’s University Belfast, Belfast BT7 1NN, Northern Ireland, UK
| | - Jacqueline Turner
- Clinical Genetics Centre for Ophthalmology, The Mater Misericordiae University Hospital, D07 R2WY Dublin, Ireland; (J.Z.); (K.S.); (J.T.); (J.J.O.); (D.K.)
| | - James J. O’Byrne
- Clinical Genetics Centre for Ophthalmology, The Mater Misericordiae University Hospital, D07 R2WY Dublin, Ireland; (J.Z.); (K.S.); (J.T.); (J.J.O.); (D.K.)
| | - Matthew Carrigan
- The School of Genetics & Microbiology, Trinity College Dublin, D02 VF25 Dublin, Ireland; (A.D.); (M.C.); (P.H.); (P.F.K.); (G.J.F.)
| | - Peter Humphries
- The School of Genetics & Microbiology, Trinity College Dublin, D02 VF25 Dublin, Ireland; (A.D.); (M.C.); (P.H.); (P.F.K.); (G.J.F.)
| | - David Keegan
- Clinical Genetics Centre for Ophthalmology, The Mater Misericordiae University Hospital, D07 R2WY Dublin, Ireland; (J.Z.); (K.S.); (J.T.); (J.J.O.); (D.K.)
| | - Paul F. Kenna
- The School of Genetics & Microbiology, Trinity College Dublin, D02 VF25 Dublin, Ireland; (A.D.); (M.C.); (P.H.); (P.F.K.); (G.J.F.)
- The Research Foundation, Royal Victoria Eye and Ear Hospital, D02 XK51 Dublin, Ireland;
| | - G. Jane Farrar
- The School of Genetics & Microbiology, Trinity College Dublin, D02 VF25 Dublin, Ireland; (A.D.); (M.C.); (P.H.); (P.F.K.); (G.J.F.)
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28
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Sun Y, Li JK, He W, Wang ZS, Bai JY, Xu L, Xing B, Zhang JG, Wang L, Li W, Chen F. Genetic and clinical analysis in Chinese patients with retinitis pigmentosa caused by EYS mutations. Mol Genet Genomic Med 2020; 8:e1117. [PMID: 31944634 PMCID: PMC7057104 DOI: 10.1002/mgg3.1117] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/21/2019] [Revised: 12/15/2019] [Accepted: 12/20/2019] [Indexed: 12/22/2022] Open
Abstract
Background Panel‐based targeted exome sequencing was applied to identify the pathogenic variants and genetic characteristics of retinitis pigmentosa (RP) in two Chinese families, and to gain a deeper understanding of the relationship between clinical manifestations and genotypes. Methods A total of 17 subjects, comprising two probands (total patients: four subjects) and their family member, were recruited in this study. All subjects underwent comprehensive ophthalmic examinations and clinical evaluations, and the complete history and medical records were collected according to the standard procedures. All participants were screened using the multigene panel test (Target_Eye_792_V2 chip), and Sanger sequencing was used to confirm the candidate variants. Results Among these two families, a total of three novel mutations in the EYS gene were identified in patients, including a homozygous frameshift mutation c.9252_9253insT detected in two patients in one family, and the compound heterozygous splicesite mutation c.5644+2T>C and frameshift mutation c.1920_1923delTGAG detected in two patients in the another family. All patients in both families had early onset of night blindness and poor visual acuity, and with typical posterior capsule opacification. The mutation co‐segregated within all recruited individuals. In addition, one patient with compound heterozygous mutations was found to have typical blue‐blindness symptoms and detected a previously reported disease‐causing mutation c.235G>A in OPN1SW gene, which caused blue blindness manifestations and was first discovered in patient combined with RP causative genes. Conclusions Panel‐based targeted exome sequencing was used to identify three novel variants of RP causative gene, and we also detected a known pathogenic variants of blue‐blindness causative genes in two patients. Our finding will provide a powerful basis for genetic counseling and enhance our current understanding of the genetics factors for RP families.
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Affiliation(s)
- Yan Sun
- Shenyang He Eye Specialist Hospital, Shenyang, China.,He University, Shenyang, China
| | - Jian-Kang Li
- Department of Computer Science, City University of Hong Kong, Kowloon, Hong Kong.,BGI-Shenzhen, Shenzhen, China
| | - Wei He
- Shenyang He Eye Specialist Hospital, Shenyang, China.,He University, Shenyang, China
| | - Zhuo-Shi Wang
- Shenyang He Eye Specialist Hospital, Shenyang, China.,He University, Shenyang, China
| | - Jin-Yue Bai
- School of Basic Medicine, Qingdao University, Qingdao, China
| | - Ling Xu
- Shenyang He Eye Specialist Hospital, Shenyang, China.,He University, Shenyang, China
| | - Bo Xing
- School of Basic Medicine, Qingdao University, Qingdao, China
| | | | - Lusheng Wang
- Department of Computer Science, City University of Hong Kong, Kowloon, Hong Kong.,BGI-Shenzhen, Shenzhen, China
| | - Wei Li
- He University, Shenyang, China.,BGI Education Center, University of Chinese Academy of Sciences, Shenzhen, China
| | - Fang Chen
- BGI-Shenzhen, Shenzhen, China.,Laboratory of Genomics and Molecular Biomedicine, Department of Biology, University of Copenhagen, Copenhagen, Denmark
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29
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Iwanami M, Oishi A, Ogino K, Seko Y, Nishida-Shimizu T, Yoshimura N, Kato S. Five major sequence variants and copy number variants in the EYS gene account for one-third of Japanese patients with autosomal recessive and simplex retinitis pigmentosa. Mol Vis 2019; 25:766-779. [PMID: 31814702 PMCID: PMC6857781] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/27/2019] [Accepted: 11/13/2019] [Indexed: 11/25/2022] Open
Abstract
PURPOSE To elucidate the variant spectrum of the EYS gene in a large cohort of Japanese patients with autosomal recessive and simplex retinitis pigmentosa (arRP and sRP). METHODS We performed a direct sequencing analysis of 44 exons of the EYS gene in 469 patients with RP (including 144 arRP, 288 sRP, and 17 autosomal dominant RP (adRP) cases) in eastern and western regions of Japan and a multiplex ligation-dependent probe amplification (MLPA) of patients who had a single heterozygous pathogenic variant. RESULTS We identified six pathogenic and 16 likely pathogenic variants from a total of 186 nucleotide sequence variants, of which five variants, c.2528G>A (p.(Gly843Glu)), c.4957dupA (p.(Ser1653Lysfs*2)), c.6557G>A (p.(Gly2186Glu)), c.6563T>C (p.(Ile2188Thr)), and c.8868C>A (p.(Tyr2956*)), were prevalent in patients with arRP and sRP. The homozygous and heterozygous combinations of these five variants accounted for 32.4% (140/432) of Japanese patients with arRP and sRP. Five patients with adRP also had these variants. These five variants segregated with the phenotype in 15 families with RP. MLPA revealed seven copy number variations (CNVs) of the EYS exon(s). CONCLUSIONS This study showed that five major sequence variants and CNVs in the EYS gene account for one-third of Japanese patients with arRP and sRP, and these variants are also responsible for RP showing an autosomal dominant inheritance pattern. This is the first report showing the pathogenicity of three missense variants (p.(Gly843Glu), p.(Gly2186Glu), and p.(Ile2188Thr)) and the presence of CNVs in the EYS gene of Japanese patients with arRP and sRP.
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Affiliation(s)
- Masaki Iwanami
- Department of Ophthalmology, Hospital, National Rehabilitation Center for Persons with Disabilities, Tokorozawa, Japan
| | - Akio Oishi
- Department of Ophthalmology and Visual Sciences, Kyoto University Graduate School of Medicine, Kyoto, Japan
| | - Ken Ogino
- Department of Ophthalmology and Visual Sciences, Kyoto University Graduate School of Medicine, Kyoto, Japan
| | - Yuko Seko
- Department of Ophthalmology, Hospital, National Rehabilitation Center for Persons with Disabilities, Tokorozawa, Japan,Department of Rehabilitation for Sensory Functions, Research Institute, National Rehabilitation Center for Persons with Disabilities, Tokorozawa, Japan
| | - Tomomi Nishida-Shimizu
- Department of Ophthalmology, Hospital, National Rehabilitation Center for Persons with Disabilities, Tokorozawa, Japan
| | - Nagahisa Yoshimura
- Department of Ophthalmology and Visual Sciences, Kyoto University Graduate School of Medicine, Kyoto, Japan
| | - Seishi Kato
- Research Institute, National Rehabilitation Center for Persons with Disabilities, Tokorozawa, Japan
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30
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Pierrache LHM, Messchaert M, Thiadens AAHJ, Haer-Wigman L, de Jong-Hesse Y, van Zelst-Stams WAG, Collin RWJ, Klaver CCW, van den Born LI. Extending the Spectrum of EYS-Associated Retinal Disease to Macular Dystrophy. Invest Ophthalmol Vis Sci 2019; 60:2049-2063. [PMID: 31074760 DOI: 10.1167/iovs.18-25531] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022] Open
Abstract
Purpose To assess the phenotypic variability and natural course of inherited retinal diseases (IRDs) caused by EYS mutations. Methods Multiethnic cohort study (N = 30) with biallelic EYS variants from a clinical IRD database (retinitis pigmentosa [RP], N = 27; cone-rod dystrophy [CRD], N = 1; and macular dystrophy, N = 2). In vitro minigene splice assay was performed to determine the effect on EYS pre-mRNA splicing of the c.1299+5_1299+8del variant in macular dystrophy patients. Results We found 27 different EYS variants in RP patients and 7 were novel. The rate of visual field loss of the V4e isopter area was -0.84 ± 0.44 ln(deg2) per year, and the rate of visual acuity loss was 0.75 Early Treatment Diabetic Retinopathy Study letters per year. Ellipsoid zone width was correlated with area of the hyperautofluorescent ring, with rs = 0.78 and P < 0.001. Rate of decline in ellipsoid zone width was -57 ± 17 μm per year (P < 0.01) (n = 14) or -3.69% ± 0.51% from baseline per year (P < 0.001). An isolated CRD patient carried a homozygous EYS variant (c.9405T>A), previously identified in RP patients. Two siblings with macular dystrophy carried compound heterozygous EYS variants: c.1299+5_1299+8del and c.6050G>T. The former was novel and shown to result in skipping of exon 8, and the latter was a known RP variant. Conclusions We report on EYS-associated macular dystrophy, extending the spectrum of EYS-associated IRDs. We observed heterogeneity between RP patients in age of onset and disease progression. Identical EYS variants were found in cases with RP, CRD, and macular dystrophy. Screening for EYS variants in CRD and macular dystrophy patients might increase the diagnostic yield in previously unsolved cases.
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Affiliation(s)
- Laurence H M Pierrache
- The Rotterdam Eye Hospital, Rotterdam, The Netherlands.,Rotterdam Ophthalmic Institute, Rotterdam, The Netherlands.,Department of Ophthalmology, Erasmus Medical Center, Rotterdam, The Netherlands.,Department of Epidemiology, Erasmus Medical Center, Rotterdam, The Netherlands
| | - Muriël Messchaert
- Department of Human Genetics, Radboud University Medical Center, Nijmegen, The Netherlands.,Donders Institute for Brain, Cognition and Behaviour, Radboud University Medical Center, Nijmegen, The Netherlands
| | | | - Lonneke Haer-Wigman
- Department of Human Genetics, Radboud University Medical Center, Nijmegen, The Netherlands
| | - Yvonne de Jong-Hesse
- Department of Ophthalmology, Amsterdam UMC, Vrije Universiteit Amsterdam, Amsterdam, The Netherlands
| | | | - Rob W J Collin
- Department of Human Genetics, Radboud University Medical Center, Nijmegen, The Netherlands.,Donders Institute for Brain, Cognition and Behaviour, Radboud University Medical Center, Nijmegen, The Netherlands
| | - Caroline C W Klaver
- Department of Ophthalmology, Erasmus Medical Center, Rotterdam, The Netherlands.,Department of Epidemiology, Erasmus Medical Center, Rotterdam, The Netherlands.,Department of Ophthalmology, Radboud University Medical Center, Nijmegen, The Netherlands
| | - L Ingeborgh van den Born
- The Rotterdam Eye Hospital, Rotterdam, The Netherlands.,Rotterdam Ophthalmic Institute, Rotterdam, The Netherlands
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31
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Nikopoulos K, Cisarova K, Quinodoz M, Koskiniemi-Kuendig H, Miyake N, Farinelli P, Rehman AU, Khan MI, Prunotto A, Akiyama M, Kamatani Y, Terao C, Miya F, Ikeda Y, Ueno S, Fuse N, Murakami A, Wada Y, Terasaki H, Sonoda KH, Ishibashi T, Kubo M, Cremers FPM, Kutalik Z, Matsumoto N, Nishiguchi KM, Nakazawa T, Rivolta C. A frequent variant in the Japanese population determines quasi-Mendelian inheritance of rare retinal ciliopathy. Nat Commun 2019; 10:2884. [PMID: 31253780 PMCID: PMC6599023 DOI: 10.1038/s41467-019-10746-4] [Citation(s) in RCA: 16] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/21/2018] [Accepted: 05/23/2019] [Indexed: 12/21/2022] Open
Abstract
Hereditary retinal degenerations (HRDs) are Mendelian diseases characterized by progressive blindness and caused by ultra-rare mutations. In a genomic screen of 331 unrelated Japanese patients, we identify a disruptive Alu insertion and a nonsense variant (p.Arg1933*) in the ciliary gene RP1, neither of which are rare alleles in Japan. p.Arg1933* is almost polymorphic (frequency = 0.6%, amongst 12,000 individuals), does not cause disease in homozygosis or heterozygosis, and yet is significantly enriched in HRD patients (frequency = 2.1%, i.e., a 3.5-fold enrichment; p-value = 9.2 × 10-5). Familial co-segregation and association analyses show that p.Arg1933* can act as a Mendelian mutation in trans with the Alu insertion, but might also associate with disease in combination with two alleles in the EYS gene in a non-Mendelian pattern of heredity. Our results suggest that rare conditions such as HRDs can be paradoxically determined by relatively common variants, following a quasi-Mendelian model linking monogenic and complex inheritance.
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Affiliation(s)
- Konstantinos Nikopoulos
- Unit of Medical Genetics, Department of Computational Biology, University of Lausanne, 1015, Lausanne, Switzerland
- Service of Medical Genetics, Lausanne University Hospital (CHUV), 1011, Lausanne, Switzerland
| | - Katarina Cisarova
- Unit of Medical Genetics, Department of Computational Biology, University of Lausanne, 1015, Lausanne, Switzerland
| | - Mathieu Quinodoz
- Unit of Medical Genetics, Department of Computational Biology, University of Lausanne, 1015, Lausanne, Switzerland
| | - Hanna Koskiniemi-Kuendig
- Unit of Medical Genetics, Department of Computational Biology, University of Lausanne, 1015, Lausanne, Switzerland
| | - Noriko Miyake
- Department of Human Genetics, Yokohama City University Graduate School of Medicine, Yokohama, 236-0004, Japan
| | - Pietro Farinelli
- Unit of Medical Genetics, Department of Computational Biology, University of Lausanne, 1015, Lausanne, Switzerland
| | - Atta Ur Rehman
- Unit of Medical Genetics, Department of Computational Biology, University of Lausanne, 1015, Lausanne, Switzerland
| | - Muhammad Imran Khan
- Department of Human Genetics, Radboud University Medical Center, 6500 HB, Nijmegen, The Netherlands
- Donders Institute for Brain, Cognition and Behaviour, Radboud University Nijmegen, 6525 GA, Nijmegen, The Netherlands
| | - Andrea Prunotto
- Unit of Medical Genetics, Department of Computational Biology, University of Lausanne, 1015, Lausanne, Switzerland
| | - Masato Akiyama
- Laboratory for Statistical Analysis, RIKEN Center for Integrative Medical Sciences, Yokohama, 230-0045, Japan
| | - Yoichiro Kamatani
- Laboratory for Statistical Analysis, RIKEN Center for Integrative Medical Sciences, Yokohama, 230-0045, Japan
| | - Chikashi Terao
- Laboratory for Statistical Analysis, RIKEN Center for Integrative Medical Sciences, Yokohama, 230-0045, Japan
| | - Fuyuki Miya
- Department of Medical Science Mathematics, Medical Research Institute, Tokyo Medical and Dental University, Tokyo, 113-8510, Japan
| | - Yasuhiro Ikeda
- Department of Ophthalmology, Graduate School of Medical Sciences, Kyushu University, Fukuoka, 812-8582, Japan
| | - Shinji Ueno
- Department of Ophthalmology, Nagoya University Graduate School of Medicine, Nagoya, 466-8550, Japan
| | - Nobuo Fuse
- Department of Integrative Genomics, Tohoku Medical Megabank Organization, Sendai, 980-8573, Japan
| | - Akira Murakami
- Department of Ophthalmology, Juntendo University School of Medicine, Tokyo, 113-8421, Japan
| | - Yuko Wada
- Yuko Wada Eye Clinic, Sendai, 980-0011, Japan
| | - Hiroko Terasaki
- Department of Ophthalmology, Nagoya University Graduate School of Medicine, Nagoya, 466-8550, Japan
| | - Koh-Hei Sonoda
- Department of Ophthalmology, Graduate School of Medical Sciences, Kyushu University, Fukuoka, 812-8582, Japan
| | - Tatsuro Ishibashi
- Department of Ophthalmology, Graduate School of Medical Sciences, Kyushu University, Fukuoka, 812-8582, Japan
| | - Michiaki Kubo
- RIKEN Center for Integrative Medical Sciences, Yokohama, 230-0045, Japan
| | - Frans P M Cremers
- Department of Human Genetics, Radboud University Medical Center, 6500 HB, Nijmegen, The Netherlands
- Donders Institute for Brain, Cognition and Behaviour, Radboud University Nijmegen, 6525 GA, Nijmegen, The Netherlands
| | - Zoltán Kutalik
- Institute of Social and Preventive Medicine, Lausanne University Hospital, 1011, Lausanne, Switzerland
| | - Naomichi Matsumoto
- Department of Human Genetics, Yokohama City University Graduate School of Medicine, Yokohama, 236-0004, Japan
| | - Koji M Nishiguchi
- Department of Ophthalmology, Tohoku University Graduate School of Medicine, Sendai, 980-8574, Japan
- Department of Advanced Ophthalmic Medicine, Tohoku University Graduate School of Medicine, Sendai, 980-8574, Japan
| | - Toru Nakazawa
- Department of Ophthalmology, Tohoku University Graduate School of Medicine, Sendai, 980-8574, Japan
- Department of Advanced Ophthalmic Medicine, Tohoku University Graduate School of Medicine, Sendai, 980-8574, Japan
| | - Carlo Rivolta
- Unit of Medical Genetics, Department of Computational Biology, University of Lausanne, 1015, Lausanne, Switzerland.
- Department of Genetics and Genome Biology, University of Leicester, Leicester, LE1 7RH, UK.
- Institute of Molecular and Clinical Ophthalmology Basel (IOB), 4031, Basel, Switzerland.
- University of Basel, 4001, Basel, Switzerland.
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Takita S, Miyamoto-Matsui K, Seko Y. Intra- and interspecies comparison of EYS transcripts highlights its characteristics in the eye. FASEB J 2019; 33:9422-9433. [PMID: 31120796 DOI: 10.1096/fj.201900056rr] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
Inherited mutations in the eyes shut homolog (EYS) gene cause retinitis pigmentosa. Although knock out of eys in zebrafish is pathogenic, the molecular function of EYS in vertebrate photoreceptors is poorly understood. Here, we show that the 5' portion of EYS is eye-specific across vertebrates. We previously determined that a 3' fragment of EYS with an unknown transcription start site is expressed in human dermal fibroblasts (HDF). To obtain insights into the molecular function of EYS in vertebrate photoreceptors, we extensively analyzed EYS (eys) expression in the human fibroblast cell line HDF-adult (HDF-a), the Y79 retinoblastoma cell line, and in zebrafish eyes using rapid amplification of cDNA end, cap analysis of gene expression, RNA sequencing, and RT-PCR. In HDF-a cells, we identified a novel transcript variant (tv), tv5, transcribed from exon 37. In Y79 cells and zebrafish eyes, EYS (eys) was predominantly transcribed from exon 1 or 2, whereas it was transcribed exclusively from exon 37 in HDF-a cells. In the zebrafish eye, there were splice variants that introduced stop codons, resulting in complete loss of the 3' portion of the RNA. These comparative approaches indicate that the 5' portion of the EYS (eys) mRNA appears to be photoreceptor-specific and that the compositions of the deduced EYS proteins in the eye are well-conserved across vertebrates.-Takita, S., Miyamoto-Matsui, K., Seko, Y. Intra- and interspecies comparison of EYS transcripts highlights its characteristics in the eye.
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Affiliation(s)
- Shimpei Takita
- Visual Functions Section, Department of Rehabilitation for Sensory Functions, Research Institute, National Rehabilitation Center for Persons with Disabilities, Tokorozawa, Japan
| | - Kiyoko Miyamoto-Matsui
- Visual Functions Section, Department of Rehabilitation for Sensory Functions, Research Institute, National Rehabilitation Center for Persons with Disabilities, Tokorozawa, Japan
| | - Yuko Seko
- Visual Functions Section, Department of Rehabilitation for Sensory Functions, Research Institute, National Rehabilitation Center for Persons with Disabilities, Tokorozawa, Japan
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