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Zhang JJ, Cao ZF, Zhou BT, Yang JH, Li Z, Lin S, Chen XL, Zhang NW, Ye Q, Ma X, Zhu YH. Abnormal function of EPHA2/p.R957P mutant in congenital cataract. Int J Ophthalmol 2024; 17:1007-1017. [PMID: 38895685 PMCID: PMC11144770 DOI: 10.18240/ijo.2024.06.04] [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: 12/07/2023] [Accepted: 03/18/2024] [Indexed: 06/21/2024] Open
Abstract
AIM To identify genetic defects in a Chinese family with congenital posterior polar cataracts and assess the pathogenicity. METHODS A four-generation Chinese family affected with autosomal dominant congenital cataract was recruited. Nineteen individuals took part in this study including 5 affected and 14 unaffected individuals. Sanger sequencing targeted hot-spot regions of 27 congenital cataract-causing genes for variant discovery. The pathogenicity of the variant was evaluated by the guidelines of American College of Medical Genetics and InterVar software. Confocal microscopy was applied to detect the subcellular localization of fluorescence-labeled ephrin type-A receptor 2 (EPHA2). Co-immunoprecipitation assay was implemented to estimate the interaction between EphA2 and other lens membrane proteins. The mRNA and protein expression were analyzed by reverse transcription-polymerase chain reaction (qRT-PCR) and Western blotting assay, respectively. The cell migration was analyzed by wound healing assay. Zebrafish model was generated by ectopic expression of human EPHA2/p.R957P mutant to demonstrate whether the mutant could cause lens opacity in vivo. RESULTS A novel missense and pathogenic variant c.2870G>C was identified in the sterile alpha motif (SAM) domain of EPHA2. Functional studies demonstrated the variant's impact: reduced EPHA2 protein expression, altered subcellular localization, and disrupted interactions with other lens membrane proteins. This mutant notably enhanced human lens epithelial cell migration, and induced a central cloudy region and roughness in zebrafish lenses with ectopic expression of human EPHA2/p.R957P mutant under differential interference contrast (DIC) optics. CONCLUSION Novel pathogenic c.2870G>C variant of EPHA2 in a Chinese congenital cataract family contributes to disease pathogenesis.
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Affiliation(s)
- Jing-Jin Zhang
- Department of Ophthalmology, the First Affiliated Hospital of Fujian Medical University; Fujian Institute of Ophthalmology; Fujian Provincial Clinical Medical Research Center of Eye Diseases and Optometry, Fuzhou 350005, Fujian Province, China
- Department of Ophthalmology, National Regional Medical Center, Binhai Campus of the First Affiliated Hospital, Fujian Medical University, Fuzhou 350005, Fujian Province, China
| | - Zong-Fu Cao
- Chinese Academy of Medical Sciences & Peking Union Medical College, Beijing 100000, China
- National Human Genetic Resources Center, National Research Institute for Family Planning, Beijing 100081, China
| | - Bi-Ting Zhou
- Department of Ophthalmology, the First Affiliated Hospital of Fujian Medical University; Fujian Institute of Ophthalmology; Fujian Provincial Clinical Medical Research Center of Eye Diseases and Optometry, Fuzhou 350005, Fujian Province, China
- Department of Ophthalmology, National Regional Medical Center, Binhai Campus of the First Affiliated Hospital, Fujian Medical University, Fuzhou 350005, Fujian Province, China
| | - Ju-Hua Yang
- Department of Ophthalmology, the First Affiliated Hospital of Fujian Medical University; Fujian Institute of Ophthalmology; Fujian Provincial Clinical Medical Research Center of Eye Diseases and Optometry, Fuzhou 350005, Fujian Province, China
- Department of Ophthalmology, National Regional Medical Center, Binhai Campus of the First Affiliated Hospital, Fujian Medical University, Fuzhou 350005, Fujian Province, China
- Department of Bioengineering and Biopharmaceutics, School of Pharmacy, Fujian Medical University, Fuzhou 350004, Fujian Province, China
| | - Zhong Li
- Department of Bioengineering and Biopharmaceutics, School of Pharmacy, Fujian Medical University, Fuzhou 350004, Fujian Province, China
| | - Shuang Lin
- Department of Bioengineering and Biopharmaceutics, School of Pharmacy, Fujian Medical University, Fuzhou 350004, Fujian Province, China
| | - Xiao-Le Chen
- Department of Bioengineering and Biopharmaceutics, School of Pharmacy, Fujian Medical University, Fuzhou 350004, Fujian Province, China
| | - Nan-Wen Zhang
- Department of Bioengineering and Biopharmaceutics, School of Pharmacy, Fujian Medical University, Fuzhou 350004, Fujian Province, China
| | - Qin Ye
- Department of Ophthalmology, the First Affiliated Hospital of Fujian Medical University; Fujian Institute of Ophthalmology; Fujian Provincial Clinical Medical Research Center of Eye Diseases and Optometry, Fuzhou 350005, Fujian Province, China
- Department of Ophthalmology, National Regional Medical Center, Binhai Campus of the First Affiliated Hospital, Fujian Medical University, Fuzhou 350005, Fujian Province, China
| | - Xu Ma
- Chinese Academy of Medical Sciences & Peking Union Medical College, Beijing 100000, China
- National Human Genetic Resources Center, National Research Institute for Family Planning, Beijing 100081, China
| | - Yi-Hua Zhu
- Department of Ophthalmology, the First Affiliated Hospital of Fujian Medical University; Fujian Institute of Ophthalmology; Fujian Provincial Clinical Medical Research Center of Eye Diseases and Optometry, Fuzhou 350005, Fujian Province, China
- Department of Ophthalmology, National Regional Medical Center, Binhai Campus of the First Affiliated Hospital, Fujian Medical University, Fuzhou 350005, Fujian Province, China
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Harding P, Gore S, Malka S, Rajkumar J, Oluonye N, Moosajee M. Real-world clinical and molecular management of 50 prospective patients with microphthalmia, anophthalmia and/or ocular coloboma. Br J Ophthalmol 2023; 107:1925-1935. [PMID: 36192130 DOI: 10.1136/bjo-2022-321991] [Citation(s) in RCA: 8] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/24/2022] [Accepted: 09/22/2022] [Indexed: 11/03/2022]
Abstract
BACKGROUND/AIMS Microphthalmia, anophthalmia and coloboma (MAC) are clinically and genetically heterogenous rare developmental eye conditions, which contribute to a significant proportion of childhood blindness worldwide. Clear understanding of MAC aetiology and comorbidities is essential to providing patients with appropriate care. However, current management is unstandardised and molecular diagnostic rates remain low, particularly in those with unilateral presentation. To further understanding of clinical and genetic management of patients with MAC, we charted their real-world experience to ascertain optimal management pathways and yield from molecular analysis. METHODS A prospective cohort study of consecutive patients with MAC referred to the ocular genetics service at Moorfields Eye Hospital between 2017-2020. RESULTS Clinical analysis of 50 MAC patients (15 microphthalmia; 2 anophthalmia; 11 coloboma; and 22 mixed) from 44 unrelated families found 44% had additional ocular features (complex) and 34% had systemic involvement, most frequently intellectual/developmental delay (8/17). Molecular analysis of 39 families using targeted gene panels, whole genome sequencing and microarray comparative genomic hybridisation identified genetic causes in, 28% including novel variants in six known MAC genes (SOX2, KMT2D, MAB21L2, ALDH1A3, BCOR and FOXE3), and a molecular diagnostic rate of 33% for both bilateral and unilateral cohorts. New phenotypic associations were found for FOXE3 (bilateral sensorineural hearing loss) and MAB21L2 (unilateral microphthalmia). CONCLUSION This study highlights the importance of thorough clinical and molecular phenotyping of MAC patients to provide appropriate multidisciplinary care. Routine genetic testing for both unilateral and bilateral cases in the clinic may increase diagnostic rates in the future, helping elucidate genotype-phenotype correlations and informing genetic counselling.
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Affiliation(s)
- Philippa Harding
- Institute of Ophthalmology, University College London, London, UK
| | - Sri Gore
- Moorfields Eye Hospital NHS Foundation Trust, London, UK
- Great Ormond Street Hospital For Children NHS Trust, London, UK
| | - Samantha Malka
- Moorfields Eye Hospital NHS Foundation Trust, London, UK
| | | | - Ngozi Oluonye
- Moorfields Eye Hospital NHS Foundation Trust, London, UK
- Great Ormond Street Hospital For Children NHS Trust, London, UK
| | - Mariya Moosajee
- Institute of Ophthalmology, University College London, London, UK
- Moorfields Eye Hospital NHS Foundation Trust, London, UK
- Great Ormond Street Hospital For Children NHS Trust, London, UK
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Zhang L, Shen M, Shu X, Zhou J, Ding J, Zhong C, Pan B, Wang B, Zhang C, Guo W. Intronic position +9 and -9 are potentially splicing sites boundary from intronic variants analysis of whole exome sequencing data. BMC Med Genomics 2023; 16:146. [PMID: 37365551 DOI: 10.1186/s12920-023-01542-7] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/25/2022] [Accepted: 05/12/2023] [Indexed: 06/28/2023] Open
Abstract
Whole exome sequencing (WES) can also detect some intronic variants, which may affect splicing and gene expression, but how to use these intronic variants, and the characteristics about them has not been reported. This study aims to reveal the characteristics of intronic variant in WES data, to further improve the clinical diagnostic value of WES. A total of 269 WES data was analyzed, 688,778 raw variants were called, among these 367,469 intronic variants were in intronic regions flanking exons which was upstream/downstream region of the exon (default is 200 bps). Contrary to expectation, the number of intronic variants with quality control (QC) passed was the lowest at the +2 and -2 positions but not at the +1 and -1 positions. The plausible explanation was that the former had the worst effect on trans-splicing, whereas the latter did not completely abolish splicing. And surprisingly, the number of intronic variants that passed QC was the highest at the +9 and -9 positions, indicating a potential splicing site boundary. The proportion of variants which could not pass QC filtering (false variants) in the intronic regions flanking exons generally accord with "S"-shaped curve. At +5 and -5 positions, the number of variants predicted damaging by software was most. This was also the position at which many pathogenic variants had been reported in recent years. Our study revealed the characteristics of intronic variant in WES data for the first time, we found the +9 and -9 positions might be a potentially splicing sites boundary and +5 and -5 positions were potentially important sites affecting splicing or gene expression, the +2 and -2 positions seem more important splicing site than +1 and -1 positions, and we found variants in intronic regions flanking exons over ± 50 bps may be unreliable. This result can help researchers find more useful variants and demonstrate that WES data is valuable for intronic variants analysis.
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Affiliation(s)
- Li Zhang
- Department of Laboratory Medicine, Zhongshan Hospital, Fudan University, Shanghai, China
| | - Minna Shen
- Department of Laboratory Medicine, Zhongshan Hospital, Fudan University, Shanghai, China
| | - Xianhong Shu
- Department of Echocardiography, Zhongshan Hospital, Shanghai Institute of Cardiovascular Diseases, Shanghai Institute of Medical Imaging, Fudan University, Shanghai, China
| | - Jingmin Zhou
- Department of Cardiology Shanghai Institute of Cardiovascular Diseases, Zhongshan Hospital, Fudan University, Shanghai, China
| | - Jing Ding
- Department of Neurology, Zhongshan Hospital, Fudan University, Shanghai, China
| | - Chunjiu Zhong
- Department of Neurology, Zhongshan Hospital, State Key Laboratory, Fudan University, Shanghai, China
| | - Baishen Pan
- Department of Laboratory Medicine, Zhongshan Hospital, Fudan University, Shanghai, China
| | - Beili Wang
- Department of Laboratory Medicine, Zhongshan Hospital, Fudan University, Shanghai, China
| | - Chunyan Zhang
- Department of Laboratory Medicine, Xiamen Branch, Zhongshan Hospital, Fudan University, Xiamen, China.
| | - Wei Guo
- Department of Laboratory Medicine, Zhongshan Hospital, Fudan University, Shanghai, China.
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Trejo-Reveles V, Owen N, Ching Chan BH, Toms M, Schoenebeck JJ, Moosajee M, Rainger J. Identification of Novel Coloboma Candidate Genes through Conserved Gene Expression Analyses across Four Vertebrate Species. Biomolecules 2023; 13:293. [PMID: 36830662 PMCID: PMC9953556 DOI: 10.3390/biom13020293] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/22/2022] [Revised: 01/23/2023] [Accepted: 01/28/2023] [Indexed: 02/08/2023] Open
Abstract
Ocular coloboma (OC) is a failure of complete optic fissure closure during embryonic development and presents as a tissue defect along the proximal-distal axis of the ventral eye. It is classed as part of the clinical spectrum of structural eye malformations with microphthalmia and anophthalmia, collectively abbreviated to MAC. Despite deliberate attempts to identify causative variants in MAC, many patients remain without a genetic diagnosis. To reveal potential candidate genes, we utilised transcriptomes experimentally generated from embryonic eye tissues derived from humans, mice, zebrafish, and chicken at stages coincident with optic fissure closure. Our in-silico analyses found 10 genes with optic fissure-specific enriched expression: ALDH1A3, BMPR1B, EMX2, EPHB3, NID1, NTN1, PAX2, SMOC1, TENM3, and VAX1. In situ hybridization revealed that all 10 genes were broadly expressed ventrally in the developing eye but that only PAX2 and NTN1 were expressed in cells at the edges of the optic fissure margin. Of these conserved optic fissure genes, EMX2, NID1, and EPHB3 have not previously been associated with human MAC cases. Targeted genetic manipulation in zebrafish embryos using CRISPR/Cas9 caused the developmental MAC phenotype for emx2 and ephb3. We analysed available whole genome sequencing datasets from MAC patients and identified a range of variants with plausible causality. In combination, our data suggest that expression of genes involved in ventral eye development is conserved across a range of vertebrate species and that EMX2, NID1, and EPHB3 are candidate loci that warrant further functional analysis in the context of MAC and should be considered for sequencing in cohorts of patients with structural eye malformations.
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Affiliation(s)
- Violeta Trejo-Reveles
- Roslin Institute, R(D)SVS, Easter Bush Campus, University of Edinburgh, Edinburgh EH25 9RG, UK
| | - Nicholas Owen
- Development, Ageing and Disease, UCL Institute of Ophthalmology, London EC1V 9EL, UK
- Ocular Genomics and Therapeutics, The Francis Crick Institute, London NW1 1A, UK
| | - Brian Ho Ching Chan
- Roslin Institute, R(D)SVS, Easter Bush Campus, University of Edinburgh, Edinburgh EH25 9RG, UK
| | - Maria Toms
- Development, Ageing and Disease, UCL Institute of Ophthalmology, London EC1V 9EL, UK
- Ocular Genomics and Therapeutics, The Francis Crick Institute, London NW1 1A, UK
| | - Jeffrey J. Schoenebeck
- Roslin Institute, R(D)SVS, Easter Bush Campus, University of Edinburgh, Edinburgh EH25 9RG, UK
| | - Mariya Moosajee
- Development, Ageing and Disease, UCL Institute of Ophthalmology, London EC1V 9EL, UK
- Ocular Genomics and Therapeutics, The Francis Crick Institute, London NW1 1A, UK
- Department of Genetics, Moorfields Eye Hospital NHS Foundation Trust, London EC1V 2PD, UK
| | - Joe Rainger
- Roslin Institute, R(D)SVS, Easter Bush Campus, University of Edinburgh, Edinburgh EH25 9RG, UK
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EPHA2 biallelic disruption causes syndromic complex microphthalmia with iris hypoplasia. Eur J Med Genet 2022; 65:104574. [DOI: 10.1016/j.ejmg.2022.104574] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/06/2022] [Revised: 06/26/2022] [Accepted: 07/20/2022] [Indexed: 11/23/2022]
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Hong Y, Luo Y. Zebrafish Model in Ophthalmology to Study Disease Mechanism and Drug Discovery. Pharmaceuticals (Basel) 2021; 14:ph14080716. [PMID: 34451814 PMCID: PMC8400593 DOI: 10.3390/ph14080716] [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: 06/09/2021] [Revised: 07/16/2021] [Accepted: 07/21/2021] [Indexed: 12/14/2022] Open
Abstract
Visual impairment and blindness are common and seriously affect people’s work and quality of life in the world. Therefore, the effective therapies for eye diseases are of high priority. Zebrafish (Danio rerio) is an alternative vertebrate model as a useful tool for the mechanism elucidation and drug discovery of various eye disorders, such as cataracts, glaucoma, diabetic retinopathy, age-related macular degeneration, photoreceptor degeneration, etc. The genetic and embryonic accessibility of zebrafish in combination with a behavioral assessment of visual function has made it a very popular model in ophthalmology. Zebrafish has also been widely used in ocular drug discovery, such as the screening of new anti-angiogenic compounds or neuroprotective drugs, and the oculotoxicity test. In this review, we summarized the applications of zebrafish as the models of eye disorders to study disease mechanism and investigate novel drug treatments.
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Affiliation(s)
| | - Yan Luo
- Correspondence: ; Tel.: +86-020-87335931
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Hayashi T, Kondo H, Matsushita I, Mizobuchi K, Baba A, Iida K, Kubo H, Nakano T. Homozygous single nucleotide duplication of SLC38A8 in autosomal recessive foveal hypoplasia: The first Japanese case report. Doc Ophthalmol 2021; 143:323-330. [PMID: 34037952 DOI: 10.1007/s10633-021-09842-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: 03/02/2021] [Accepted: 05/13/2021] [Indexed: 10/21/2022]
Abstract
PURPOSE To characterize the clinical and genetic features of a Japanese male patient with foveal hypoplasia caused by a homozygous single nucleotide duplication in the SLC38A8 gene. METHODS We performed a comprehensive ophthalmic examination including full-field electroretinography (FF-ERG) and pattern-reversal visual evoked potentials (PR-VEPs). Whole-exome sequencing (WES) was performed to identify the disease-causing variant; Sanger sequencing was used for confirmation. RESULTS In the WES analysis, a homozygous single nucleotide duplication (c.995dupG; p.Trp333MetfsTer35) was identified in SLC38A8 of the patient. His unaffected mother carried the variant heterozygously. The patient exhibited hyperopia, congenital nystagmus, low visual acuity, and grade 4 foveal hypoplasia. Slit-lamp examination revealed mild posterior embryotoxon and goniodysgenesis. Fundus examination revealed the absence of foveal hyperpigmentation and foveal avascularity, but there were no retinal degenerative lesions. In the FF-ERG, the amplitudes of rod ERG, standard-flash, and bright-flash ERG were within the normal range; cone-mediated responses also showed nearly normal amplitudes. The PR-VEP findings revealed delayed P100 latencies and decreased amplitudes of the P100 components, but no chiasmal misrouting. CONCLUSIONS This report is the first report on the clinical and genetic characteristics of SLC38A8-associated foveal hypoplasia in the Japanese population. This is also the first report of normal rod- and cone-mediated responses in a patient with this disorder.
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Affiliation(s)
- Takaaki Hayashi
- Department of Ophthalmology, The Jikei University School of Medicine, Minato-ku, Tokyo, 105-8461, Japan. .,Department of Ophthalmology, Katsushika Medical Center, The Jikei University School of Medicine, 6-41-2 Aoto, Katsushika-ku, Tokyo, 125-8506, Japan.
| | - Hiroyuki Kondo
- Department of Ophthalmology, University of Occupational and Environmental Health, Kitakyushu, Fukuoka, 807-8555, Japan
| | - Itsuka Matsushita
- Department of Ophthalmology, University of Occupational and Environmental Health, Kitakyushu, Fukuoka, 807-8555, Japan
| | - Kei Mizobuchi
- Department of Ophthalmology, The Jikei University School of Medicine, Minato-ku, Tokyo, 105-8461, Japan
| | - Akinori Baba
- Department of Ophthalmology, The Jikei University School of Medicine, Minato-ku, Tokyo, 105-8461, Japan
| | - Kie Iida
- Department of Ophthalmology, The Jikei University School of Medicine, Minato-ku, Tokyo, 105-8461, Japan
| | - Hiroyuki Kubo
- Department of Ophthalmology, The Jikei University School of Medicine, Minato-ku, Tokyo, 105-8461, Japan
| | - Tadashi Nakano
- Department of Ophthalmology, The Jikei University School of Medicine, Minato-ku, Tokyo, 105-8461, Japan
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