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Huang Y, Yuan L, He G, Cao Y, Deng X, Deng H. Novel compound heterozygous variants in the USH2A gene associated with autosomal recessive retinitis pigmentosa without hearing loss. Front Cell Dev Biol 2023; 11:1129862. [PMID: 36875754 PMCID: PMC9974670 DOI: 10.3389/fcell.2023.1129862] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/22/2022] [Accepted: 01/25/2023] [Indexed: 02/17/2023] Open
Abstract
Background: Retinitis pigmentosa (RP) is a group of progressive inherited retinal dystrophies characterized by the primary degeneration of rod photoreceptors and the subsequent loss of cone photoreceptors because of cell death. It is caused by different mechanisms, including inflammation, apoptosis, necroptosis, pyroptosis, and autophagy. Variants in the usherin gene (USH2A) have been reported in autosomal recessive RP with or without hearing loss. In the present study, we aimed to identify causative variants in a Han-Chinese pedigree with autosomal recessive RP. Methods: A six-member, three-generation Han-Chinese family with autosomal recessive RP was recruited. A full clinical examination, whole exome sequencing, and Sanger sequencing, as well as co-segregation analysis were performed. Results: Three heterozygous variants in the USH2A gene, c.3304C>T (p.Q1102*), c.4745T>C (p.L1582P), and c.14740G>A (p.E4914K), were identified in the proband, which were inherited from parents and transmitted to the daughters. Bioinformatics analysis supported the pathogenicity of the c.3304C>T (p.Q1102*) and c.4745T>C (p.L1582P) variants. Conclusions: Novel compound heterozygous variants in the USH2A gene, c.3304C>T (p.Q1102*) and c.4745T>C (p.L1582P), were identified as the genetic causes of autosomal recessive RP. The findings may enhance the current knowledge of the pathogenesis of USH2A-associated phenotypes, expand the spectrum of the USH2A gene variants, and contribute to improved genetic counseling, prenatal diagnosis, and disease management.
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Affiliation(s)
- Yanxia Huang
- Health Management Center, The Third Xiangya Hospital, Central South University, Changsha, China.,Center for Experimental Medicine, The Third Xiangya Hospital, Central South University, Changsha, China.,Disease Genome Research Center, Central South University, Changsha, China
| | - Lamei Yuan
- Health Management Center, The Third Xiangya Hospital, Central South University, Changsha, China.,Center for Experimental Medicine, The Third Xiangya Hospital, Central South University, Changsha, China.,Disease Genome Research Center, Central South University, Changsha, China
| | - Guiyun He
- Department of Ophthalmology, Hunan Provincial People's Hospital, The First Affiliated Hospital of Hunan Normal University, Changsha, China
| | - Yanna Cao
- Department of Ophthalmology, The Third Xiangya Hospital, Central South University, Changsha, China
| | - Xiong Deng
- Health Management Center, The Third Xiangya Hospital, Central South University, Changsha, China.,Center for Experimental Medicine, The Third Xiangya Hospital, Central South University, Changsha, China.,Disease Genome Research Center, Central South University, Changsha, China
| | - Hao Deng
- Health Management Center, The Third Xiangya Hospital, Central South University, Changsha, China.,Center for Experimental Medicine, The Third Xiangya Hospital, Central South University, Changsha, China.,Disease Genome Research Center, Central South University, Changsha, China.,Department of Neurology, The Third Xiangya Hospital, Central South University, Changsha, China
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A comprehensive WGS-based pipeline for the identification of new candidate genes in inherited retinal dystrophies. NPJ Genom Med 2022; 7:17. [PMID: 35246562 PMCID: PMC8897414 DOI: 10.1038/s41525-022-00286-0] [Citation(s) in RCA: 8] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/29/2021] [Accepted: 02/04/2022] [Indexed: 12/11/2022] Open
Abstract
To enhance the use of Whole Genome Sequencing (WGS) in clinical practice, it is still necessary to standardize data analysis pipelines. Herein, we aimed to define a WGS-based algorithm for the accurate interpretation of variants in inherited retinal dystrophies (IRD). This study comprised 429 phenotyped individuals divided into three cohorts. A comparison of 14 pathogenicity predictors, and the re-definition of its cutoffs, were performed using panel-sequencing curated data from 209 genetically diagnosed individuals with IRD (training cohort). The optimal tool combinations, previously validated in 50 additional IRD individuals, were also tested in patients with hereditary cancer (n = 109), and with neurological diseases (n = 47) to evaluate the translational value of this approach (validation cohort). Then, our workflow was applied for the WGS-data analysis of 14 individuals from genetically undiagnosed IRD families (discovery cohort). The statistical analysis showed that the optimal filtering combination included CADDv1.6, MAPP, Grantham, and SIFT tools. Our pipeline allowed the identification of one homozygous variant in the candidate gene CFAP20 (c.337 C > T; p.Arg113Trp), a conserved ciliary gene, which was abundantly expressed in human retina and was located in the photoreceptors layer. Although further studies are needed, we propose CFAP20 as a candidate gene for autosomal recessive retinitis pigmentosa. Moreover, we offer a translational strategy for accurate WGS-data prioritization, which is essential for the advancement of personalized medicine.
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Fu J, Cheng J, Zhou Q, Khan MA, Duan C, Peng J, Lv H, Fu J. Novel compound heterozygous nonsense variants, p.L150* and p.Y3565*, of the USH2A gene in a Chinese pedigree are associated with Usher syndrome type IIA. Mol Med Rep 2020; 22:3464-3472. [PMID: 32945453 PMCID: PMC7453661 DOI: 10.3892/mmr.2020.11400] [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: 01/08/2020] [Accepted: 07/06/2020] [Indexed: 12/14/2022] Open
Abstract
Usher syndrome refers to a group of genetically and clinically heterogeneous autosomal recessive diseases with retinitis pigmentosa (RP) and hearing deficiencies. The association between Usher syndrome-causative genes and resultant Usher syndrome phenotypes in patients are highly variable. In the present study, a Chinese family with Usher syndrome was recruited, and targeted next-generation sequencing, Sanger sequencing and segregation analysis were performed. The expression profiles and functional effects of the pathogenic variants of USH2A identified were analyzed. Novel nonsense compound heterozygous variants, c.T449G (p.L150*) and c.T10695A (p.Y3565*), were identified in the USH2A gene, which showed co-segregation with the disease phenotype causing Usher syndrome type IIA in the recruited Chinese pedigree. The p.L150* variant was predicted to produce a truncated protein which lacked almost all the functional domains of USH2A, whereas the p.Y3565* variant is located in one of the fibronectin type 3 domains, resulting in the loss of several fibronectin type 3 domains at the C-terminus of USH2A by producing the truncated protein. It was shown that Ush2a mRNA expression levels were higher in the retina compared with those in the eye tissues (lens, sclera and cornea), uterus, ovary, breast, testis, spleen, kidney, liver, intestine, brain, skeletal muscle and blood. Additionally, the protein structure was shown to be highly conserved by comparing Homo sapiens USH2A to eight other species. To the best of our knowledge, the present study is the first to identify two novel pathogenic variants, c.T449G (p.L150*) and c.T10695A (p.Y3565*), in the USH2A gene in a patient with Usher syndrome type IIA, thereby expanding the known spectrums of USH2A causative mutations. The present discovery may assist in understanding the molecular pathogenesis underlying the development of RP and Usher syndrome type IIA, and in the development of diagnostic, therapeutic and genetic counseling strategies in patients with Usher syndrome type IIA disease.
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Affiliation(s)
- Jiewen Fu
- Key Laboratory of Epigenetics and Oncology, Research Center for Preclinical Medicine, Southwest Medical University, Luzhou, Sichuan 646000, P.R. China
| | - Jingliang Cheng
- Key Laboratory of Epigenetics and Oncology, Research Center for Preclinical Medicine, Southwest Medical University, Luzhou, Sichuan 646000, P.R. China
| | - Qi Zhou
- Department of Ophthalmology, The Affiliated Hospital of Southwest Medical University, Luzhou, Sichuan 646000, P.R. China
| | - Md Asaduzzaman Khan
- Key Laboratory of Epigenetics and Oncology, Research Center for Preclinical Medicine, Southwest Medical University, Luzhou, Sichuan 646000, P.R. China
| | - Chengxia Duan
- Department of Ophthalmology, The Affiliated Hospital of Southwest Medical University, Luzhou, Sichuan 646000, P.R. China
| | - Jiangzhou Peng
- Department of Thoracic Surgery, The Third Affiliated Hospital of Southern Medical University, Guangzhou, Guangdong 510630, P.R. China
| | - Hongbin Lv
- Department of Ophthalmology, The Affiliated Hospital of Southwest Medical University, Luzhou, Sichuan 646000, P.R. China
| | - Junjiang Fu
- Key Laboratory of Epigenetics and Oncology, Research Center for Preclinical Medicine, Southwest Medical University, Luzhou, Sichuan 646000, P.R. ChinaDepartment of Ophthalmology, The Affiliated Hospital of Southwest Medical University, Luzhou, Sichuan 646000
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