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Cesca F, Bettella E, Polli R, Leonardi E, Aspromonte MC, Sicilian B, Stanzial F, Benedicenti F, Sensi A, Ciorba A, Bigoni S, Cama E, Scimemi P, Santarelli R, Murgia A. Frequency of Usher gene mutations in non-syndromic hearing loss: higher variability of the Usher phenotype. J Hum Genet 2020; 65:855-864. [PMID: 32467589 DOI: 10.1038/s10038-020-0783-1] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/17/2020] [Revised: 05/05/2020] [Accepted: 05/15/2020] [Indexed: 11/09/2022]
Abstract
Non-syndromic hearing loss (NSHL) is characterized by a vast genetic heterogeneity; some syndromic forms as Usher syndrome (USH) have onset as isolated deafness and then evolve later in life. We developed an NGS targeted gene-panel containing 59 genes and a customized bioinformatic pipeline for the analysis of DNA samples from clinically highly selected subjects with sensorineural hearing loss, previously resulted negative for GJB2 mutations/GJB6 deletions. Among the 217 tested subjects, 24 (11.1%) were found to carry mutations in genes involved both in NSHL and USH. For 6 out of 24 patients a diagnosis of USH was performed. Eleven subjects out of 24 had hearing loss without vestibular or ocular dysfunction and, due to their young age, it was not possible to establish whether their phenotype could be NSHL or USH. Seven subjects were diagnosed with NSHL, due to their age and phenotype. A total of 41 likely pathogenic/pathogenic mutations were identified, among which 17 novel ones. We report a high frequency of mutations in genes involved both in NSHL and in USH in a cohort of individuals tested for seemingly isolated deafness. Our data also highlight a wider than expected phenotypic variability in the USH phenotype.
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Affiliation(s)
- Federica Cesca
- Laboratory of Molecular Genetics of Neurodevelopment, Department of Women's and Children's Health, University of Padua, Padua, Italy.,Fondazione Istituto di Ricerca Pediatrica (IRP), Città della Speranza, Padua, Italy
| | - Elisa Bettella
- Laboratory of Molecular Genetics of Neurodevelopment, Department of Women's and Children's Health, University of Padua, Padua, Italy.,Fondazione Istituto di Ricerca Pediatrica (IRP), Città della Speranza, Padua, Italy
| | - Roberta Polli
- Laboratory of Molecular Genetics of Neurodevelopment, Department of Women's and Children's Health, University of Padua, Padua, Italy.,Fondazione Istituto di Ricerca Pediatrica (IRP), Città della Speranza, Padua, Italy
| | - Emanuela Leonardi
- Laboratory of Molecular Genetics of Neurodevelopment, Department of Women's and Children's Health, University of Padua, Padua, Italy.,Fondazione Istituto di Ricerca Pediatrica (IRP), Città della Speranza, Padua, Italy
| | - Maria Cristina Aspromonte
- Laboratory of Molecular Genetics of Neurodevelopment, Department of Women's and Children's Health, University of Padua, Padua, Italy.,Fondazione Istituto di Ricerca Pediatrica (IRP), Città della Speranza, Padua, Italy
| | - Barbara Sicilian
- Medical Center of Phoniatrics, Casa di Cura Trieste, Padua, Italy
| | - Franco Stanzial
- Genetic Counseling Service, Regional Hospital of Bolzano, Bolzano, Italy
| | | | - Alberto Sensi
- U.O. Medical Genetics Romagna, AULS Romagna, Cesena, Italy
| | - Andrea Ciorba
- ENT and Audiology Department, University Hospital of Ferrara, Ferrara, Italy
| | - Stefania Bigoni
- Medical Genetics Unit, University Hospital of Ferrara, Ferrara, Italy
| | - Elona Cama
- Department of Neurosciences, University of Padua, Padua, Italy.,Audiology Service, Santi Giovanni e Paolo Hospital, ULSS3 Serenissima, Venice, Italy
| | - Pietro Scimemi
- Department of Neurosciences, University of Padua, Padua, Italy.,Audiology Service, Santi Giovanni e Paolo Hospital, ULSS3 Serenissima, Venice, Italy
| | - Rosamaria Santarelli
- Department of Neurosciences, University of Padua, Padua, Italy.,Audiology Service, Santi Giovanni e Paolo Hospital, ULSS3 Serenissima, Venice, Italy
| | - Alessandra Murgia
- Laboratory of Molecular Genetics of Neurodevelopment, Department of Women's and Children's Health, University of Padua, Padua, Italy. .,Fondazione Istituto di Ricerca Pediatrica (IRP), Città della Speranza, Padua, Italy.
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52
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Jiman OA, Taylor RL, Lenassi E, Smith JC, Douzgou S, Ellingford JM, Barton S, Hardcastle C, Fletcher T, Campbell C, Ashworth J, Biswas S, Ramsden SC, Manson FD, Black GC. Diagnostic yield of panel-based genetic testing in syndromic inherited retinal disease. Eur J Hum Genet 2020; 28:576-586. [PMID: 31836858 PMCID: PMC7171123 DOI: 10.1038/s41431-019-0548-5] [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: 05/30/2019] [Revised: 10/22/2019] [Accepted: 10/29/2019] [Indexed: 01/22/2023] Open
Abstract
Thirty percent of all inherited retinal disease (IRD) is accounted for by conditions with extra-ocular features. This study aimed to establish the genetic diagnostic pick-up rate for IRD patients with one or more extra-ocular features undergoing panel-based screening in a clinical setting. One hundred and six participants, tested on a gene panel which contained both isolated and syndromic IRD genes, were retrospectively ascertained from the Manchester Genomic Diagnostics Laboratory database spanning 6 years (2012-2017). Phenotypic features were extracted from the clinical notes and classified according to Human Phenotype Ontology; all identified genetic variants were interpreted in accordance to the American College of Medical Genetics and Genomics guidelines. Overall, 49% (n = 52) of patients received a probable genetic diagnosis. A further 6% (n = 6) had a single disease-associated variant in an autosomal recessive disease-relevant gene. Fifty-two percent (n = 55) of patients had a clinical diagnosis at the time of testing. Of these, 71% (n = 39) received a probable genetic diagnosis. By contrast, for those without a provisional clinical diagnosis (n = 51), only 25% (n = 13) received a probable genetic diagnosis. The clinical diagnosis of Usher (n = 33) and Bardet-Biedl syndrome (n = 10) was confirmed in 67% (n = 22) and 80% (n = 8), respectively. The testing diagnostic rate in patients with clinically diagnosed multisystemic IRD conditions was significantly higher than those without one (71% versus 25%; p value < 0.001). The lower pick-up rate in patients without a clinical diagnosis suggests that panel-based approaches are unlikely to be the most effective means of achieving a molecular diagnosis for this group. Here, we suggest that genome-wide approaches (whole exome or genome) are more appropriate.
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Affiliation(s)
- Omamah A Jiman
- Division of Evolution and Genomic Sciences, School of Biological Sciences, Faculty of Biology, Medicine and Health, Manchester Academic Health Science Centre (MAHSC), University of Manchester, Manchester, UK
- Department of Genetic Medicine, Faculty of Medicine, King Abdulaziz University, Jeddah, Saudi Arabia
| | - Rachel L Taylor
- Division of Evolution and Genomic Sciences, School of Biological Sciences, Faculty of Biology, Medicine and Health, Manchester Academic Health Science Centre (MAHSC), University of Manchester, Manchester, UK
- Manchester Centre for Genomic Medicine, St Mary's Hospital, Central Manchester University Hospitals NHS Foundation Trust, MAHSC, Manchester, UK
| | - Eva Lenassi
- Manchester Centre for Genomic Medicine, St Mary's Hospital, Central Manchester University Hospitals NHS Foundation Trust, MAHSC, Manchester, UK
| | - Jill Clayton Smith
- Division of Evolution and Genomic Sciences, School of Biological Sciences, Faculty of Biology, Medicine and Health, Manchester Academic Health Science Centre (MAHSC), University of Manchester, Manchester, UK
- Manchester Centre for Genomic Medicine, St Mary's Hospital, Central Manchester University Hospitals NHS Foundation Trust, MAHSC, Manchester, UK
| | - Sofia Douzgou
- Division of Evolution and Genomic Sciences, School of Biological Sciences, Faculty of Biology, Medicine and Health, Manchester Academic Health Science Centre (MAHSC), University of Manchester, Manchester, UK
- Manchester Centre for Genomic Medicine, St Mary's Hospital, Central Manchester University Hospitals NHS Foundation Trust, MAHSC, Manchester, UK
| | - Jamie M Ellingford
- Division of Evolution and Genomic Sciences, School of Biological Sciences, Faculty of Biology, Medicine and Health, Manchester Academic Health Science Centre (MAHSC), University of Manchester, Manchester, UK
- Manchester Centre for Genomic Medicine, St Mary's Hospital, Central Manchester University Hospitals NHS Foundation Trust, MAHSC, Manchester, UK
| | - Stephanie Barton
- Manchester Centre for Genomic Medicine, St Mary's Hospital, Central Manchester University Hospitals NHS Foundation Trust, MAHSC, Manchester, UK
| | - Claire Hardcastle
- Manchester Centre for Genomic Medicine, St Mary's Hospital, Central Manchester University Hospitals NHS Foundation Trust, MAHSC, Manchester, UK
| | - Tracy Fletcher
- Manchester Centre for Genomic Medicine, St Mary's Hospital, Central Manchester University Hospitals NHS Foundation Trust, MAHSC, Manchester, UK
| | - Christopher Campbell
- Manchester Centre for Genomic Medicine, St Mary's Hospital, Central Manchester University Hospitals NHS Foundation Trust, MAHSC, Manchester, UK
| | - Jane Ashworth
- Division of Evolution and Genomic Sciences, School of Biological Sciences, Faculty of Biology, Medicine and Health, Manchester Academic Health Science Centre (MAHSC), University of Manchester, Manchester, UK
- Manchester Royal Eye Hospital, Central Manchester University Hospitals NHS Foundation Trust, Manchester Academic Health Science Centre, Manchester, UK
| | - Susmito Biswas
- Manchester Royal Eye Hospital, Central Manchester University Hospitals NHS Foundation Trust, Manchester Academic Health Science Centre, Manchester, UK
| | - Simon C Ramsden
- Division of Evolution and Genomic Sciences, School of Biological Sciences, Faculty of Biology, Medicine and Health, Manchester Academic Health Science Centre (MAHSC), University of Manchester, Manchester, UK
- Manchester Centre for Genomic Medicine, St Mary's Hospital, Central Manchester University Hospitals NHS Foundation Trust, MAHSC, Manchester, UK
| | - Forbes D Manson
- Division of Evolution and Genomic Sciences, School of Biological Sciences, Faculty of Biology, Medicine and Health, Manchester Academic Health Science Centre (MAHSC), University of Manchester, Manchester, UK
| | - Graeme C Black
- Division of Evolution and Genomic Sciences, School of Biological Sciences, Faculty of Biology, Medicine and Health, Manchester Academic Health Science Centre (MAHSC), University of Manchester, Manchester, UK.
- Manchester Centre for Genomic Medicine, St Mary's Hospital, Central Manchester University Hospitals NHS Foundation Trust, MAHSC, Manchester, UK.
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53
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Zhang L, Cheng J, Zhou Q, Khan MA, Fu J, Duan C, Sun S, Lv H, Fu J. Targeted Next-Generation Sequencing Identified Novel Compound Heterozygous Variants in the CDH23 Gene Causing Usher Syndrome Type ID in a Chinese Patient. Front Genet 2020; 11:422. [PMID: 32425987 PMCID: PMC7204213 DOI: 10.3389/fgene.2020.00422] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/19/2019] [Accepted: 04/03/2020] [Indexed: 01/15/2023] Open
Abstract
Usher syndrome includes a group of genetically and clinically heterogeneous autosomal recessive diseases, such as retinitis pigmentosa (RP) and sensorineural hearing loss. Usher syndrome type I (USHI) is characterized by profound hearing impairment beginning at birth, vestibular dysfunction, and unintelligible speech in addition to RP. The relationships between the Usher syndrome causing genes and the resultant phenotypes of Usher syndrome have not yet been fully elucidated. In the present study, we recruited a Chinese family with Usher syndrome and conducted paneled next-generation sequencing, Sanger sequencing, segregation analysis, and expression profile analysis. The functional effects of the identified cadherin-related 23 (CDH23) pathogenic variants were analyzed. The M101 pedigree consisted of a proband and seven family members, and the proband was a 39-year-old Chinese male who claimed that he first began to experience night blindness 11 years ago. We revealed novel, missense compound heterozygous variants c. 2572G > A (p.V858I) and c. 2891G > A (p.R964Q) in the CDH23 gene, which co-segregated with the disease phenotype causing Usher syndrome type ID (USH1D) in this Chinese pedigree. CDH23 mRNA was highly expressed in the retina, and this protein was highly conserved as revealed by the comparison of Homo sapiens CDH23 with those from nine other species. This is the first study to identify the novel, missense compound heterozygous variants c. 2572G > A (p.V858I) and c.2891G > A (p.R964Q) of CDH23, which might cause USH1D in the studied Chinese family, thereby extending CDH23 mutation spectra. Identifying CDH23 pathogenic variants should help in the detailed phenotypic characterization of USH1D.
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Affiliation(s)
- Lianmei Zhang
- Department of Pathology, The Affiliated Huaian No. 1 People's Hospital of Nanjing Medical University, Huai'an, China.,Key Laboratory of Epigenetics and Oncology, The Research Center for Preclinical Medicine, Southwest Medical University, Luzhou, China
| | - Jingliang Cheng
- Key Laboratory of Epigenetics and Oncology, The Research Center for Preclinical Medicine, Southwest Medical University, Luzhou, China
| | - Qi Zhou
- Department of Ophthalmology, The Affiliated Hospital of Southwest Medical University, Luzhou, China
| | - Md Asaduzzaman Khan
- Key Laboratory of Epigenetics and Oncology, The Research Center for Preclinical Medicine, Southwest Medical University, Luzhou, China
| | - Jiewen Fu
- Key Laboratory of Epigenetics and Oncology, The Research Center for Preclinical Medicine, Southwest Medical University, Luzhou, China
| | - Chengxia Duan
- Department of Ophthalmology, The Affiliated Hospital of Southwest Medical University, Luzhou, China
| | - Suan Sun
- Department of Pathology, The Affiliated Huaian No. 1 People's Hospital of Nanjing Medical University, Huai'an, China
| | - Hongbin Lv
- Department of Ophthalmology, The Affiliated Hospital of Southwest Medical University, Luzhou, China
| | - Junjiang Fu
- Key Laboratory of Epigenetics and Oncology, The Research Center for Preclinical Medicine, Southwest Medical University, Luzhou, China
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54
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Ataluren for the Treatment of Usher Syndrome 2A Caused by Nonsense Mutations. Int J Mol Sci 2019; 20:ijms20246274. [PMID: 31842393 PMCID: PMC6940777 DOI: 10.3390/ijms20246274] [Citation(s) in RCA: 20] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/22/2019] [Revised: 12/05/2019] [Accepted: 12/10/2019] [Indexed: 12/18/2022] Open
Abstract
The identification of genetic defects that underlie inherited retinal diseases (IRDs) paves the way for the development of therapeutic strategies. Nonsense mutations caused approximately 12% of all IRD cases, resulting in a premature termination codon (PTC). Therefore, an approach that targets nonsense mutations could be a promising pharmacogenetic strategy for the treatment of IRDs. Small molecules (translational read-through inducing drugs; TRIDs) have the potential to mediate the read-through of nonsense mutations by inducing expression of the full-length protein. We provide novel data on the read-through efficacy of Ataluren on a nonsense mutation in the Usher syndrome gene USH2A that causes deaf-blindness in humans. We demonstrate Ataluren´s efficacy in both transiently USH2AG3142*-transfected HEK293T cells and patient-derived fibroblasts by restoring USH2A protein expression. Furthermore, we observed enhanced ciliogenesis in patient-derived fibroblasts after treatment with TRIDs, thereby restoring a phenotype that is similar to that found in healthy donors. In light of recent findings, we validated Ataluren´s efficacy to induce read-through on a nonsense mutation in USH2A-related IRD. In line with published data, our findings support the use of patient-derived fibroblasts as a platform for the validation of preclinical therapies. The excellent biocompatibility combined with sustained read-through efficacy makes Ataluren an ideal TRID for treating nonsense mutations based IRDs.
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55
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Identification of a novel CDH23 gene variant associated with non-syndromic progressive hearing loss in a Chinese family: Individualized hearing rehabilitation guided by genetic diagnosis. Int J Pediatr Otorhinolaryngol 2019; 127:109649. [PMID: 31445392 DOI: 10.1016/j.ijporl.2019.109649] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/28/2019] [Revised: 08/16/2019] [Accepted: 08/17/2019] [Indexed: 01/20/2023]
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56
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Wheway G, Lord J, Baralle D. Splicing in the pathogenesis, diagnosis and treatment of ciliopathies. BIOCHIMICA ET BIOPHYSICA ACTA-GENE REGULATORY MECHANISMS 2019; 1862:194433. [PMID: 31698098 DOI: 10.1016/j.bbagrm.2019.194433] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/05/2019] [Revised: 09/12/2019] [Accepted: 09/17/2019] [Indexed: 12/12/2022]
Abstract
Primary cilia are essential signalling organelles found on the apical surface of epithelial cells, where they coordinate chemosensation, mechanosensation and light sensation. Motile cilia play a central role in establishing fluid flow in the respiratory tract, reproductive tract, brain ventricles and ear. Genetic defects affecting the structure or function of cilia can lead to a broad range of developmental and degenerative diseases known as ciliopathies. Splicing contributes to the pathogenesis, diagnosis and treatment of ciliopathies. Tissue-specific alternative splicing contributes to the tissue-specific manifestation of ciliopathy phenotypes, for example the retinal-specific effects of some genetic defects, due to specific transcript expression in the highly specialised ciliated cells of the retina, the photoreceptor cells. Ciliopathies can arise both as a result of genetic variants in spliceosomal proteins, or as a result of variants affecting splicing of specific cilia genes. Here we discuss the opportunities and challenges in diagnosing ciliopathies using RNA sequence analysis and the potential for treating ciliopathies in a relatively mutation-neutral way by targeting splicing. This article is part of a Special Issue entitled: RNA structure and splicing regulation edited by Francisco Baralle, Ravindra Singh and Stefan Stamm.
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Affiliation(s)
- Gabrielle Wheway
- Faculty of Medicine, University of Southampton, Human Development and Health, United Kingdom of Great Britain and Northern Ireland; University Hospital Southampton NHS Foundation Trust, United Kingdom of Great Britain and Northern Ireland
| | - Jenny Lord
- Faculty of Medicine, University of Southampton, Human Development and Health, United Kingdom of Great Britain and Northern Ireland; University Hospital Southampton NHS Foundation Trust, United Kingdom of Great Britain and Northern Ireland
| | - Diana Baralle
- Faculty of Medicine, University of Southampton, Human Development and Health, United Kingdom of Great Britain and Northern Ireland; University Hospital Southampton NHS Foundation Trust, United Kingdom of Great Britain and Northern Ireland.
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57
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Guo Y, Wang P, Ma JH, Cui Z, Yu Q, Liu S, Xue Y, Zhu D, Cao J, Li Z, Tang S, Chen J. Modeling Retinitis Pigmentosa: Retinal Organoids Generated From the iPSCs of a Patient With the USH2A Mutation Show Early Developmental Abnormalities. Front Cell Neurosci 2019; 13:361. [PMID: 31481876 PMCID: PMC6709881 DOI: 10.3389/fncel.2019.00361] [Citation(s) in RCA: 49] [Impact Index Per Article: 9.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/03/2019] [Accepted: 07/23/2019] [Indexed: 11/21/2022] Open
Abstract
Retinitis pigmentosa (RP) represents a group of inherited retinopathies with early-onset nyctalopia followed by progressive photoreceptor degeneration causing irreversible vision loss. Mutations in USH2A are the most common cause of non-syndromic RP. Here, we reprogrammed induced pluripotent stem cells (iPSCs) from a RP patient with a mutation in USH2A (c.8559-2A > G/c.9127_9129delTCC). Then, multilayer retinal organoids including neural retina (NR) and retinal pigment epithelium (RPE) were generated by three-step “induction-reversal culture.” The early retinal organoids derived from the RP patient with the USH2A mutation exhibited significant defects in terms of morphology, immunofluorescence staining and transcriptional profiling. To the best of our knowledge, the pathogenic mutation (c.9127_9129delTCC) in USH2A has not been reported previously among RP patients. Notably, the expression of laminin in the USH2A mutation organoids was significantly lower than in the iPSCs derived from healthy, age- and sex-matched controls during the retinal organogenesis. We also observed that abnormal retinal neuroepithelium differentiation and polarization caused defective retinal progenitor cell development and retinal layer formation, disordered organization of NRs in the presence of the USH2A mutation. Furthermore, the USH2A mutation bearing RPE cells presented abnormal morphology, lacking pigmented foci and showing an apoptotic trend and reduced expression of specific makers, such as MITF, PEDF, and RPE65. In addition, the USH2A mutation organoids had lower expression of cilium-associated (especially CFAP43, PIFO) and dopaminergic synapse-related genes (including DLGAP1, GRIK1, SLC17A7, and SLC17A8), while there was higher expression of neuron apoptotic process-related genes (especially HIF1A, ADARB1, and CASP3). This study may provide essential assistance in the molecular diagnosis and screening of RP. This work recapitulates the pathogenesis of USH2A using patient-specific organoids and demonstrated that alterations in USH2A function due to mutations may lead to cellular and molecular abnormalities.
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Affiliation(s)
- Yonglong Guo
- Ophthalmology Department, The First Affiliated Hospital of Jinan University, Guangzhou, China.,Key Laboratory for Regenerative Medicine of Ministry of Education, Jinan University, Guangzhou, China
| | - Peiyuan Wang
- Ophthalmology Department, The First Affiliated Hospital of Jinan University, Guangzhou, China
| | - Jacey Hongjie Ma
- Aier School of Ophthalmology, Central South University, Changsha, China.,Shenzhen Aier Eye Hospital, Shenzhen, China
| | - Zekai Cui
- Aier School of Ophthalmology, Central South University, Changsha, China.,Aier Eye Institute, Changsha, China
| | - Quan Yu
- Centric Laboratory, Medical College, Jinan University, Guangzhou, China
| | - Shiwei Liu
- Ophthalmology Department, The First Affiliated Hospital of Jinan University, Guangzhou, China
| | - Yunxia Xue
- Institute of Ophthalmology, Medical College, Jinan University, Guangzhou, China
| | - Deliang Zhu
- Key Laboratory for Regenerative Medicine of Ministry of Education, Jinan University, Guangzhou, China
| | - Jixing Cao
- Ophthalmology Department, The First Affiliated Hospital of Jinan University, Guangzhou, China
| | - Zhijie Li
- Institute of Ophthalmology, Medical College, Jinan University, Guangzhou, China
| | - Shibo Tang
- Aier School of Ophthalmology, Central South University, Changsha, China.,Aier Eye Institute, Changsha, China
| | - Jiansu Chen
- Ophthalmology Department, The First Affiliated Hospital of Jinan University, Guangzhou, China.,Key Laboratory for Regenerative Medicine of Ministry of Education, Jinan University, Guangzhou, China.,Aier School of Ophthalmology, Central South University, Changsha, China.,Aier Eye Institute, Changsha, China.,Institute of Ophthalmology, Medical College, Jinan University, Guangzhou, China
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58
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Pater JA, Green J, O'Rielly DD, Griffin A, Squires J, Burt T, Fernandez S, Fernandez B, Houston J, Zhou J, Roslin NM, Young TL. Novel Usher syndrome pathogenic variants identified in cases with hearing and vision loss. BMC MEDICAL GENETICS 2019; 20:68. [PMID: 31046701 PMCID: PMC6498547 DOI: 10.1186/s12881-019-0777-z] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 10/13/2018] [Accepted: 03/01/2019] [Indexed: 12/14/2022]
Abstract
Background Usher syndrome, the most common form of inherited deaf-blindness, is unlike many other forms of syndromic hereditary hearing loss in that the extra aural clinical manifestations are also detrimental to communication. Usher syndrome patients with early onset deafness also experience vision loss due to progressive retinitis pigmentosa that can lead to legal blindness in their third or fourth decade. Methods Using a multi-omic approach, we identified three novel pathogenic variants in two Usher syndrome genes (USH2A and ADGRV1) in cases initially referred for isolated vision or hearing loss. Results In a multiplex hearing loss family, two affected sisters, the product of a second cousin union, are homozygous for a novel nonsense pathogenic variant in ADGRV1 (c.17062C > T, p.Arg5688*), predicted to create a premature stop codon near the N-terminus of ADGRV1. Ophthalmological examination of the sisters confirmed typical retinitis pigmentosa and prompted a corrected Usher syndrome diagnosis. In an unrelated clinical case, a child with hearing loss tested positive for two novel USH2A splicing variants (c.5777-1G > A, p. Glu1926_Ala1952del and c.10388-2A > G, p.Asp3463Alafs*6) and RNA studies confirmed that both pathogenic variants cause splicing errors. Interestingly, these same USH2A variants are also identified in another family with vision loss where subsequent clinical follow-up confirmed pre-existing hearing loss since early childhood, eventually resulting in a reassigned diagnosis of Usher syndrome. Conclusion These findings provide empirical evidence to increase Usher syndrome surveillance of at-risk children. Given that novel antisense oligonucleotide therapies have been shown to rescue retinal degeneration caused by USH2A splicing pathogenic variants, these solved USH2A patients may now be eligible to be enrolled in therapeutic trials.
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Affiliation(s)
- Justin A Pater
- Craig L. Dobbin Research Centre, Discipline of Genetics, Faculty of Medicine, Memorial University, St. John's, Newfoundland & Labrador, AIB 3V6, Canada
| | - Jane Green
- Craig L. Dobbin Research Centre, Discipline of Genetics, Faculty of Medicine, Memorial University, St. John's, Newfoundland & Labrador, AIB 3V6, Canada
| | - Darren D O'Rielly
- Molecular Diagnostic Laboratory, Eastern Health, Craig L. Dobbin Genetics Research Centre, Faculty of Medicine, Memorial University, 300 Prince Phillip Drive, St. John's, Newfoundland and Labrador, A1B 3V6, Canada
| | - Anne Griffin
- Craig L. Dobbin Research Centre, Discipline of Genetics, Faculty of Medicine, Memorial University, St. John's, Newfoundland & Labrador, AIB 3V6, Canada
| | - Jessica Squires
- Craig L. Dobbin Research Centre, Discipline of Genetics, Faculty of Medicine, Memorial University, St. John's, Newfoundland & Labrador, AIB 3V6, Canada
| | - Taylor Burt
- Craig L. Dobbin Research Centre, Discipline of Genetics, Faculty of Medicine, Memorial University, St. John's, Newfoundland & Labrador, AIB 3V6, Canada
| | - Sara Fernandez
- Provincial Medical Genetics, Craig L. Dobbin Research Centre, Eastern Health, 300 Prince Phillip Drive, St. John's, Newfoundland and Labrador, A1B 3V6, Canada
| | - Bridget Fernandez
- Craig L. Dobbin Research Centre, Discipline of Genetics, Faculty of Medicine, Memorial University, St. John's, Newfoundland & Labrador, AIB 3V6, Canada.,Provincial Medical Genetics, Craig L. Dobbin Research Centre, Eastern Health, 300 Prince Phillip Drive, St. John's, Newfoundland and Labrador, A1B 3V6, Canada
| | - Jim Houston
- Craig L. Dobbin Research Centre, Discipline of Genetics, Faculty of Medicine, Memorial University, St. John's, Newfoundland & Labrador, AIB 3V6, Canada
| | - Jiayi Zhou
- Craig L. Dobbin Research Centre, Discipline of Genetics, Faculty of Medicine, Memorial University, St. John's, Newfoundland & Labrador, AIB 3V6, Canada
| | - Nicole M Roslin
- The Centre for Applied Genomics, The Hospital for Sick Children, 686 Bay Street, Toronto, Ontario, M5G 0A4, Canada
| | - Terry-Lynn Young
- Craig L. Dobbin Research Centre, Discipline of Genetics, Faculty of Medicine, Memorial University, St. John's, Newfoundland & Labrador, AIB 3V6, Canada. .,Molecular Diagnostic Laboratory, Eastern Health, Craig L. Dobbin Genetics Research Centre, Faculty of Medicine, Memorial University, 300 Prince Phillip Drive, St. John's, Newfoundland and Labrador, A1B 3V6, Canada.
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