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Brotto D, Greggio M, De Filippis C, Trevisi P. Autosomal Recessive Non-Syndromic Deafness: Is AAV Gene Therapy a Real Chance? Audiol Res 2024; 14:239-253. [PMID: 38525683 PMCID: PMC10961695 DOI: 10.3390/audiolres14020022] [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: 11/17/2023] [Revised: 02/01/2024] [Accepted: 02/15/2024] [Indexed: 03/26/2024] Open
Abstract
The etiology of sensorineural hearing loss is heavily influenced by genetic mutations, with approximately 80% of cases attributed to genetic causes and only 20% to environmental factors. Over 100 non-syndromic deafness genes have been identified in humans thus far. In non-syndromic sensorineural hearing impairment, around 75-85% of cases follow an autosomal recessive inheritance pattern. In recent years, groundbreaking advancements in molecular gene therapy for inner-ear disorders have shown promising results. Experimental studies have demonstrated improvements in hearing following a single local injection of adeno-associated virus-derived vectors carrying an additional normal gene or using ribozymes to modify the genome. These pioneering approaches have opened new possibilities for potential therapeutic interventions. Following the PRISMA criteria, we summarized the AAV gene therapy experiments showing hearing improvement in the preclinical phases of development in different animal models of DFNB deafness and the AAV gene therapy programs currently in clinical phases targeting autosomal recessive non syndromic hearing loss. A total of 17 preclinical studies and 3 clinical studies were found and listed. Despite the hurdles, there have been significant breakthroughs in the path of HL gene therapy, holding great potential for providing patients with novel and effective treatment.
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Affiliation(s)
- Davide Brotto
- Department of Neuroscience DNS, Otolaryngology Section, Padova University, 35128 Padova, Italy; (D.B.); (C.D.F.); (P.T.)
- Otolaryngology Unit, Azienda Ospedale Università Padova, 35128 Padova, Italy
| | - Marco Greggio
- Department of Neuroscience DNS, Otolaryngology Section, Padova University, 35128 Padova, Italy; (D.B.); (C.D.F.); (P.T.)
- Otolaryngology Unit, Azienda Ospedale Università Padova, 35128 Padova, Italy
| | - Cosimo De Filippis
- Department of Neuroscience DNS, Otolaryngology Section, Padova University, 35128 Padova, Italy; (D.B.); (C.D.F.); (P.T.)
| | - Patrizia Trevisi
- Department of Neuroscience DNS, Otolaryngology Section, Padova University, 35128 Padova, Italy; (D.B.); (C.D.F.); (P.T.)
- Otolaryngology Unit, Azienda Ospedale Università Padova, 35128 Padova, Italy
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Tollefson MR, Gogal RA, Weaver AM, Schaefer AM, Marini RJ, Azaiez H, Kolbe DL, Wang D, Weaver AE, Casavant TL, Braun TA, Smith RJH, Schnieders MJ. Assessing variants of uncertain significance implicated in hearing loss using a comprehensive deafness proteome. Hum Genet 2023; 142:819-834. [PMID: 37086329 PMCID: PMC10182131 DOI: 10.1007/s00439-023-02559-9] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/23/2023] [Accepted: 04/11/2023] [Indexed: 04/23/2023]
Abstract
Hearing loss is the leading sensory deficit, affecting ~ 5% of the population. It exhibits remarkable heterogeneity across 223 genes with 6328 pathogenic missense variants, making deafness-specific expertise a prerequisite for ascribing phenotypic consequences to genetic variants. Deafness-implicated variants are curated in the Deafness Variation Database (DVD) after classification by a genetic hearing loss expert panel and thorough informatics pipeline. However, seventy percent of the 128,167 missense variants in the DVD are "variants of uncertain significance" (VUS) due to insufficient evidence for classification. Here, we use the deep learning protein prediction algorithm, AlphaFold2, to curate structures for all DVD genes. We refine these structures with global optimization and the AMOEBA force field and use DDGun3D to predict folding free energy differences (∆∆GFold) for all DVD missense variants. We find that 5772 VUSs have a large, destabilizing ∆∆GFold that is consistent with pathogenic variants. When also filtered for CADD scores (> 25.7), we determine 3456 VUSs are likely pathogenic at a probability of 99.0%. Of the 224 genes in the DVD, 166 genes (74%) exhibit one or more missense variants predicted to cause a pathogenic change in protein folding stability. The VUSs prioritized here affect 119 patients (~ 3% of cases) sequenced by the OtoSCOPE targeted panel. Approximately half of these patients previously received an inconclusive report, and reclassification of these VUSs as pathogenic provides a new genetic diagnosis for six patients.
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Affiliation(s)
- Mallory R Tollefson
- Roy J. Carver Department of Biomedical Engineering, University of Iowa, Iowa City, IA, 52242, USA
- Molecular Otolaryngology and Renal Research Laboratories, Department of Otolaryngology, University of Iowa Hospitals and Clinics, Iowa City, IA, 52242, USA
| | - Rose A Gogal
- Roy J. Carver Department of Biomedical Engineering, University of Iowa, Iowa City, IA, 52242, USA
| | - A Monique Weaver
- Molecular Otolaryngology and Renal Research Laboratories, Department of Otolaryngology, University of Iowa Hospitals and Clinics, Iowa City, IA, 52242, USA
| | - Amanda M Schaefer
- Molecular Otolaryngology and Renal Research Laboratories, Department of Otolaryngology, University of Iowa Hospitals and Clinics, Iowa City, IA, 52242, USA
| | - Robert J Marini
- Molecular Otolaryngology and Renal Research Laboratories, Department of Otolaryngology, University of Iowa Hospitals and Clinics, Iowa City, IA, 52242, USA
| | - Hela Azaiez
- Molecular Otolaryngology and Renal Research Laboratories, Department of Otolaryngology, University of Iowa Hospitals and Clinics, Iowa City, IA, 52242, USA
| | - Diana L Kolbe
- Molecular Otolaryngology and Renal Research Laboratories, Department of Otolaryngology, University of Iowa Hospitals and Clinics, Iowa City, IA, 52242, USA
| | - Donghong Wang
- Molecular Otolaryngology and Renal Research Laboratories, Department of Otolaryngology, University of Iowa Hospitals and Clinics, Iowa City, IA, 52242, USA
| | - Amy E Weaver
- Molecular Otolaryngology and Renal Research Laboratories, Department of Otolaryngology, University of Iowa Hospitals and Clinics, Iowa City, IA, 52242, USA
| | - Thomas L Casavant
- Roy J. Carver Department of Biomedical Engineering, University of Iowa, Iowa City, IA, 52242, USA
| | - Terry A Braun
- Roy J. Carver Department of Biomedical Engineering, University of Iowa, Iowa City, IA, 52242, USA
| | - Richard J H Smith
- Molecular Otolaryngology and Renal Research Laboratories, Department of Otolaryngology, University of Iowa Hospitals and Clinics, Iowa City, IA, 52242, USA.
| | - Michael J Schnieders
- Roy J. Carver Department of Biomedical Engineering, University of Iowa, Iowa City, IA, 52242, USA.
- Department of Biochemistry and Molecular Biology, University of Iowa, Iowa City, IA, 52242, USA.
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3
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Tollefson MR, Gogal RA, Weaver AM, Schaefer AM, Marini RJ, Azaiez H, Kolbe DL, Wang D, Weaver AE, Casavant TL, Braun TA, Smith RJH, Schnieders M. Assessing Variants of Uncertain Significance Implicated in Hearing Loss Using a Comprehensive Deafness Proteome. RESEARCH SQUARE 2023:rs.3.rs-2508462. [PMID: 36778238 PMCID: PMC9915777 DOI: 10.21203/rs.3.rs-2508462/v1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
Abstract
Hearing loss is the leading sensory deficit, affecting ~ 5% of the population. It exhibits remarkable heterogeneity across 223 genes with 6,328 pathogenic missense variants, making deafness-specific expertise a prerequisite for ascribing phenotypic consequences to genetic variants. Deafness-implicated variants are curated in the Deafness Variation Database (DVD) after classification by a genetic hearing loss expert panel and thorough informatics pipeline. However, seventy percent of the 128,167 missense variants in the DVD are "variants of uncertain significance" (VUS) due to insufficient evidence for classification. Here, we use the deep learning protein prediction algorithm, AlphaFold2, to curate structures for all DVD genes. We refine these structures with global optimization and the AMOEBA force field and use DDGun3D to predict folding free energy differences (∆∆G Fold ) for all DVD missense variants. We find that 5,772 VUSs have a large, destabilizing ∆∆G Fold that is consistent with pathogenic variants. When also filtered for CADD scores (> 25.7), we determine 3,456 VUSs are likely pathogenic at a probability of 99.0%. These VUSs affect 119 patients (~ 3% of cases) sequenced by the OtoSCOPE targeted panel. Approximately half of these patients previously received an inconclusive report, and reclassification of these VUSs as pathogenic provides a new genetic diagnosis for six patients.
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Functional consequences of Genetics variant in TMC1 and TMC2 within a United Arab Emirates family with Pre-lingual hearing loss. Saudi J Biol Sci 2023; 30:103520. [PMID: 36568409 PMCID: PMC9772550 DOI: 10.1016/j.sjbs.2022.103520] [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: 07/07/2022] [Revised: 10/30/2022] [Accepted: 11/25/2022] [Indexed: 12/03/2022] Open
Abstract
Hearing loss (HL) is the most prevalent sensory disorder whose etiology comes from environmental and/or genetic factors. Approximately 60 % of HL cases are due to mutations in genes responsible for maintaining a normal hearing function. Despite the monogenic inheritance of hereditary hearing loss (HHL), its diagnosis is challenging as both clinical and genetic heterogeneity characterizes it. Through the development of next-generation sequencing (NGS) techniques, the number of identified mutations responsible for HHL has increased exponentially during the last decade. Mutations in the TMC1 have been reported in several patients with nonsyndromic hereditary hearing loss (NSHHL), more precisely in cases with an autosomal recessive inheritance pattern. In this study, we conducted whole-exome sequencing (WES) analysis of a United Arabs Emirates (UAE) family with autosomal recessive nonsyndromic hearing loss (ARNSHL). This analysis revealed segregation of the TMC1 missense mutation c.596A > T (p.Asn199Ile) with the disease. Bioinformatics analysis supported the pathogenic effect of this mutation and predicted its impact at the proteomics level. Molecular docking analysis of TMC2WT, TMC2R123K, TMC2Q205R, and TMC2R123K + Q205R. Finally, protein docking results suggest a role for TMC2 variants in the phenotypic variability observed within the investigated family.
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Key Words
- ARNSHL, Autosomal Recessive Nonsyndromic Hearing Loss
- GATK, Genome Analysis Toolkit
- GnomAD, Genome Aggregation Database
- HHL, Hereditary Hearing Loss
- HL, Hearing Loss
- NGS, Next Generation Sequencing
- NSHHL, Nonsyndromic Hereditary Hearing Loss
- Non-syndromic Hearing Loss
- PCR, Polymerase Chain Reaction
- Phenotypic variability
- Protein docking
- TMC1
- UAE, United Arabs Emirates
- WES, Whole-Exome Sequencing
- Whole-exome sequencing
- c.596A > T mutation
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Jin X, Huang S, An L, Zhang C, Dai P, Gao H, Ma X. Variant analysis of 92 Chinese Han families with hearing loss. BMC Med Genomics 2022; 15:12. [PMID: 35062939 PMCID: PMC8781451 DOI: 10.1186/s12920-022-01158-3] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/18/2021] [Accepted: 01/07/2022] [Indexed: 01/31/2024] Open
Abstract
Abstract
Background
Hearing loss (HL) is the most frequent sensory deficit in humans, HL has strong genetic heterogeneity. The genetic diagnosis of HL is very important to aid treatment decisions and to provide prognostic information and genetic counseling for the patient’s family.
Methods
We undertook pedigree analysis in 92 Chinese non-syndromic HL patients by targeted next-generation sequencing and Sanger sequencing.
Results
Among the 92 HL patients, 18 were assigned a molecular diagnosis with 33 different variants in 14 deafness genes. Eighteen of the variants in 12 deafness genes were novel. Variants in TMC1, CDH23, LOXHD1 and USH2A were each detected in two probands, and variants in POU3F4, OTOA, GPR98, GJB6, TRIOBP, SLC26A4, MYO15A, TNC, STRC and TMPRSS3 were each detected in one proband.
Conclusion
Our findings expand the spectrum of deafness gene variation, which will inform genetic diagnosis of deafness and add to the theoretical basis for the prevention of deafness.
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Mosrati MA, Fadhlaoui-Zid K, Benammar-Elgaaied A, Gibriel AA, Ben Said M, Masmoudi S. Deep analysis of the LRTOMTc.242G>A variant in non-syndromic hearing loss North African patients and the Berber population: Implications for genetic diagnosis and genealogical studies. Mol Genet Genomic Med 2021; 9:e1810. [PMID: 34514748 PMCID: PMC8580077 DOI: 10.1002/mgg3.1810] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/25/2021] [Revised: 05/15/2021] [Accepted: 08/24/2021] [Indexed: 11/13/2022] Open
Abstract
Autosomal recessive non‐syndromic hearing loss (ARNSHL) is the most common inherited sensory impairment. It is particularly frequent in North African populations who have a high rate of consanguineous marriage. The c.242G>A homozygous variant in LRTOMT gene was previously established as pathogenic and is associated with NSHL in both humans and mice. The aim of this study is to determine the carrier frequency for the LRTOMT c.242G>A variant and also to estimate its age in addition to evaluating its diagnostic potential as a deafness biomarker among various populations and ethnicities in Northern African countries. A total of 179 Tunisian and 34 Libyan unrelated deafness patients were screened for this variant. The homozygous c.242G>A variant was found in 5.02% and 2.94% in Tunisian and Libyan families, respectively. Subsequent screening for this variant in 263 healthy controls of various ethnicities (136 Tunisian Berbers, 32 Andalusian and 95 Tunisian from undefined ethnic origin) revealed higher frequency for the heterozygous state among Tunisians of Berber origin only (19.11%). Genotyping 7 microsatellite markers nearby the variant location in ARNSHL patients who had the homozygous variant revealed the same haplotype suggesting a common founder origin for this variant. The age of this variant was estimated to be between 2025 and 3425 years (this corresponds to 3400 years when the variant rate was set at 10−3 or 2600 years when the variant rate is set at 10−2), spreading along with the Berber population who migrated to North Africa. In conclusion, the LRTOMT c.242G>A homozygous variant could be used as a useful deafness biomarker for North African ARNSHL patients meanwhile the heterozygous variant could be utilized in genealogical studies for tracing those of the Berber ethnic group.
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Affiliation(s)
- Mohamed Ali Mosrati
- Laboratoire de Procédés de Criblages Moléculaire et Cellulaire, Centre de Biotechnologie de Sfax, Université de Sfax, Sfax, Tunisie
| | - Karima Fadhlaoui-Zid
- Laboratory of Genetics, Immunology, and Human Pathologies, Faculty of Science of Tunis, University Tunis El Manar, Tunis, Tunisia.,Department of Biology, College of Science, Taibah University, Al Madinah Al Munawarah, Saudi Arabia.,Higher Institute of Biotechnology of Beja, University of Jendouba, Beja, Tunisia
| | - Amel Benammar-Elgaaied
- Laboratory of Genetics, Immunology, and Human Pathologies, Faculty of Science of Tunis, University Tunis El Manar, Tunis, Tunisia
| | - Abdullah Ahmed Gibriel
- Department of Biochemistry and Molecular Biology, Faculty of Pharmacy, The British University in Egypt (BUE), Cairo, Egypt
| | - Mariem Ben Said
- Laboratoire de Procédés de Criblages Moléculaire et Cellulaire, Centre de Biotechnologie de Sfax, Université de Sfax, Sfax, Tunisie
| | - Saber Masmoudi
- Laboratoire de Procédés de Criblages Moléculaire et Cellulaire, Centre de Biotechnologie de Sfax, Université de Sfax, Sfax, Tunisie
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Souissi A, Gibriel AA, Masmoudi S. Genetics and meta-analysis of recessive non-syndromic hearing impairment and Usher syndrome in Maghreb population: lessons from the past, contemporary actualities and future challenges. Hum Genet 2021; 141:583-593. [PMID: 34268600 DOI: 10.1007/s00439-021-02314-y] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/30/2021] [Accepted: 07/08/2021] [Indexed: 11/29/2022]
Abstract
Hereditary hearing impairment (HI) is a heterogeneous condition with over 130 genes associated with genetic non-syndromic HI (NSHI) and Usher syndrome (USH). Approximately 80% of hereditary NSHI cases have autosomal recessive (AR) mode of inheritance. The high rate of consanguinity and endogamy in the Maghreb countries, including Tunisia, Algeria and Morocco, represents a major contributing factor to the development of ARHI. Since the 90s, those populations, with their particular large familiar structure, represented an effective key towards the discovery of the first HI loci and genes. In this study, we performed a deep literature database search to analyze the mutational spectrum and the distribution of pathogenic variants responsible of USH and the NSHI among those populations. To date, 124 pathogenic variants were identified in 32 genes of which over 70% represent population-specific variants. The particular variants' distribution is related to the high rate of consanguinity as well as the multiple shared features such as demographic history of migrations and social behavior that promoted the spreading of several founder mutations within those countries. This is the first study to report lessons from the past and current actualities of HI within the three Maghreb countries. However, despite the great impact placed by such population for the HI genetic studies, only a few next-generation sequencing platforms have so far been implemented with those countries. We, therefore, believe that those countries should be supported to implement this technology that would definitely be of great value in the discovery of additional novel HI genes/variants.
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Affiliation(s)
- Amal Souissi
- Laboratory of Molecular and Cellular Screening Processes, Center of Biotechnology of Sfax, University of Sfax, Sidi Mansour road Km 6, BP "1177", 3018, Sfax, Tunisia
| | - Abdullah A Gibriel
- Biochemistry and Molecular Biology Department, Faculty of Pharmacy, The British University in Egypt (BUE), Cairo, Egypt
| | - Saber Masmoudi
- Laboratory of Molecular and Cellular Screening Processes, Center of Biotechnology of Sfax, University of Sfax, Sidi Mansour road Km 6, BP "1177", 3018, Sfax, Tunisia.
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Frohne A, Koenighofer M, Liu DT, Laccone F, Neesen J, Gstoettner W, Schoefer C, Lucas T, Frei K, Parzefall T. High Prevalence of MYO6 Variants in an Austrian Patient Cohort With Autosomal Dominant Hereditary Hearing Loss. Otol Neurotol 2021; 42:e648-e657. [PMID: 33710140 DOI: 10.1097/mao.0000000000003076] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
Abstract
INTRODUCTION Genetic hearing loss (HL) is often monogenic. Whereas more than half of autosomal recessive (AR) cases in Austria are caused by mutations in a single gene, no disproportionately frequent contributing genetic factor has been identified in cases of autosomal dominant (AD) HL. The genetic characterization of HL continues to improve diagnosis, genetic counseling, and lays a foundation for the development of personalized medicine approaches. METHODS Diagnostic HL panel screening was performed in an Austrian multiplex family with AD HL, and segregation was tested with polymerase chain reaction and Sanger sequencing. In an independent approach, 18 unrelated patients with AD HL were screened for causative variants in all known HL genes to date and segregation was tested if additional family members were available. The pathogenicity of novel variants was assessed based on previous literature and bioinformatic tools such as prediction software and protein modeling. RESULTS In six of the 19 families under study, candidate pathogenic variants were identified in MYO6, including three novel variants (p.Gln441Pro, p.Ser612Tyr, and p.Gln650ValfsTer7). Some patients carried more than one likely pathogenic variant in known deafness genes. CONCLUSION These results suggest a potential high prevalence of MYO6 variants in Austrian cases of AD HL. The presence of multiple rare HL variants in some patients highlights the relevance of considering multiple-hit diagnoses for genetic counseling and targeted therapy design.
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Affiliation(s)
- Alexandra Frohne
- Department of Otorhinolaryngology, Head and Neck Surgery
- Department for Cell and Developmental Biology, Center for Anatomy and Cell Biology
| | | | | | - Franco Laccone
- Institute of Medical Genetics, Center for Pathobiochemistry and Genetics, Medical University of Vienna, Vienna, Austria
| | - Juergen Neesen
- Institute of Medical Genetics, Center for Pathobiochemistry and Genetics, Medical University of Vienna, Vienna, Austria
| | | | - Christian Schoefer
- Department for Cell and Developmental Biology, Center for Anatomy and Cell Biology
| | - Trevor Lucas
- Department for Cell and Developmental Biology, Center for Anatomy and Cell Biology
| | - Klemens Frei
- Department of Otorhinolaryngology, Head and Neck Surgery
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Bankoti K, Generotti C, Hwa T, Wang L, O'Malley BW, Li D. Advances and challenges in adeno-associated viral inner-ear gene therapy for sensorineural hearing loss. MOLECULAR THERAPY-METHODS & CLINICAL DEVELOPMENT 2021; 21:209-236. [PMID: 33850952 PMCID: PMC8010215 DOI: 10.1016/j.omtm.2021.03.005] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
Abstract
There is growing attention and effort focused on treating the root cause of sensorineural hearing loss rather than managing associated secondary characteristic features. With recent substantial advances in understanding sensorineural hearing-loss mechanisms, gene delivery has emerged as a promising strategy for the biological treatment of hearing loss associated with genetic dysfunction. There are several successful and promising proof-of-principle examples of transgene deliveries in animal models; however, there remains substantial further progress to be made in these avenues before realizing their clinical application in humans. Herein, we review different aspects of development, ongoing preclinical studies, and challenges to the clinical transition of transgene delivery of the inner ear toward the restoration of lost auditory and vestibular function.
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Affiliation(s)
- Kamakshi Bankoti
- Department of Otorhinolaryngology, Head and Neck Surgery, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA 19104, USA
| | - Charles Generotti
- Department of Otorhinolaryngology, Head and Neck Surgery, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA 19104, USA
| | - Tiffany Hwa
- Department of Otorhinolaryngology, Head and Neck Surgery, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA 19104, USA
| | - Lili Wang
- Department of Medicine, Gene Therapy Program, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA 19104, USA
| | - Bert W O'Malley
- Department of Otorhinolaryngology, Head and Neck Surgery, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA 19104, USA
| | - Daqing Li
- Department of Otorhinolaryngology, Head and Neck Surgery, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA 19104, USA
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Gallo S, Trevisi P, Rigon C, Caserta E, Seif Ali D, Bovo R, Martini A, Cassina M. Auditory Outcome after Cochlear Implantation in Children with DFNB7/11 Caused by Pathogenic Variants in TMC1 Gene. Audiol Neurootol 2020; 26:157-163. [PMID: 33352559 DOI: 10.1159/000510156] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/13/2020] [Accepted: 07/14/2020] [Indexed: 11/19/2022] Open
Abstract
INTRODUCTION Non-syndromic hereditary hearing loss is characterized by extreme genetic heterogeneity. So far, more than 100 pathogenic or likely pathogenic variants in TMC1 gene have been reported in patients with autosomal recessive hearing loss (HL) DFNB7/11. The prevailing auditory phenotype of individuals with DFNB7/11 is congenital, profound, bilateral HL, but the functional outcome after cochlear implantation (CI) described in the literature is variable. The objective of this work is to evaluate the auditory outcome after CI in pediatric patients with DFNB7/11, born to non-consanguineous parents. METHODS A retrospective analysis of genetic and audiological data of DFNB7/11 patients followed up in a single Italian otolaryngology clinic was performed. Cases with biallelic pathogenic variants in TMC1 were selected from the cohort of children with non-syndromic hearing loss who had undergone CI and had been molecularly characterized by multigene panel testing. All patients underwent extensive audiological assessment, and the auditory outcome after CI was evaluated. RESULTS DFNB7/11 was diagnosed in a total of 3 patients from 2 non-consanguineous families; a novel disease-causing variant in TMC1 was detected [c.962G>A p.(Trp321*)]. All the affected children showed the typical DFNB7/11 phenotype characterized by prelingual, severe-to-profound HL. The patients showed an excellent functional outcome after CI; speech perception, nonverbal cognition, and speech performance were comparable to those of patients with DFNB1 deafness. DISCUSSION/CONCLUSION Our results do not support the variable auditory outcome reported in the literature, which may be affected by several social and environmental factors and by the genetic background.
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Affiliation(s)
- Samanta Gallo
- Otolaryngology Unit, Department of Neurosciences, University of Padova, Padova, Italy
| | - Patrizia Trevisi
- Otolaryngology Unit, Department of Neurosciences, University of Padova, Padova, Italy
| | - Chiara Rigon
- Clinical Genetics Unit, Department of Women's and Children's Health, University of Padova, Padova, Italy
| | - Ezio Caserta
- Otolaryngology Unit, Department of Neurosciences, University of Padova, Padova, Italy
| | - Dario Seif Ali
- Clinical Genetics Unit, Department of Women's and Children's Health, University of Padova, Padova, Italy
| | - Roberto Bovo
- Otolaryngology Unit, Department of Neurosciences, University of Padova, Padova, Italy
| | - Alessandro Martini
- Otolaryngology Unit, Department of Neurosciences, University of Padova, Padova, Italy
| | - Matteo Cassina
- Clinical Genetics Unit, Department of Women's and Children's Health, University of Padova, Padova, Italy,
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Zardadi S, Razmara E, Asgaritarghi G, Jafarinia E, Bitarafan F, Rayat S, Almadani N, Morovvati S, Garshasbi M. Novel homozygous variants in the TMC1 and CDH23 genes cause autosomal recessive nonsyndromic hearing loss. Mol Genet Genomic Med 2020; 8:e1550. [PMID: 33205915 PMCID: PMC7767568 DOI: 10.1002/mgg3.1550] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/28/2020] [Revised: 08/22/2020] [Accepted: 10/29/2020] [Indexed: 12/14/2022] Open
Abstract
Background Hereditary hearing loss (HL) is a heterogeneous and most common sensory neural disorder. At least, 76 genes have been reported in association with autosomal recessive nonsyndromic HL (ARNSHL). Herein, we subjected two patients with bilateral sensorineural HL in two distinct consanguineous Iranian families to figure out the underlying genetic factors. Methods Physical and sensorineural examinations were performed on the patients. Imaging also was applied to unveil any abnormalities in anatomical structures of the middle and inner ear. In order to decipher the possible genetic causes of the verified GJB2‐negative samples, the probands were subjected to whole‐exome sequencing and, subsequently, Sanger sequencing was applied for variant confirmation. Results Clinical examinations showed ARNSHL in the patients. After doing whole exome sequencing, two novel variants were identified that were co‐segregating with HL that were absent in 100 ethnically matched controls. In the first family, a novel homozygous variant, NM_138691.2: c.530T>C; p.(lle177Thr), in TMC1 gene co‐segregated with prelingual ARNSHL. In the second family, NM_022124.6: c.2334G>A; p.(Trp778*) was reported as a nonsense variant causing prelingual ARNSHL. Conclusion These findings can, in turn, endorse how TMC1 and CDH23 screening is critical to detecting HL in Iranian patients. Identifying TMC1 and CDH23 pathogenic variants doubtlessly help in the detailed genotypic characterization of HL.
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Affiliation(s)
- Safoura Zardadi
- Department of Biology, School of Basic Sciences, Science and Research Branch, Islamic Azad University, Tehran, Iran
| | - Ehsan Razmara
- Department of Medical Genetics, Faculty of Medical Sciences, Tarbiat Modares University, Tehran, Iran
| | - Golareh Asgaritarghi
- Department of Genetics, Faculty of Biological Sciences, Tarbiat Modares University, Tehran, Iran
| | - Ehsan Jafarinia
- Department of Medical Genetics, Faculty of Medical Sciences, Tarbiat Modares University, Tehran, Iran
| | - Fatemeh Bitarafan
- Department of Cellular and Molecular Biology, North Tehran Branch, Islamic Azad University, Tehran, Iran
| | - Sima Rayat
- Department of Biology, School of Basic Sciences, Science and Research Branch, Islamic Azad University, Tehran, Iran
| | - Navid Almadani
- Department of Genetics, Reproductive Biomedicine Research Center, Royan Institute for Reproductive Biomedicine, ACECR, Tehran, Iran
| | - Saeid Morovvati
- Department of Genetics, Faculty of Advanced Sciences and Technology, Tehran Medical Sciences, Islamic Azad University, Tehran, Iran
| | - Masoud Garshasbi
- Department of Medical Genetics, Faculty of Medical Sciences, Tarbiat Modares University, Tehran, Iran
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12
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Askew C, Chien WW. Adeno-associated virus gene replacement for recessive inner ear dysfunction: Progress and challenges. Hear Res 2020; 394:107947. [PMID: 32247629 DOI: 10.1016/j.heares.2020.107947] [Citation(s) in RCA: 16] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/01/2019] [Revised: 03/02/2020] [Accepted: 03/04/2020] [Indexed: 01/08/2023]
Abstract
Approximately 3 in 1000 children in the US under 4 years of age are affected by hearing loss. Currently, cochlear implants represent the only line of treatment for patients with severe to profound hearing loss, and there are no targeted drug or biological based therapies available. Gene replacement is a promising therapeutic approach for hereditary hearing loss, where viral vectors are used to deliver functional cDNA to "replace" defective genes in dysfunctional cells in the inner ear. Proof-of-concept studies have successfully used this approach to improve auditory function in mouse models of hereditary hearing loss, and human clinical trials are on the immediate horizon. The success of this method is ultimately determined by the underlying biology of the defective gene and design of the treatment strategy, relying on intervention before degeneration of the sensory structures occurs. A challenge will be the delivery of a corrective gene to the proper target within the therapeutic window of opportunity, which may be unique for each specific defective gene. Although rescue of pre-lingual forms of recessive deafness have been explored in animal models thus far, future identification of genes with post-lingual onset that are amenable to gene replacement holds even greater promise for treatment, since the therapeutic window is likely open for a much longer period of time. This review summarizes the current state of adeno-associated virus (AAV) gene replacement therapy for recessive hereditary hearing loss and discusses potential challenges and opportunities for translating inner ear gene replacement therapy for patients with hereditary hearing loss.
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Affiliation(s)
- Charles Askew
- Gene Therapy Center, University of North Carolina at Chapel Hill, Chapel Hill, NC, USA
| | - Wade W Chien
- Inner Ear Gene Therapy Program, National Institute on Deafness and Other Communication Disorders (NIDCD), National Institutes of Health, Bethesda, MD, USA; Department of Otolaryngology-Head and Neck Surgery, Johns Hopkins School of Medicine, Baltimore, MD, USA.
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13
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Ramzan K, Al-Owain M, Al-Numair NS, Afzal S, Al-Ageel S, Al-Amer S, Al-Baik L, Al-Otaibi GF, Hashem A, Al-Mashharawi E, Basit S, Al-Mazroea AH, Softah A, Sogaty S, Imtiaz F. Identification of TMC1 as a relatively common cause for nonsyndromic hearing loss in the Saudi population. Am J Med Genet B Neuropsychiatr Genet 2020; 183:172-180. [PMID: 31854501 DOI: 10.1002/ajmg.b.32774] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/01/2019] [Revised: 11/06/2019] [Accepted: 12/02/2019] [Indexed: 11/11/2022]
Abstract
Hearing loss (HL) is the most common sensory disorder worldwide and genetic factors contribute to approximately half of congenital HL cases. HL is subject to extensive genetic heterogeneity, rendering molecular diagnosis difficult. Mutations of the transmembrane channel-like 1 (TMC1) gene cause hearing defects in humans and mice. The precise function of TMC1 protein in the inner ear is unknown, although it is predicted to be involved in functional maturation of cochlear hair cells. TMC1 mutations result in autosomal recessive (DFNB7/11) and sometimes dominant (DFNA36) nonsyndromic HL. Mutations in TMC1 are responsible for a significant portion of HL, particularly in consanguineous populations. To evaluate the importance of TMC1 mutations in the Saudi population, we used a combination of autozygome-guided candidate gene mutation analysis and targeted next generation sequencing in 366 families with HL previously shown to lack mutations in GJB2. We identified 12 families that carried five causative TMC1 mutations; including three novel (c.362+3A > G; c.758C > T [p.Ser253Phe]; c.1396_1398delACC [p.Asn466del]) and two reported mutations (c.100C > T [p.Arg34Ter]; c.1714G > A [p.Asp572Asn]). Each of the identified recessive mutation was classified as severe, by both age of onset and severity of HL. Similarly, consistent with the previously reported dominant variant p.Asp572Asn, the HL phenotype was progressive. Eight families in our cohort were found to share the pathogenic p.Arg34Ter mutation and linkage disequilibrium was observed between p.Arg34Ter and SNPs investigated. Our results indicate that TMC1 mutations account for about 3.3% (12/366) of Saudi HL cases and that the recurrent TMC1 mutation p.Arg34Ter is likely to be a founder mutation.
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Affiliation(s)
- Khushnooda Ramzan
- Department of Genetics, King Faisal Specialist Hospital and Research Centre, Riyadh, Saudi Arabia
| | - Mohammed Al-Owain
- Department of Medical Genetics, King Faisal Specialist Hospital and Research Centre, Riyadh, Saudi Arabia
| | - Nouf S Al-Numair
- Department of Genetics, King Faisal Specialist Hospital and Research Centre, Riyadh, Saudi Arabia
| | - Sibtain Afzal
- College of Medicine, King Saud University, Riyadh, Saudi Arabia
| | - Sarah Al-Ageel
- Department of Otolaryngology Head and Neck Surgery, King Faisal Specialist Hospital and Research Centre, Riyadh, Saudi Arabia
| | - Sultan Al-Amer
- Department of Genetics, King Faisal Specialist Hospital and Research Centre, Riyadh, Saudi Arabia
| | - Lina Al-Baik
- Department of Genetics, King Faisal Specialist Hospital and Research Centre, Riyadh, Saudi Arabia
| | - Ghoson F Al-Otaibi
- Department of Genetics, King Faisal Specialist Hospital and Research Centre, Riyadh, Saudi Arabia
| | - Amal Hashem
- Department of Pediatrics, Prince Sultan Military Medical City, Riyadh, Saudi Arabia
| | - Eman Al-Mashharawi
- Department of Otolaryngology, Prince Sultan Military Medical City, Riyadh, Saudi Arabia
| | - Sulman Basit
- Center for Genetics and Inherited Diseases, Taibah University, Al-Madinah, Saudi Arabia
| | - Abdal H Al-Mazroea
- Pediatrics Department, College of Medicine, Taibah University, Al-Madinah, Saudi Arabia
| | - Ameen Softah
- King Fahad Armed Forces Hospital, Jeddah, Saudi Arabia
| | - Sameera Sogaty
- Medical Genetics Unit, King Fahad Hospital, Jeddah, Saudi Arabia
| | - Faiqa Imtiaz
- Department of Genetics, King Faisal Specialist Hospital and Research Centre, Riyadh, Saudi Arabia
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14
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Yao Q, Wang L, Mittal R, Yan D, Richmond MT, Denyer S, Requena T, Liu K, Varshney GK, Lu Z, Liu XZ. Transcriptomic Analyses of Inner Ear Sensory Epithelia in Zebrafish. Anat Rec (Hoboken) 2019; 303:527-543. [PMID: 31883312 DOI: 10.1002/ar.24331] [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] [Received: 12/07/2018] [Revised: 08/01/2019] [Accepted: 11/18/2019] [Indexed: 12/25/2022]
Abstract
Analysis of gene expression has the potential to assist in the understanding of multiple cellular processes including proliferation, cell-fate specification, senesence, and activity in both healthy and disease states. Zebrafish model has been increasingly used to understand the process of hearing and the development of the vertebrate auditory system. Within the zebrafish inner ear, there are three otolith organs, each containing a sensory macula of hair cells. The saccular macula is primarily involved in hearing, the utricular macula is primarily involved in balance and the function of the lagenar macula is not completely understood. The goal of this study is to understand the transcriptional differences in the sensory macula associated with different otolith organs with the intention of understanding the genetic mechanisms responsible for the distinct role each organ plays in sensory perception. The sensory maculae of the saccule, utricle, and lagena were dissected out of adult Et(krt4:GFP)sqet4 zebrafish expressing green fluorescent protein in hair cells for transcriptional analysis. The total RNAs of the maculae were isolated and analyzed by RNA GeneChip microarray. Several of the differentially expressed genes are known to be involved in deafness, otolith development and balance. Gene expression among these otolith organs was very well conserved with less than 10% of genes showing differential expression. Data from this study will help to elucidate which genes are involved in hearing and balance. Furthermore, the findings of this study will assist in the development of the zebrafish model for human hearing and balance disorders. Anat Rec, 303:527-543, 2020. © 2019 American Association for Anatomy.
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Affiliation(s)
- Qi Yao
- Department of Otolaryngology, Miller School of Medicine, University of Miami, Miami, Florida.,Department of Biology, University of Miami, Miami, Florida
| | - Lingyu Wang
- Department of Biology, University of Miami, Miami, Florida
| | - Rahul Mittal
- Department of Otolaryngology, Miller School of Medicine, University of Miami, Miami, Florida
| | - Denise Yan
- Department of Otolaryngology, Miller School of Medicine, University of Miami, Miami, Florida
| | | | - Steven Denyer
- Department of Biology, University of Miami, Miami, Florida
| | - Teresa Requena
- Genes & Human Disease Research Program, Oklahoma Medical Research Foundation, Oklahoma City, Oklahoma
| | - Kaili Liu
- Genes & Human Disease Research Program, Oklahoma Medical Research Foundation, Oklahoma City, Oklahoma
| | - Gaurav K Varshney
- Genes & Human Disease Research Program, Oklahoma Medical Research Foundation, Oklahoma City, Oklahoma
| | - Zhongmin Lu
- Department of Biology, University of Miami, Miami, Florida
| | - Xue Zhong Liu
- Department of Otolaryngology, Miller School of Medicine, University of Miami, Miami, Florida.,Department of Otolaryngology, Xiangya Hospital, Central South University, Changsha, Hunan, China
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15
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Yue X, Sheng Y, Kang L, Xiao R. Distinct functions of TMC channels: a comparative overview. Cell Mol Life Sci 2019; 76:4221-4232. [PMID: 31584127 PMCID: PMC11105308 DOI: 10.1007/s00018-019-03214-1] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/14/2019] [Revised: 06/25/2019] [Accepted: 06/28/2019] [Indexed: 12/18/2022]
Abstract
In the past two decades, transmembrane channel-like (TMC) proteins have attracted a significant amount of research interest, because mutations of Tmc1 lead to hereditary deafness. As evolutionarily conserved membrane proteins, TMC proteins are widely involved in diverse sensorimotor functions of many species, such as hearing, chemosensation, egg laying, and food texture detection. Interestingly, recent structural and physiological studies suggest that TMC channels may share a similar membrane topology with the Ca2+-activated Cl- channel TMEM16 and the mechanically activated OSCA1.2/TMEM63 channel. Namely, these channels form dimers and each subunit consists of ten transmembrane segments. Despite this important structural insight, a key question remains: what is the gating mechanism of TMC channels? The major technical hurdle to answer this question is that the reconstitution of TMC proteins as functional ion channels has been challenging in mammalian heterologous systems. Since TMC channels are conserved across taxa, genetic studies of TMC channels in model organisms such as C. elegans, Drosophila, and zebrafish may provide us critical information on the physiological function and regulation of TMCs. Here, we present a comparative overview on the diverse functions of TMC channels in different species.
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Affiliation(s)
- Xiaomin Yue
- Department of Neurosurgery of the First Affiliated Hospital, Institute of Neuroscience, NHC and CAMS Key Laboratory of Medical Neurobiology, Zhejiang University School of Medicine, Hangzhou, China
| | - Yi Sheng
- Department of Aging and Geriatric Research, Institute on Aging, University of Florida, Gainesville, FL, USA
| | - Lijun Kang
- Department of Neurosurgery of the First Affiliated Hospital, Institute of Neuroscience, NHC and CAMS Key Laboratory of Medical Neurobiology, Zhejiang University School of Medicine, Hangzhou, China.
| | - Rui Xiao
- Department of Aging and Geriatric Research, Institute on Aging, University of Florida, Gainesville, FL, USA.
- Department of Pharmacology and Therapeutics, College of Medicine, University of Florida, Gainesville, FL, USA.
- Center for Smell and Taste, University of Florida, Gainesville, FL, USA.
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16
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Sadeghian L, Tabatabaiefar MA, Fattahi N, Pourreza MR, Tahmasebi P, Alavi Z, Hashemzadeh Chaleshtori M. Next-generation sequencing reveals a novel pathological mutation in the TMC1 gene causing autosomal recessive non-syndromic hearing loss in an Iranian kindred. Int J Pediatr Otorhinolaryngol 2019; 124:99-105. [PMID: 31176026 DOI: 10.1016/j.ijporl.2019.05.023] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/14/2018] [Revised: 05/18/2019] [Accepted: 05/19/2019] [Indexed: 01/08/2023]
Abstract
OBJECTIVES Hearing loss (HL) is the most common sensory-neural disorder with excessive clinical and genetic heterogeneity, which negatively affects life quality. Autosomal recessive non-syndromic hearing loss (ARNSHL) is the most common form of the disease with no specific genotype-phenotype correlation in most of the cases. Whole exome sequencing (WES) is a powerful tool to overcome the problem of finding mutations in heterogeneous disorders. METHODS A comprehensive clinical and pedigree examination was performed on a multiplex family from Khuzestan province suffering from hereditary HL. Direct sequencing of GJB2 and genetic linkage analysis of DFNB1A/B was accomplished. WES was utilized to find possible genetic etiology of the disease. Co-segregation analysis of the candidate variant was done. High resolution melting analysis was applied to detect variant status in 50 healthy matched controls. RESULTS Clinical investigations suggested ARNSHL in the pedigree. The family was negative for DFNB1A/B. WES revealed a novel nonsense mutation, c.256G > T (p.Glu86*), in TMC1 segregating with the phenotype in the pedigree. The variant was absent in the controls. CONCLUSION Here, we report successful application of WES to identify the molecular pathogenesis of ARNSHL in a large family. The novel nonsense TMC1 variant meets the criteria of being pathogenic according to the ACMG-AMP variant interpretation guideline.
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Affiliation(s)
- Ladan Sadeghian
- Cellular and Molecular Research Center, Basic Health Sciences Institute, Shahrekord University of Medical Sciences, Shahrekord, Iran
| | - Mohammad Amin Tabatabaiefar
- Department of Genetics and Molecular Biology, School of Medicine, Isfahan University of Medical Sciences, Isfahan, Iran; Pediatric Inherited Diseases Research Center, Research Institute for Primordial Prevention of Non-communicable Disease, Isfahan University of Medical Sciences, Isfahan, Iran
| | - Najmeh Fattahi
- Cilinical Biochemistry Research Center, Basic Health Sciences Institute, Shahrekord University of Medical Sciences, Shahrekord, Iran
| | - Mohammad Reza Pourreza
- Department of Genetics and Molecular Biology, School of Medicine, Isfahan University of Medical Sciences, Isfahan, Iran
| | - Parisa Tahmasebi
- Department of Biology, Faculty of Sciences, Ilam University, Ilam, Iran
| | - Zahra Alavi
- Department of Genetics, Islamic Azad University, Shahrekord Branch, Shahrekord, Iran
| | - Morteza Hashemzadeh Chaleshtori
- Cellular and Molecular Research Center, Basic Health Sciences Institute, Shahrekord University of Medical Sciences, Shahrekord, Iran.
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17
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Liang S, Yang J, Wu H, Teng X, Duan T. Effects of chromosome 9 inversion on IVF/ICSI: A 7-year retrospective cohort study. Mol Genet Genomic Med 2019; 7:e856. [PMID: 31353845 PMCID: PMC6732300 DOI: 10.1002/mgg3.856] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/18/2019] [Revised: 06/20/2019] [Accepted: 07/01/2019] [Indexed: 11/16/2022] Open
Abstract
Background This study focused on the outcomes of patients with pericentric inversion of chromosome 9 who underwent IVF/ICSI and fresh day 2 or day 3 embryo transfer and the possible impacts of carrier gender and chromosome karyotype on pregnancy outcomes. Methods A total of 214 couples (107 couples with one pericentric inversion of chromosome 9 in one partner [Group 1], 107 couples with normal karyotypes [Group 2]) underwent their first IVF/ICSI treatment and were included in this study. Oocyte number, normal fertilization rates, abnormal fertilization rates, cleavage rates, embryo utilization rates, fresh embryo transfer rates, clinical pregnancy rates (CPR), implantation rates, miscarriage rates, and live birth rates per embryo transfer (LBR) were compared between groups. Results Group 1 did not show any disadvantage when compared with Group 2. The CPR and LBR were similar between all groups. The female carrier group had a higher normal fertilization rate and higher utilization rate than the male carrier group. Cases with inv(9)(p12;q13) had a lower utilization rate but a higher implantation rate than the remaining karyotypes. Conclusion In the first IVF or ICSI cycle, couples with one pericentric inversion of chromosome 9 in one partner had satisfactory outcomes. The subgroup analysis showed a tendency of better prognosis for the female carrier and inv(9)(p12;q13) type. This is a retrospective cohort study during 7 years period. In the first IVF or ICSI cycle, couples with one pericentric inversion of chromosome 9 in one partner had satisfactory outcomes. The subgroup analysis showed a tendency of better prognosis for the female carrier and inv(9)(p12;q13) type.
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Affiliation(s)
- Shanshan Liang
- Shanghai First Maternity and Infant Hospital, Tongji University School of Medicine, Shanghai, China
| | - Jianzhi Yang
- Shanghai First Maternity and Infant Hospital, Tongji University School of Medicine, Shanghai, China
| | - Haixia Wu
- Shanghai First Maternity and Infant Hospital, Tongji University School of Medicine, Shanghai, China
| | - Xiaoming Teng
- Shanghai First Maternity and Infant Hospital, Tongji University School of Medicine, Shanghai, China
| | - Tao Duan
- Shanghai First Maternity and Infant Hospital, Tongji University School of Medicine, Shanghai, China
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18
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Singh PK, Ghosh M, Sharma S, Shastri S, Gupta N, Chowdhury MR, Anand A, Kabra M. Identification of a novel homozygous mutation in transmembrane channel like 1 ( TMC1) gene, one of the second-tier hearing loss genes after GJB2 in India. Indian J Med Res 2018; 145:492-497. [PMID: 28862181 PMCID: PMC5663163 DOI: 10.4103/ijmr.ijmr_397_15] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Background & objectives: Hearing impairment is a common and heterogeneous sensory disorder in humans. Among about 90 genes, which are known to be associated with hearing impairment, mutations in the GJB2 (gap junction protein beta 2) gene are the most prevalent in individuals with hereditary hearing loss. Contribution of the other deafness-causing genes is relatively poorly understood. Here, we present our findings on two families with transmembrane channel like 1 (TMC1) gene variants of the 47 families with nonsyndromic hearing loss (NSHL) studied. Methods: Forty seven families including 26 consanguineous families with at least two hearing impaired children and one normal hearing child and 21 non-consanguineous families having at least three hearing impaired children and one normal hearing child were enrolled for this study. Genetic linkage studies were carried out in 41 families that were GJB2 (Connexin 26) negative. Seven polymorphic short tandem repeat markers at the DFNB7/11 locus were studied employing fluorescently labelled markers. Results: A novel homozygous missense mutation c.1283C>A (p.Ala428Asp) was identified co-segregating with hearing loss. This change results in substitution of a highly conserved polar alanine to a charged aspartic acid and is predicted to be deleterious. In addition, a previously reported nonsense mutation, p.R34X in TMC1, was found. Interpretation & conclusions: While mutations in TMC1 are not as common a cause of NSHL as those in GJB2, TMC1 should be considered for diagnostic investigations in cases of NSHL in GJB2-negative families.
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Affiliation(s)
- Pawan Kumar Singh
- Division of Genetics, Department of Pediatrics, All Institute of Medical Sciences, New Delhi, India
| | - Manju Ghosh
- Division of Genetics, Department of Pediatrics, All Institute of Medical Sciences, New Delhi, India
| | - Shipra Sharma
- Division of Genetics, Department of Pediatrics, All Institute of Medical Sciences, New Delhi, India
| | - Shivaram Shastri
- Division of Genetics, Department of Pediatrics, All Institute of Medical Sciences, New Delhi, India
| | - Neerja Gupta
- Division of Genetics, Department of Pediatrics, All Institute of Medical Sciences, New Delhi, India
| | - Madhumita Roy Chowdhury
- Division of Genetics, Department of Pediatrics, All Institute of Medical Sciences, New Delhi, India
| | - Anuranjan Anand
- Molecular Biology & Genetics Unit, Jawaharlal Nehru Centre for Advanced Scientific Research, Bengaluru, India
| | - Madhulika Kabra
- Division of Genetics, Department of Pediatrics, All Institute of Medical Sciences, New Delhi, India
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Wang H, Wu K, Guan J, Yang J, Xie L, Xiong F, Lan L, Wang D, Wang Q. Identification of four TMC1 variations in different Chinese families with hereditary hearing loss. Mol Genet Genomic Med 2018; 6:504-513. [PMID: 29654653 PMCID: PMC6081220 DOI: 10.1002/mgg3.394] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/10/2018] [Revised: 03/07/2018] [Accepted: 03/09/2018] [Indexed: 11/12/2022] Open
Abstract
BACKGROUND Variants in TMC1 (transmembrane channel-like 1) can cause both autosomal dominant and recessive hearing loss in human population. Mice with Tmc1 variants have been shown to be ideal animal models for gene therapy. In this article, we report four TMC1 variants in four different Chinese families and the follow-up auditory phenotype of a previously reported family. METHODS Four families with TMC1 variants, as well as a previously described family with TMC1 variant orthologous to the Beethoven mouse, were recruited in this study. A comprehensive auditory evaluation was performed on all ascertained family members. High-throughput sequencing was conducted using genomic DNA from the probands and other family members to identify probable deafness genes. RESULTS We identified four TMC1 (NM_138691.2) variations, including two pathogenic variants, c.1714G>A, and c.1253T>A, one likely pathogenic variant, c.[797T>C];[797T>C], and one single nucleotide polymorphism (SNP), c.2276G>A. Among these variants, c.[797T>C];[797T>C] is a novel likely pathogenic variant, and c.1714G>A and c.1253T>A are known pathogenic variants at the DFNB7/11 (DFNA36) locus. Phenotype-genotype correlation analysis of TMC1 variants showed that the TMC1 dominant variation-related phenotype was late-onset, progressive, high frequency to all frequency sensorineural hearing loss, while the TMC1 recessive variant was related to congenital all frequency sensorineural hearing impairment. CONCLUSIONS Two pathogenic, one likely pathogenic variants and one SNP of TMC1 were identified in four Chinese families with hereditary hearing loss, indicating that TMC1 may be a more frequent cause of hearing loss than expected. TMC1 variants related to hearing loss result in specific phenotypes. The TMC1 c.1253T>A (p.M418K) variation, homologous to the Tmc1 c. 1235 T> A (p.M412K) variant in Beethoven mice, was the second report of this variant in human patients with hearing loss, suggesting the possibility to translational gene therapy from Beethoven mice to human patients.
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Affiliation(s)
- Hongyang Wang
- Institute of OtolaryngologyChinese PLA General HospitalMedical School of Chinese PLABeijingChina
| | - Kaiwen Wu
- Institute of OtolaryngologyChinese PLA General HospitalMedical School of Chinese PLABeijingChina
| | - Jing Guan
- Institute of OtolaryngologyChinese PLA General HospitalMedical School of Chinese PLABeijingChina
| | - Ju Yang
- Institute of OtolaryngologyChinese PLA General HospitalMedical School of Chinese PLABeijingChina
| | - Linyi Xie
- Institute of OtolaryngologyChinese PLA General HospitalMedical School of Chinese PLABeijingChina
| | - Fen Xiong
- Institute of OtolaryngologyChinese PLA General HospitalMedical School of Chinese PLABeijingChina
| | - Lan Lan
- Institute of OtolaryngologyChinese PLA General HospitalMedical School of Chinese PLABeijingChina
| | - Dayong Wang
- Institute of OtolaryngologyChinese PLA General HospitalMedical School of Chinese PLABeijingChina
| | - Qiuju Wang
- Institute of OtolaryngologyChinese PLA General HospitalMedical School of Chinese PLABeijingChina
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20
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Ahmed H, Shubina-Oleinik O, Holt JR. Emerging Gene Therapies for Genetic Hearing Loss. J Assoc Res Otolaryngol 2017; 18:649-670. [PMID: 28815315 PMCID: PMC5612923 DOI: 10.1007/s10162-017-0634-8] [Citation(s) in RCA: 78] [Impact Index Per Article: 11.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/10/2017] [Accepted: 07/04/2017] [Indexed: 12/31/2022] Open
Abstract
Gene therapy, or the treatment of human disease using genetic material, for inner ear dysfunction is coming of age. Recent progress in developing gene therapy treatments for genetic hearing loss has demonstrated tantalizing proof-of-principle in animal models. While successful translation of this progress into treatments for humans awaits, there is growing interest from patients, scientists, clinicians, and industry. Nonetheless, it is clear that a number of hurdles remain, and expectations for total restoration of auditory function should remain tempered until these challenges have been overcome. Here, we review progress, prospects, and challenges for gene therapy in the inner ear. We focus on technical aspects, including routes of gene delivery to the inner ear, choice of vectors, promoters, inner ear targets, therapeutic strategies, preliminary success stories, and points to consider for translating of these successes to the clinic.
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Affiliation(s)
- Hena Ahmed
- Departments of Otolaryngology and Neurology, F.M. Kirby Neurobiology Center Boston Children's Hospital and Harvard Medical School, Boston, MA, USA
| | - Olga Shubina-Oleinik
- Departments of Otolaryngology and Neurology, F.M. Kirby Neurobiology Center Boston Children's Hospital and Harvard Medical School, Boston, MA, USA
| | - Jeffrey R Holt
- Departments of Otolaryngology and Neurology, F.M. Kirby Neurobiology Center Boston Children's Hospital and Harvard Medical School, Boston, MA, USA.
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21
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Ghasemnejad T, Shekari Khaniani M, Zarei F, Farbodnia M, Mansoori Derakhshan S. An update of common autosomal recessive non-syndromic hearing loss genes in Iranian population. Int J Pediatr Otorhinolaryngol 2017; 97:113-126. [PMID: 28483220 DOI: 10.1016/j.ijporl.2017.04.007] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/03/2016] [Revised: 04/03/2017] [Accepted: 04/04/2017] [Indexed: 11/16/2022]
Abstract
Autosomal-recessive genes are responsible for about 80% of the hereditary non-syndromic hearing loss (NSHL) cases. In Iran, due to consanguineous marriages, NSHL is the second most frequent disability after intellectual disability, occurring one in 16 individuals. Enormous heterogeneity in the genetic pathology of hearing loss causes a major challenge in identification of responsible genes. In Iran, GJB2 is responsible for the most cases of pre-lingual and non-syndromic hearing loss (with frequency of 16.7%) which followed by other genes with lower frequency. Although several studies have indicated that a large proportion of both syndromic and non-syndromic hearing loss in Iranian populations are caused by defects in just a few genes, new detection strategies such as NGS (Next-generation sequencing) have increased the spectrum of responsible mutations. However, by applying this technique in Iran patients screening, the role of lots of novel related genes have been reported. In this review, we aim to describe function of these genes and their contribution to non-syndromic genetic hearing loss in Iranian population and we classify the genes by their functions.
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Affiliation(s)
- Tohid Ghasemnejad
- Neurosciences Research Center, Tabriz University of Medical Sciences, Tabriz, Iran; Department of Medical Genetic, Faculty of Medicine, Tabriz University of Medical Sciences, Tabriz, Iran
| | | | - Fatemeh Zarei
- Department of Stem Cells and Developmental Biology at Cell Science Research Center, Royan Institute for Stem Cell Biology and Technology, ACECR, Tehran, Iran
| | - Mina Farbodnia
- Department of Cellular and Molecular Biology, Faculty of Sciences, Saba University, Urmia, Iran
| | - Sima Mansoori Derakhshan
- Neurosciences Research Center, Tabriz University of Medical Sciences, Tabriz, Iran; Department of Medical Genetic, Faculty of Medicine, Tabriz University of Medical Sciences, Tabriz, Iran.
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Wang HY, Zhao YL, Liu Q, Yuan H, Gao Y, Lan L, Yu L, Wang DY, Guan J, Wang QJ. Identification of Two Disease-causing Genes TJP2 and GJB2 in a Chinese Family with Unconditional Autosomal Dominant Nonsyndromic Hereditary Hearing Impairment. Chin Med J (Engl) 2016; 128:3345-51. [PMID: 26668150 PMCID: PMC4797511 DOI: 10.4103/0366-6999.171440] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022] Open
Abstract
Background: There are more than 300 genetic loci that have been found to be related to hereditary hearing impairment (HHI), including 92 causative genes for nonsyndromic hearing loss, among which 34 genes are related to autosomal dominant nonsyndromic HHI (ADNSHHI). Traditional linkage analysis and candidate gene sequencing are not effective at detecting the ADNSHHI, especially for the unconditional families that may have more than one pathogenic cause. This study identified two disease-causing genes TJP2 and GJB2 in a Chinese family with unconditional ADNSHHI. Methods: To decipher the genetic code of a Chinese family (family 686) with ADNSHHI, different gene screening techniques have been performed, including linkage analysis, candidate genes screening, high-throughput sequencing and Sanger sequencing. These techniques were done on samples obtained from this family over a period of 10 years. Results: We identified a pathogenic missense mutation, c. 2081G>A (p.G694E), in TJP2, a gene that plays a crucial role in apoptosis and age-related hearing loss (ARHL). The mutation was co-segregated in this pedigree in all, but not in the two patients who presented with different phenotypes from the other affected family members. In one of the two patients, we confirmed that the compound heterozygosity for p. Y136* and p.G45E in the GJB2 gene may account for the phenotype shown in this patient. Conclusions: We identified the co-occurrence of two genetic causes in family 686. The possible disease-causing missense mutation of TJP2 in family 686 presents an opportunity for further investigation into ARHL. It is necessary to combine various genes screening methods, especially for some unconventional cases.
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Affiliation(s)
| | | | | | | | | | | | | | | | | | - Qiu-Ju Wang
- Department of Otolaryngology-Head and Neck, Chinese People's Liberation Army Institute of Otolaryngology, Chinese People's Liberation Army General Hospital, Beijing 100853, China
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Xue G, Sha-Sha H, Yu S, Jin-Cao X, Pu D. Identification of Novel TMC1 Compound Heterozygous Mutations Related to Autosomal Recessive Hearing Loss by Targeted Capture Sequencing. ACTA ACUST UNITED AC 2016. [DOI: 10.17352/sjggt.000009] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
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24
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Moradipour N, Ghasemi-Dehkordi P, Heibati F, Parchami-Barjui S, Abolhasani M, Rashki A, Hashemzadeh-Chaleshtori M. Mutation Screening of Exons 7 and 13 of the TMC1 Gene in Autosomal Recessive Non-syndromic Hearing Loss (ARNSHL) in Iran. IRANIAN RED CRESCENT MEDICAL JOURNAL 2016; 18:e22076. [PMID: 27247785 PMCID: PMC4884626 DOI: 10.5812/ircmj.22076] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 07/15/2014] [Revised: 11/14/2014] [Accepted: 04/19/2015] [Indexed: 11/29/2022]
Abstract
Background: Non-syndromic hearing loss (NSHL) is the most common birth defect and occurs in approximately 1/1,000 newborns. NSHL is a heterogeneous trait and can arise due to both genetic and environmental factors. Mutations of the transmembrane channel-like 1 (TMC1) gene cause non-syndromic deafness in humans and mice. Objectives: The aim of the present study was to investigate the association of TMC1 gene mutations of the locus DFNB7/11 in exons 7 and 13 in a cohort of 100 patients with hearing loss in Iran using polymerase chain reaction–single-stranded conformation polymorphism (PCR-SSCP), heteroduplex analysis (HA), and DNA sequencing. Patients and Methods: In this experimental study, the blood samples of 100 NSHL patients were collected from 10 provinces in Iran. These patients had a mean age of 16.5 ± 2.01 years and 74.15% of their parents had consanguinity. DNA was extracted from specimens and mutations of exons 7 and 13 of the TMC1 gene were investigated using PCR-SSCP. All samples were checked via HA reaction and suspected specimens with shift bands were subjected to DNA sequencing for investigation of any gene variation. Results: In this study, no mutation was found in the two exons of TMC1 gene. It was concluded from these results that mutations of the TMC1 gene’s special exons 7 and 13 have a low contribution in patients and are not great of clinical importance in these Iranian provinces. Conclusions: More studies are needed to investigate the relationship between other parts of this gene with hearing loss in different populations through the country. More research could clarify the role of this gene and its relation with deafness and provide essential information for the prevention and management of auditory disorders caused by genetic factors in the Iranian population.
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Affiliation(s)
- Negar Moradipour
- Cellular and Molecular Research Center, Shahrekord University of Medical Sciences, Shahrekord, IR Iran
| | - Payam Ghasemi-Dehkordi
- Cellular and Molecular Research Center, Shahrekord University of Medical Sciences, Shahrekord, IR Iran
| | - Fatemeh Heibati
- Clinical Biochemistry Research Center, Shahrekord University of Medical Sciences, Sharekord, IR Iran
| | | | - Marziyeh Abolhasani
- Cellular and Molecular Research Center, Shahrekord University of Medical Sciences, Shahrekord, IR Iran
| | - Ahmad Rashki
- Department of Physiopathology, Faculty of Veterinary Medicine, Zabol University, Zabol, IR Iran
| | - Morteza Hashemzadeh-Chaleshtori
- Cellular and Molecular Research Center, Shahrekord University of Medical Sciences, Shahrekord, IR Iran
- Corresponding Author: Morteza Hashemzadeh-Chaleshtori, Cellular and Molecular Research Center, Shahrekord University of Medical Sciences, P. O. Box: 8813833435, Shahrekord, IR Iran. Tel: +98-3833346692, Fax: +98-3833330709, E-mail:
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25
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Imtiaz A, Maqsood A, Rehman AU, Morell RJ, Holt JR, Friedman TB, Naz S. Recessive mutations of TMC1 associated with moderate to severe hearing loss. Neurogenetics 2016; 17:115-123. [PMID: 26879195 PMCID: PMC4795972 DOI: 10.1007/s10048-016-0477-1] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/18/2016] [Accepted: 02/09/2016] [Indexed: 12/12/2022]
Abstract
TMC1 encodes a protein required for the normal function of mechanically activated channels that enable sensory transduction in auditory and vestibular hair cells. TMC1 protein is localized at the tips of the hair cell stereocilia, the site of conventional mechanotransduction. In many populations, loss-of-function recessive mutations of TMC1 are associated with profound deafness across all frequencies tested. In six families reported here, variable moderate-to-severe or moderate-to-profound hearing loss co-segregated with STR (short tandem repeats) markers at the TMC1 locus DFNB7/11. Massively parallel and Sanger sequencing of genomic DNA revealed each family co-segregating hearing loss with a homozygous TMC1 mutation: two reported mutations (p.R34X and p.R389Q) and three novel mutations (p.S596R, p.N199I, and c.1404 + 1G > T). TMC1 cDNA sequence from affected subjects homozygous for the donor splice site transversion c.1404 + 1G > T revealed skipping of exon 16, deleting 60 amino acids from the TMC1 protein. Since the mutations in our study cause less than profound hearing loss, we speculate that there is hypo-functional TMC1 mechanotransduction channel activity and that other even less damaging variants of TMC1 may be associated with more common mild-to-severe sensorineural hearing loss.
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Affiliation(s)
- Ayesha Imtiaz
- School of Biological Sciences, University of the Punjab, Quaid-i-Azam Campus, Lahore 54590, Pakistan
- National Institute on Deafness and Other Communication Disorders, National Institutes of Health, USA 20892
| | - Azra Maqsood
- School of Biological Sciences, University of the Punjab, Quaid-i-Azam Campus, Lahore 54590, Pakistan
| | - Atteeq U. Rehman
- National Institute on Deafness and Other Communication Disorders, National Institutes of Health, USA 20892
| | - Robert J. Morell
- National Institute on Deafness and Other Communication Disorders, National Institutes of Health, USA 20892
| | - Jeffrey R. Holt
- Department of Otolaryngology, F. M. Kirby Neurobiology Center, Boston Children’s Hospital, Harvard Medical School, Boston, MA 02114, USA
| | - Thomas B. Friedman
- National Institute on Deafness and Other Communication Disorders, National Institutes of Health, USA 20892
| | - Sadaf Naz
- School of Biological Sciences, University of the Punjab, Quaid-i-Azam Campus, Lahore 54590, Pakistan
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26
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A novel mutation in the TMC1 gene causes non-syndromic hearing loss in a Moroccan family. Gene 2015; 574:28-33. [PMID: 26226225 DOI: 10.1016/j.gene.2015.07.075] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/12/2015] [Revised: 06/29/2015] [Accepted: 07/22/2015] [Indexed: 01/28/2023]
Abstract
Autosomal recessive non-syndromic hearing loss (ARNSHL) is one of the most common genetic diseases in human and is subject to important genetic heterogeneity, rendering molecular diagnosis difficult. Whole-exome sequencing is thus a powerful strategy for this purpose. After excluding GJB2 mutation and other common mutations associated with hearing loss in Morocco, whole-exome sequencing was performed to study the genetic causes of one sibling with ARSHNL in a consanguineous Moroccan family. After filtering data and Sanger sequencing validation, one novel pathogenic homozygous mutation c.1810C>G (p.Arg604Gly) was identified in TMC1, a gene reported to cause deafness in various populations. Thus, we identified here the first mutation in the TMC1 gene in the Moroccan population causing non-syndromic hearing loss.
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Gao X, Huang SS, Yuan YY, Wang GJ, Xu JC, Ji YB, Han MY, Yu F, Kang DY, Lin X, Dai P. Targeted gene capture and massively parallel sequencing identify TMC1 as the causative gene in a six-generation Chinese family with autosomal dominant hearing loss. Am J Med Genet A 2015; 167A:2357-65. [PMID: 26079994 DOI: 10.1002/ajmg.a.37206] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/11/2014] [Accepted: 05/25/2015] [Indexed: 12/26/2022]
Abstract
Hereditary nonsyndromic hearing loss is extremely heterogeneous. Mutations in the transmembrane channel-like gene1 (TMC1) are known to cause autosomal dominant and recessive forms of nonsyndromic hearing loss linked to the loci of DFNA36 and DFNB7/11, respectively. We characterized a six-generation Chinese family (5315) with progressive, postlingual autosomal dominant nonsyndromic hearing loss (ADNSHL). By combining targeted capture of 82 known deafness genes, next-generation sequencing and bioinformatic analysis, we identified TMC1 c.1714G>A (p. D572N) as the disease-causing mutation. This mutation co-segregated with hearing loss in other family members and was not detected in 308 normal controls. In order to determine the prevalence of TMC1 c.1714G>A in Chinese ADNSHL families, we used DNA samples from 67 ADNSHL families with sloping audiogram and identified two families carry this mutation. To determine whether it arose from a common ancestor, we analyzed nine STR markers. Our results indicated that TMC1 c.1714G>A (p.D572N) account for about 4.4% (3/68) of ADNSHL in the Chinese population.
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Affiliation(s)
- Xue Gao
- Department of Otorhinolaryngology, Head and Neck Surgery, PLA General Hospital, Beijing, P. R. China.,Department of Otolaryngology, Hainan Branch of PLA General Hospital, Sanya, P. R. China.,Department of Otorhinolaryngology, Second Artillery General Hospital, Beijing, P. R. China
| | - Sha-Sha Huang
- Department of Otorhinolaryngology, Head and Neck Surgery, PLA General Hospital, Beijing, P. R. China
| | - Yong-Yi Yuan
- Department of Otorhinolaryngology, Head and Neck Surgery, PLA General Hospital, Beijing, P. R. China
| | - Guo-Jian Wang
- Department of Otorhinolaryngology, Head and Neck Surgery, PLA General Hospital, Beijing, P. R. China.,Department of Otolaryngology, Hainan Branch of PLA General Hospital, Sanya, P. R. China
| | - Jin-Cao Xu
- Department of Otorhinolaryngology, Second Artillery General Hospital, Beijing, P. R. China
| | - Yu-Bin Ji
- Department of Otorhinolaryngology, Second Artillery General Hospital, Beijing, P. R. China
| | - Ming-Yu Han
- Department of Otorhinolaryngology, Head and Neck Surgery, PLA General Hospital, Beijing, P. R. China.,Department of Otolaryngology, Hainan Branch of PLA General Hospital, Sanya, P. R. China
| | - Fei Yu
- Department of Otorhinolaryngology, Head and Neck Surgery, PLA General Hospital, Beijing, P. R. China
| | - Dong-Yang Kang
- Department of Otorhinolaryngology, Head and Neck Surgery, PLA General Hospital, Beijing, P. R. China
| | - Xi Lin
- Department of Otolaryngology, Emory University School of Medicine, Atlanta, GA
| | - Pu Dai
- Department of Otorhinolaryngology, Head and Neck Surgery, PLA General Hospital, Beijing, P. R. China.,Department of Otolaryngology, Hainan Branch of PLA General Hospital, Sanya, P. R. China
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28
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Zhou YC, Zhang C, Zhai JS, Li TF, Wu QY, Li WW, Li N, Li XJ, Huang YF, Cui YX, Xia XY. A patient with unusual features and a 69.5 Mb duplication from a de novo extra der (9): a case report. Mol Med Rep 2015; 12:155-8. [PMID: 25760145 PMCID: PMC4438924 DOI: 10.3892/mmr.2015.3436] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/29/2014] [Accepted: 02/11/2015] [Indexed: 11/30/2022] Open
Abstract
Partial trisomy 9 is a common autosomal trisomy, which is characterized by non-specific psychomotor delay, mental retardation and moderately abnormal characteristic facial features. Generally, partial trisomy 9 leads to variable phenotypes depending on the size and position of the duplicated region. However, a precise genotype/phenotype map has not been determined. The present study reports the case of a 3-year-old female with certain typical features of trisomy 9p syndrome, who presented with a number of the distinctive symptoms, as well as sensorineural hearing loss, which has not previously been associated with this trisomy. Karyotype, M-FISH and OaCGH analysis were performed on the patient and her parents. The final karyotype was determined to be 47, XX, +mar.ish der (9) (wcp9+). arr cgh 9pterq21.12 (DOCK8→LOC138225)×3. Cytogenetic results showed a de novo extra der (9) with 69.5 Mb duplication. Although the molecular mechanism underlying the hearing loss is unclear, it was proposed that the 9q13→9q21 region may be critical for hearing.
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Affiliation(s)
- Yu-Chun Zhou
- Institute of Laboratory Medicine, Jinling Hospital, Nanjing University School of Medicine, Nanjing 210002, P.R. China
| | - Cui Zhang
- Institute of Laboratory Medicine, Jinling Hospital, Nanjing University School of Medicine, Nanjing 210002, P.R. China
| | - Jin-Sheng Zhai
- Department of Healthcare, Jinling Hospital, Nanjing University School of Medicine, Nanjing 210002, P.R. China
| | - Tian-Fu Li
- Institute of Laboratory Medicine, Jinling Hospital, Nanjing University School of Medicine, Nanjing 210002, P.R. China
| | - Qiu-Yue Wu
- Institute of Laboratory Medicine, Jinling Hospital, Nanjing University School of Medicine, Nanjing 210002, P.R. China
| | - Wei-Wei Li
- Institute of Laboratory Medicine, Jinling Hospital, Nanjing University School of Medicine, Nanjing 210002, P.R. China
| | - Na Li
- Institute of Laboratory Medicine, Jinling Hospital, Nanjing University School of Medicine, Nanjing 210002, P.R. China
| | - Xiao-Jun Li
- Institute of Laboratory Medicine, Jinling Hospital, Nanjing University School of Medicine, Nanjing 210002, P.R. China
| | - Yu-Feng Huang
- Institute of Laboratory Medicine, Jinling Hospital, Nanjing University School of Medicine, Nanjing 210002, P.R. China
| | - Ying-Xia Cui
- Institute of Laboratory Medicine, Jinling Hospital, Nanjing University School of Medicine, Nanjing 210002, P.R. China
| | - Xin-Yi Xia
- Institute of Laboratory Medicine, Jinling Hospital, Nanjing University School of Medicine, Nanjing 210002, P.R. China
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29
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Davoudi-Dehaghani E, Fallah MS, Tavakkoly-Bazzaz J, Bagherian H, Zeinali S. Allelic heterogeneity among Iranian DFNB7/11 families: report of a new Iranian deaf family with TMC1 mutation identified by next-generation sequencing. Acta Otolaryngol 2015; 135:125-9. [PMID: 25423259 DOI: 10.3109/00016489.2014.969383] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
Abstract
CONCLUSION Co-segregation of c.2030T>C mutation with hearing loss in an Iranian family and absence of this mutation in 100 Iranian controls confirms the pathogenicity of this mutation. Allelic heterogeneity among Iranian DFNB7/11 families has been shown by the identification of six different mutations in eight families. OBJECTIVES Transmembrane channel-like 1 (TMC1) gene encodes an integral membrane protein such that its mutations can cause DFNB7/11 hearing loss. To date, several TMC1 mutations have been reported from Iran. Here we report a new DFNB7/11 Iranian family with an unreported TMC1 mutation in Iran. METHODS A total of 66 genes related to hearing loss were analyzed using the OtoSCOPE platform in an affected member of an Iranian deaf family (Irn-Deaf-6866). Sanger sequencing was performed to confirm next-generation sequencing findings. RESULTS A mutation, c.2030T>C, was identified in exon 21 of the TMC1 gene in the investigated member of the family. Sequencing results in all members of the family confirmed association of this mutation with hearing loss. None of 100 ethnically matched healthy controls had this mutation.
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30
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Hassan MA, Shah AA, Szmida E, Smigiel R, Sasiadek MM, Pfister M, Blin N, Bress A. A TMC1 (transmembrane channel-like 1) mutation (p.S320R) in a Polish family with hearing impairment. J Appl Genet 2015; 56:311-6. [PMID: 25560804 DOI: 10.1007/s13353-014-0263-4] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/26/2014] [Revised: 11/21/2014] [Accepted: 11/26/2014] [Indexed: 11/25/2022]
Abstract
After excluding frequent mutations in common genes like GJB2, SLC26A4 and MT-RNR1 by straightforward Sanger sequencing in about 20 Polish families with hearing impairment, new and possibly pathogenic mutations were searched for by next-generation sequencing (NGS) screening using a specialised panel including more than 80 genes connected with hearing disorders. Due to high rates of false-positive pathogen predictions for newly discovered single-nucleotide polymorphisms (SNPs), different prediction models were combined to enhance the prediction power. In one family with a record of over four generations, II,3 and II,4 were suspected of hearing impairment without medical records. A male person (III,2) displayed hearing loss of 40 dB hearing level (HL) and his two sons, IV,1 and IV,2, were both affected; one with 90 dB HL and the other with 40 dB HL. Here, one heterozygous, non-synonymous variant was detected, with the SNP causing an amino acid substitution in TMC1 (transmembrane channel-like 1), a gene reported with many mutations in DFNA36 and DFNB7/11 (OMIM #606705 and #600974, respectively). Until now, the substitution p.S320R has not been described in any database. Instead of the significance of this mutation by bioinformatics tools, we confirmed the genotype-phenotype co-segregation in family members. The involvement of TMC1 in hereditary hearing impairment has not been observed in the Polish population so far.
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Lin F, Li D, Wang P, Fan D, De J, Zhu W. Autosomal recessive non-syndromic hearing loss is caused by novel compound heterozygous mutations in TMC1 from a Tibetan Chinese family. Int J Pediatr Otorhinolaryngol 2014; 78:2216-21. [PMID: 25458163 DOI: 10.1016/j.ijporl.2014.10.016] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/24/2014] [Revised: 10/07/2014] [Accepted: 10/10/2014] [Indexed: 10/24/2022]
Abstract
OBJECTIVES Hearing loss is the most common sensory disorder worldwide. Biallelic mutations in 42 different genes have been identified as associated with autosomal recessive non-syndromic hearing loss (ARNSHL). One of the common genes responsible for ARNSHL is TMC1. TMC1 mutations have been reported to cause non-syndromic hearing loss in a variety of populations. The current study is designed to investigate mutations prevalent among Chinese ethnic groups with ARNSHL. METHODS Targeted exome sequencing (TES) was employed to study the genetic causes of two siblings with ARNSHL in a Tibetan Chinese family. Variants identified by TES were further confirmed by Sanger sequencing. RESULTS We identified two distinct variants in the TMC1 gene in two deaf siblings of one Tibetan Chinese family using TES. Both siblings inherited a paternal allele containing a deletion of c.1396_1398AAC (p.Asn466del) and a maternal allele containing an insertion of c.2210_2211insCT (p.Glu737HisfsX2). The former disrupts a highly conserved residue in the large intracellular loop domain adjacent to the fourth transmembrane domain, and the latter causes a truncation of a portion of the C-terminal domain. These variants were compound heterzygous and segregated with the hearing impairment in this family. CONCLUSION The novel compound heterozygous mutant alleles of TMC1 identified in this study were responsible for the ARNSHL in this Tibetan Chinese family. Although compound heterozygous mutations in TMC1 occurring in different TMC1 domains have been previously described in Han Chinese; this result suggests that the TMC1 variants contributing to hereditary deafness in Chinese populations may be more complex than initially assumed and that sequence-based diagnostics will be required for a comprehensive evaluation of ARNSHL.
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Affiliation(s)
- Fangzhu Lin
- Department of Otolaryngology-Head and Neck Surgery, First Hospital of Jilin University, Changchun 130021, China
| | - Dejun Li
- Center for Prenatal Diagnosis, First Hospital of Jilin University, Changchun 130021, China
| | - Ping Wang
- Department of Otolaryngology-Head and Neck Surgery, First Hospital of Jilin University, Changchun 130021, China
| | - Dongyan Fan
- School of Medicine, Tibet University, Lhasa 850000, China
| | - Ji De
- School of Medicine, Tibet University, Lhasa 850000, China
| | - Wei Zhu
- Department of Otolaryngology-Head and Neck Surgery, First Hospital of Jilin University, Changchun 130021, China.
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Najmabadi H, Kahrizi K. Genetics of non-syndromic hearing loss in the Middle East. Int J Pediatr Otorhinolaryngol 2014; 78:2026-36. [PMID: 25281338 DOI: 10.1016/j.ijporl.2014.08.036] [Citation(s) in RCA: 34] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/18/2014] [Revised: 08/24/2014] [Accepted: 08/25/2014] [Indexed: 12/23/2022]
Abstract
Hearing impairment is the most common sensory disorder, present 1 in every 500 newborns. About 80% of genetic HL is classified as non-syndromic deafness. To date, over 115 non-syndromic loci have been identified of which fifty associated with autosomal recessive non-syndromic hearing loss (ARNSHL). In this review article, we represent the 40 genes function and contribution to genetic deafness in different Middle Eastern populations as well as gene frequencies and mutation spectrum. The wide variety of mutations have so far detected in 19 countries reflects the heterogeneity of the genes involved in HL in this region. The deafness genes can cause dysfunction of cochlear homeostasis, cellular organization, neuronal transmission, cell growth, differentiation, and survival, some coding for tectorial membrane-associated proteins, and the remaining with unknown functions. Non-syndromic deafness is highly heterogeneous and mutations in the GJB2 are responsible for almost 30-50% in northwest to as low as 0-5% in south and southeast of the Middle East, it remain as major gene in ARNSHL in Middle East. The other genes contributing to AR/ADNSHL in some countries have been determined while for many other countries in the Middle East have not been studied or little study has been done. With the advancement of next generation sequencing one could expect in next coming year many of the remaining genes to be determine and to understand their function in the inner ear.
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Affiliation(s)
- Hossein Najmabadi
- Genetics Research Centre (GRC), University of Social Welfare and Rehabilitation Sciences, Tehran, Iran.
| | - Kimia Kahrizi
- Genetics Research Centre (GRC), University of Social Welfare and Rehabilitation Sciences, Tehran, Iran
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33
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Shafique S, Siddiqi S, Schraders M, Oostrik J, Ayub H, Bilal A, Ajmal M, Seco CZ, Strom TM, Mansoor A, Mazhar K, Shah STA, Hussain A, Azam M, Kremer H, Qamar R. Genetic spectrum of autosomal recessive non-syndromic hearing loss in Pakistani families. PLoS One 2014; 9:e100146. [PMID: 24949729 PMCID: PMC4065008 DOI: 10.1371/journal.pone.0100146] [Citation(s) in RCA: 47] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/01/2014] [Accepted: 05/22/2014] [Indexed: 12/01/2022] Open
Abstract
The frequency of inherited bilateral autosomal recessive non-syndromic hearing loss (ARNSHL) in Pakistan is 1.6/1000 individuals. More than 50% of the families carry mutations in GJB2 while mutations in MYO15A account for about 5% of recessive deafness. In the present study a cohort of 30 ARNSHL families was initially screened for mutations in GJB2 and MYO15A. Homozygosity mapping was performed by employing whole genome single nucleotide polymorphism (SNP) genotyping in the families that did not carry mutations in GJB2 or MYO15A. Mutation analysis was performed for the known ARNSHL genes present in the homozygous regions to determine the causative mutations. This allowed the identification of a causative mutation in all the 30 families including 9 novel mutations, which were identified in 9 different families (GJB2 (c.598G>A, p.Gly200Arg); MYO15A (c.9948G>A, p.Gln3316Gln; c.3866+1G>A; c.8767C>T, p.Arg2923* and c.8222T>C, p.Phe2741Ser), TMC1 (c.362+18A>G), BSND (c.97G>C, p.Val33Leu), TMPRSS3 (c.726C>G, p.Cys242Trp) and MSRB3 (c.20T>G, p.Leu7Arg)). Furthermore, 12 recurrent mutations were detected in 21 other families. The 21 identified mutations included 10 (48%) missense changes, 4 (19%) nonsense mutations, 3 (14%) intronic mutations, 2 (9%) splice site mutations and 2 (9%) frameshift mutations. GJB2 accounted for 53% of the families, while mutations in MYO15A were the second most frequent (13%) cause of ARNSHL in these 30 families. The identification of novel as well as recurrent mutations in the present study increases the spectrum of mutations in known deafness genes which could lead to the identification of novel founder mutations and population specific mutated deafness genes causative of ARNSHL. These results provide detailed genetic information that has potential diagnostic implication in the establishment of cost-efficient allele-specific analysis of frequently occurring variants in combination with other reported mutations in Pakistani populations.
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Affiliation(s)
- Sobia Shafique
- COMSATS Institute of Information Technology, Park Road, Islamabad, Pakistan
| | - Saima Siddiqi
- Institute of Biomedical and Genetic Engineering (IBGE), Islamabad, Pakistan
| | - Margit Schraders
- Department of Otorhinolaryngology, Hearing and Genes, Radboud University Medical Center, Nijmegen, The Netherlands
- Nijmegen Centre for Molecular Life Sciences, Radboud University Medical Center, Nijmegen, The Netherlands
- Donders Institute for Brain, Cognition and Behaviour, Radboud University Medical Center, Nijmegen, The Netherlands
| | - Jaap Oostrik
- Department of Otorhinolaryngology, Hearing and Genes, Radboud University Medical Center, Nijmegen, The Netherlands
- Nijmegen Centre for Molecular Life Sciences, Radboud University Medical Center, Nijmegen, The Netherlands
- Donders Institute for Brain, Cognition and Behaviour, Radboud University Medical Center, Nijmegen, The Netherlands
| | - Humaira Ayub
- COMSATS Institute of Information Technology, Park Road, Islamabad, Pakistan
| | - Ammad Bilal
- Simon Fraser University, Vancouver, British Colombia, Canada
| | - Muhammad Ajmal
- COMSATS Institute of Information Technology, Park Road, Islamabad, Pakistan
| | - Celia Zazo Seco
- Department of Otorhinolaryngology, Hearing and Genes, Radboud University Medical Center, Nijmegen, The Netherlands
- Nijmegen Centre for Molecular Life Sciences, Radboud University Medical Center, Nijmegen, The Netherlands
- Donders Institute for Brain, Cognition and Behaviour, Radboud University Medical Center, Nijmegen, The Netherlands
| | - Tim M. Strom
- Institute of Human Genetics, Helmholtz Zentrum München, German Research Center for Environmental Health, Neuherberg, Germany
| | - Atika Mansoor
- Institute of Biomedical and Genetic Engineering (IBGE), Islamabad, Pakistan
| | - Kehkashan Mazhar
- Institute of Biomedical and Genetic Engineering (IBGE), Islamabad, Pakistan
| | - Syed Tahir A. Shah
- COMSATS Institute of Information Technology, Park Road, Islamabad, Pakistan
| | - Alamdar Hussain
- COMSATS Institute of Information Technology, Park Road, Islamabad, Pakistan
| | - Maleeha Azam
- COMSATS Institute of Information Technology, Park Road, Islamabad, Pakistan
| | - Hannie Kremer
- Department of Otorhinolaryngology, Hearing and Genes, Radboud University Medical Center, Nijmegen, The Netherlands
- Nijmegen Centre for Molecular Life Sciences, Radboud University Medical Center, Nijmegen, The Netherlands
- Donders Institute for Brain, Cognition and Behaviour, Radboud University Medical Center, Nijmegen, The Netherlands
- Department of Human Genetics, Radboud university medical center, Nijmegen, The Netherlands
- * E-mail: (HK); (RQ)
| | - Raheel Qamar
- COMSATS Institute of Information Technology, Park Road, Islamabad, Pakistan
- Al-Nafees Medical College & Hospital, Isra University, Islamabad, Pakistan
- * E-mail: (HK); (RQ)
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Nakanishi H, Kurima K, Kawashima Y, Griffith AJ. Mutations of TMC1 cause deafness by disrupting mechanoelectrical transduction. Auris Nasus Larynx 2014; 41:399-408. [PMID: 24933710 DOI: 10.1016/j.anl.2014.04.001] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/26/2014] [Accepted: 04/22/2014] [Indexed: 01/05/2023]
Abstract
OBJECTIVE Mutations of transmembrane channel-like 1 gene (TMC1) can cause dominant (DFNA36) or recessive (DFNB7/B11) deafness. In this article, we describe the characteristics of DFNA36 and DFNB7/B11 deafness, the features of the Tmc1 mutant mouse strains, and recent advances in our understanding of TMC1 function. METHODS Publications related to TMC1, DFNA36, or DFNB7/B11 were identified through PubMed. RESULTS All affected DFNA36 subjects showed post-lingual, progressive, sensorineural hearing loss (HL), initially affecting high frequencies. In contrast, almost all affected DFNB7/B11 subjects demonstrated congenital or prelingual severe to profound sensorineural HL. The mouse Tmc1 gene also has dominant and recessive mutant alleles that cause HL in mutant strains, including Beethoven, deafness, and Tmc1 knockout mice. These mutant mice have been instrumental for revealing that Tmc1 and its closely related paralog Tmc2 are expressed in cochlear and vestibular hair cells, and are required for hair cell mechanoelectrical transduction (MET). Recent studies suggest that TMC1 and TMC2 may be components of the long-sought hair cell MET channel. CONCLUSION TMC1 mutations disrupt hair cell MET.
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Affiliation(s)
- Hiroshi Nakanishi
- Molecular Biology and Genetics Section, National Institute on Deafness and Other Communication Disorders (NIDCD), NIH, 35A Convent Dr, Bethesda, MD 20892, USA
| | - Kiyoto Kurima
- Molecular Biology and Genetics Section, National Institute on Deafness and Other Communication Disorders (NIDCD), NIH, 35A Convent Dr, Bethesda, MD 20892, USA
| | - Yoshiyuki Kawashima
- Department of Otolaryngology, Tokyo Medical and Dental University, 1-5-45 Yushima, Bunkyo-ku, Tokyo 113-8519, Japan
| | - Andrew J Griffith
- Molecular Biology and Genetics Section, National Institute on Deafness and Other Communication Disorders (NIDCD), NIH, 35A Convent Dr, Bethesda, MD 20892, USA.
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Shearer AE, Kolbe DL, Azaiez H, Sloan CM, Frees KL, Weaver AE, Clark ET, Nishimura CJ, Black-Ziegelbein EA, Smith RJH. Copy number variants are a common cause of non-syndromic hearing loss. Genome Med 2014; 6:37. [PMID: 24963352 PMCID: PMC4067994 DOI: 10.1186/gm554] [Citation(s) in RCA: 118] [Impact Index Per Article: 11.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/14/2014] [Accepted: 05/14/2014] [Indexed: 01/10/2023] Open
Abstract
BACKGROUND Copy number variants (CNVs) are a well-recognized cause of genetic disease; however, methods for their identification are often gene-specific, excluded as 'routine' in screens of genetically heterogeneous disorders, and not implemented in most next-generation sequencing pipelines. For this reason, the contribution of CNVs to non-syndromic hearing loss (NSHL) is most likely under-recognized. We aimed to incorporate a method for CNV identification as part of our standard analysis pipeline and to determine the contribution of CNVs to genetic hearing loss. METHODS We used targeted genomic enrichment and massively parallel sequencing to isolate and sequence all exons of all genes known to cause NSHL. We completed testing on 686 patients with hearing loss with no exclusions based on type of hearing loss or any other clinical features. For analysis we used an integrated method for detection of single nucleotide changes, indels and CNVs. CNVs were identified using a previously published method that utilizes median read-depth ratios and a sliding-window approach. RESULTS Of 686 patients tested, 15.2% (104) carried at least one CNV within a known deafness gene. Of the 38.9% (267) of individuals for whom we were able to determine a genetic cause of hearing loss, a CNV was implicated in 18.7% (50). We identified CNVs in 16 different genes including 7 genes for which no CNVs have been previously reported. CNVs of STRC were most common (73% of CNVs identified) followed by CNVs of OTOA (13% of CNVs identified). CONCLUSION CNVs are an important cause of NSHL and their detection must be included in comprehensive genetic testing for hearing loss.
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Affiliation(s)
- A Eliot Shearer
- Department of Otolaryngology - Head and Neck Surgery, Molecular Otolaryngology & Renal Research Labs, University of Iowa Hospitals and Clinics, Iowa City, Iowa 52242, USA
| | - Diana L Kolbe
- Department of Otolaryngology - Head and Neck Surgery, Molecular Otolaryngology & Renal Research Labs, University of Iowa Hospitals and Clinics, Iowa City, Iowa 52242, USA ; Iowa Institute of Human Genetics, University of Iowa College of Medicine, Iowa City, Iowa 52242, USA
| | - Hela Azaiez
- Department of Otolaryngology - Head and Neck Surgery, Molecular Otolaryngology & Renal Research Labs, University of Iowa Hospitals and Clinics, Iowa City, Iowa 52242, USA
| | - Christina M Sloan
- Department of Otolaryngology - Head and Neck Surgery, Molecular Otolaryngology & Renal Research Labs, University of Iowa Hospitals and Clinics, Iowa City, Iowa 52242, USA
| | - Kathy L Frees
- Department of Otolaryngology - Head and Neck Surgery, Molecular Otolaryngology & Renal Research Labs, University of Iowa Hospitals and Clinics, Iowa City, Iowa 52242, USA
| | - Amy E Weaver
- Department of Otolaryngology - Head and Neck Surgery, Molecular Otolaryngology & Renal Research Labs, University of Iowa Hospitals and Clinics, Iowa City, Iowa 52242, USA
| | - Erika T Clark
- Department of Otolaryngology - Head and Neck Surgery, Molecular Otolaryngology & Renal Research Labs, University of Iowa Hospitals and Clinics, Iowa City, Iowa 52242, USA
| | - Carla J Nishimura
- Department of Otolaryngology - Head and Neck Surgery, Molecular Otolaryngology & Renal Research Labs, University of Iowa Hospitals and Clinics, Iowa City, Iowa 52242, USA ; Iowa Institute of Human Genetics, University of Iowa College of Medicine, Iowa City, Iowa 52242, USA
| | - E Ann Black-Ziegelbein
- Department of Otolaryngology - Head and Neck Surgery, Molecular Otolaryngology & Renal Research Labs, University of Iowa Hospitals and Clinics, Iowa City, Iowa 52242, USA ; Iowa Institute of Human Genetics, University of Iowa College of Medicine, Iowa City, Iowa 52242, USA
| | - Richard J H Smith
- Department of Otolaryngology - Head and Neck Surgery, Molecular Otolaryngology & Renal Research Labs, University of Iowa Hospitals and Clinics, Iowa City, Iowa 52242, USA ; Iowa Institute of Human Genetics, University of Iowa College of Medicine, Iowa City, Iowa 52242, USA ; Interdepartmental PhD Program in Genetics, University of Iowa, Iowa City, Iowa 52242, USA
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A novel DFNA36 mutation in TMC1 orthologous to the Beethoven (Bth) mouse associated with autosomal dominant hearing loss in a Chinese family. PLoS One 2014; 9:e97064. [PMID: 24827932 PMCID: PMC4020765 DOI: 10.1371/journal.pone.0097064] [Citation(s) in RCA: 55] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/04/2013] [Accepted: 04/15/2014] [Indexed: 11/19/2022] Open
Abstract
Mutations in the transmembrane channel-like gene 1 (TMC1) can cause both DFNA36 and DFNB7/11 hearing loss. More than thirty DFNB7/11 mutations have been reported, but only three DFNA36 mutations were reported previously. In this study, we found a large Chinese family with 222 family members showing post-lingual, progressive sensorineural hearing loss which were consistent with DFNA36 hearing loss. Auditory brainstem response (ABR) test of the youngest patient showed a special result with nearly normal threshold but prolonged latency, decreased amplitude, and the abnormal waveform morphology. Exome sequencing of the proband found four candidate variants in known hearing loss genes. Sanger sequencing in all family members found a novel variant c.1253T>A (p.M418K) in TMC1 at DFNA36 that co-segregated with the phenotype. This mutation in TMC1 is orthologous to the mutation found in the hearing loss mouse model named Bth ten years ago. In another 51 Chinese autosomal dominant hearing loss families, we screened the segments containing the dominant mutations of TMC1 and no functional variants were found. TMC1 is expressed in the hair cells in inner ear. Given the already known roles of TMC1 in the mechanotransduction in the cochlea and its expression in inner ear, our results may provide an interesting perspective into its function in inner ear.
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Yoshimura H, Takumi Y, Nishio SY, Suzuki N, Iwasa YI, Usami SI. Deafness gene expression patterns in the mouse cochlea found by microarray analysis. PLoS One 2014; 9:e92547. [PMID: 24676347 PMCID: PMC3967995 DOI: 10.1371/journal.pone.0092547] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/20/2013] [Accepted: 02/24/2014] [Indexed: 11/19/2022] Open
Abstract
BACKGROUND Tonotopy is one of the most fundamental principles of auditory function. While gradients in various morphological and physiological characteristics of the cochlea have been reported, little information is available on gradient patterns of gene expression. In addition, the audiograms in autosomal dominant non syndromic hearing loss can be distinctive, however, the mechanism that accounts for that has not been clarified. We thought that it is possible that tonotopic gradients of gene expression within the cochlea account for the distinct audiograms. METHODOLOGY/PRINCIPAL FINDINGS We compared expression profiles of genes in the cochlea between the apical, middle, and basal turns of the mouse cochlea by microarray technology and quantitative RT-PCR. Of 24,547 genes, 783 annotated genes expressed more than 2-fold. The most remarkable finding was a gradient of gene expression changes in four genes (Pou4f3, Slc17a8, Tmc1, and Crym) whose mutations cause autosomal dominant deafness. Expression of these genes was greater in the apex than in the base. Interestingly, expression of the Emilin-2 and Tectb genes, which may have crucial roles in the cochlea, was also greater in the apex than in the base. CONCLUSIONS/SIGNIFICANCE This study provides baseline data of gradient gene expression in the cochlea. Especially for genes whose mutations cause autosomal dominant non syndromic hearing loss (Pou4f3, Slc17a8, Tmc1, and Crym) as well as genes important for cochlear function (Emilin-2 and Tectb), gradual expression changes may help to explain the various pathological conditions.
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Affiliation(s)
- Hidekane Yoshimura
- Department of Otorhinolaryngology, Shinshu University School of Medicine, Matsumoto, Nagano, Japan
| | - Yutaka Takumi
- Department of Otorhinolaryngology, Shinshu University School of Medicine, Matsumoto, Nagano, Japan
| | - Shin-ya Nishio
- Department of Otorhinolaryngology, Shinshu University School of Medicine, Matsumoto, Nagano, Japan
| | - Nobuyoshi Suzuki
- Department of Otorhinolaryngology, Shinshu University School of Medicine, Matsumoto, Nagano, Japan
| | - Yoh-ichiro Iwasa
- Department of Otorhinolaryngology, Shinshu University School of Medicine, Matsumoto, Nagano, Japan
| | - Shin-ichi Usami
- Department of Otorhinolaryngology, Shinshu University School of Medicine, Matsumoto, Nagano, Japan
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Abstract
Transmembrane channel-like (TMC) proteins 1 and 2 are necessary for hair cell mechanotransduction but their precise function is controversial. A growing body of evidence supports a direct role for TMC1 and TMC2 as components of the transduction complex. However, a number of important questions remain and alternate hypotheses have been proposed. Here we present an historical overview of the identification and cloning of Tmc genes, a discussion of mutations in TMC1 that cause deafness in mice and humans and a brief review of other members of the Tmc gene superfamily. We also examine expression of Tmc mRNAs and localization of the protein products. The review focuses on potential functions of TMC proteins and the evidence from Beethoven mice that suggests a direct role for TMC1 in hair cell mechanotransduction. Data that support alternate interpretations are also considered. The article concludes with a discussion of outstanding questions and future directions for TMC research. This article is part of a Special Issue entitled <Annual Reviews 2014>.
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Gao X, Su Y, Guan LP, Yuan YY, Huang SS, Lu Y, Wang GJ, Han MY, Yu F, Song YS, Zhu QY, Wu J, Dai P. Novel compound heterozygous TMC1 mutations associated with autosomal recessive hearing loss in a Chinese family. PLoS One 2013; 8:e63026. [PMID: 23690975 PMCID: PMC3653921 DOI: 10.1371/journal.pone.0063026] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/13/2013] [Accepted: 03/27/2013] [Indexed: 11/19/2022] Open
Abstract
Hereditary nonsyndromic hearing loss is highly heterogeneous and most patients with a presumed genetic etiology lack a specific diagnosis. It has been estimated that several hundred genes may be associated with this sensory deficit in humans. Here, we identified compound heterozygous mutations in the TMC1 gene as the cause of recessively inherited sensorineural hearing loss by using whole-exome sequencing in a family with two deaf siblings. Sanger sequencing confirmed that both siblings inherited a missense mutation, c.589G>A p.G197R (maternal allele), and a nonsense mutation, c.1171C>T p.Q391X (paternal allele), in TMC1. We also used DNA from 50 Chinese familial patients with ARNSHL and 208 ethnicity-matched negative samples to perform extended variants analysis. Both variants co-segregated in family 1953, which had the hearing loss phenotype, but were absent in 50 patients and 208 ethnicity-matched controls. Therefore, we concluded that the hearing loss in this family was caused by novel compound heterozygous mutations in TMC1.
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Affiliation(s)
- Xue Gao
- Department of Otorhinolaryngology, Head and Neck Surgery, PLA General Hospital, Beijing, P. R. China
- Department of Otorhinolaryngology, Hainan Branch of PLA General Hospital, Sanya, P. R. China
- Department of Otorhinolaryngology, the Second Artillery General Hospital, Beijing, P. R. China
| | - Yu Su
- Department of Otorhinolaryngology, Head and Neck Surgery, PLA General Hospital, Beijing, P. R. China
| | - Li-Ping Guan
- BGI-Shenzhen, Beishan Industrial Zone, Yantian District, Shenzhen, P. R. China
| | - Yong-Yi Yuan
- Department of Otorhinolaryngology, Head and Neck Surgery, PLA General Hospital, Beijing, P. R. China
| | - Sha-Sha Huang
- Department of Otorhinolaryngology, Head and Neck Surgery, PLA General Hospital, Beijing, P. R. China
| | - Yu Lu
- Department of Otorhinolaryngology, Head and Neck Surgery, PLA General Hospital, Beijing, P. R. China
| | - Guo-Jian Wang
- Department of Otorhinolaryngology, Head and Neck Surgery, PLA General Hospital, Beijing, P. R. China
| | - Ming-Yu Han
- Department of Otorhinolaryngology, Head and Neck Surgery, PLA General Hospital, Beijing, P. R. China
- Department of Otorhinolaryngology, Hainan Branch of PLA General Hospital, Sanya, P. R. China
| | - Fei Yu
- Department of Otorhinolaryngology, Head and Neck Surgery, PLA General Hospital, Beijing, P. R. China
| | - Yue-Shuai Song
- Department of Otorhinolaryngology, Head and Neck Surgery, PLA General Hospital, Beijing, P. R. China
- Department of Otorhinolaryngology, Hainan Branch of PLA General Hospital, Sanya, P. R. China
| | - Qing-Yan Zhu
- BGI-Shenzhen, Beishan Industrial Zone, Yantian District, Shenzhen, P. R. China
| | - Jing Wu
- BGI-Tianjin, Tianjin, P. R. China
| | - Pu Dai
- Department of Otorhinolaryngology, Head and Neck Surgery, PLA General Hospital, Beijing, P. R. China
- Department of Otorhinolaryngology, Hainan Branch of PLA General Hospital, Sanya, P. R. China
- * E-mail:
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40
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Davoudi-Dehaghani E, Zeinali S, Mahdieh N, Shirkavand A, Bagherian H, Tabatabaiefar MA. A transversion mutation in non-coding exon 3 of the TMC1 gene in two ethnically related Iranian deaf families from different geographical regions; evidence for founder effect. Int J Pediatr Otorhinolaryngol 2013; 77:821-6. [PMID: 23523375 DOI: 10.1016/j.ijporl.2013.02.021] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/18/2012] [Revised: 02/23/2013] [Accepted: 02/25/2013] [Indexed: 11/18/2022]
Abstract
OBJECTIVES Transmembrane channel-like 1 (TMC1) gene is a member of the transmembrane channel-like (TMC) gene family that encodes an integral membrane protein of the inner ear. It is suggested that mutation in this gene is one of the main causes of autosomal recessive non-syndromic hearing loss (ARNSHL) in different populations. The aim of this study was to determine the contribution of the TMC1 gene mutations in causing hearing loss in Iran. METHODS In total 54 unrelated Iranian families containing 159 affected individuals with ARNSHL detected by audiometric and otologic examinations were analyzed. Haplotype analysis of all members of 45 GJB2- & GJB6-negative families, using four microsatellite markers linked to DFNB7/11 was performed. RESULTS Co-segregation of hearing loss with all investigated markers for the DFNB7/11 locus was found in one family. DNA sequencing of all coding and non-coding exons and intron boundaries of the TMC1 gene identified c.-258A>C mutation in non-coding exon 3 only in individuals with hearing loss. This mutation has been previously reported in another Iranian family (G9) that share similar ethnicity. This variant was not detected in 300 ethnically matched healthy controls. CONCLUSIONS These results increase the probability that this nucleotide variation may be a pathogenic mutation. This study showed that the ethnicity may be more useful than geographical location to design research strategy for determining which genes should be considered when a heterogeneous disorder is under investigation.
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Affiliation(s)
- Elham Davoudi-Dehaghani
- Department of Molecular Medicine, Biotechnology Research Center, Pasteur Institute of Iran, Pasteur St., Tehran, Iran
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ANGELI SIMON, LIN XI, LIU XUEZHONG. Genetics of hearing and deafness. Anat Rec (Hoboken) 2012; 295:1812-29. [PMID: 23044516 PMCID: PMC4523052 DOI: 10.1002/ar.22579] [Citation(s) in RCA: 77] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/24/2012] [Accepted: 07/24/2012] [Indexed: 01/20/2023]
Abstract
This article is a review of the genes and genetic disorders that affect hearing in humans and a few selected mouse models of deafness. Genetics is playing an increasingly critical role in the practice of medicine. This is not only in part to the importance that genetic knowledge has on traditional genetic diseases but also in part to the fact that genetic knowledge provides an understanding of the fundamental biological process of most diseases. The proteins coded by the genes related to hearing loss (HL) are involved in many functions in the ear, such as cochlear fluid homeostasis, ionic channels, stereocilia morphology and function, synaptic transmission, gene regulation, and others. Mouse models play a crucial role in understanding of the pathogenesis associated with these genes. Different types of familial HL have been recognized for years; however, in the last two decades, there has been tremendous progress in the discovery of gene mutations that cause deafness. Most of the cases of genetic deafness recognized today are monogenic disorders that can be broadly classified by the mode of inheritance (i.e., autosomal dominant, autosomal recessive, X-linked, and mitochondrial inheritance) and by the presence of associated phenotypic features (i.e., syndromic; and nonsyndromic). In terms of nonsyndromic HL, the chromosomal locations are currently known for ∼ 125 loci (54 for dominant and 71 for recessive deafness), 64 genes have been identified (24 for dominant and 40 for recessive deafness), and there are many more loci for syndromic deafness and X-linked and mitochondrial DNA disorders (http://hereditaryhearingloss.org). Thus, today's clinician must understand the science of medical genetics as this knowledge can lead to more effective disease diagnosis, counseling, treatment, and prevention.
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Affiliation(s)
- SIMON ANGELI
- Department of Otolaryngology, University of Miami, Miami, Florida
| | - XI LIN
- Department of Otolaryngology, Emory University School of Medicine, Atlanta, Georgia
| | - XUE ZHONG LIU
- Department of Otolaryngology, University of Miami, Miami, Florida
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Searle C, Mavrogiannis LA, Bennett CP, Charlton RS. The common TMC1 mutation c.100C>T (p.Arg34X) is not a significant cause of deafness in British Asians. Genet Test Mol Biomarkers 2012; 16:453-5. [PMID: 22288896 DOI: 10.1089/gtmb.2011.0254] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
TMC1, a second-tier deafness gene below GJB2, is an appreciable cause of recessive nonsyndromic hearing loss (DFNB7/11) in North Africa, the Middle East, and parts of South Asia. Additionally, a single founder mutation, c.100C>T (p.Arg34X), dominates the TMC1 mutation spectrum. We investigated the frequency of TMC1 c.100C>T in a large set of British Asians with hearing loss, collectively a group with high prevalence of genetic deafness and limited routine clinical testing options beyond GJB2, on a candidate basis. An estimate of 0.21% (95% confidence interval, 0.04%-1.18%) was gained, indicating no significant enrichment in our set. Identification of the common non-GJB2 deafness genes and mutations in British Asian communities would require data from autozygosity mapping and/or massively parallel sequencing of gene panels.
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Affiliation(s)
- Claire Searle
- Clinical Genetics, Yorkshire Regional Genetics Service, Leeds, United Kingdom
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Lenz DR, Avraham KB. Hereditary hearing loss: from human mutation to mechanism. Hear Res 2011; 281:3-10. [PMID: 21664957 DOI: 10.1016/j.heares.2011.05.021] [Citation(s) in RCA: 42] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/28/2011] [Revised: 05/26/2011] [Accepted: 05/27/2011] [Indexed: 11/17/2022]
Abstract
The genetic heterogeneity of hereditary hearing loss is thus far represented by hundreds of genes encoding a large variety of proteins. Mutations in these genes have been discovered for patients with different modes of inheritance and types of hearing loss, ranging from syndromic to non-syndromic and mild to profound. In many cases, the mechanisms whereby the mutations lead to hearing loss have been partly elucidated using cell culture systems and mouse and other animal models. The discovery of the genes has completely changed the practice of genetic counseling in this area, providing potential diagnosis in many cases that can be coupled with clinical phenotypes and offer predictive information for families. In this review we provide three examples of gene discovery in families with hereditary hearing loss, all associated with elucidation of some of the mechanisms leading to hair cell degeneration and pathology of deafness.
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Affiliation(s)
- Danielle R Lenz
- Department of Human Molecular Genetics and Biochemistry, Sackler Faculty of Medicine, Tel Aviv University, Tel Aviv, Israel
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Kim HK, Kim YH, Sagong B, Kwon TJ, Oh SK, Lee HJ, Lee KY, Lee SH, Kim UK. Molecular analysis of TMC1 gene in the Korean patients with nonsyndromic hearing loss. Genes Genomics 2011. [DOI: 10.1007/s13258-010-0132-4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
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45
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Hildebrand MS, Kahrizi K, Bromhead CJ, Shearer AE, Webster JA, Khodaei H, Abtahi R, Bazazzadegan N, Babanejad M, Nikzat N, Kimberling WJ, Stephan D, Huygen PLM, Bahlo M, Smith RJH, Najmabadi H. Mutations in TMC1 are a common cause of DFNB7/11 hearing loss in the Iranian population. Ann Otol Rhinol Laryngol 2011; 119:830-5. [PMID: 21250555 DOI: 10.1177/000348941011901207] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
OBJECTIVES We investigated the cause of autosomal recessive nonsyndromic hearing loss (ARNSHL) that segregated in 2 consanguineous Iranian families. METHODS Otologic and audiometric examinations were performed on affected members of each family. Genome-wide parametric multipoint linkage mapping using a recessive model was performed with Affymetrix 50K GeneChips or short tandem repeat polymorphisms. Direct sequencing was used to confirm the causative mutation in each family. RESULTS In 2 Iranian families, L-1651 and L-8600606, with ARNSHL that mapped to the DFNB7/11 locus, homozygosity for a reported splice site mutation (c.776+1G>A), and a novel deletion (c.1589_1590delCT; p.S530*) were identified in the TMC1 gene, respectively. CONCLUSIONS Consistent with the previously reported phenotype in DFNB7/11 families, the 2 Iranian families had segregated congenital, profound hearing impairment. However, in family L-1651, one affected family member (IV:3) has milder hearing impairment than expected, suggesting a potential genetic modifier effect. These results indicate that DFNB7/11 is a common form of genetic hearing loss in Iran, because this population is the source of 6 of the 29 TMC1 mutations reported worldwide.
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Affiliation(s)
- Michael S Hildebrand
- Department of Otolaryngology-Head and Neck Surgery, University of Iowa, Iowa City, IA 52242, USA
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Ben Saïd M, Hmani-Aifa M, Amar I, Baig SM, Mustapha M, Delmaghani S, Tlili A, Ghorbel A, Ayadi H, Van Camp G, Smith RJH, Tekin M, Masmoudi S. High frequency of the p.R34X mutation in the TMC1 gene associated with nonsyndromic hearing loss is due to founder effects. Genet Test Mol Biomarkers 2010; 14:307-11. [PMID: 20373850 DOI: 10.1089/gtmb.2009.0174] [Citation(s) in RCA: 33] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
Founder mutations, particularly 35delG in the GJB2 gene, have to a large extent contributed to the high frequency of autosomal recessive nonsyndromic hearing loss (ARNSHL). Mutations in transmembrane channel-like gene 1 (TMC1) cause ARNSHL. The p.R34X mutation is the most frequent known mutation in the TMC1 gene. To study the origin of this mutation and determine whether it arose in a common ancestor, we analyzed 21 polymorphic markers spanning the TMC1 gene in 11 unrelated individuals from Algeria, Iran, Iraq, Lebanon, Pakistan, Tunisia, and Turkey who carry this mutation. In nine individuals, we observed significant linkage disequilibrium between p.R34X and five polymorphic markers within a 220 kb interval, suggesting that p.R34X arose from a common founder. We estimated the age of this mutation to be between 1075 and 1900 years, perhaps spreading along the third Hadramaout population movements during the seventh century. A second founder effect was observed in Turkish and Lebanese individuals with markers in a 920 kb interval. Screening for the TMC1 p.R34X mutation is indicated in the genetic evaluation of persons with ARNSHL from North African and Southwest Asia.
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Affiliation(s)
- Mariem Ben Saïd
- Targets for Diagnosis and Therapy Unit, Centre of Biotechnology of Sfax, Sfax, Tunisia
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47
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Yang T, Kahrizi K, Bazazzadeghan N, Meyer N, Najmabadi H, Smith RJH. A novel mutation adjacent to the Bth mouse mutation in the TMC1 gene makes this mouse an excellent model of human deafness at the DFNA36 locus. Clin Genet 2010; 77:395-8. [PMID: 20447146 DOI: 10.1111/j.1399-0004.2009.01338.x] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
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48
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Mahdieh N, Rabbani B, Wiley S, Akbari MT, Zeinali S. Genetic causes of nonsyndromic hearing loss in Iran in comparison with other populations. J Hum Genet 2010; 55:639-48. [PMID: 20739942 DOI: 10.1038/jhg.2010.96] [Citation(s) in RCA: 52] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/02/2023]
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49
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Walsh T, Pierce SB, Lenz DR, Brownstein Z, Dagan-Rosenfeld O, Shahin H, Roeb W, McCarthy S, Nord AS, Gordon CR, Ben-Neriah Z, Sebat J, Kanaan M, Lee MK, Frydman M, King MC, Avraham KB. Genomic duplication and overexpression of TJP2/ZO-2 leads to altered expression of apoptosis genes in progressive nonsyndromic hearing loss DFNA51. Am J Hum Genet 2010; 87:101-9. [PMID: 20602916 DOI: 10.1016/j.ajhg.2010.05.011] [Citation(s) in RCA: 81] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/03/2010] [Revised: 05/11/2010] [Accepted: 05/14/2010] [Indexed: 12/12/2022] Open
Abstract
Age-related hearing loss is due to death over time, primarily by apoptosis, of hair cells in the inner ear. Studies of mutant genes responsible for inherited progressive hearing loss have suggested possible mechanisms for hair cell death, but critical connections between these mutations and the causes of progressive hearing loss have been elusive. In an Israeli kindred, dominant, adult-onset, progressive nonsyndromic hearing loss DFNA51 is due to a tandem inverted genomic duplication of 270 kb that includes the entire wild-type gene encoding the tight junction protein TJP2 (ZO-2). In the mammalian inner ear, TJP2 is expressed mainly in tight junctions, and also in the cytoplasm and nuclei. TJP2 expression normally decreases with age from embryonic development to adulthood. In cells of affected family members, TJP2 transcript and protein are overexpressed, leading to decreased phosphorylation of GSK-3beta and to altered expression of genes that regulate apoptosis. These results suggest that TJP2- and GSK-3beta-mediated increased susceptibility to apoptosis of cells of the inner ear is the mechanism for adult-onset hearing loss in this kindred and may serve as one model for age-related hearing loss in the general population.
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Affiliation(s)
- Tom Walsh
- Department of Medicine (Medical Genetics), University of Washington, Seattle, WA 98195, USA
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50
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Sirmaci A, Duman D, Oztürkmen-Akay H, Erbek S, Incesulu A, Oztürk-Hişmi B, Arici ZS, Yüksel-Konuk EB, Taşir-Yilmaz S, Tokgöz-Yilmaz S, Cengiz FB, Aslan I, Yildirim M, Hasanefendioğlu-Bayrak A, Ayçiçek A, Yilmaz I, Fitoz S, Altin F, Ozdağ H, Tekin M. Mutations in TMC1 contribute significantly to nonsyndromic autosomal recessive sensorineural hearing loss: a report of five novel mutations. Int J Pediatr Otorhinolaryngol 2009; 73:699-705. [PMID: 19187973 DOI: 10.1016/j.ijporl.2009.01.005] [Citation(s) in RCA: 44] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/29/2008] [Revised: 01/05/2009] [Accepted: 01/06/2009] [Indexed: 10/21/2022]
Abstract
Genome wide homozygosity mapping using Affymetrix 10K arrays revealed the DFNB7/11 locus including the TMC1 gene in 5 of 35 Turkish families with autosomal recessive nonsyndromic severe to profound congenital or prelingual-onset sensorineural hearing loss (SNHL). Additional 51 families were later screened for co-segregation of the locus with the phenotype using microsatellite markers. GJB2 and mtDNA A1555G mutations were negative in probands from each family. Mutation analysis was performed in families showing co-segregation of autosomal recessive SNHL with haplotypes at the DFNB7/11 locus. A total of six different mutations in seven families were identified, including novel missense alterations, p.G444R (c.1330G>A), p.R445C (c.1333C>T), and p.I677T (c.2030T>C), one novel splice site mutation IVS6+2 T>A (c.64+2T>A), and a novel large deletion of approximately 31kb at the 3' region of the gene including exons 19-24, as well as a previously reported nonsense mutation, p.R34X (c.100C>T). All identified mutations co-segregated with autosomal recessive SNHL in all families and were not found in Turkish hearing controls. These results expand the mutation spectrum of TMC1 with five novel mutations and provide data for the significant contribution of TMC1 mutations in hearing loss.
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Affiliation(s)
- Asli Sirmaci
- Division of Clinical Molecular Pathology and Genetics, Department of Pediatrics, Ankara University School of Medicine, Ankara, Turkey
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