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Drabkin M, Jean MM, Noy Y, Halperin D, Yogev Y, Wormser O, Proskorovski-Ohayon R, Dolgin V, Levaot N, Brumfeld V, Ovadia S, Kishner M, Kazenell U, Avraham KB, Shelef I, Birk OS. SMARCA4 mutation causes human otosclerosis and a similar phenotype in mice. J Med Genet 2024; 61:117-124. [PMID: 37399313 PMCID: PMC10756932 DOI: 10.1136/jmg-2023-109264] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/08/2023] [Accepted: 06/09/2023] [Indexed: 07/05/2023]
Abstract
BACKGROUND Otosclerosis is a common cause of adult-onset progressive hearing loss, affecting 0.3%-0.4% of the population. It results from dysregulation of bone homeostasis in the otic capsule, most commonly leading to fixation of the stapes bone, impairing sound conduction through the middle ear. Otosclerosis has a well-known genetic predisposition including familial cases with apparent autosomal dominant mode of inheritance. While linkage analysis and genome-wide association studies suggested an association with several genomic loci and with genes encoding structural proteins involved in bone formation or metabolism, the molecular genetic pathophysiology of human otosclerosis is yet mostly unknown. METHODS Whole-exome sequencing, linkage analysis, generation of CRISPR mutant mice, hearing tests and micro-CT. RESULTS Through genetic studies of kindred with seven individuals affected by apparent autosomal dominant otosclerosis, we identified a disease-causing variant in SMARCA4, encoding a key component of the PBAF chromatin remodelling complex. We generated CRISPR-Cas9 transgenic mice carrying the human mutation in the mouse SMARCA4 orthologue. Mutant Smarca4+/E1548K mice exhibited marked hearing impairment demonstrated through acoustic startle response and auditory brainstem response tests. Isolated ossicles of the auditory bullae of mutant mice exhibited a highly irregular structure of the incus bone, and their in situ micro-CT studies demonstrated the anomalous structure of the incus bone, causing disruption in the ossicular chain. CONCLUSION We demonstrate that otosclerosis can be caused by a variant in SMARCA4, with a similar phenotype of hearing impairment and abnormal bone formation in the auditory bullae in transgenic mice carrying the human mutation in the mouse SMARCA4 orthologue.
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Affiliation(s)
- Max Drabkin
- The Morris Kahn Laboratory of Human Genetics, Shraga Segal Department of Microbiology, Immunology and Genetics, Faculty of Health Sciences, Ben-Gurion University of the Negev, Beer Sheva, Israel
| | - Matan M Jean
- The Morris Kahn Laboratory of Human Genetics, Shraga Segal Department of Microbiology, Immunology and Genetics, Faculty of Health Sciences, Ben-Gurion University of the Negev, Beer Sheva, Israel
| | - Yael Noy
- Department of Human Molecular Genetics and Biochemistry, Faculty of Medicine and Sagol School of Neuroscience, Tel Aviv University, Tel Aviv, Israel
| | - Daniel Halperin
- The Morris Kahn Laboratory of Human Genetics, Shraga Segal Department of Microbiology, Immunology and Genetics, Faculty of Health Sciences, Ben-Gurion University of the Negev, Beer Sheva, Israel
| | - Yuval Yogev
- The Morris Kahn Laboratory of Human Genetics, Shraga Segal Department of Microbiology, Immunology and Genetics, Faculty of Health Sciences, Ben-Gurion University of the Negev, Beer Sheva, Israel
| | - Ohad Wormser
- The Morris Kahn Laboratory of Human Genetics, Shraga Segal Department of Microbiology, Immunology and Genetics, Faculty of Health Sciences, Ben-Gurion University of the Negev, Beer Sheva, Israel
| | - Regina Proskorovski-Ohayon
- The Morris Kahn Laboratory of Human Genetics, Shraga Segal Department of Microbiology, Immunology and Genetics, Faculty of Health Sciences, Ben-Gurion University of the Negev, Beer Sheva, Israel
| | - Vadim Dolgin
- The Morris Kahn Laboratory of Human Genetics, Shraga Segal Department of Microbiology, Immunology and Genetics, Faculty of Health Sciences, Ben-Gurion University of the Negev, Beer Sheva, Israel
| | - Noam Levaot
- Department of Physiology and Cell Biology, Ben-Gurion University of the Negev, Beer-Sheva, Israel
| | - Vlad Brumfeld
- Department of Chemical Research Support, Weizmann Institute of Science, Rehovot, Israel
| | - Shira Ovadia
- Ben-Gurion University of the Negev, Beer-Sheva, Israel
| | - Mor Kishner
- Department of Life Sciences, Ben-Gurion University of the Negev, Beer-Sheva, Israel
| | - Udi Kazenell
- Department of Otolaryngology, Head and Neck Surgery, Kaplan Medical Center, Rehovot, Israel
| | - Karen B Avraham
- Department of Human Molecular Genetics and Biochemistry, Faculty of Medicine and Sagol School of Neuroscience, Tel Aviv University, Tel Aviv, Israel
| | - Ilan Shelef
- Department of Radiology, Ben-Gurion University of the Negev, Beer-Sheva, Israel
| | - Ohad S Birk
- The Morris Kahn Laboratory of Human Genetics, Shraga Segal Department of Microbiology, Immunology and Genetics, Faculty of Health Sciences, Ben-Gurion University of the Negev, Beer Sheva, Israel
- Genetics Institute, Soroka University Medical Center, Faculty of Health Sciences, Ben-Gurion University of the Negev, Beer-Sheva, Israel
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Singh N, Hansdah K, Bouzid A, Ray CS, Desai A, Panda KC, Choudhury JC, Tekari A, Masmoudi S, Ramchander PV. Genetic variants and altered expression of SERPINF1 confer disease susceptibility in patients with otosclerosis. J Hum Genet 2023; 68:635-642. [PMID: 37308566 DOI: 10.1038/s10038-023-01158-w] [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: 12/15/2022] [Revised: 03/27/2023] [Accepted: 04/27/2023] [Indexed: 06/14/2023]
Abstract
Otosclerosis (OTSC) is a focal and diffuse bone disorder of the human middle ear characterized by abnormal bone growth and deposition at the stapes' footplate. This hinders the transmission of acoustic waves to the inner ear leading to subsequent conductive hearing loss. The plausible convections for the disease are genetic and environmental factors with yet an unraveled root cause. Recently, exome sequencing of European individuals with OTSC revealed rare pathogenic variants in the Serpin Peptidase Inhibitor, Clade F (SERPINF1) gene. Here, we sought to investigate the causal variants of SERPINF1 in the Indian population. The gene and protein expression was also evaluated in otosclerotic stapes to ameliorate our understanding of the potential effect of this gene in OTSC. A total of 230 OTSC patients and 230 healthy controls were genotyped by single-strand conformational polymorphism and Sanger sequencing methods. By comparing the case controls, we identified five rare variants (c.72 C > T, c.151 G > A, c.242 C > G, c.823 A > T, and c.826 T > A) only in patients. Four variants c.390 T > C (p = 0.048), c.440-39 C > T (p = 0.007), c.643 + 9 G > A (p = 0.035), and c.643 + 82 T > C (p = 0.005) were found to be significantly associated with the disease. Down-regulation of SERPINF1 transcript level in otosclerotic stapes was quantified by qRT-PCR, ddPCR and further validated by in situ hybridization. Similarly, reduced protein expression was observed by immunohistochemistry and immunofluorescence in otosclerotic stapes that corroborate with immunoblotting of patients' plasma samples. Our findings identified that SERPINF1 variants are associated with the disease. Furthermore, reduced expression of SERPINF1 in otosclerotic stapes might contribute to OTSC pathophysiology.
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Affiliation(s)
- Neha Singh
- Institute of Life Sciences, Nalco Square, Chandrasekharpur, Bhubaneswar, India
- Regional Centre for Biotechnology, Faridabad, India
| | - Kirtal Hansdah
- Institute of Life Sciences, Nalco Square, Chandrasekharpur, Bhubaneswar, India
| | - Amal Bouzid
- Laboratory of Molecular and Cellular Screening Processes, Centre of Biotechnology of Sfax, University of Sfax, Sfax, Tunisia
- Sharjah Institute for Medical Research, College of Medicine, University of Sharjah, Sharjah, United Arab Emirates
| | - Chinmay Sundar Ray
- Department of Ear, Nose, and Throat (ENT), Shrirama Chandra Bhanja (SCB) Medical College & Hospital, Cuttack, India
| | - Ashim Desai
- Dr. ABR Desai Ear, Nose and Throat (ENT) Clinic and Research Centre, Mumbai, India
| | - Khirod Chandra Panda
- Department of Ear, Nose, and Throat (ENT), Shrirama Chandra Bhanja (SCB) Medical College & Hospital, Cuttack, India
| | - Jyotish Chandra Choudhury
- Department of Forensic Medicine & Toxicology (FMT), Shrirama Chandra Bhanja (SCB) Medical College & Hospital, Cuttack, India
| | - Adel Tekari
- Laboratory of Molecular and Cellular Screening Processes, Centre of Biotechnology of Sfax, University of Sfax, Sfax, Tunisia
| | - Saber Masmoudi
- Laboratory of Molecular and Cellular Screening Processes, Centre of Biotechnology of Sfax, University of Sfax, Sfax, Tunisia
| | - Puppala Venkat Ramchander
- Institute of Life Sciences, Nalco Square, Chandrasekharpur, Bhubaneswar, India.
- Regional Centre for Biotechnology, Faridabad, India.
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3
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Silva VAR, Pauna HF, Lavinsky J, Guimarães GC, Abrahão NM, Massuda ET, Vianna MF, Ikino CMY, Santos VM, Polanski JF, Silva MNLD, Sampaio ALL, Zanini RVR, Lourençone LFM, Denaro MMDC, Calil DB, Chone CT, Castilho AM. Brazilian Society of Otology task force - Otosclerosis: evaluation and treatment. Braz J Otorhinolaryngol 2023; 89:101303. [PMID: 37647735 PMCID: PMC10474207 DOI: 10.1016/j.bjorl.2023.101303] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/21/2023] [Accepted: 08/06/2023] [Indexed: 09/01/2023] Open
Abstract
OBJECTIVES To review and provide evidence-based recommendations for the diagnosis and treatment of otosclerosis. METHODS Task force members were educated on knowledge synthesis methods, including electronic database search, review and selection of relevant citations, and critical appraisal of selected studies. Articles written in English or Portuguese on otosclerosis were eligible for inclusion. The American College of Physicians' guideline grading system and the American Thyroid Association's guideline criteria were used for critical appraisal of evidence and recommendations for therapeutic interventions. RESULTS The topics were divided into 2 parts: 1) Diagnosis - audiologic and radiologic; 2) Treatment - hearing AIDS, pharmacological therapy, stapes surgery, and implantable devices - bone-anchored devices, active middle ear implants, and Cochlear Implants (CI). CONCLUSIONS The pathophysiology of otosclerosis has not yet been fully elucidated, but environmental factors and unidentified genes are likely to play a significant role in it. Women with otosclerosis are not at increased risk of worsening clinical condition due to the use of contraceptives or during pregnancy. Drug treatment has shown little benefit. If the patient does not want to undergo stapedotomy, the use of hearing aids is well indicated. Implantable systems should be indicated only in rare cases, and the CI should be indicated in cases of profound deafness.
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Affiliation(s)
- Vagner Antonio Rodrigues Silva
- Universidade Estadual de Campinas (Unicamp), Faculdade de Ciências Médicas (FCM), Departamento de Otorrinolaringologia, Cirurgia de Cabeça e Pescoço, Campinas, SP, Brazil
| | - Henrique Furlan Pauna
- Hospital Universitário Cajuru, Departamento de Otorrinolaringologia, Curitiba, PR, Brazil
| | - Joel Lavinsky
- Universidade Federal do Rio Grande do Sul (UFRGS), Departamento de Ciências Morfológicas, Porto Alegre, RS, Brazil
| | - Guilherme Corrêa Guimarães
- Universidade Estadual de Campinas (Unicamp), Faculdade de Ciências Médicas (FCM), Departamento de Otorrinolaringologia, Cirurgia de Cabeça e Pescoço, Campinas, SP, Brazil
| | - Nicolau Moreira Abrahão
- Universidade Estadual de Campinas (Unicamp), Faculdade de Ciências Médicas (FCM), Departamento de Otorrinolaringologia, Cirurgia de Cabeça e Pescoço, Campinas, SP, Brazil
| | - Eduardo Tanaka Massuda
- Universidade de São Paulo (USP), Faculdade de Medicina de Ribeirão Preto, Departamento de Oftalmologia, Otorrinolaringologia e Cirurgia de Cabeça e Pescoço, Ribeirão Preto, SP, Brazil
| | - Melissa Ferreira Vianna
- Irmandade Santa Casa de Misericordia de São Paulo, Departamento de Otorrinolaringologia, São Paulo, SP, Brazil
| | - Cláudio Márcio Yudi Ikino
- Universidade Federal de Santa Catarina, Departamento de Cirurgia e Hospital Universitário, Florianópolis, SC, Brazil
| | - Vanessa Mazanek Santos
- Universidade Federal do Paraná, Hospital de Clínicas, Departamento de Otorrinolaringologia e Cirurgia de Cabeça e Pescoço, Curitiba, PR, Brazil
| | - José Fernando Polanski
- Universidade Federal do Paraná, Hospital de Clínicas, Departamento de Otorrinolaringologia e Cirurgia de Cabeça e Pescoço, Curitiba, PR, Brazil; Faculdade Evangélica Mackensie do Paraná, Curitiba, PR, Brazil
| | | | - André Luiz Lopes Sampaio
- Universidade de Brasília (UnB), Faculdade de Medicina, Laboratório de Ensino e Pesquisa em Otorrinolaringologia, Brasília, DF, Brazil
| | | | - Luiz Fernando Manzoni Lourençone
- Universidade de São Paulo, Faculdade de Odontologia de Bauru, Bauru, SP, Brazil; Universidade de São Paulo, Hospital de Reabilitação de Anomalias Craniofaciais, Bauru, SP, Brazil
| | | | - Daniela Bortoloti Calil
- Universidade Estadual de Campinas (Unicamp), Faculdade de Ciências Médicas (FCM), Departamento de Otorrinolaringologia, Cirurgia de Cabeça e Pescoço, Campinas, SP, Brazil
| | - Carlos Takahiro Chone
- Universidade Estadual de Campinas (Unicamp), Faculdade de Ciências Médicas (FCM), Departamento de Otorrinolaringologia, Cirurgia de Cabeça e Pescoço, Campinas, SP, Brazil
| | - Arthur Menino Castilho
- Universidade Estadual de Campinas (Unicamp), Faculdade de Ciências Médicas (FCM), Departamento de Otorrinolaringologia, Cirurgia de Cabeça e Pescoço, Campinas, SP, Brazil.
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Priyadarshi S, Hansdah K, Singh N, Bouzid A, Ray CS, Panda KC, Biswal NC, Desai A, Choudhury JC, Tekari A, Masmoudi S, Ramchander PV. The risks of RELN polymorphisms and its expression in the development of otosclerosis. PLoS One 2022; 17:e0269558. [PMID: 35658052 PMCID: PMC9165908 DOI: 10.1371/journal.pone.0269558] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/31/2021] [Accepted: 05/23/2022] [Indexed: 11/19/2022] Open
Abstract
Otosclerosis (OTSC) is the primary form of conductive hearing loss characterized by abnormal bone remodelling within the otic capsule of the human middle ear. A genetic association of the RELN SNP rs3914132 with OTSC has been identified in European population. Previously, we showed a trend towards association of this polymorphism with OTSC and identified a rare variant rs74503667 in a familial case. Here, we genotyped these variants in an Indian cohort composed of 254 OTSC cases and 262 controls. We detected a significant association of rs3914132 with OTSC (OR = 0.569, 95%CI = 0.386–0.838, p = 0.0041). To confirm this finding, we completed a meta-analysis which revealed a significant association of the rs3914132 polymorphism with OTSC (Z = 6.707, p<0.0001) across different ethnic populations. Linkage analysis found the evidence of linkage at RELN locus (LOD score 2.1059) in the OTSC family which has shown the transmission of rare variant rs74503667 in the affected individuals. To understand the role of RELN and its receptors in the development of OTSC, we went further to perform a functional analysis of RELN/reelin. Here we detected a reduced RELN (p = 0.0068) and VLDLR (p = 0.0348) mRNA levels in the otosclerotic stapes tissues. Furthermore, a reduced reelin protein expression by immunohistochemistry was confirmed in the otosclerotic tissues. Electrophoretic mobility shift assays for rs3914132 and rs74503667 variants revealed an altered binding of transcription factors in the mutated sequences which indicates the regulatory role of these variations in the RELN gene regulation. Subsequently, we showed by scanning electron microscopy a change in stapes bone morphology of otosclerotic patients. In conclusion, this study evidenced that the rare variation rs74503667 and the common polymorphism rs3914132 in the RELN gene and its reduced expressions that were associated with OTSC.
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Affiliation(s)
- Saurabh Priyadarshi
- Institute of Life Sciences, Nalco Square, Chandrasekharpur, Bhubaneswar, India
| | - Kirtal Hansdah
- Institute of Life Sciences, Nalco Square, Chandrasekharpur, Bhubaneswar, India
| | - Neha Singh
- Institute of Life Sciences, Nalco Square, Chandrasekharpur, Bhubaneswar, India
| | - Amal Bouzid
- Laboratory of Molecular and Cellular Screening Processes, Centre of Biotechnology of Sfax, University of Sfax, Sfax, Tunisia
| | - Chinmay Sundar Ray
- Department of Ear, Nose, and Throat (ENT), Shrirama Chandra Bhanj (SCB) Medical College & Hospital, Cuttack, India
| | | | - Narayan Chandra Biswal
- Department of Ear, Nose, and Throat (ENT), Shrirama Chandra Bhanj (SCB) Medical College & Hospital, Cuttack, India
| | - Ashim Desai
- Dr. ABR Desai Ear, Nose and Throat (ENT) Clinic and Research Centre, Mumbai, India
| | - Jyotish Chandra Choudhury
- Department of Forensic Medicine & Toxicology (FMT), Shrirama Chandra Bhanj (SCB) Medical College & Hospital, Cuttack, India
| | - Adel Tekari
- Laboratory of Molecular and Cellular Screening Processes, Centre of Biotechnology of Sfax, University of Sfax, Sfax, Tunisia
| | - Saber Masmoudi
- Laboratory of Molecular and Cellular Screening Processes, Centre of Biotechnology of Sfax, University of Sfax, Sfax, Tunisia
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Bouzid A, Chelly A, Tekari A, Singh N, Hansdah K, Achour I, Ben Ayed I, Jbeli F, Charfeddine I, Ramchander PV, Hamoudi R, Masmoudi S. Genetic Association of rs1021188 and DNA Methylation Signatures of TNFSF11 in the Risk of Conductive Hearing Loss. Front Med (Lausanne) 2022; 9:870244. [PMID: 35510247 PMCID: PMC9058115 DOI: 10.3389/fmed.2022.870244] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/06/2022] [Accepted: 03/08/2022] [Indexed: 11/25/2022] Open
Abstract
Otosclerosis (OTSC) is a complex bone disorder of the otic capsule, which causes conductive hearing impairment in human adults. The dysregulation of the signaling axis mediated by the receptor activator of nuclear factor-kappa-B (RANK), RANK ligand (RANKL), and osteoprotegerin has been widely attributed to the context of metabolic bone disorders. While genetic associations and epigenetic alterations in the TNFSF11 gene (RANKL) have been well-linked to metabolic bone diseases of the skeleton, particularly osteoporosis, they have never been addressed in OTSC. This study aimed to assess whether the genetic association of rs1021188 polymorphism in the upstream of TNFSF11 and the DNA methylation changes in its promoter CpG-region reveal the susceptibility of OTSC. Peripheral blood DNA samples were collected from unrelated Tunisian-North African subjects for genotyping (109 cases and 120 controls) and for DNA methylation analysis (40 cases and 40 controls). The gender-stratified analysis showed that the TNFSF11 rs1021188 C/T was associated with OTSC in men (p = 0.023), but not in women (p = 0.458). Individuals with CC genotype were more susceptible to OTSC, suggesting an increased risk to disease development. Using publicly available data, the rs1021188 was within a cluster grouping the subpopulations with African ethnicity. Moreover, 26 loci in the TNFSF11 gene were in linkage disequilibrium with rs1021188, revealing relative similarities between different populations. Significant differences in both DNA methylation and unmethylation status were detected with 4.53- and 4.83-fold decreases in the global DNA methylation levels in female and male OTSC groups, respectively. These changes could contribute to an increased risk of OTSC development. Bioinformatic analyses indicated that each of the rs1021188 variations and the DNA methylation changes in the promoter CpG-sites within TNFSF11 may play an important role in its transcription regulation. To our knowledge, this is the first study that investigates an independent effect of the rs1021188 polymorphism and DNA hypomethylation of TNFSF11 promoter in OTSC. Genetic and epigenetic changes in the regulatory regions of TNFSF11 could offer new molecular insights into the understanding of the complexity of OTSC.
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Affiliation(s)
- Amal Bouzid
- Sharjah Institute for Medical Research, College of Medicine, University of Sharjah, Sharjah, United Arab Emirates
- Laboratory of Molecular and Cellular Screening Processes, Centre of Biotechnology of Sfax, University of Sfax, Sfax, Tunisia
- *Correspondence: Amal Bouzid
| | - Ameni Chelly
- Laboratory of Molecular and Cellular Screening Processes, Centre of Biotechnology of Sfax, University of Sfax, Sfax, Tunisia
| | - Adel Tekari
- Laboratory of Molecular and Cellular Screening Processes, Centre of Biotechnology of Sfax, University of Sfax, Sfax, Tunisia
| | - Neha Singh
- Institute of Life Sciences, Nalco Square, Bhubaneswar, India
| | - Kirtal Hansdah
- Institute of Life Sciences, Nalco Square, Bhubaneswar, India
| | - Imen Achour
- Department of Otorhinolaryngology, Habib Bourguiba Hospital, University of Sfax, Sfax, Tunisia
| | - Ikhlas Ben Ayed
- Medical Genetic Department, University Hedi Chaker Hospital of Sfax, Sfax, Tunisia
| | - Fida Jbeli
- Laboratory of Molecular and Cellular Screening Processes, Centre of Biotechnology of Sfax, University of Sfax, Sfax, Tunisia
| | - Ilhem Charfeddine
- Department of Otorhinolaryngology, Habib Bourguiba Hospital, University of Sfax, Sfax, Tunisia
| | | | - Rifat Hamoudi
- Sharjah Institute for Medical Research, College of Medicine, University of Sharjah, Sharjah, United Arab Emirates
- Division of Surgery and Interventional Science, University College London, London, United Kingdom
| | - Saber Masmoudi
- Laboratory of Molecular and Cellular Screening Processes, Centre of Biotechnology of Sfax, University of Sfax, Sfax, Tunisia
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Genetics of otosclerosis: finally catching up with other complex traits? Hum Genet 2021; 141:939-950. [PMID: 34498117 DOI: 10.1007/s00439-021-02357-1] [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: 08/29/2021] [Indexed: 10/20/2022]
Abstract
Otosclerosis is a relatively common cause of hearing impairment, characterized by abnormal bone remodeling of the middle and inner ear. In about 50-60% of the patients, the disease is present in a familial form. In most of these families, otosclerosis seems to be caused by a small number of genetic factors (oligogenic) while only in a small number of families the disease seems to be truly monogenic. In the remaining patients a complex genetic form of otosclerosis is present. Several studies have aimed to identify the genetic factors underlying otosclerosis, which has led to the identification of eight published loci for monogenic otosclerosis, as well as several genes and one chromosomal region (11q13.1) with a clear association with otosclerosis. Implementation of next-generation sequencing (NGS) in otosclerosis research has led to the identification of pathogenic variants in MEPE, ACAN and SERPINF1, although the pathogenic role of the latter is under debate. In addition, a recent GWAS can be considered a breakthrough for otosclerosis as it identified several strong associations with otosclerosis and suggested new potential candidate genes. These recent findings are important for unraveling the genetic architecture of otosclerosis. More future studies will help to understand the complete pathogenesis of the disease.
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Mutations in the osteoprotegerin-encoding gene are associated with temporomandibular joint ankylosis. Oral Surg Oral Med Oral Pathol Oral Radiol 2021; 133:308-314. [PMID: 34758942 DOI: 10.1016/j.oooo.2021.08.017] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/03/2021] [Revised: 06/15/2021] [Accepted: 08/22/2021] [Indexed: 11/20/2022]
Abstract
OBJECTIVE This study aimed to investigate genetic variations in the osteoprotegerin-encoding gene (TNFRSF11B) in patients with temporomandibular joint ankylosis (TMJA). STUDY DESIGN The sample comprised 17 patients diagnosed with TMJA, of both sexes with ages ranging from 6 to 57 years old. TNFRSF11B mutational analysis was performed using the Sanger sequencing method with DNA extracted from oral cells, and the functional impact prediction of the variants was assessed using bioinformatic analysis. RESULTS Sequencing analysis identified 15 (88.23%) patients that presented at least 1 genetic variant in TNFRSF11B. The mutation rs202090603 (p.E33K) was found in 6 individuals, and rs140782326 (p.V281M), rs11573942 (p.L295), and rs1375250340 (p.I389T) were identified in 1 subject each. According to the pathogenicity potential of mutations, 3 variants were considered of low impact (rs2073618, rs202090603, and rs2228568) and 3 as disease causing (rs140782326, rs11573942, and rs1375250340). The variant rs202090603 (p.E33K) was found in the first cysteine domain with differences in the loop positions of p.E33K mutated the 3D structure of osteoprotegerin. CONCLUSION Two polymorphisms (rs2073618 and rs2228568) and the mutations rs202090603 (p.E33K), rs140782326 (p.V281M), rs11573942 (p.L295), and rs1375250340 (p.I389T) in the TNFRSF11B gene may be associated with TMJA.
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