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Watanabe K, Nishio SY, Usami SI. The prevalence and clinical features of MYO7A-related hearing loss including DFNA11, DFNB2 and USH1B. Sci Rep 2024; 14:8326. [PMID: 38594301 PMCID: PMC11003999 DOI: 10.1038/s41598-024-57415-1] [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: 11/29/2023] [Accepted: 03/18/2024] [Indexed: 04/11/2024] Open
Abstract
The MYO7A gene is known to be responsible for both syndromic hearing loss (Usher syndrome type1B:USH1B) and non-syndromic hearing loss including autosomal dominant and autosomal recessive inheritance (DFNA11, DFNB2). However, the prevalence and detailed clinical features of MYO7A-associated hearing loss across a large population remain unclear. In this study, we conducted next-generation sequencing analysis for a large cohort of 10,042 Japanese hearing loss patients. As a result, 137 patients were identified with MYO7A-associated hearing loss so that the prevalence among Japanese hearing loss patients was 1.36%. We identified 70 disease-causing candidate variants in this study, with 36 of them being novel variants. All variants identified in autosomal dominant cases were missense or in-frame deletion variants. Among the autosomal recessive cases, all patients had at least one missense variant. On the other hand, in patients with Usher syndrome, almost half of the patients carried biallelic null variants (nonsense, splicing, and frameshift variants). Most of the autosomal dominant cases showed late-onset progressive hearing loss. On the other hand, cases with autosomal recessive inheritance or Usher syndrome showed congenital or early-onset hearing loss. The visual symptoms in the Usher syndrome cases developed between age 5-15, and the condition was diagnosed at about 6-15 years of age.
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Affiliation(s)
- Kizuki Watanabe
- Department of Otorhinolaryngology, Shinshu University School of Medicine, 3-1-1 Asahi, Matsumoto, Japan
| | - Shin-Ya Nishio
- Department of Hearing Implant Sciences, Shinshu University School of Medicine, 3-1-1 Asahi, Matsumoto, 390-8621, Japan
| | - Shin-Ichi Usami
- Department of Hearing Implant Sciences, Shinshu University School of Medicine, 3-1-1 Asahi, Matsumoto, 390-8621, Japan.
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2
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Xia CF, Yan R, Su WW, Liu YH. Autosomal dominant non-syndromic hearing loss caused by a novel mutation in MYO7A: A case report and review of the literature. World J Clin Cases 2023; 11:5962-5969. [PMID: 37727480 PMCID: PMC10506018 DOI: 10.12998/wjcc.v11.i25.5962] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/13/2023] [Revised: 07/16/2023] [Accepted: 08/08/2023] [Indexed: 09/01/2023] Open
Abstract
BACKGROUND Variants in the MYO7A gene commonly result in Usher syndrome, and in rare cases lead to autosomal dominant non-syndromic deafness (DFNA11). Currently, only nine variants have been reported to be responsible for DFNA11 and their clinical phenotypes are not identical. Here we present a novel variant causing DFNA11 identified in a three-generation Chinese family. CASE SUMMARY The proband was a 53-year-old Han male who presented with post-lingual bilateral symmetrical moderate sensorineural hearing loss. We learned from the patient's medical history collection that multiple family members also had similar hearing loss, generally occurring around the age of 40. Subsequent investigation by high-throughput sequencing identified a novel MYO7A variant. To provide evidence supporting that this variant is responsible for the hearing loss in the studied family, we performed Sanger sequencing on 11 family members and found that the variant co-segregated with the deafness phenotype. In addition, the clinical manifestation of the 11 affected family members was found to be late-onset bilateral slowly progressive hearing loss, inherited in this family in an autosomal dominant manner. None of the affected family members had visual impairment or vestibular symptoms; therefore, we believe that this novel MYO7A variant is responsible for the rare DFNA11 in this family. CONCLUSION We report a novel variant leading to DFNA11 which further enriches the collection of MYO7A variants, and our review of the nine previous variants that have been identified to cause DFNA11 provides a reference for clinical genetic counseling.
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Affiliation(s)
- Cai-Feng Xia
- Department of Otolaryngology Head and Neck Surgery, Peking University First Hospital, Beijing 100034, China
| | - Rong Yan
- Department of Otolaryngology Head and Neck Surgery, Peking University First Hospital, Beijing 100034, China
| | - Wen-Wen Su
- Department of Otolaryngology Head and Neck Surgery, Peking University First Hospital, Beijing 100034, China
| | - Yu-He Liu
- Department of Otolaryngology Head and Neck Surgery, Peking University First Hospital, Beijing 100034, China
- Department of Otolaryngology Head and Neck Surgery, Beijing Friendship Hospital, Capital Medical University, Beijing 100050, China
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3
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Gan NS, Oziębło D, Skarżyński H, Ołdak M. Monogenic Causes of Low-Frequency Non-Syndromic Hearing Loss. Audiol Neurootol 2023; 28:327-337. [PMID: 37121227 DOI: 10.1159/000529464] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/22/2022] [Accepted: 01/23/2023] [Indexed: 05/02/2023] Open
Abstract
BACKGROUND Low-frequency non-syndromic hearing loss (LFNSHL) is a rare form of hearing loss (HL). It is defined as HL at low frequencies (≤2,000 Hz) resulting in a characteristic ascending audiogram. LFNSHL is usually diagnosed postlingually and is progressive, leading to HL affecting other frequencies as well. Sometimes it occurs with tinnitus. Around half of the diagnosed prelingual HL cases have a genetic cause and it is usually inherited in an autosomal recessive mode. Postlingual HL caused by genetic changes generally has an autosomal dominant pattern of inheritance and its incidence remains unknown. SUMMARY To date, only a handful of genes have been found as causing LFNSHL: well-established WFS1 and, reported in some cases, DIAPH1, MYO7A, TNC, and CCDC50 (respectively, responsible for DFNA6/14/38, DFNA1, DFNA11, DFNA56, and DFNA44). In this review, we set out audiological phenotypes, causative genetic changes, and molecular mechanisms leading to the development of LFNSHL. KEY MESSAGES LFNSHL is most commonly caused by pathogenic variants in the WFS1 gene, but it is also important to consider changes in other HL genes, which may result in similar audiological phenotype.
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Affiliation(s)
- Nina Sara Gan
- Department of Genetics, Institute of Physiology and Pathology of Hearing, Warsaw, Poland
| | - Dominika Oziębło
- Department of Genetics, Institute of Physiology and Pathology of Hearing, Warsaw, Poland
| | - Henryk Skarżyński
- Oto-Rhino-Laryngology Surgery Clinic, Institute of Physiology and Pathology of Hearing, Warsaw, Poland
| | - Monika Ołdak
- Department of Genetics, Institute of Physiology and Pathology of Hearing, Warsaw, Poland
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4
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Kim YR, Kim HM, Lee B, Baek JI, Lee KY, Park HJ, Kim UK. Identification of novel missense mutation related with non-syndromic sensorineural deafness, DFNA11 in korean family by NGS. Genes Genomics 2023; 45:225-230. [PMID: 36630074 DOI: 10.1007/s13258-022-01357-3] [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: 11/24/2022] [Accepted: 12/17/2022] [Indexed: 01/12/2023]
Abstract
BACKGOUND Hereditary hearing loss is one of the most common genetically heterogeneous defects in human. About 70% of hereditary hearing loss is defined as non-syndromic hearing loss showing loss of hearing ability without any other symptoms. Up to date, the identified genes associated with non-syndromic hearing loss are 128, including 52 genes for DFNA and 76 genes for DFNB. Because of high levels of heterogeneity, it is difficult to identify the causative factors for hearing loss using Sanger sequencing. OBJECTIVE Our aim was to detect causative factors and investigate pathogenic mutations, which co-segregates within the candidate family. METHODS We used Next Generation Sequencing technique to investigate whole-exome sequences of a Korean family with non-syndromic hereditary hearing loss. The family showed autosomal dominant inheritance pattern. RESULTS We identified a novel missense variation, c.1978G > A in MYO7A gene, in the family with the autosomal dominant inheritance pattern. c.1978G > A produced Gly660Arg in the motor head domain of Myosin VIIA disrupt the ATP- and actin-binding motif function. CONCLUSION This study is the first to report pathogenic mutations within MYO7A gene in Korean family and our data would facilitate diagnosing the primary cause of hereditary hearing loss in Korean.
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Affiliation(s)
- Ye-Ri Kim
- Department of Biology, College of Natural Sciences, Kyungpook National University, Daegu, Republic of Korea
- Advanced Bio-Resource Research Center, Kyungpook National University, Daegu, Republic of Korea
| | - Hye-Min Kim
- Department of Biology, College of Natural Sciences, Kyungpook National University, Daegu, Republic of Korea
- School of Life Sciences, BK21 Plus KNU Creative BioResearch Group, Kyungpook National University, Daegu, Republic of Korea
| | - Byeonghyeon Lee
- New Drug Development Center, Daegu-Gyeongbuk Medical Innovation Foundation, Daegu, Republic of Korea
| | - Jeong-In Baek
- Department of Companion Animal Health, College of Rehabilitation and Health, Deagu Haany University, Gyeongsan, Republic of Korea
| | - Kyu-Yup Lee
- Department of Internal Medicine, Research Institute of Aging and Metabolism, School of Medicine, Kyungpook National University, Daegu, Republic of Korea
| | | | - Un-Kyung Kim
- Department of Biology, College of Natural Sciences, Kyungpook National University, Daegu, Republic of Korea.
- School of Life Sciences, BK21 Plus KNU Creative BioResearch Group, Kyungpook National University, Daegu, Republic of Korea.
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5
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Sharma N, Kumari D, Panigrahi I, Khetarpal P. A systematic review of the monogenic causes of Non-Syndromic Hearing Loss (NSHL) and discussion of Current Diagnosis and Treatment options. Clin Genet 2023; 103:16-34. [PMID: 36089522 DOI: 10.1111/cge.14228] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/26/2022] [Revised: 09/02/2022] [Accepted: 09/06/2022] [Indexed: 12/13/2022]
Abstract
Hearing impairment is one of the most widespread inheritable sensory disorder affecting at least 1 in every 1000 born. About two-third of hereditary hearing loss (HHL) disorders are non-syndromic. To provide comprehensive update of monogenic causes of non-syndromic hearing loss (NSHL), literature search has been carried out with appropriate keywords in the following databases-PubMed, Google Scholar, Cochrane library, and Science Direct. Out of 2214 papers, 271 papers were shortlisted after applying inclusion and exclusion criterion. Data extracted from selected papers include information about gene name, identified pathogenic variants, ethnicity of the patient, age of onset, gender, title, authors' name, and year of publication. Overall, pathogenic variants in 98 different genes have been associated with NSHL. These genes have important role to play during early embryonic development in ear structure formation and hearing development. Here, we also review briefly the recent information about diagnosis and treatment approaches. Understanding pathogenic genetic variants are helpful in the management of affected and may offer targeted therapies in future.
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Affiliation(s)
- Nandita Sharma
- Department of Human Genetics and Molecular Medicine, School of Health Sciences, Central University of Punjab, Bathinda, India
| | - Divya Kumari
- Department of Pediatrics Medicine, Post Graduate Institute of Medical Education and Research, Chandigarh, India
| | - Inusha Panigrahi
- Department of Pediatrics Medicine, Post Graduate Institute of Medical Education and Research, Chandigarh, India
| | - Preeti Khetarpal
- Department of Human Genetics and Molecular Medicine, School of Health Sciences, Central University of Punjab, Bathinda, India
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Joo SY, Na G, Kim JA, Yoo JE, Kim DH, Kim SJ, Jang SH, Yu S, Kim HY, Choi JY, Gee HY, Jung J. Clinical Heterogeneity Associated with MYO7A Variants Relies on Affected Domains. Biomedicines 2022; 10:biomedicines10040798. [PMID: 35453549 PMCID: PMC9028242 DOI: 10.3390/biomedicines10040798] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/08/2022] [Revised: 03/26/2022] [Accepted: 03/28/2022] [Indexed: 02/04/2023] Open
Abstract
Autosomal dominant hearing loss (ADHL) manifests as an adult-onset disease or a progressive disease. MYO7A variants are associated with DFNA11, a subtype of ADHL. Here, we examined the role and genotype–phenotype correlation of MYO7A in ADHL. Enrolled families suspected of having post-lingual sensorineural hearing loss were selected for exome sequencing. Mutational alleles in MYO7A were identified according to ACMG guidelines. Segregation analysis was performed to examine whether pathogenic variants segregated with affected status of families. All identified pathogenic variants were evaluated for a phenotype–genotype correlation. MYO7A variants were detected in 4.7% of post-lingual families, and 12 of 14 families were multiplex. Five potentially pathogenic missense variants were identified. Fourteen variants causing autosomal dominant deafness were clustered in motor and MyTH4 domains of MYO7A protein. Missense variants in the motor domain caused late onset of hearing loss with ascending tendency. A severe audiological phenotype was apparent in individuals carrying tail domain variants. We report two new pathogenic variants responsible for DFNA11 in the Korean ADHL population. Dominant pathogenic variants of MYO7A occur frequently in motor and MyTH4 domains. Audiological differences among individuals correspond to specific domains which contain the variants. Therefore, appropriate rehabilitation is needed, particularly for patients with late-onset familial hearing loss.
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Affiliation(s)
- Sun Young Joo
- Department of Pharmacology, Graduate School of Medical Science, Brain Korea 21 Project, Yonsei University College of Medicine, Seoul 03722, Korea; (S.Y.J.); (J.A.K.); (S.J.K.); (S.H.J.); (S.Y.); (H.-Y.K.)
| | - Gina Na
- Department of Otorhinolaryngology, Ilsan Paik Hospital, Inje University College of Medicine, Goyang 10380, Korea;
- Department of Otorhinolaryngology, Yonsei University College of Medicine, Seoul 03722, Korea; (J.E.Y.); (D.H.K.); (J.Y.C.)
| | - Jung Ah Kim
- Department of Pharmacology, Graduate School of Medical Science, Brain Korea 21 Project, Yonsei University College of Medicine, Seoul 03722, Korea; (S.Y.J.); (J.A.K.); (S.J.K.); (S.H.J.); (S.Y.); (H.-Y.K.)
| | - Jee Eun Yoo
- Department of Otorhinolaryngology, Yonsei University College of Medicine, Seoul 03722, Korea; (J.E.Y.); (D.H.K.); (J.Y.C.)
| | - Da Hye Kim
- Department of Otorhinolaryngology, Yonsei University College of Medicine, Seoul 03722, Korea; (J.E.Y.); (D.H.K.); (J.Y.C.)
| | - Se Jin Kim
- Department of Pharmacology, Graduate School of Medical Science, Brain Korea 21 Project, Yonsei University College of Medicine, Seoul 03722, Korea; (S.Y.J.); (J.A.K.); (S.J.K.); (S.H.J.); (S.Y.); (H.-Y.K.)
| | - Seung Hyun Jang
- Department of Pharmacology, Graduate School of Medical Science, Brain Korea 21 Project, Yonsei University College of Medicine, Seoul 03722, Korea; (S.Y.J.); (J.A.K.); (S.J.K.); (S.H.J.); (S.Y.); (H.-Y.K.)
| | - Seyoung Yu
- Department of Pharmacology, Graduate School of Medical Science, Brain Korea 21 Project, Yonsei University College of Medicine, Seoul 03722, Korea; (S.Y.J.); (J.A.K.); (S.J.K.); (S.H.J.); (S.Y.); (H.-Y.K.)
| | - Hye-Youn Kim
- Department of Pharmacology, Graduate School of Medical Science, Brain Korea 21 Project, Yonsei University College of Medicine, Seoul 03722, Korea; (S.Y.J.); (J.A.K.); (S.J.K.); (S.H.J.); (S.Y.); (H.-Y.K.)
| | - Jae Young Choi
- Department of Otorhinolaryngology, Yonsei University College of Medicine, Seoul 03722, Korea; (J.E.Y.); (D.H.K.); (J.Y.C.)
| | - Heon Yung Gee
- Department of Pharmacology, Graduate School of Medical Science, Brain Korea 21 Project, Yonsei University College of Medicine, Seoul 03722, Korea; (S.Y.J.); (J.A.K.); (S.J.K.); (S.H.J.); (S.Y.); (H.-Y.K.)
- Correspondence: (H.Y.G.); (J.J.); Tel.: +82-2-2228-0755 (H.Y.G.); +82-2228-3622 (J.J.)
| | - Jinsei Jung
- Department of Otorhinolaryngology, Yonsei University College of Medicine, Seoul 03722, Korea; (J.E.Y.); (D.H.K.); (J.Y.C.)
- Correspondence: (H.Y.G.); (J.J.); Tel.: +82-2-2228-0755 (H.Y.G.); +82-2228-3622 (J.J.)
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7
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Sirko P, Kozlov AS. Immunohistochemistry localises myosin-7a to cochlear efferent boutons. Wellcome Open Res 2022; 7:1. [PMID: 35224213 PMCID: PMC8866907 DOI: 10.12688/wellcomeopenres.17428.2] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 02/14/2022] [Indexed: 11/26/2022] Open
Abstract
Background: Myosin 7a is an actin-binding motor protein involved in the formation of hair-cell stereocilia both in the cochlea and in the vestibular system. Mutations in myosin 7a are linked to congenital hearing loss and are present in 50% of Type-1 Usher syndrome patients who suffer from progressive hearing loss and vestibular system dysfunction. Methods: Myosin 7a is often used to visualise sensory hair cells due to its well characterised and localised expression profile. We thus conducted myosin-7a immunostaining across all three turns of the adult rat organ of Corti to visualise hair cells. Results: As expected, we observed myosin 7a staining in both inner and outer hair cells. Unexpectedly, we also observed strong myosin 7a staining in the medial olivocochlear efferent synaptic boutons contacting the outer hair cells. Efferent bouton myosin-7a staining was present across all three turns of the cochlea. We verified this localisation by co-staining with a known efferent bouton marker, the vesicular acetylcholine transporter. Conclusions: In addition to its role in stereocilia formation and maintenance, myosin 7a or certain myosin-7a expression variants might play a role in efferent synaptic transmission in the cochlea and thus ultimately influence cochlear gain regulation. Our immunohistochemistry results should be validated with other methods to confirm these serendipitous findings.
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Affiliation(s)
- Piotr Sirko
- Laboratory of Auditory Neuroscience and Biophysics, Department of Bioengineering, Imperial College London, London, SW7 2AZ, UK
| | - Andrei S. Kozlov
- Laboratory of Auditory Neuroscience and Biophysics, Department of Bioengineering, Imperial College London, London, SW7 2AZ, UK
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8
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Sirko P, Kozlov AS. Immunohistochemistry localises myosin-7a to cochlear efferent boutons. Wellcome Open Res 2022; 7:1. [PMID: 35224213 PMCID: PMC8866907 DOI: 10.12688/wellcomeopenres.17428.1] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 02/14/2022] [Indexed: 08/11/2023] Open
Abstract
Background: Myosin 7a is an actin-binding motor protein involved in the formation of hair-cell stereocilia both in the cochlea and in the vestibular system. Mutations in myosin 7a are linked to congenital hearing loss and are present in 50% of Type-1 Usher syndrome patients who suffer from progressive hearing loss and vestibular system dysfunction. Methods: Myosin 7a is often used to visualise sensory hair cells due to its well characterised and localised expression profile. We thus conducted myosin-7a immunostaining across all three turns of the adult rat organ of Corti to visualise hair cells. Results: As expected, we observed myosin 7a staining in both inner and outer hair cells. Unexpectedly, we also observed strong myosin 7a staining in the medial olivocochlear efferent synaptic boutons contacting the outer hair cells. Efferent bouton myosin-7a staining was present across all three turns of the cochlea. We verified this localisation by co-staining with a known efferent bouton marker, the vesicular acetylcholine transporter. Conclusions: In addition to its role in stereocilia formation and maintenance, myosin 7a or certain myosin-7a expression variants might play a role in efferent synaptic transmission in the cochlea and thus ultimately influence cochlear gain regulation. Our immunohistochemistry results should be validated with other methods to confirm these serendipitous findings.
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Affiliation(s)
- Piotr Sirko
- Laboratory of Auditory Neuroscience and Biophysics, Department of Bioengineering, Imperial College London, London, SW7 2AZ, UK
| | - Andrei S. Kozlov
- Laboratory of Auditory Neuroscience and Biophysics, Department of Bioengineering, Imperial College London, London, SW7 2AZ, UK
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9
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Mei C, Dong H, Nisenbaum E, Thielhelm T, Nourbakhsh A, Yan D, Smeal M, Lundberg Y, Hoffer ME, Angeli S, Telischi F, Nie G, Blanton SH, Liu X. Genetics and the Individualized Therapy of Vestibular Disorders. Front Neurol 2021; 12:633207. [PMID: 33613440 PMCID: PMC7892966 DOI: 10.3389/fneur.2021.633207] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/24/2020] [Accepted: 01/13/2021] [Indexed: 02/06/2023] Open
Abstract
Background: Vestibular disorders (VDs) are a clinically divergent group of conditions that stem from pathology at the level of the inner ear, vestibulocochlear nerve, or central vestibular pathway. No etiology can be identified in the majority of patients with VDs. Relatively few families have been reported with VD, and so far, no causative genes have been identified despite the fact that more than 100 genes have been identified for inherited hearing loss. Inherited VDs, similar to deafness, are genetically heterogeneous and follow Mendelian inheritance patterns with all modes of transmission, as well as multifactorial inheritance. With advances in genetic sequencing, evidence of familial clustering in VD has begun to highlight the genetic causes of these disorders, potentially opening up new avenues of treatment, particularly in Meniere's disease and disorders with comorbid hearing loss, such as Usher syndrome. In this review, we aim to present recent findings on the genetics of VDs, review the role of genetic sequencing tools, and explore the potential for individualized medicine in the treatment of these disorders. Methods: A search of the PubMed database was performed for English language studies relevant to the genetic basis of and therapies for vestibular disorders, using search terms including but not limited to: “genetics,” “genomics,” “vestibular disorders,” “hearing loss with vestibular dysfunction,” “individualized medicine,” “genome-wide association studies,” “precision medicine,” and “Meniere's syndrome.” Results: Increasing numbers of studies on vestibular disorder genetics have been published in recent years. Next-generation sequencing and new genetic tools are being utilized to unearth the significance of the genomic findings in terms of understanding disease etiology and clinical utility, with growing research interest being shown for individualized gene therapy for some disorders. Conclusions: The genetic knowledge base for vestibular disorders is still in its infancy. Identifying the genetic causes of balance problems is imperative in our understanding of the biology of normal function of the vestibule and the disease etiology and process. There is an increasing effort to use new and efficient genetic sequencing tools to discover the genetic causes for these diseases, leading to the hope for precise and personalized treatment for these patients.
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Affiliation(s)
- Christine Mei
- Department of Otolaryngology, University of Miami, Coral Gables, FL, United States
| | - Hongsong Dong
- Department of Otolaryngology, University of Miami, Coral Gables, FL, United States.,Shenzhen Second People's Hospital, Shenzhen, China
| | - Eric Nisenbaum
- Department of Otolaryngology, University of Miami, Coral Gables, FL, United States
| | - Torin Thielhelm
- Department of Otolaryngology, University of Miami, Coral Gables, FL, United States
| | - Aida Nourbakhsh
- Department of Otolaryngology, University of Miami, Coral Gables, FL, United States
| | - Denise Yan
- Department of Otolaryngology, University of Miami, Coral Gables, FL, United States
| | - Molly Smeal
- Department of Otolaryngology, University of Miami, Coral Gables, FL, United States
| | - Yesha Lundberg
- Department of Otolaryngology, Boys Town National Research Hospital, Omaha, NE, United States
| | - Michael E Hoffer
- Department of Otolaryngology, University of Miami, Coral Gables, FL, United States
| | - Simon Angeli
- Department of Otolaryngology, University of Miami, Coral Gables, FL, United States
| | - Fred Telischi
- Department of Otolaryngology, University of Miami, Coral Gables, FL, United States
| | - Guohui Nie
- Shenzhen Second People's Hospital, Shenzhen, China
| | - Susan H Blanton
- Department of Otolaryngology, University of Miami, Coral Gables, FL, United States
| | - Xuezhong Liu
- Department of Otolaryngology, University of Miami, Coral Gables, FL, United States
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10
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Ramzan M, Bashir R, Salman M, Mujtaba G, Sobreira N, Witmer PD, Naz S. Spectrum of genetic variants in moderate to severe sporadic hearing loss in Pakistan. Sci Rep 2020; 10:11902. [PMID: 32681043 PMCID: PMC7368073 DOI: 10.1038/s41598-020-68779-5] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/11/2020] [Accepted: 04/09/2020] [Indexed: 01/18/2023] Open
Abstract
Hearing loss affects 380 million people worldwide due to environmental or genetic causes. Determining the cause of deafness in individuals without previous family history of hearing loss is challenging and has been relatively unexplored in Pakistan. We investigated the spectrum of genetic variants in hearing loss in a cohort of singleton affected individuals born to consanguineous parents. Twenty-one individuals with moderate to severe hearing loss were recruited. We performed whole-exome sequencing on DNA samples from the participants, which identified seventeen variants in ten known deafness genes and one novel candidate gene. All identified variants were homozygous except for two. Eleven of the variants were novel, including one multi-exonic homozygous deletion in OTOA. A missense variant in ESRRB was implicated for recessively inherited moderate to severe hearing loss. Two individuals were heterozygous for variants in MYO7A and CHD7, respectively, consistent with de novo variants or dominant inheritance with incomplete penetrance as the reason for their hearing loss. Our results indicate that similar to familial cases of deafness, variants in a large number of genes are responsible for moderate to severe hearing loss in sporadic individuals born to consanguineous couples.
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Affiliation(s)
- Memoona Ramzan
- School of Biological Sciences, University of the Punjab, Quaid-i-Azam campus, Lahore, 54590, Pakistan
| | - Rasheeda Bashir
- School of Biological Sciences, University of the Punjab, Quaid-i-Azam campus, Lahore, 54590, Pakistan.,Department of Biotechnology, Lahore College for Women University, Lahore, Pakistan
| | - Midhat Salman
- School of Biological Sciences, University of the Punjab, Quaid-i-Azam campus, Lahore, 54590, Pakistan.,Virtual University of Pakistan, Lahore, Pakistan
| | - Ghulam Mujtaba
- School of Biological Sciences, University of the Punjab, Quaid-i-Azam campus, Lahore, 54590, Pakistan.,Institute of Nuclear Medicine and Oncology (INMOL), Lahore, Pakistan
| | - Nara Sobreira
- McKusick-Nathans Department of Genetic Medicine, Johns Hopkins University, Baltimore, MD, USA
| | - P Dane Witmer
- McKusick-Nathans Department of Genetic Medicine, Johns Hopkins University, Baltimore, MD, USA.,Johns Hopkins Genomics, Johns Hopkins University, Baltimore, MD, USA
| | | | - Sadaf Naz
- School of Biological Sciences, University of the Punjab, Quaid-i-Azam campus, Lahore, 54590, Pakistan.
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11
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Lu J, Chen P, Chen T, Li L, Fu X, Yang T, Wu H. The p.R206C Mutation in MYO7A Leads to Autosomal Dominant Nonsyndromic Hearing Loss. ORL J Otorhinolaryngol Relat Spec 2020; 82:181-187. [PMID: 32428919 DOI: 10.1159/000506208] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/14/2019] [Accepted: 01/24/2020] [Indexed: 11/19/2022]
Abstract
BACKGROUND Dominant mutations in MYO7A may lead to nonsyndromic deafness DFNA11. A p.R206C variant in MYO7A has previously been reported in a small deaf family from Taiwan but with ambiguous pathogenicity and inheritance pattern. AIMS/OBJECTIVES Our study aims to clarify the pathogenicity of this variant by clinical characterization and genetic analysis of a separate autosomal dominant deaf family harboring this variant in mainland China. MATERIALS AND METHODS Auditory features of hearing loss were characterized in representative affected family members. Mutation screening was performed by targeted next-generation sequencing of 138 known deafness genes in the proband. Candidate pathogenic mutations were confirmed by Sanger sequencing in family members and ethnically matched controls. RESULTS Consistent with typical DFNA11 phenotype, the affected family members in this study showed delayed-onset, progressive hearing loss affecting mostly high frequencies. Targeted next-generation sequencing identified a p.R206C mutation in MYO7A as the only candidate pathogenic mutation cosegregating with the hearing phenotype. This mutation is not seen in 200 Chinese Han normal-hearing controls. CONCLUSIONS AND SIGNIFICANCE The recurrent p.R206C variant in MYO7A is pathogenic and is likely in a mutation hot spot or due to a founder effect. Reports of such rare variants in multiple patients or families may facilitate exploitation of its pathogenicity.
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Affiliation(s)
- Jiawen Lu
- Department of Otorhinolaryngology-Head and Neck Surgery, Ninth People's Hospital, Shanghai Jiaotong University School of Medicine, Shanghai, China.,Ear Institute, Shanghai Jiaotong University School of Medicine, Shanghai, China.,Shanghai Key Laboratory of Translational Medicine on Ear and Nose Diseases, Shanghai, China
| | - Penghui Chen
- Department of Otorhinolaryngology-Head and Neck Surgery, Ninth People's Hospital, Shanghai Jiaotong University School of Medicine, Shanghai, China.,Ear Institute, Shanghai Jiaotong University School of Medicine, Shanghai, China.,Shanghai Key Laboratory of Translational Medicine on Ear and Nose Diseases, Shanghai, China
| | - Tuanjie Chen
- Key Laboratory of Functional Genomic and Molecular Diagnosis of Gansu Province, Lanzhou, China
| | - Lin Li
- Laboratory of Precision and Translational Medicine, Suzhou Hospital affiliated to Nanjing Medical University, Suzhou Science and Technology Town Hospital, Suzhou, China
| | - Xiaoli Fu
- Department of Hydraulic Engineering, School of Civil Engineering, Tongji University, Shanghai, China
| | - Tao Yang
- Department of Otorhinolaryngology-Head and Neck Surgery, Ninth People's Hospital, Shanghai Jiaotong University School of Medicine, Shanghai, China, .,Ear Institute, Shanghai Jiaotong University School of Medicine, Shanghai, China, .,Shanghai Key Laboratory of Translational Medicine on Ear and Nose Diseases, Shanghai, China,
| | - Hao Wu
- Department of Otorhinolaryngology-Head and Neck Surgery, Ninth People's Hospital, Shanghai Jiaotong University School of Medicine, Shanghai, China.,Ear Institute, Shanghai Jiaotong University School of Medicine, Shanghai, China.,Shanghai Key Laboratory of Translational Medicine on Ear and Nose Diseases, Shanghai, China
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Clinical Profiles of DFNA11 at Diverse Stages of Development and Aging in a Large Family Identified by Linkage Analysis. Otol Neurotol 2020; 41:e663-e673. [DOI: 10.1097/mao.0000000000002604] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
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Genetic Etiology Study of Ten Chinese Families with Nonsyndromic Hearing Loss. Neural Plast 2018; 2018:4920980. [PMID: 30123251 PMCID: PMC6079373 DOI: 10.1155/2018/4920980] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/24/2018] [Revised: 04/28/2018] [Accepted: 05/13/2018] [Indexed: 01/26/2023] Open
Abstract
Nonsyndromic hearing loss has been shown to have high genetic heterogeneity. In this report, we aimed to disclose the genetic causes of the subjects from the ten Chinese deaf families who did not have pathogenic common genes/mutation. Next-generation sequencing (NGS) of 142 known deafness genes was performed in the probands of ten families followed by cosegregation analysis of all family members. We identified novel pathogenic variants in six families including p.D1806E/p.R1588W, p.R964W/p.R1588W, and p.G17C/p.G1449D in CDH23; p.T584M/p.D1939N in LOXHD1; p.P1225L in MYO7A; and p.K612X in EYA4. Sanger sequencing confirmed that these mutations segregated with the hearing loss of each family. In four families, no pathogenic variants were identified. Our study provided better understanding of the mutation spectrum of hearing loss in the Chinese population.
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Li L, Yuan H, Wang H, Guan J, Lan L, Wang D, Zong L, Liu Q, Han B, Huang D, Wang Q. Identification of a MYO7A mutation in a large Chinese DFNA11 family and genotype-phenotype review for DFNA11. Acta Otolaryngol 2018; 138:463-470. [PMID: 29400105 DOI: 10.1080/00016489.2017.1397743] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
Abstract
BACKGROUND The molecular and genetic research showed the association between DFNA11 and mutations in MYO7A. This research aimed to identify a MYO7A mutation in a family with nonsyndromic autosomal dominant hearing loss. METHODS We have ascertained one large multigenerational Chinese family (Z029) with autosomal dominant late-onset progressive non-syndromic sensorineural hearing loss. Genome-wide linkage analysis of the family mapped the disease locus to the DFNA11 interval, where the MYO7A was considered as a candidate gene. Sequencing of the PCR products was carried out for each sample. One hundred and fifty one control subjects with normal hearing functions were also evaluated. RESULTS The pathogenic mutation (c.2011G>A) was identified in the family. This mutation co-segregated with hearing loss in this family. No mutation of MYO7A gene was found in the 151 controls. CONCLUSIONS The missense mutation of MYO7A is identified in the family displaying the pedigree consistent with DFNA11. We not only examined the clinical and genetic characteristics of the family, but also provided a basis for genetic counseling. We also summarized and analyzed the phenotypes and genotypes of all DFNA11 families, four of nine are Chinese families, suggesting that MYO7A mutations are not rare. Therefore, we should pay more attention to Chinese patients.
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Affiliation(s)
- Lina Li
- Department of Otolaryngology-Head and Neck Surgery, Chinese PLA Institute of Otolaryngology, Chinese PLA General Hospital, Beijing, China
- Department of Otolaryngology, The 309th Hospital of Chinese People’s Liberation Army, Beijing, China
| | - Hu Yuan
- Department of Otolaryngology-Head and Neck Surgery, Chinese PLA Institute of Otolaryngology, Chinese PLA General Hospital, Beijing, China
| | - Hongyang Wang
- Department of Otolaryngology-Head and Neck Surgery, Chinese PLA Institute of Otolaryngology, Chinese PLA General Hospital, Beijing, China
| | - Jing Guan
- Department of Otolaryngology-Head and Neck Surgery, Chinese PLA Institute of Otolaryngology, Chinese PLA General Hospital, Beijing, China
| | - Lan Lan
- Department of Otolaryngology-Head and Neck Surgery, Chinese PLA Institute of Otolaryngology, Chinese PLA General Hospital, Beijing, China
| | - Dayong Wang
- Department of Otolaryngology-Head and Neck Surgery, Chinese PLA Institute of Otolaryngology, Chinese PLA General Hospital, Beijing, China
| | - Liang Zong
- Department of Otolaryngology-Head and Neck Surgery, Chinese PLA Institute of Otolaryngology, Chinese PLA General Hospital, Beijing, China
| | - Qiong Liu
- Department of Otolaryngology-Head and Neck Surgery, Chinese PLA Institute of Otolaryngology, Chinese PLA General Hospital, Beijing, China
| | - Bing Han
- Department of Otolaryngology-Head and Neck Surgery, Chinese PLA Institute of Otolaryngology, Chinese PLA General Hospital, Beijing, China
| | - Deliang Huang
- Department of Otolaryngology-Head and Neck Surgery, Chinese PLA Institute of Otolaryngology, Chinese PLA General Hospital, Beijing, China
| | - Qiuju Wang
- Department of Otolaryngology-Head and Neck Surgery, Chinese PLA Institute of Otolaryngology, Chinese PLA General Hospital, Beijing, China
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Kaneko Y, Nakano A, Arimoto Y, Nara K, Mutai H, Matsunaga T. The first sporadic case of DFNA11 identified by next-generation sequencing. Int J Pediatr Otorhinolaryngol 2017; 100:183-186. [PMID: 28802369 DOI: 10.1016/j.ijporl.2017.07.007] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/07/2017] [Revised: 07/06/2017] [Accepted: 07/07/2017] [Indexed: 10/19/2022]
Abstract
We report the first sporadic case of nonsyndromic autosomal dominant hearing loss (DFNA11). The patient was a 5-year-old boy with moderate bilateral hearing loss. Targeted next-generation sequencing analysis of patient DNA identified a known heterozygous DFNA11 mutation, c.689C > T, in MYO7A, encoding p.Ala230Val. The mutation was not detected in the parents of the patient and is considered to be de novo. This mutation is identical to the one reported previously in an Italian family. Accumulation of mutation data increases the feasibility of identifying autosomal dominant mutations in sporadic sensorineural hearing loss.
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Affiliation(s)
- Yuka Kaneko
- Division of Otolaryngology, Chiba Children's Hospital, 579-1, Hetacho Midori-ku, Chiba City, Chiba, Japan; Department of Otolaryngology, Japanese Red Cross Narita Hospital, 90-1, Iida Town, Narita City, Chiba, Japan
| | - Atsuko Nakano
- Division of Otolaryngology, Chiba Children's Hospital, 579-1, Hetacho Midori-ku, Chiba City, Chiba, Japan
| | - Yukiko Arimoto
- Division of Otolaryngology, Chiba Children's Hospital, 579-1, Hetacho Midori-ku, Chiba City, Chiba, Japan
| | - Kiyomitsu Nara
- Division of Hearing and Balance Research, National Institute of Sensory Organs, National Hospital Organization Tokyo Medical Center, 2-5-1 Higashigaoka, Meguro, Tokyo 152‒8902, Japan
| | - Hideki Mutai
- Division of Hearing and Balance Research, National Institute of Sensory Organs, National Hospital Organization Tokyo Medical Center, 2-5-1 Higashigaoka, Meguro, Tokyo 152‒8902, Japan
| | - Tatsuo Matsunaga
- Division of Hearing and Balance Research, National Institute of Sensory Organs, National Hospital Organization Tokyo Medical Center, 2-5-1 Higashigaoka, Meguro, Tokyo 152‒8902, Japan.
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ASGHARZADE S, REIISI S, TABATABAIEFAR MA, CHALESHTORI MHASHEMZADEH. Screening of Myo7A Mutations in Iranian Patients with Autosomal Recessive Hearing Loss from West of Iran. IRANIAN JOURNAL OF PUBLIC HEALTH 2017; 46:76-82. [PMID: 28451532 PMCID: PMC5401939] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
BACKGROUND Hearing loss (HL) is the most frequent neurosensory impairment. HL is highly heterogeneous defect. This disorder affects 1 out of 500 newborns. This study aimed to determine the role of DFNB2 locus and frequency of MYO7A gene mutations in a population from west of Iran. METHODS Thirty families investigated in Shahrekord University of Medical Sciences in 2014, genetic linkage analysis via four short tandem repeat markers linked to MYO7A was performed for two consanguineous families originating from Hamedan (family-13) and Chaharmahal-Bakhtiari (family-32) provinces of Iran, co-segregating autosomal recessive HL and showed no mutation in GJB2 gene in our preliminary investigation. All 49 coding exons and exon- intron boundaries of the MYO7A gene were amplified by PCR and analyzed using direct DNA sequencing. RESULTS Two of families displayed linkage to DFNB2. Family-13 segregated a homozygous missense mutation (c.6487G>A) in exon 48 that results in a p.G2163S amino acid substitution in C-terminal domain of the myosin VIIA protein. While family-32 segregated a homozygous nonsense mutation (c.448 C>T) in exon five, resulting in a premature truncation at amino acid position 150 (p.Arg150X) in the motor domain of this protein. CONCLUSION Mutation frequency of MYO7A gene in different populations of Iran as well as cause of HL in most cases are still unknown and more extensive studies have to be done.
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Affiliation(s)
- Samira ASGHARZADE
- Dept. of Molecular Medicine, School of Advanced Technologies in Medicine, Tehran University of Medical Sciences, Tehran, Iran,Cellular and Molecular Research Center, Shahrekord University of Medical Sciences, Shahrekord, Iran
| | - Somayeh REIISI
- Dept. of Genetics, Faculty of Basic Sciences, University of Shahrekord, Shahrekord, Iran
| | - Mohammad Amin TABATABAIEFAR
- Dept. of Genetics and Molecular Biology, School of Medicine, Isfahan University of Medical Sciences, Isfahan, Iran
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Zong L, Chen K, Wu X, Liu M, Jiang H. Compound heterozygous MYO7A mutations segregating Usher syndrome type 2 in a Han family. Int J Pediatr Otorhinolaryngol 2016; 90:150-155. [PMID: 27729122 DOI: 10.1016/j.ijporl.2016.09.010] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/23/2016] [Revised: 09/10/2016] [Accepted: 09/11/2016] [Indexed: 12/01/2022]
Abstract
OBJECTIVE Identification of rare deafness genes for inherited congenital sensorineural hearing impairment remains difficult, because a large variety of genes are implicated. In this study we applied targeted capture and next-generation sequencing to uncover the underlying gene in a three-generation Han family segregating recessive inherited hearing loss and retinitis pigmentosa. METHODS After excluding mutations in common deafness genes GJB2, SLC26A4 and the mitochondrial gene, genomic DNA of the proband of a Han family was subjected to targeted next-generation sequencing. The candidate mutations were confirmed by Sanger sequencing and subsequently analyzed with in silico tools. RESULTS An unreported splice site mutation c.3924+1G > C compound with c.6028G > A in the MYO7A gene were detected to cosegregate with the phenotype in this pedigree. Both mutations, located in the evolutionarily conserved FERM domain in myosin VIIA, were predicted to be pathogenic. In this family, profound sensorineural hearing impairment and retinitis pigmentosa without vestibular disorder, constituted the typical Usher syndrome type 2. CONCLUSION Identification of novel mutation in compound heterozygosity in MYO7A gene revealed the genetic origin of Usher syndrome type 2 in this Han family.
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Affiliation(s)
- Ling Zong
- Department of Otorhinolaryngology, The Second Affiliated Hospital of Guangzhou Medical University, Guangzhou, 510260, PR China; Department of Otorhinolaryngology, The First Affiliated Hospital, Sun Yat-sen University and Institute of Otorhinolaryngology, Sun Yat-sen University, Guangzhou, 510080, PR China
| | - Kaitian Chen
- Department of Otorhinolaryngology, The First Affiliated Hospital, Sun Yat-sen University and Institute of Otorhinolaryngology, Sun Yat-sen University, Guangzhou, 510080, PR China
| | - Xuan Wu
- Department of Otorhinolaryngology, The First Affiliated Hospital, Sun Yat-sen University and Institute of Otorhinolaryngology, Sun Yat-sen University, Guangzhou, 510080, PR China
| | - Min Liu
- Department of Otorhinolaryngology, The First Affiliated Hospital, Sun Yat-sen University and Institute of Otorhinolaryngology, Sun Yat-sen University, Guangzhou, 510080, PR China
| | - Hongyan Jiang
- Department of Otorhinolaryngology, The First Affiliated Hospital, Sun Yat-sen University and Institute of Otorhinolaryngology, Sun Yat-sen University, Guangzhou, 510080, PR China; Department of Otorhinolaryngology, Hainan General Hospital, Haikou, 570311, PR China.
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Qu R, Sang Q, Xu Y, Feng R, Jin L, He L, Wang L. Identification of a novel homozygous mutation in MYO3A in a Chinese family with DFNB30 non-syndromic hearing impairment. Int J Pediatr Otorhinolaryngol 2016; 84:43-7. [PMID: 27063751 DOI: 10.1016/j.ijporl.2016.02.036] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/01/2015] [Revised: 02/25/2016] [Accepted: 02/26/2016] [Indexed: 10/22/2022]
Abstract
INTRODUCTION Hearing loss is a common sensory impairment. Several genetic loci or genes responsible for non-syndrome hearing loss have been identified, including the well-known deafness genes GJB2, MT-RNR1 and SLC26A4. MYO3A belongs to the myosin superfamily. Previously only three mutations in this gene have been found in an Isreali family with DFNB30, in which patients demonstrated progressive hearing loss. METHODS In this study, we characterized a consanguineous Kazakh family with congenital hearing loss. By targeted sequence capture and next-generation sequencing, we identified a homozygous mutation and did bioinformatics analysis to this mutation. RESULTS A homozygous mutation, MYO3A:c.1841C>T (p.S614F), was identified to be responsible for the disease. Ser614 is located in the motor domain of MYO3A that is highly conserved among different species. Molecular modeling predicts that the conserved Ser614 may play an important role in maintaining the stability of β-sheet and the interaction between neighboring β-strand. CONCLUSIONS This is the second report on MYO3A mutations in deafness and the first report in China. The finding help facilitate establishing a better relationship between MYO3A mutation and hearing phenotypes.
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Affiliation(s)
- Ronggui Qu
- State Key Laboratory of Genetic Engineering and MOE Key Laboratory of Contemporary Anthropology, School of Life Sciences, Fudan University, Shanghai, China; Institutes of Biomedical Sciences, Fudan University, Shanghai, China
| | - Qing Sang
- State Key Laboratory of Genetic Engineering and MOE Key Laboratory of Contemporary Anthropology, School of Life Sciences, Fudan University, Shanghai, China; Institutes of Biomedical Sciences, Fudan University, Shanghai, China
| | - Yao Xu
- State Key Laboratory of Genetic Engineering and MOE Key Laboratory of Contemporary Anthropology, School of Life Sciences, Fudan University, Shanghai, China; Institutes of Biomedical Sciences, Fudan University, Shanghai, China
| | - Ruizhi Feng
- State Key Laboratory of Genetic Engineering and MOE Key Laboratory of Contemporary Anthropology, School of Life Sciences, Fudan University, Shanghai, China; Institutes of Biomedical Sciences, Fudan University, Shanghai, China
| | - Li Jin
- State Key Laboratory of Genetic Engineering and MOE Key Laboratory of Contemporary Anthropology, School of Life Sciences, Fudan University, Shanghai, China
| | - Lin He
- Institutes of Biomedical Sciences, Fudan University, Shanghai, China; Bio-X Center, Key Laboratory for the Genetics of Developmental and Neuropsychiatric Disorders, Ministry of Education, Shanghai Jiao Tong University, Shanghai, China
| | - Lei Wang
- State Key Laboratory of Genetic Engineering and MOE Key Laboratory of Contemporary Anthropology, School of Life Sciences, Fudan University, Shanghai, China; Institutes of Biomedical Sciences, Fudan University, Shanghai, China.
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Genetics of vestibular disorders: pathophysiological insights. J Neurol 2016; 263 Suppl 1:S45-53. [PMID: 27083884 PMCID: PMC4833787 DOI: 10.1007/s00415-015-7988-9] [Citation(s) in RCA: 55] [Impact Index Per Article: 6.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/20/2015] [Revised: 11/01/2015] [Accepted: 11/29/2015] [Indexed: 01/09/2023]
Abstract
The two most common vestibular disorders are motion sickness and vestibular migraine, affecting 30 and 1–2 % of the population respectively. Both are related to migraine and show a familial trend. Bilateral vestibular hypofunction is a rare condition, and some of patients also present cerebellar ataxia and neuropathy. We present recent advances in the genetics of vestibular disorders with familial aggregation. The clinical heterogeneity observed in different relatives of the same families suggests a variable penetrance and the interaction of several genes in each family. Some Mendelian sensorineural hearing loss also exhibits vestibular dysfunction, including DFNA9, DFNA11, DFNA15 and DFNA28. However, the most relevant finding during the past years is the familial clustering observed in Meniere’s disease. By using whole exome sequencing and combining bioinformatics tools, novel variants in DTNA and FAM136A genes have been identified in familial Meniere’s disease, and this genomic strategy will facilitate the discovery of the genetic basis of familial vestibular disorders.
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Abstract
PURPOSE OF REVIEW Recent advances in next generation sequencing techniques (NGS) are increasing the number of novel genes associated with cerebellar and vestibular disorders. We have summarized clinical and molecular genetics findings in neuro-otolology during the last 2 years. RECENT FINDINGS Whole-exome and targeted sequencing have defined the genetic basis of dizziness including new genes causing ataxia: GBA2, TGM6, ANO10 and SYT14. Novel mutations in KCNA1 and CACNA1A genes are associated with episodic ataxia type 1 and type 2, respectively. Moreover, new variants in genes such as COCH, MYO7A and POU4F3 are associated with nonsyndromic deafness and vestibular dysfunction. Several susceptibility loci have been linked to familial vestibular migraine, suggesting genetic heterogeneity, but no specific gene has been identified. Finally, loci for complex and heterogeneous diseases such as bilateral vestibular hypofunction or familial Ménière disease have not been identified yet, despite their strong familial aggregation. SUMMARY Cerebellar and vestibular disorders leading to dizziness or episodic vertigo may show overlapping clinical features. A deep phenotyping including a complete familial history is a key step in performing a reliable molecular genetic diagnosis using NGS. Personalized molecular medicine will be essential to understand disease mechanisms as well as to improve their diagnosis and treatment.
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Abstract
The 10 different genes associated with the deaf/blind disorder, Usher syndrome, encode a number of structurally and functionally distinct proteins, most expressed as multiple isoforms/protein variants. Functional characterization of these proteins suggests a role in stereocilia development in cochlear hair cells, likely owing to adhesive interactions in hair bundles. In mature hair cells, homodimers of the Usher cadherins, cadherin 23 and protocadherin 15, interact to form a structural fiber, the tip link, and the linkages that anchor the taller stereocilia's actin cytoskeleton core to the shorter adjacent stereocilia and the elusive mechanotransduction channels, explaining the deafness phenotype when these molecular interactions are perturbed. The conundrum is that photoreceptors lack a synonymous mechanotransduction apparatus, and so a common theory for Usher protein function in the two neurosensory cell types affected in Usher syndrome is lacking. Recent evidence linking photoreceptor cell dysfunction in the shaker 1 mouse model for Usher syndrome to light-induced protein translocation defects, combined with localization of an Usher protein interactome at the periciliary region of the photoreceptors suggests Usher proteins might regulate protein trafficking between the inner and outer segments of photoreceptors. A distinct Usher protein complex is trafficked to the ribbon synapses of hair cells, and synaptic defects have been reported in Usher mutants in both hair cells and photoreceptors. This review aims to clarify what is known about Usher protein function at the synaptic and apical poles of hair cells and photoreceptors and the prospects for identifying a unifying pathobiological mechanism to explain deaf/blindness in Usher syndrome.
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