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Qi J, Tan F, Zhang L, Lu L, Zhang S, Zhai Y, Lu Y, Qian X, Dong W, Zhou Y, Zhang Z, Yang X, Jiang L, Yu C, Liu J, Chen T, Wu L, Tan C, Sun S, Song H, Shu Y, Xu L, Gao X, Li H, Chai R. AAV-Mediated Gene Therapy Restores Hearing in Patients with DFNB9 Deafness. ADVANCED SCIENCE (WEINHEIM, BADEN-WURTTEMBERG, GERMANY) 2024; 11:e2306788. [PMID: 38189623 PMCID: PMC10953563 DOI: 10.1002/advs.202306788] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/18/2023] [Revised: 11/18/2023] [Indexed: 01/09/2024]
Abstract
Mutations in OTOFERLIN (OTOF) lead to the autosomal recessive deafness 9 (DFNB9). The efficacy of adeno-associated virus (AAV)-mediated OTOF gene replacement therapy is extensively validated in Otof-deficient mice. However, the clinical safety and efficacy of AAV-OTOF is not reported. Here, AAV-OTOF is generated using good manufacturing practice and validated its efficacy and safety in mouse and non-human primates in order to determine the optimal injection dose, volume, and administration route for clinical trials. Subsequently, AAV-OTOF is delivered into one cochlea of a 5-year-old deaf patient and into the bilateral cochleae of an 8-year-old deaf patient with OTOF mutations. Obvious hearing improvement is detected by the auditory brainstem response (ABR) and the pure-tone audiometry (PTA) in these two patients. Hearing in the injected ear of the 5-year-old patient can be restored to the normal range at 1 month after AAV-OTOF injection, while the 8-year-old patient can hear the conversational sounds. Most importantly, the 5-year-old patient can hear and recognize speech only through the AAV-OTOF-injected ear. This study is the first to demonstrate the safety and efficacy of AAV-OTOF in patients, expands and optimizes current OTOF-related gene therapy and provides valuable information for further application of gene therapies for deafness.
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Affiliation(s)
- Jieyu Qi
- State Key Laboratory of Digital Medical EngineeringDepartment of Otolaryngology Head and Neck SurgeryZhongda HospitalSchool of Life Sciences and TechnologySchool of MedicineAdvanced Institute for Life and HealthJiangsu Province High‐Tech Key Laboratory for Bio‐Medical ResearchSoutheast UniversityNanjing210096China
- Co‐Innovation Center of NeuroregenerationNantong UniversityNantong226001China
- Department of Neurology, Aerospace Center Hospital, School of Life ScienceBeijing Institute of TechnologyBeijing100081China
| | - Fangzhi Tan
- State Key Laboratory of Digital Medical EngineeringDepartment of Otolaryngology Head and Neck SurgeryZhongda HospitalSchool of Life Sciences and TechnologySchool of MedicineAdvanced Institute for Life and HealthJiangsu Province High‐Tech Key Laboratory for Bio‐Medical ResearchSoutheast UniversityNanjing210096China
| | - Liyan Zhang
- State Key Laboratory of Digital Medical EngineeringDepartment of Otolaryngology Head and Neck SurgeryZhongda HospitalSchool of Life Sciences and TechnologySchool of MedicineAdvanced Institute for Life and HealthJiangsu Province High‐Tech Key Laboratory for Bio‐Medical ResearchSoutheast UniversityNanjing210096China
| | - Ling Lu
- Department of Otolaryngology‐Head and Neck Surgerythe Affiliated Drum Tower Hospital of Nanjing University Medical SchoolJiangsu Provincial Key Medical Discipline (Laboratory)Nanjing210008China
| | | | - Yabo Zhai
- School of MedicineSoutheast UniversityNanjing210009China
| | - Yicheng Lu
- State Key Laboratory of Digital Medical EngineeringDepartment of Otolaryngology Head and Neck SurgeryZhongda HospitalSchool of Life Sciences and TechnologySchool of MedicineAdvanced Institute for Life and HealthJiangsu Province High‐Tech Key Laboratory for Bio‐Medical ResearchSoutheast UniversityNanjing210096China
| | - Xiaoyun Qian
- Department of Otolaryngology‐Head and Neck Surgerythe Affiliated Drum Tower Hospital of Nanjing University Medical SchoolJiangsu Provincial Key Medical Discipline (Laboratory)Nanjing210008China
| | | | - Yinyi Zhou
- State Key Laboratory of Digital Medical EngineeringDepartment of Otolaryngology Head and Neck SurgeryZhongda HospitalSchool of Life Sciences and TechnologySchool of MedicineAdvanced Institute for Life and HealthJiangsu Province High‐Tech Key Laboratory for Bio‐Medical ResearchSoutheast UniversityNanjing210096China
| | - Ziyu Zhang
- State Key Laboratory of Digital Medical EngineeringDepartment of Otolaryngology Head and Neck SurgeryZhongda HospitalSchool of Life Sciences and TechnologySchool of MedicineAdvanced Institute for Life and HealthJiangsu Province High‐Tech Key Laboratory for Bio‐Medical ResearchSoutheast UniversityNanjing210096China
| | - Xuehan Yang
- State Key Laboratory of Digital Medical EngineeringDepartment of Otolaryngology Head and Neck SurgeryZhongda HospitalSchool of Life Sciences and TechnologySchool of MedicineAdvanced Institute for Life and HealthJiangsu Province High‐Tech Key Laboratory for Bio‐Medical ResearchSoutheast UniversityNanjing210096China
| | - Lulu Jiang
- Otovia Therapeutics IncSuzhou215101China
| | | | | | - Tian Chen
- State Key Laboratory of Digital Medical EngineeringDepartment of Otolaryngology Head and Neck SurgeryZhongda HospitalSchool of Life Sciences and TechnologySchool of MedicineAdvanced Institute for Life and HealthJiangsu Province High‐Tech Key Laboratory for Bio‐Medical ResearchSoutheast UniversityNanjing210096China
| | - Lianqiu Wu
- Otovia Therapeutics IncSuzhou215101China
| | - Chang Tan
- Otovia Therapeutics IncSuzhou215101China
| | - Sijie Sun
- Otovia Therapeutics IncSuzhou215101China
- Fosun Health CapitalShanghai200233China
| | | | - Yilai Shu
- ENT Institute and Department of OtorhinolaryngologyEye & ENT HospitalState Key Laboratory of Medical Neurobiology and MOE Frontiers Center for Brain ScienceFudan UniversityShanghai200031China
- Institute of Biomedical ScienceFudan UniversityShanghai200032China
- NHC Key Laboratory of Hearing MedicineFudan UniversityShanghai200032China
| | - Lei Xu
- Department of Otolaryngology‐Head and Neck SurgeryShandong Provincial ENT HospitalShandong UniversityJinanShandong250022China
| | - Xia Gao
- Department of Otolaryngology‐Head and Neck Surgerythe Affiliated Drum Tower Hospital of Nanjing University Medical SchoolJiangsu Provincial Key Medical Discipline (Laboratory)Nanjing210008China
| | - Huawei Li
- ENT Institute and Department of OtorhinolaryngologyEye & ENT HospitalState Key Laboratory of Medical Neurobiology and MOE Frontiers Center for Brain ScienceFudan UniversityShanghai200031China
- Institute of Biomedical ScienceFudan UniversityShanghai200032China
- NHC Key Laboratory of Hearing MedicineFudan UniversityShanghai200032China
- The Institutes of Brain Science and the Collaborative Innovation Center for Brain ScienceFudan UniversityShanghai200032China
| | - Renjie Chai
- State Key Laboratory of Digital Medical EngineeringDepartment of Otolaryngology Head and Neck SurgeryZhongda HospitalSchool of Life Sciences and TechnologySchool of MedicineAdvanced Institute for Life and HealthJiangsu Province High‐Tech Key Laboratory for Bio‐Medical ResearchSoutheast UniversityNanjing210096China
- Co‐Innovation Center of NeuroregenerationNantong UniversityNantong226001China
- Department of Neurology, Aerospace Center Hospital, School of Life ScienceBeijing Institute of TechnologyBeijing100081China
- Department of Otolaryngology Head and Neck SurgerySichuan Provincial People's HospitalUniversity of Electronic Science and Technology of ChinaChengdu610072China
- Southeast University Shenzhen Research InstituteShenzhen518063China
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2
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Cepeda AP, Ninov M, Neef J, Parfentev I, Kusch K, Reisinger E, Jahn R, Moser T, Urlaub H. Proteomic Analysis Reveals the Composition of Glutamatergic Organelles of Auditory Inner Hair Cells. Mol Cell Proteomics 2024; 23:100704. [PMID: 38128648 PMCID: PMC10832297 DOI: 10.1016/j.mcpro.2023.100704] [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: 05/31/2023] [Revised: 11/08/2023] [Accepted: 12/18/2023] [Indexed: 12/23/2023] Open
Abstract
In the ear, inner hair cells (IHCs) employ sophisticated glutamatergic ribbon synapses with afferent neurons to transmit auditory information to the brain. The presynaptic machinery responsible for neurotransmitter release in IHC synapses includes proteins such as the multi-C2-domain protein otoferlin and the vesicular glutamate transporter 3 (VGluT3). Yet, much of this likely unique molecular machinery remains to be deciphered. The scarcity of material has so far hampered biochemical studies which require large amounts of purified samples. We developed a subcellular fractionation workflow combined with immunoisolation of VGluT3-containing membrane vesicles, allowing for the enrichment of glutamatergic organelles that are likely dominated by synaptic vesicles (SVs) of IHCs. We have characterized their protein composition in mice before and after hearing onset using mass spectrometry and confocal imaging and provide a fully annotated proteome with hitherto unidentified proteins. Despite the prevalence of IHC marker proteins across IHC maturation, the profiles of trafficking proteins differed markedly before and after hearing onset. Among the proteins enriched after hearing onset were VAMP-7, syntaxin-7, syntaxin-8, syntaxin-12/13, SCAMP1, V-ATPase, SV2, and PKCα. Our study provides an inventory of the machinery associated with synaptic vesicle-mediated trafficking and presynaptic activity at IHC ribbon synapses and serves as a foundation for future functional studies.
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Affiliation(s)
- Andreia P Cepeda
- Bioanalytical Mass Spectrometry Group, Max Planck Institute for Multidisciplinary Sciences, Göttingen, Germany
| | - Momchil Ninov
- Bioanalytical Mass Spectrometry Group, Max Planck Institute for Multidisciplinary Sciences, Göttingen, Germany; Department of Clinical Chemistry, University Medical Center Göttingen, Göttingen, Germany
| | - Jakob Neef
- Institute for Auditory Neuroscience and InnerEarLab, University Medical Center Göttingen, Göttingen, Germany; Auditory Neuroscience & Synaptic Nanophysiology Group Max-Planck-Institute for Multidisciplinary Sciences, Göttingen, Germany
| | - Iwan Parfentev
- Bioanalytical Mass Spectrometry Group, Max Planck Institute for Multidisciplinary Sciences, Göttingen, Germany
| | - Kathrin Kusch
- Functional Auditory Genomics Group, Institute for Auditory Neuroscience and InnerEarLab, University Medical Center Göttingen, Göttingen, Germany
| | - Ellen Reisinger
- Gene Therapy for Hearing Impairment and Deafness, Department for Otolaryngology, Head & Neck Surgery, University Hospital Tübingen, Tübingen, Germany
| | - Reinhard Jahn
- Laboratory of Neurobiology, Max Planck Institute for Multidisciplinary Sciences, Göttingen, Germany; Cluster of Excellence "Multiscale Bioimaging: from Molecular Machines to Networks of Excitable Cells" (MBExC), University of Göttingen, Göttingen, Germany.
| | - Tobias Moser
- Institute for Auditory Neuroscience and InnerEarLab, University Medical Center Göttingen, Göttingen, Germany; Auditory Neuroscience & Synaptic Nanophysiology Group Max-Planck-Institute for Multidisciplinary Sciences, Göttingen, Germany; Cluster of Excellence "Multiscale Bioimaging: from Molecular Machines to Networks of Excitable Cells" (MBExC), University of Göttingen, Göttingen, Germany.
| | - Henning Urlaub
- Bioanalytical Mass Spectrometry Group, Max Planck Institute for Multidisciplinary Sciences, Göttingen, Germany; Department of Clinical Chemistry, University Medical Center Göttingen, Göttingen, Germany; Cluster of Excellence "Multiscale Bioimaging: from Molecular Machines to Networks of Excitable Cells" (MBExC), University of Göttingen, Göttingen, Germany.
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3
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Chen H, Fang Q, Benseler F, Brose N, Moser T. Probing the role of the C 2F domain of otoferlin. Front Mol Neurosci 2023; 16:1299509. [PMID: 38152587 PMCID: PMC10751786 DOI: 10.3389/fnmol.2023.1299509] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/22/2023] [Accepted: 11/07/2023] [Indexed: 12/29/2023] Open
Abstract
Afferent synapses of cochlear inner hair cells (IHCs) employ a unique molecular machinery. Otoferlin is a key player in this machinery, and its genetic defects cause human auditory synaptopathy. We employed site-directed mutagenesis in mice to investigate the role of Ca2+ binding to the C2F domain of otoferlin. Substituting two aspartate residues of the C2F top loops, which are thought to coordinate Ca2+-ions, by alanines (OtofD1841/1842A) abolished Ca2+-influx-triggered IHC exocytosis and synchronous signaling in the auditory pathway despite substantial expression (~60%) of the mutant otoferlin in the basolateral IHC pole. Ca2+ influx of IHCs and their resting membrane capacitance, reflecting IHC size, as well as the number of IHC synapses were maintained. The mutant otoferlin showed a strong apex-to-base abundance gradient in IHCs, suggesting impaired protein targeting. Our results indicate a role of the C2F domain in otoferlin targeting and of Ca2+ binding by the C2F domain for IHC exocytosis and hearing.
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Affiliation(s)
- Han Chen
- Institute for Auditory Neuroscience and InnerEarLab, University Medical Center Göttingen, Göttingen, Germany
- Collaborative Research Center 889, University of Göttingen, Göttingen, Germany
- Auditory Neuroscience and Synaptic Nanophysiology Group, Max Planck Institute for Multidisciplinary Sciences, Göttingen, Germany
- Göttingen Graduate Center for Neurosciences, Biophysics and Molecular Biosciences, University of Göttingen, Göttingen, Germany
| | - Qinghua Fang
- Institute for Auditory Neuroscience and InnerEarLab, University Medical Center Göttingen, Göttingen, Germany
- Collaborative Research Center 889, University of Göttingen, Göttingen, Germany
- Auditory Neuroscience and Synaptic Nanophysiology Group, Max Planck Institute for Multidisciplinary Sciences, Göttingen, Germany
| | - Fritz Benseler
- Department of Molecular Neurobiology, Max Planck Institute for Multidisciplinary Sciences, Göttingen, Germany
| | - Nils Brose
- Collaborative Research Center 889, University of Göttingen, Göttingen, Germany
- Department of Molecular Neurobiology, Max Planck Institute for Multidisciplinary Sciences, Göttingen, Germany
- Multiscale Bioimaging Cluster of Excellence (MBExC), University of Göttingen, Göttingen, Germany
| | - Tobias Moser
- Institute for Auditory Neuroscience and InnerEarLab, University Medical Center Göttingen, Göttingen, Germany
- Collaborative Research Center 889, University of Göttingen, Göttingen, Germany
- Auditory Neuroscience and Synaptic Nanophysiology Group, Max Planck Institute for Multidisciplinary Sciences, Göttingen, Germany
- Multiscale Bioimaging Cluster of Excellence (MBExC), University of Göttingen, Göttingen, Germany
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4
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Ford CL, Riggs WJ, Quigley T, Keifer OP, Whitton JP, Valayannopoulos V. The natural history, clinical outcomes, and genotype-phenotype relationship of otoferlin-related hearing loss: a systematic, quantitative literature review. Hum Genet 2023; 142:1429-1449. [PMID: 37679651 PMCID: PMC10511631 DOI: 10.1007/s00439-023-02595-5] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/09/2023] [Accepted: 08/09/2023] [Indexed: 09/09/2023]
Abstract
Congenital hearing loss affects one in 500 newborns. Sequence variations in OTOF, which encodes the calcium-binding protein otoferlin, are responsible for 1-8% of congenital, nonsyndromic hearing loss and are the leading cause of auditory neuropathy spectrum disorders. The natural history of otoferlin-related hearing loss, the relationship between OTOF genotype and hearing loss phenotype, and the outcomes of clinical practices in patients with this genetic disorder are incompletely understood because most analyses have reported on small numbers of cases with homogeneous OTOF genotypes. Here, we present the first systematic, quantitative literature review of otoferlin-related hearing loss, which analyzes patient-specific data from 422 individuals across 61 publications. While most patients display a typical phenotype of severe-to-profound hearing loss with prelingual onset, 10-15% of patients display atypical phenotypes, including mild-to-moderate, progressive, and temperature-sensitive hearing loss. Patients' phenotypic presentations appear to depend on their specific genotypes. For example, non-truncating variants located in and immediately downstream of the C2E calcium-binding domain are more likely to produce atypical phenotypes. Additionally, the prevalence of certain sequence variants and their associated phenotypes varies between populations due to evolutionary founder effects. Our analyses also suggest otoacoustic emissions are less common in older patients and those with two truncating OTOF variants. Critically, our review has implications for the application and limitations of clinical practices, including newborn hearing screenings, hearing aid trials, cochlear implants, and upcoming gene therapy clinical trials. We conclude by discussing the limitations of available research and recommendations for future studies on this genetic cause of hearing loss.
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5
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Leclère JC, Dulon D. Otoferlin as a multirole Ca 2+ signaling protein: from inner ear synapses to cancer pathways. Front Cell Neurosci 2023; 17:1197611. [PMID: 37538852 PMCID: PMC10394277 DOI: 10.3389/fncel.2023.1197611] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/31/2023] [Accepted: 06/28/2023] [Indexed: 08/05/2023] Open
Abstract
Humans have six members of the ferlin protein family: dysferlin, myoferlin, otoferlin, fer1L4, fer1L5, and fer1L6. These proteins share common features such as multiple Ca2+-binding C2 domains, FerA domains, and membrane anchoring through their single C-terminal transmembrane domain, and are believed to play a key role in calcium-triggered membrane fusion and vesicle trafficking. Otoferlin plays a crucial role in hearing and vestibular function. In this review, we will discuss how we see otoferlin working as a Ca2+-dependent mechanical sensor regulating synaptic vesicle fusion at the hair cell ribbon synapses. Although otoferlin is also present in the central nervous system, particularly in the cortex and amygdala, its role in brain tissues remains unknown. Mutations in the OTOF gene cause one of the most frequent genetic forms of congenital deafness, DFNB9. These mutations produce severe to profound hearing loss due to a defect in synaptic excitatory glutamatergic transmission between the inner hair cells and the nerve fibers of the auditory nerve. Gene therapy protocols that allow normal rescue expression of otoferlin in hair cells have just started and are currently in pre-clinical phase. In parallel, studies have linked ferlins to cancer through their effect on cell signaling and development, allowing tumors to form and cancer cells to adapt to a hostile environment. Modulation by mechanical forces and Ca2+ signaling are key determinants of the metastatic process. Although ferlins importance in cancer has not been extensively studied, data show that otoferlin expression is significantly associated with survival in specific cancer types, including clear cell and papillary cell renal carcinoma, and urothelial bladder cancer. These findings indicate a role for otoferlin in the carcinogenesis of these tumors, which requires further investigation to confirm and understand its exact role, particularly as it varies by tumor site. Targeting this protein may lead to new cancer therapies.
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Affiliation(s)
- Jean-Christophe Leclère
- Department of Head and Neck Surgery, Brest University Hospital, Brest, France
- Laboratory of Neurophysiologie de la Synapse Auditive, Université de Bordeaux, Bordeaux, France
| | - Didier Dulon
- Laboratory of Neurophysiologie de la Synapse Auditive, Université de Bordeaux, Bordeaux, France
- Institut de l’Audition, Institut Pasteur & INSERM UA06, Paris, France
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6
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Jonard L, Brotto D, Moreno-Pelayo MA, Del Castillo I, Kremer H, Pennings R, Caria H, Fialho G, Boudewyns A, Van Camp G, Ołdak M, Oziębło D, Deggouj N, De Siati RD, Gasparini P, Girotto G, Verstreken M, Dossena S, Roesch S, Battelino S, Trebušak Podkrajšek K, Warnecke A, Lenarz T, Lesinski-Schiedat A, Mondain M, Roux AF, Denoyelle F, Loundon N, Serey Gaut M, Trevisi P, Rubinato E, Martini A, Marlin S. Genetic Evaluation of Prelingual Hearing Impairment: Recommendations of an European Network for Genetic Hearing Impairment. Audiol Res 2023; 13:341-346. [PMID: 37218840 DOI: 10.3390/audiolres13030029] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/18/2023] [Revised: 02/23/2023] [Accepted: 03/03/2023] [Indexed: 05/24/2023] Open
Abstract
The cause of childhood hearing impairment (excluding infectious pathology of the middle ear) can be extrinsic (embryofoetopathy, meningitis, trauma, drug ototoxicity, noise trauma, etc [...].
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Affiliation(s)
- Laurence Jonard
- Centre de Référence «Surdités Génétiques», Fédération de Génétique, Centre de Recherche en Audiologie (CREA), Hôpital Necker-Enfants Malades, Assistance Publique Hôpitaux de Paris, 75015 Paris, France
| | - Davide Brotto
- ENT Unit, Neurosciences Department, University of Padova, 35122 Padova, Italy
| | - Miguel A Moreno-Pelayo
- Centro de Investigación Biomédica en Red de Enfermedades Raras (CIBERER), Instituto Ramón y Cajal deInvestigaciones Sani-tarias (IRYCIS), Genetics Department, University hospital Ramón y Cajal, 28034 Madrid, Spain
| | - Ignacio Del Castillo
- Centro de Investigación Biomédica en Red de Enfermedades Raras (CIBERER), Instituto Ramón y Cajal deInvestigaciones Sani-tarias (IRYCIS), Genetics Department, University hospital Ramón y Cajal, 28034 Madrid, Spain
| | - Hannie Kremer
- Department of Otorhinolaryngology and Department of Human Genetics, Hearing & Genes, Radboud University Medical Center, Donders Institute for Brain, Cognition and Behaviour, Radboud University, 6525 XZ Nijmegen, The Netherlands
| | - Ronald Pennings
- Department of Otorhinolaryngology and Department of Human Genetics, Hearing & Genes, Radboud University Medical Center, Donders Institute for Brain, Cognition and Behaviour, Radboud University, 6525 XZ Nijmegen, The Netherlands
- Donders Institute for Brain, Cognition and Behaviour, Radboud University, 6525 XZ Nijmegen, The Netherlands
| | - Helena Caria
- BioISI-Biosystems & Integrative Sciences Institute, Faculty of Sciences, University of Lisboa, 1649-004 Lisboa, Portugal
- Biomedical Sciences Department, CIIAS-School of Health, Polytechnic Institute of Setubal, 2914-503 Setubal, Portugal
| | - Graça Fialho
- BioISI-Biosystems & Integrative Sciences Institute, Faculty of Sciences, University of Lisboa, 1649-004 Lisboa, Portugal
| | - An Boudewyns
- Department of Otorhinolaryngology, Head and Neck Surgery, Antwerp University Hospital, University of Antwerp, 2000 Edegem, Belgium
| | - Guy Van Camp
- Center for Medical Genetics, University of Antwerp, 2000 Antwerp, Belgium
| | - Monika Ołdak
- Department of Genetics, Institute of Physiology and Pathology of Hearing, 02-042 Warsaw, Poland
| | - Dominika Oziębło
- Department of Genetics, Institute of Physiology and Pathology of Hearing, 02-042 Warsaw, Poland
| | - Naïma Deggouj
- ENT Department, UCLouvain, Academic Hospital Saint-Luc-Brussels, 1200 Bruxelles, Belgium
| | | | - Paolo Gasparini
- Medical Genetics, Institute for Ma-ternal and Child Health (IRCCS) "Burlo Garofolo", Department of Medical, Surgery and Health Sciences, University of Trieste, 34127 Trieste, Italy
| | - Giorgia Girotto
- Medical Genetics, Institute for Ma-ternal and Child Health (IRCCS) "Burlo Garofolo", Department of Medical, Surgery and Health Sciences, University of Trieste, 34127 Trieste, Italy
| | | | - Silvia Dossena
- Institute of Pharmacology and Toxicology, Paracelsus Medical University, 5020 Salzburg, Austria
| | - Sebastian Roesch
- Department of Otorhinolaryngology, Head and Neck Surgery, Paracelsus Medical University, 5020 Salzburg, Austria
| | - Saba Battelino
- Department of Otorhinolaryngology and Cervicofacial Surgery, University Medical Centre Ljubljana, Medical Faculty, University of Ljubljana, 1000 Ljubljana, Slovenia
| | - Katarina Trebušak Podkrajšek
- Institute of Biochemistry and Molecular Genetics, Medical Faculty, University of Ljubljana, 1000 Ljubljana, Slovenia
| | - Athanasia Warnecke
- Department of Otorhinolaryngology-Head and Neck Surgery, Hannover Medical School, D-30625 Hannover, Germany
- Cluster of Excellence Hearing4all, German Research Foundation, Oldenburg 26129, Germany
| | - Thomas Lenarz
- Department of Otorhinolaryngology-Head and Neck Surgery, Hannover Medical School, D-30625 Hannover, Germany
- Cluster of Excellence Hearing4all, German Research Foundation, Oldenburg 26129, Germany
| | - Anke Lesinski-Schiedat
- Medical Head German Hearing Center, Department of Otorhinolaryngology, Medical University of Hannover, D-30625 Hannover, Germany
| | - Michel Mondain
- ENT Department, CHU Montpellier, Université de Montpellier, 34090 Montpellier, France
| | - Anne-Françoise Roux
- Laboratoire de Génétique Moléculaire, CHU de Montpellier, Université de Montpellier, 34090 Montpellier, France
| | - Françoise Denoyelle
- Service d'ORL Pédiatrique et de Chirurgie Cervico-Faciale, INSERM UMR 1120, Hôpital Necker-Enfants Malades, Assistance Publique Hôpitaux de Paris, 75015 Paris, France
| | - Natalie Loundon
- Centre de Référence «Surdités Génétiques», Fédération de Génétique, Centre de Recherche en Audiologie (CREA), Hôpital Necker-Enfants Malades, Assistance Publique Hôpitaux de Paris, 75015 Paris, France
- Service d'ORL Pédiatrique et de Chirurgie Cervico-Faciale, INSERM UMR 1120, Hôpital Necker-Enfants Malades, Assistance Publique Hôpitaux de Paris, 75015 Paris, France
| | - Margaux Serey Gaut
- Centre de Référence «Surdités Génétiques», Fédération de Génétique, Centre de Recherche en Audiologie (CREA), Hôpital Necker-Enfants Malades, Assistance Publique Hôpitaux de Paris, 75015 Paris, France
| | - Patrizia Trevisi
- ENT Unit, Neurosciences Department, University of Padova, 35122 Padova, Italy
| | - Elisa Rubinato
- Medical Genetics, Institute for Ma-ternal and Child Health (IRCCS) "Burlo Garofolo", Department of Medical, Surgery and Health Sciences, University of Trieste, 34127 Trieste, Italy
| | - Alessandro Martini
- ENT Unit, Neurosciences Department, University of Padova, 35122 Padova, Italy
| | - Sandrine Marlin
- Centre de Référence «Surdités Génétiques», Fédération de Génétique, Centre de Recherche en Audiologie (CREA), Hôpital Necker-Enfants Malades, Assistance Publique Hôpitaux de Paris, 75015 Paris, France
- Laboratory of Embryology and Genetics of Malformations, Imagine Institute, INSERM UMR 1163, Université de Paris, 75015 Paris, France
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Forli F, Capobianco S, Berrettini S, Bruschini L, Romano S, Fogli A, Bertini V, Lazzerini F. Temperature-Sensitive Auditory Neuropathy: Report of a Novel Variant of OTOF Gene and Review of Current Literature. MEDICINA (KAUNAS, LITHUANIA) 2023; 59:medicina59020352. [PMID: 36837553 PMCID: PMC9962730 DOI: 10.3390/medicina59020352] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 12/20/2022] [Revised: 02/08/2023] [Accepted: 02/10/2023] [Indexed: 02/16/2023]
Abstract
Background and objectives: Otoferlin is a multi-C2 domain protein implicated in neurotransmitter-containing vesicle release and replenishment of the cochlear inner hair cell (IHC) synapses. Mutations in the OTOF gene have been associated with two different clinical phenotypes: a prelingual severe-to-profound sensorineural hearing loss (ANSD-DFNB9); and the peculiar temperature-sensitive auditory neuropathy (TS-ANSD), characterized by a baseline mild-to-moderate hearing threshold that worsens to severe-to-profound when the body temperature rises that returns to a baseline a few hours after the temperature has fallen again. The latter clinical phenotype has been described only with a few OTOF variants with an autosomal recessive biallelic pattern of inheritance. Case report: A 7-year-old boy presented a picture compatible with TS-ANSD exacerbated by febrile states or physical exercise with mild-to-moderate hearing loss at low and medium frequencies and a decrease in speech discrimination that worsened with an unfavorable speech-to-noise ratio. Otoacoustic emissions (OAEs) were present whereas auditory brainstem responses (ABRs) evoked by a click or tone-burst were generally absent. No inner ear malformations were described from the CT scan or MRI. Next-generation sequencing (NGS) of the known deafness genes and multi-phasic bioinformatic analyses of the data detected in OTOF a c.2521G>A missense variant and the deletion of 7.4 Kb, which was confirmed by array-comparative genomic hybridization (array-CGH). The proband's parents, who were asymptomatic, were tested by Sanger sequencing and the father presented the c.2521G>A missense variant. Conclusions: The picture presented by the patient was compatible with OTOF-induced TS-ANSD. OTOF has been generally associated with an autosomal recessive biallelic pattern of inheritance; in this clinical report, two pathogenic variants never previously associated with TS-ANSD were described.
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Affiliation(s)
- Francesca Forli
- ENT, Audiology and Phoniatrics Unit, University of Pisa, 56124 Pisa, Italy
- Correspondence: ; Tel.: +39-050-997381
| | - Silvia Capobianco
- ENT, Audiology and Phoniatrics Unit, University of Pisa, 56124 Pisa, Italy
| | - Stefano Berrettini
- ENT, Audiology and Phoniatrics Unit, University of Pisa, 56124 Pisa, Italy
- Division of ENT Diseases, Karolinska Institutet, 171 77 Stockholm, Sweden
| | - Luca Bruschini
- ENT, Audiology and Phoniatrics Unit, University of Pisa, 56124 Pisa, Italy
| | - Silvia Romano
- Department of Medical and Oncological Area, Section of Medical Genetics, Azienda Ospedaliero Universitaria Pisana, 56124 Pisa, Italy
| | - Antonella Fogli
- Department of Laboratory Medicine, Section of Molecular Genetics, Azienda Ospedaliero Universitaria Pisana, 56124 Pisa, Italy
| | - Veronica Bertini
- Department of Laboratory Medicine, Section of Cytogenetics, Azienda Ospedaliero Universitaria Pisana, 56124 Pisa, Italy
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8
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Almishaal AA, Saleh S, Alferaih H, Alhelo O. Prevalence, risk factors, and audiological characteristics of auditory neuropathy. Int J Audiol 2021; 61:1018-1026. [PMID: 34928752 DOI: 10.1080/14992027.2021.2014074] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/19/2022]
Abstract
OBJECTIVE The objective of this study was to determine the prevalence, risk factors, and audiological characteristics of auditory neuropathy spectrum disorder (ANSD) in the pediatric population. DESIGN A retrospective review of medical charts was conducted for children visiting two hospitals in Saudi Arabia. STUDY SAMPLE Medical records of 1025 patients with sensorineural hearing loss (SNHL) were reviewed. We analyzed the databases for results of audiological examinations, risk factors, and outcomes of intervention including hearing aid (HA) and cochlear implantation (CI). RESULTS Out of 1025 children with SNHL, 101 patients (9.85%) were identified to have ANSD. Audiological characteristics of the ANSD group revealed a severe-to-profound degree of hearing loss, all showed type A tympanogram and absent reflexes, absent auditory brainstem response (ABR) findings with present cochlear microphonic while otoacoustic emissions were absent in 54.5% of patients. The most prevalent risk factors for ANSD in this group were family history of hearing loss, consanguinity, hyperbilirubinemia, and low birth weight. Pure tone and speech detection thresholds improved significantly with CI compared to HA use in this sample of patients with ANSD. CONCLUSION This study shows that ANSD is not extremely rare among Saudi children with severe to profound hearing loss, with a prevalence of 9.85%.
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Affiliation(s)
- Ali A Almishaal
- College of Applied Medical Sciences, University of Hail, Hail, Saudi Arabia
| | - Shaza Saleh
- King Abdullah Ear Specialist Center, King Saud University Medical City, Riyadh, Saudi Arabia
| | - Hala Alferaih
- Ear, Nose, and Throat Department, Audiology Clinic, King Fahad General Hospital, Jeddah, Saudi Arabia
| | - Osamah Alhelo
- College of Applied Medical Sciences, University of Hail, Hail, Saudi Arabia
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Burdo S, Di Berardino F, Bruno G. Is auditory neuropathy an appropriate term? A systematic literature review on its aetiology and pathogenesis. ACTA OTORHINOLARYNGOLOGICA ITALICA 2021; 41:496-506. [PMID: 34825666 PMCID: PMC8686806 DOI: 10.14639/0392-100x-n0932] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 07/10/2020] [Accepted: 05/15/2021] [Indexed: 11/23/2022]
Abstract
To clarify the aetio-pathogenesis of Auditory Neuropathy Spectrum Disorder (ANSD), a total of 845 papers were divided into four categories: Review, Audiology, Treatment and Aetiology. Aetiology was the topic analysed categorising papers as: Genetics, Histopathology, Imaging and Medical diseases. Isolated ANs were in relation to Otoferlin, Pejvakin and DIAPH3 deficiency, and the syndromes were mainly Charcot Marie Tooth, Friedreich Ataxia, mitochondrial disorders and those associated with optic neuropathies. In histopathology papers, important information was available from analyses on human premature newborns and on some syndromic neuropathies. From cochlear dysmorphism to cerebral tumours associated with ANs, these are described in what is identified as the Imaging area. Finally, the prevalent clinical pathology was bilirubinopathy, followed by diabetes. In conclusion, AN/ANSDs do not refer to a clear pathological condition, but to an instrumental pattern without any evidence of auditory nerve involvement, except in a few conditions. The terms AN/ANSD are misleading and should be avoided, including terms such as “synaptopathy” or “dis-synchrony”.
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Zhu YM, Li Q, Gao X, Li YF, Liu YL, Dai P, Li XP. Familial Temperature-Sensitive Auditory Neuropathy: Distinctive Clinical Courses Caused by Variants of the OTOF Gene. Front Cell Dev Biol 2021; 9:732930. [PMID: 34692690 PMCID: PMC8529165 DOI: 10.3389/fcell.2021.732930] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/29/2021] [Accepted: 08/31/2021] [Indexed: 11/13/2022] Open
Abstract
Objective: To investigate the clinical course and genetic etiology of familial temperature-sensitive auditory neuropathy (TSAN), which is a very rare subtype of auditory neuropathy (AN) that involves an elevation of hearing thresholds due to an increase in the core body temperature, and to evaluate the genotype-phenotype correlations in a family with TSAN. Methods: Six members of a non-consanguineous Chinese family, including four siblings complaining of communication difficulties when febrile, were enrolled in this study. The clinical and audiological profiles of the four siblings were fully evaluated during both febrile and afebrile episodes, and the genetic etiology of hearing loss (HL) was explored using next-generation sequencing (NGS) technology. Their parents, who had no complaints of fluctuating HL due to body temperature variation, were enrolled for the genetics portion only. Results: Audiological tests during the patients' febrile episodes met the classical diagnostic criteria for AN, including mild HL, poor speech discrimination, preserved cochlear microphonics (CMs), and absent auditory brainstem responses (ABRs). Importantly, unlike the pattern observed in previously reported cases of TSAN, the ABRs and electrocochleography (ECochG) signals of our patients improved to normal during afebrile periods. Genetic analysis identified a compound heterozygous variant of the OTOF gene (which encodes the otoferlin protein), including one previously reported pathogenic variant, c.5098G > C (p.Glu1700Gln), and one novel variant, c.4882C > A (p.Pro1628Thr). Neither of the identified variants affected the C2 domains related to the main function of otoferlin. Both variants faithfully cosegregated with TSAN within the pedigree, suggesting that OTOF is the causative gene of the autosomal recessive trait segregation in this family. Conclusion: The presence of CMs with absent (or markedly abnormal) ABRs is a reliable criterion for diagnosing AN. The severity of the phenotype caused by dysfunctional neurotransmitter release in TSAN may reflect variants that alter the C2 domains of otoferlin. The observations from this study enrich the current understanding of the phenotype and genotype of TSAN and may lay a foundation for further research on its pathogenesis.
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Affiliation(s)
- Yi-Ming Zhu
- Department of Otolaryngology-Head and Neck Surgery, Nanfang Hospital, Southern Medical University, Guangzhou, China
- Department of Otolaryngology-Head and Neck Surgery, Lanzhou University Second Hospital, Lanzhou, China
| | - Qi Li
- Department of Otolaryngology-Head and Neck Surgery, Nanfang Hospital, Southern Medical University, Guangzhou, China
| | - Xue Gao
- Department of Otolaryngology, PLA Rocket Force Characteristic Medical Center, Beijing, China
| | - Yan-Fei Li
- Department of Otolaryngology-Head and Neck Surgery, Nanfang Hospital, Southern Medical University, Guangzhou, China
| | - You-Li Liu
- Department of Otolaryngology-Head and Neck Surgery, Nanfang Hospital, Southern Medical University, Guangzhou, China
| | - Pu Dai
- Department of Otolaryngology-Head and Neck Surgery, Nanfang Hospital, Southern Medical University, Guangzhou, China
- Department of Otolaryngology-Head and Neck Surgery, Chinese PLA General Hospital, Beijing, China
| | - Xiang-Ping Li
- Department of Otolaryngology-Head and Neck Surgery, Nanfang Hospital, Southern Medical University, Guangzhou, China
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11
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Iwasa YI, Nishio SY, Yoshimura H, Sugaya A, Kataoka Y, Maeda Y, Kanda Y, Nagai K, Naito Y, Yamazaki H, Ikezono T, Matsuda H, Nakai M, Tona R, Sakurai Y, Motegi R, Takeda H, Kobayashi M, Kihara C, Ishino T, Morita SY, Iwasaki S, Takahashi M, Furutate S, Oka SI, Kubota T, Arai Y, Kobayashi Y, Kikuchi D, Shintani T, Ogasawara N, Honkura Y, Izumi S, Hyogo M, Ninoyu Y, Suematsu M, Nakayama J, Tsuchihashi N, Okami M, Sakata H, Yoshihashi H, Kobayashi T, Kumakawa K, Yoshida T, Esaki T, Usami SI. Detailed clinical features and genotype-phenotype correlation in an OTOF-related hearing loss cohort in Japan. Hum Genet 2021; 141:865-875. [PMID: 34536124 PMCID: PMC9034993 DOI: 10.1007/s00439-021-02351-7] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/01/2021] [Accepted: 08/23/2021] [Indexed: 11/26/2022]
Abstract
Mutations in the OTOF gene are a common cause of hereditary hearing loss and the main cause of auditory neuropathy spectrum disorder (ANSD). Although it is reported that most of the patients with OTOF mutations have stable, congenital or prelingual onset severe-to-profound hearing loss, some patients show atypical clinical phenotypes, and the genotype–phenotype correlation in patients with OTOF mutations is not yet fully understood. In this study, we aimed to reveal detailed clinical characteristics of OTOF-related hearing loss patients and the genotype–phenotype correlation. Detailed clinical information was available for 64 patients in our database who were diagnosed with OTOF-related hearing loss. As reported previously, most of the patients (90.6%) showed a “typical” phenotype; prelingual and severe-to-profound hearing loss. Forty-seven patients (73.4%) underwent cochlear implantation surgery and showed successful outcomes; approximately 85–90% of the patients showed a hearing level of 20–39 dB with cochlear implant and a Categories of Auditory Performance (CAP) scale level 6 or better. Although truncating mutations and p.Arg1939Gln were clearly related to severe phenotype, almost half of the patients with one or more non-truncating mutations showed mild-to-moderate hearing loss. Notably, patients with p.His513Arg, p.Ile1573Thr and p.Glu1910Lys showed “true” auditory neuropathy-like clinical characteristics. In this study, we have clarified genotype–phenotype correlation and efficacy of cochlear implantation for OTOF-related hearing loss patients in the biggest cohort studied to date. We believe that the clinical characteristics and genotype–phenotype correlation found in this study will support preoperative counseling and appropriate intervention for OTOF-related hearing loss patients.
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Affiliation(s)
- Yoh-Ichiro Iwasa
- Department of Otorhinolaryngology, Shinshu University School of Medicine, Matsumoto, Japan
| | - Shin-Ya Nishio
- Department of Hearing Implant Sciences, Shinshu University School of Medicine, 3-1-1, Asahi, Matsumoto City, 390-8621, Japan
| | - Hidekane Yoshimura
- Department of Otorhinolaryngology, Shinshu University School of Medicine, Matsumoto, Japan
| | - Akiko Sugaya
- Department of Otolaryngology-Head and Neck Surgery, Okayama University Graduate School of Medicine, Dentistry and Pharmaceutical Sciences, Okayama, Japan
| | - Yuko Kataoka
- Department of Otolaryngology-Head and Neck Surgery, Okayama University Graduate School of Medicine, Dentistry and Pharmaceutical Sciences, Okayama, Japan
| | - Yukihide Maeda
- Department of Otolaryngology-Head and Neck Surgery, Okayama University Graduate School of Medicine, Dentistry and Pharmaceutical Sciences, Okayama, Japan
| | - Yukihiko Kanda
- Kanda ENT Clinic, Nagasaki Bell Hearing Center, Nagasaki, Japan
| | - Kyoko Nagai
- TAKASAKI Ear Nose and Throat Clinic, Takasaki, Japan
| | - Yasushi Naito
- Department of Otolaryngology, Kobe City Medical Center General Hospital, Kobe, Japan
| | - Hiroshi Yamazaki
- Department of Otolaryngology, Kobe City Medical Center General Hospital, Kobe, Japan
| | - Tetsuo Ikezono
- Department of Otorhinolaryngology, Saitama School of Medicine, Moroyama, Japan
| | - Han Matsuda
- Department of Otorhinolaryngology, Saitama School of Medicine, Moroyama, Japan
| | | | - Risa Tona
- Shiga Medical Center for Children, Shiga, Japan
| | - Yuika Sakurai
- Department of Otorhinolaryngology, Jikei University School of Medicine, Tokyo, Japan
| | - Remi Motegi
- Department of Otorhinolaryngology, Juntendo University Faculty of Medicine, Tokyo, Japan
| | - Hidehiko Takeda
- Department of Otorhinolaryngology, Toranomon Hospital, Tokyo, Japan
| | - Marina Kobayashi
- Department of Otorhinolaryngology, Toranomon Hospital, Tokyo, Japan
| | - Chiharu Kihara
- Department of Otolaryngology-Head and Neck Surgery, Nagasaki University Graduate School of Biomedical Sciences, Nagasaki, Japan
| | - Takashi Ishino
- Department of Otorhinolaryngology, Head and Neck Surgery, Hiroshima University Hospital, Hiroshima, Japan
| | - Shin-Ya Morita
- Department of Otolaryngology-Head and Neck Surgery, Faculty of Medicine and Graduate School of Medicine, Hokkaido University, Sapporo, Japan
| | - Satoshi Iwasaki
- Department of Otorhinolaryngology, International University of Health and Welfare, Mita Hospital, Tokyo, Japan
| | - Masahiro Takahashi
- Department of Otorhinolaryngology, International University of Health and Welfare, Mita Hospital, Tokyo, Japan
| | - Sakiko Furutate
- Department of Otorhinolaryngology, International University of Health and Welfare, Mita Hospital, Tokyo, Japan
| | - Shin-Ichiro Oka
- Department of Otorhinolaryngology, International University of Health and Welfare, Mita Hospital, Tokyo, Japan
| | - Toshinori Kubota
- Department of Otolaryngology, Head and Neck Surgery, Yamagata University Faculty of Medicine, Yamagata, Japan
| | - Yasuhiro Arai
- Department of Otorhinolaryngology-Head and Neck Surgery, Yokohama City University School of Medicine, Yokohama, Japan
| | - Yumiko Kobayashi
- Department of Otolaryngology-Head and Neck Surgery, Iwate Medical University, Morioka, Japan
| | - Daisuke Kikuchi
- Department of Otolaryngology, Fukushima Medical University, Fukushima, Japan
| | - Tomoko Shintani
- Department of Microbiology, Sapporo Medical University School of Medicine, Sapporo, Japan
| | - Noriko Ogasawara
- Department of Microbiology, Sapporo Medical University School of Medicine, Sapporo, Japan
| | - Yohei Honkura
- Department of Otolaryngology-Head and Neck Surgery, Tohoku University School of Medicine, Sendai, Japan
| | - Shuji Izumi
- Department of Otolaryngology Head and Neck Surgery, Niigata University Graduate School of Medical and Dental Sciences, Niigata, Japan
| | - Misako Hyogo
- Department of Otolaryngology-Head and Neck Surgery, Kyoto Prefectural University of Medicine, Kyoto, Japan
| | - Yuzuru Ninoyu
- Department of Otolaryngology-Head and Neck Surgery, Kyoto Prefectural University of Medicine, Kyoto, Japan
| | - Mayumi Suematsu
- Department of Otolaryngology-Head and Neck Surgery, Kyoto Prefectural University of Medicine, Kyoto, Japan
| | - Jun Nakayama
- Department of Otorhinolaryngology, Shiga University School of Medical Science, Otsu, Japan
| | - Nana Tsuchihashi
- Department of Otorhinolaryngology, Graduate School of Medical Sciences, Kyushu University, Fukuoka, Japan
| | - Mayuri Okami
- Department of Otorhinolaryngology, Tokai University School of Medicine, Isehara, Japan
| | | | - Hiroshi Yoshihashi
- Department of Medical Genetics, Tokyo Metropolitan Children's Medical Center, Tokyo, Japan
| | - Taisuke Kobayashi
- Department of Otolaryngology, Kochi University Medical School, Kochi, Japan
| | - Kozo Kumakawa
- Department of Otolaryngology, Kamio Memorial Hospital, Tokyo, Japan
| | - Tadao Yoshida
- Department of Otorhinolaryngology, Nagoya University Graduate School of Medicine, Nagoya, Japan
| | - Tomoko Esaki
- Department of Otolaryngology, Aichi Children's Health and Medical Center, Obu, Japan
| | - Shin-Ichi Usami
- Department of Hearing Implant Sciences, Shinshu University School of Medicine, 3-1-1, Asahi, Matsumoto City, 390-8621, Japan.
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Abstract
Patients with auditory neuropathy (AN)/auditory synaptopathy (AS) present unique evaluation and management challenges. Communication ability using auditory stimuli varies among patients, with particular difficulty understanding speech in noise. Auditory physiologic responses are key to accurate identification and monitoring of patients with AN/AS. Management approaches should consider individual variation and the possibility of change over time. Many patients with accurately characterized AN/AS demonstrate success with cochlear implants. Areas of discovery, including understanding of synaptic and neural mechanisms, genotype/phenotype relationships, and use of cochlear and cortical evoked potentials, will promote accurate clinical evaluation and management of infants, children, and adults with AN/AS.
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Cochlear Synaptopathy due to Mutations in OTOF Gene May Result in Stable Mild Hearing Loss and Severe Impairment of Speech Perception. Ear Hear 2021; 42:1627-1639. [PMID: 33908410 PMCID: PMC9973442 DOI: 10.1097/aud.0000000000001052] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
OBJECTIVES Congenital profound hearing loss with preserved cochlear outer hair cell activity (otoacoustic emissions and cochlear microphonic) is the most common phenotype associated with mutations in the OTOF gene. The aim of this study was to investigate the pathophysiological mechanisms behind the auditory dysfunction in five patients (2 adults and 3 children) carrying biallelic mutations in OTOF, who showed an uncommon phenotype of mild hearing impairment associated with severe difficulties in speech perception and delay of language development. DESIGN Patients underwent audiometric assessment with pure-tone and speech perception evaluation, and otoacoustic emissions and auditory brainstem response recording. Cochlear potentials were recorded in all subjects through transtympanic electrocochleography in response to clicks delivered in the free field from 120 to 60 dB peak equivalent SPL and were compared to recordings obtained from 20 normally hearing controls and from eight children with profound deafness due to mutations in the OTOF gene. Three patients out of five underwent unilateral cochlear implantation. Speech perception measures and electrically evoked auditory nerve potentials were obtained within 1 year of cochlear implant use. RESULTS Pathogenic mutations in the two alleles of OTOF were found in all five patients, and five novel mutations were identified. Hearing thresholds indicated mild hearing loss in four patients and moderate hearing loss in one. Distortion product otoacoustic emissions were recorded in all subjects, whereas auditory brainstem responses were absent in all but two patients, who showed a delayed wave V in one ear. In electrocochleography recordings, cochlear microphonics and summating potentials showed normal latency and peak amplitude, consistently with preservation of both outer and inner hair cell activity. In contrast, the neural compound action potential recorded in normally hearing controls was replaced by a prolonged, low-amplitude negative response. No differences in cochlear potentials were found between OTOF subjects showing mild or profound hearing loss. Electrical stimulation through the cochlear implant improved speech perception and restored synchronized auditory nerve responses in all cochlear implant recipients. CONCLUSIONS These findings indicate that disordered synchrony in auditory fiber activity underlies the impairment of speech perception in patients carrying biallelic mutations in OTOF gene who show a stable phenotype of mild hearing loss. Abnormal nerve synchrony with preservation of hearing sensitivity is consistent with selective impairment of vesicle replenishment at the ribbon synapses with relative preservation of synaptic exocytosis. Cochlear implants are effective in restoring speech perception and synchronous activation of the auditory pathway by directly stimulating auditory fibers.
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14
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Vona B, Rad A, Reisinger E. The Many Faces of DFNB9: Relating OTOF Variants to Hearing Impairment. Genes (Basel) 2020; 11:genes11121411. [PMID: 33256196 PMCID: PMC7768390 DOI: 10.3390/genes11121411] [Citation(s) in RCA: 26] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/03/2020] [Revised: 11/23/2020] [Accepted: 11/25/2020] [Indexed: 01/05/2023] Open
Abstract
The OTOF gene encodes otoferlin, a critical protein at the synapse of auditory sensory cells, the inner hair cells (IHCs). In the absence of otoferlin, signal transmission of IHCs fails due to impaired release of synaptic vesicles at the IHC synapse. Biallelic pathogenic and likely pathogenic variants in OTOF predominantly cause autosomal recessive profound prelingual deafness, DFNB9. Due to the isolated defect of synaptic transmission and initially preserved otoacoustic emissions (OAEs), the clinical characteristics have been termed "auditory synaptopathy". We review the broad phenotypic spectrum reported in patients with variants in OTOF that includes milder hearing loss, as well as progressive and temperature-sensitive hearing loss. We highlight several challenges that must be addressed for rapid clinical and genetic diagnosis. Importantly, we call for changes in newborn hearing screening protocols, since OAE tests fail to diagnose deafness in this case. Continued research appears to be needed to complete otoferlin isoform expression characterization to enhance genetic diagnostics. This timely review is meant to sensitize the field to clinical characteristics of DFNB9 and current limitations in preparation for clinical trials for OTOF gene therapies that are projected to start in 2021.
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15
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Lalayants MR, Mironovich OL, Bliznets EA, Markova TG, Polyakov AV, Tavartkiladze GA. [OTOF-related auditory neuropathy spectrum disorder]. Vestn Otorinolaringol 2020; 85:21-25. [PMID: 32476384 DOI: 10.17116/otorino20208502121] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Abstract
Otoferlin (OTOF) gene mutations are the most common cause of hereditary ANSD according to investigations in several countries. THE AIM Of this study was to estimate the prevalence of OTOF mutations in Russian children with ANSD and evaluate audiological and clinical features of OTOF-related ANSD. PATIENTS AND METHODS 28 children with bilateral ANSDwere enrolled in the investigation. Two step genetic testing was performed: first step - GJB2 gene testing to exclude GJB2-related hearing loss; second step - NGS-based sequencing to explore another 35 hearing loss genes (including OTOF). RESULTS OTOF mutations, including 6 new variants, were found in 5 children with ANSD (18%). All 5 children had no risk factors for hearing loss and passed hearing screening. OAE and cochlear microphonics were present till the last testing at the age of 4-5 years. ABR were not detectable. The ASSR were measurable bilaterally at all frequencies in all cases, but they did not correlate with behavioral thresholds that revealed severe hearing loss. Hearing thresholds were stable during follow up period. 3 children underwent cochlear implantation. After cochlear implantation auditory nerve action potentials to electric stimulation were detected within normal range. CONCLUSION Genetic testing of children with ANSD and first of all OTOF testing enables to reveal hearing loss etiology and provide the optimal rehabilitation approach, including cochlear implantation, as early as possible.
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Affiliation(s)
- M R Lalayants
- National Research Center for Audiology and Hearing Rehabilitation, Moscow, Russia
| | - O L Mironovich
- Academician N.P. Bochkov Medical and Genetic Research Center, Moscow, Russia
| | - E A Bliznets
- Academician N.P. Bochkov Medical and Genetic Research Center, Moscow, Russia
| | - T G Markova
- National Research Center for Audiology and Hearing Rehabilitation, Moscow, Russia.,Russian Medical Academy for Continuing Professional Education of the Ministry of Health of Russia, Moscow, Russia
| | - A V Polyakov
- Academician N.P. Bochkov Medical and Genetic Research Center, Moscow, Russia
| | - G A Tavartkiladze
- National Research Center for Audiology and Hearing Rehabilitation, Moscow, Russia.,Russian Medical Academy for Continuing Professional Education of the Ministry of Health of Russia, Moscow, Russia
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Roman AN, Runge CL. Update on Auditory Neuropathy/Dyssynchrony in Children. CURRENT OTORHINOLARYNGOLOGY REPORTS 2020. [DOI: 10.1007/s40136-020-00297-4] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/24/2022]
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17
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Auditory Neuropathy Spectrum Disorders: From Diagnosis to Treatment: Literature Review and Case Reports. J Clin Med 2020; 9:jcm9041074. [PMID: 32290039 PMCID: PMC7230308 DOI: 10.3390/jcm9041074] [Citation(s) in RCA: 39] [Impact Index Per Article: 9.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/28/2020] [Revised: 03/21/2020] [Accepted: 04/01/2020] [Indexed: 12/21/2022] Open
Abstract
Auditory neuropathy spectrum disorder (ANSD) refers to a range of hearing impairments characterized by deteriorated speech perception, despite relatively preserved pure-tone detection thresholds. Affected individuals usually present with abnormal auditory brainstem responses (ABRs), but normal otoacoustic emissions (OAEs). These electrophysiological characteristics have led to the hypothesis that ANSD may be caused by various dysfunctions at the cochlear inner hair cell (IHC) and spiral ganglion neuron (SGN) levels, while the activity of outer hair cells (OHCs) is preserved, resulting in discrepancies between pure-tone and speech comprehension thresholds. The exact prevalence of ANSD remains unknown; clinical findings show a large variability among subjects with hearing impairment ranging from mild to profound hearing loss. A wide range of prenatal and postnatal etiologies have been proposed. The study of genetics and of the implicated sites of lesion correlated with clinical findings have also led to a better understanding of the molecular mechanisms underlying the various forms of ANSD, and may guide clinicians in better screening, assessment and treatment of ANSD patients. Besides OAEs and ABRs, audiological assessment includes stapedial reflex measurements, supraliminal psychoacoustic tests, electrocochleography (ECochG), auditory steady-state responses (ASSRs) and cortical auditory evoked potentials (CAEPs). Hearing aids are indicated in the treatment of ANSD with mild to moderate hearing loss, whereas cochlear implantation is the first choice of treatment in case of profound hearing loss, especially in case of IHC presynaptic disorders, or in case of poor auditory outcomes with conventional hearing aids.
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Abstract
Ferlins are multiple-C2-domain proteins involved in Ca2+-triggered membrane dynamics within the secretory, endocytic and lysosomal pathways. In bony vertebrates there are six ferlin genes encoding, in humans, dysferlin, otoferlin, myoferlin, Fer1L5 and 6 and the long noncoding RNA Fer1L4. Mutations in DYSF (dysferlin) can cause a range of muscle diseases with various clinical manifestations collectively known as dysferlinopathies, including limb-girdle muscular dystrophy type 2B (LGMD2B) and Miyoshi myopathy. A mutation in MYOF (myoferlin) was linked to a muscular dystrophy accompanied by cardiomyopathy. Mutations in OTOF (otoferlin) can be the cause of nonsyndromic deafness DFNB9. Dysregulated expression of any human ferlin may be associated with development of cancer. This review provides a detailed description of functions of the vertebrate ferlins with a focus on muscle ferlins and discusses the mechanisms leading to disease development.
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Shearer AE, Hansen MR. Auditory synaptopathy, auditory neuropathy, and cochlear implantation. Laryngoscope Investig Otolaryngol 2019; 4:429-440. [PMID: 31453354 PMCID: PMC6703118 DOI: 10.1002/lio2.288] [Citation(s) in RCA: 59] [Impact Index Per Article: 11.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/25/2019] [Revised: 05/17/2019] [Accepted: 06/13/2019] [Indexed: 02/03/2023] Open
Abstract
Cochlear implantation has become the standard-of-care for adults and children with severe to profound hearing loss. There is growing evidence that qualitative as well as quantitative deficits in the auditory nerve may affect cochlear implant (CI) outcomes. Auditory neuropathy spectrum disorder (ANSD) is characterized by dysfunctional transmission of sound from the cochlea to the brain due to defective synaptic function or neural conduction. In this review, we examine the precise mechanisms of genetic lesions causing ANSD and the effect of these lesions on CI outcomes. Reviewed data show that individuals with lesions that primarily affect the cochlear sensory system and the synapse, which are bypassed by the CI, have optimal CI outcomes. Individuals with lesions that affect the auditory nerve show poor performance with CIs, likely because neural transmission of the electrical signal from the CI is affected. We put forth a nuanced molecular classification of ANSD that has implications for preoperative counseling for patients with this disorder prior to cochlear implantation. We propose that description of ANSD patients should be based on the molecular site of lesion typically derived from genetic evaluation (synaptopathy vs. neuropathy) as this has implications for expected CI outcomes. Improvements in our understanding of genetic site of lesions and their effects on CI function should lead to better CI outcomes, not just for individuals with auditory neuropathy, but all individuals with hearing loss.
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Affiliation(s)
- Aiden Eliot Shearer
- Department of Otolaryngology-Head and Neck Surgery University of Iowa Carver College of Medicine Iowa City Iowa U.S.A
| | - Marlan R Hansen
- Department of Otolaryngology-Head and Neck Surgery University of Iowa Carver College of Medicine Iowa City Iowa U.S.A.,Department of Neurosurgery University of Iowa Carver College of Medicine Iowa City Iowa U.S.A
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Takago H, Oshima-Takago T, Moser T. Disruption of Otoferlin Alters the Mode of Exocytosis at the Mouse Inner Hair Cell Ribbon Synapse. Front Mol Neurosci 2019; 11:492. [PMID: 30687007 PMCID: PMC6338019 DOI: 10.3389/fnmol.2018.00492] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/29/2018] [Accepted: 12/19/2018] [Indexed: 11/24/2022] Open
Abstract
Sound encoding relies on Ca2+-mediated exocytosis at the ribbon synapse between cochlear inner hair cells (IHCs) and type I spiral ganglion neurons (SGNs). Otoferlin, a multi-C2 domain protein, is proposed to regulate Ca2+-triggered exocytosis at this synapse, but the precise mechanisms of otoferlin function remain to be elucidated. Here, performing whole-cell voltage-clamp recordings of excitatory postsynaptic currents (EPSCs) from SGNs in otoferlin mutant mice, we investigated the impact of Otof disruption at individual synapses with single release event resolution. Otof deletion decreased the spontaneous release rate and abolished the stimulus-secretion coupling. This was evident from failure of potassium-induced IHC depolarization to stimulate release and supports the proposed role of otoferlin in Ca2+ sensing for fusion. A missense mutation in the Otof gene (pachanga), in which otoferlin level at the IHC plasma membrane was lowered without changing its Ca2+ binding, also reduced the spontaneous release rate but spared the stimulus-secretion coupling. The slowed stimulated release rate supports the hypothesis that a sufficient abundance of otoferlin at the plasma membrane is crucial for the vesicle supply. Large-sized monophasic EPSCs remained present upon Otof deletion despite the drastic reduction of the rate of exocytosis. However, EPSC amplitude, on average, was modestly decreased. Moreover, a reduced contribution of multiphasic EPSC was observed in both Otof mutants. We argue that the presence of large monophasic EPSCs despite the exocytic defect upon Otof deletion supports the uniquantal hypothesis of transmitter release at the IHC ribbon synapse. Based upon the reduced contribution of multiphasic EPSC, we propose a role of otoferlin in regulating the mode of exocytosis in IHCs.
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Affiliation(s)
- Hideki Takago
- Institute for Auditory Neuroscience and InnerEarLab, University Medical Center Göttingen, Göttingen, Germany.,Department of Rehabilitation for Sensory Functions, Research Institute, National Rehabilitation Center for Persons with Disabilities, Saitama, Japan.,Collaborative Research Center 889 Cellular Mechanisms of Sensory Processing, Göttingen, Germany
| | - Tomoko Oshima-Takago
- Institute for Auditory Neuroscience and InnerEarLab, University Medical Center Göttingen, Göttingen, Germany.,Department of Rehabilitation for Sensory Functions, Research Institute, National Rehabilitation Center for Persons with Disabilities, Saitama, Japan.,Collaborative Research Center 889 Cellular Mechanisms of Sensory Processing, Göttingen, Germany.,Göttingen Graduate School for Neurosciences and Molecular Biosciences, University of Göttingen, Göttingen, Germany
| | - Tobias Moser
- Institute for Auditory Neuroscience and InnerEarLab, University Medical Center Göttingen, Göttingen, Germany.,Collaborative Research Center 889 Cellular Mechanisms of Sensory Processing, Göttingen, Germany.,Göttingen Graduate School for Neurosciences and Molecular Biosciences, University of Göttingen, Göttingen, Germany.,Auditory Neuroscience Group, Max Planck Institute for Experimental Medicine, Göttingen, Germany.,Synaptic Nanophysiology Group, Max Planck Institute for Biophysical Chemistry, Göttingen, Germany
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21
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Bonventre JA, Holman C, Manchanda A, Codding SJ, Chau T, Huegel J, Barton C, Tanguay R, Johnson CP. Fer1l6 is essential for the development of vertebrate muscle tissue in zebrafish. Mol Biol Cell 2018; 30:293-301. [PMID: 30516436 PMCID: PMC6589578 DOI: 10.1091/mbc.e18-06-0401] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022] Open
Abstract
The precise spatial and temporal expression of genes is essential for proper organismal development. Despite their importance, however, many developmental genes have yet to be identified. We have determined that Fer1l6, a member of the ferlin family of genes, is a novel factor in zebrafish development. We find that Fer1l6 is expressed broadly in the trunk and head of zebrafish larvae and is more restricted to gills and female gonads in adult zebrafish. Using both genetic mutant and morpholino knockdown models, we found that loss of Fer1l6 led to deformation of striated muscle tissues, delayed development of the heart, and high morbidity. Further, expression of genes associated with muscle cell proliferation and differentiation were affected. Fer1l6 was also detected in the C2C12 cell line, and unlike other ferlin homologues, we found Fer1l6 expression was independent of the myoblast-to-myotube transition. Finally, analysis of cell and recombinant protein-based assays indicate that Fer1l6 colocalizes with syntaxin 4 and vinculin, and that the putative C2 domains interact with lipid membranes. We conclude that Fer1l6 has diverged from other vertebrate ferlins to play an essential role in zebrafish skeletal and cardiac muscle development.
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Affiliation(s)
- Josephine A Bonventre
- Department of Biochemistry and Biophysics, Oregon State University, Corvallis, OR 97331
| | - Chelsea Holman
- Department of Biochemistry and Biophysics, Oregon State University, Corvallis, OR 97331
| | - Aayushi Manchanda
- Molecular and Cellular Biology Program, Oregon State University, Corvallis, OR 97331
| | - Sara J Codding
- Department of Biochemistry and Biophysics, Oregon State University, Corvallis, OR 97331
| | - Trisha Chau
- Department of Biochemistry and Biophysics, Oregon State University, Corvallis, OR 97331
| | - Jacob Huegel
- Department of Biochemistry and Biophysics, Oregon State University, Corvallis, OR 97331
| | - Carrie Barton
- Department of Environmental and Molecular Toxicology, Oregon State University, Corvallis, OR 97331
| | - Robert Tanguay
- Department of Environmental and Molecular Toxicology, Oregon State University, Corvallis, OR 97331
| | - Colin P Johnson
- Department of Biochemistry and Biophysics, Oregon State University, Corvallis, OR 97331.,Molecular and Cellular Biology Program, Oregon State University, Corvallis, OR 97331
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22
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Kim BJ, Jang JH, Han JH, Park HR, Oh DY, Lee S, Kim MY, Kim AR, Lee C, Kim NKD, Park WY, Choung YH, Choi BY. Mutational and phenotypic spectrum of OTOF-related auditory neuropathy in Koreans: eliciting reciprocal interaction between bench and clinics. J Transl Med 2018; 16:330. [PMID: 30482216 PMCID: PMC6260760 DOI: 10.1186/s12967-018-1708-z] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/27/2018] [Accepted: 11/22/2018] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND While auditory neuropathy spectrum disorder (ANSD) is a heterogeneous disorder and its management quite varies depending upon the etiology, even including self-resolution, OTOF is an important molecular etiology of prelingual ANSD and has emerged as an attractive target for implementation of precision medicine in terms of timing and prognosis prediction of auditory rehabilitation. However, to date, the literature is lacking in the genotype-phenotype relationship of this gene as well as efficient molecular testing strategy in the clinic in many populations and to make things more complicated in Koreans, the most prevalent variant p.Arg1939Gln among Korean ANSD children frequently evaded detection by next generation sequencing (NGS), resulting in delayed genetic diagnosis and late cochlear implantation (CI). The aims of this study are to document the mutational and phenotypic spectrum of OTOF-related ANSD (DFNB9) in the Korean population, further establishing genotype-phenotype correlation and proposing a set of the most commonly found OTOF variants to be screened first. METHODS Genetic diagnosis through the NGS-based sequencing was made on patients with ANSD in two tertiary hospitals. Genotype and phenotypes of eleven DFNB9 patients were reviewed. For data analysis, Mann-Whitney test and Fisher's exact test were applied. RESULTS This study disclosed four prevalent variants in Koreans: p.Arg1939Gln with an allele frequency of 40.9%, p.Glu841Lys (13.6%), p.Leu1011Pro and p.Arg1856Trp (9.1%). Three novel variants (c.4227 + 5G > C, p.Gly1845Glu, and p.Pro1931Thr) were identified. Interestingly, a significant association of p.Arg1939Gln with worse ASSR thresholds was observed despite consistently no ABR response. Ten of 11 DFNB9 patients received CI for auditory rehabilitation, showing favorable outcomes with more rapid improvement on early-CI group (age at CI ≤ 18 mo.) than late-CI group. CONCLUSIONS This study included the largest Korean DFNB9 cohort to date and proposed a set of the most frequent four OTOF variants, allowing the potential prioritization of exons during Sanger sequencing. Further, a significant association of p.Arg1939Gln homozygotes with poor residual hearing was observed. We may have to suspect p.Arg1939Gln homozygosity in cases of poor auditory thresholds in ANSD children with putative negative OTOF variants solely screened by NGS. Reciprocal feedback between bench and clinics regarding DFNB9 would complement each other.
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Affiliation(s)
- Bong Jik Kim
- Department of Otolaryngology-Head and Neck Surgery, Chungnam National University College of Medicine, Daejeon, 35015, Korea.,Department of Otorhinolaryngology-Head and Neck Surgery, Seoul National University Bundang Hospital, Seoul National University College of Medicine, 300 Gumi-dong, Bundang-gu, Seongnam, 13620, Republic of South Korea
| | - Jeong Hun Jang
- Department of Otorhinolaryngology-Head and Neck Surgery, Ajou University School of Medicine, Suwon, 16499, Korea
| | - Jin Hee Han
- Department of Otorhinolaryngology-Head and Neck Surgery, Seoul National University Bundang Hospital, Seoul National University College of Medicine, 300 Gumi-dong, Bundang-gu, Seongnam, 13620, Republic of South Korea
| | - Hye-Rim Park
- Department of Otorhinolaryngology-Head and Neck Surgery, Seoul National University Bundang Hospital, Seoul National University College of Medicine, 300 Gumi-dong, Bundang-gu, Seongnam, 13620, Republic of South Korea
| | - Doo Yi Oh
- Department of Otorhinolaryngology-Head and Neck Surgery, Seoul National University Bundang Hospital, Seoul National University College of Medicine, 300 Gumi-dong, Bundang-gu, Seongnam, 13620, Republic of South Korea
| | - Seungmin Lee
- Department of Otorhinolaryngology-Head and Neck Surgery, Seoul National University Bundang Hospital, Seoul National University College of Medicine, 300 Gumi-dong, Bundang-gu, Seongnam, 13620, Republic of South Korea
| | - Min Young Kim
- Department of Otorhinolaryngology-Head and Neck Surgery, Seoul National University Bundang Hospital, Seoul National University College of Medicine, 300 Gumi-dong, Bundang-gu, Seongnam, 13620, Republic of South Korea
| | - Ah Reum Kim
- Samsung Genome Institute, Samsung Medical Center, Seoul, 06351, Korea
| | - Chung Lee
- Samsung Genome Institute, Samsung Medical Center, Seoul, 06351, Korea
| | - Nayoung K D Kim
- Samsung Genome Institute, Samsung Medical Center, Seoul, 06351, Korea
| | - Woong-Yang Park
- Samsung Genome Institute, Samsung Medical Center, Seoul, 06351, Korea.,Department of Molecular Cell Biology, School of Medicine, Sungkyunkwan University, Seoul, 06351, Korea
| | - Yun-Hoon Choung
- Department of Otorhinolaryngology-Head and Neck Surgery, Ajou University School of Medicine, Suwon, 16499, Korea.
| | - Byung Yoon Choi
- Department of Otorhinolaryngology-Head and Neck Surgery, Seoul National University Bundang Hospital, Seoul National University College of Medicine, 300 Gumi-dong, Bundang-gu, Seongnam, 13620, Republic of South Korea. .,Sensory Organ Research Institute, Seoul National University Medical Research Center, Seoul, 03080, Korea.
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23
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Wang Y, Lu Y, Cheng J, Zhang L, Han D, Yuan H. Novel OTOF gene mutations identified using a massively parallel DNA sequencing technique in DFNB9 deafness. Acta Otolaryngol 2018; 138:865-870. [PMID: 30073893 DOI: 10.1080/00016489.2018.1476777] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/28/2022]
Abstract
OBJECTIVES This study examined the causative genes in patients with early-onset hearing loss from two Chinese families. METHOD Massively parallel sequencing, designed to screen all reported genes associated with hearing loss, was performed in a large number of Chinese individuals with hearing loss. This study enrolled patients with the same OTOF mutation and analyzed their phenotype-genotype correlations. RESULTS Three novel OTOF mutations (NM_001287489) [c.1550T > C (p.L517P), c.5900_5902delTCA (p.I1967del), and c.4669_4677delCTGACGGTG (p.L1557-V1559del)] were found to be the cause of hearing loss in five patients. In family AH-890, the affected subject homozygous for p.L517P presented with profound hearing loss, while the affected sisters compound heterozygous for p.L517P and p.I1967del had mild-to-moderate hearing loss. The patient with hearing loss in family SD-345 was found to be compound heterozygous for p.L517P and p.L1557-V1559del. CONCLUSION Three presumably pathogenic mutations in the OTOF gene were detected for the first time, including the first pathogenic mutation detected in the TM domain. In addition to expanding the spectrum of OTOF mutations resulting in DFNB9, our findings present the diversity of its clinical presentation and indicate that MPS is an efficient approach to identify the causative genes associated with hereditary hearing loss.
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Affiliation(s)
- Yanfei Wang
- Department of Otolaryngology Head and Neck Surgery, Chinese PLA General Hospital, Beijing, China
| | - Yu Lu
- Medical Genetics Center, Southwest Hospital, Army Medical University, Chongqing, China
| | - Jing Cheng
- Medical Genetics Center, Southwest Hospital, Army Medical University, Chongqing, China
| | - Lei Zhang
- Medical Genetics Center, Southwest Hospital, Army Medical University, Chongqing, China
| | - Dongyi Han
- Department of Otolaryngology Head and Neck Surgery, Chinese PLA General Hospital, Beijing, China
| | - Huijun Yuan
- Medical Genetics Center, Southwest Hospital, Army Medical University, Chongqing, China
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24
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Johnson CP. Emerging Functional Differences between the Synaptotagmin and Ferlin Calcium Sensor Families. Biochemistry 2017; 56:6413-6417. [PMID: 29110470 PMCID: PMC5730944 DOI: 10.1021/acs.biochem.7b00928] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
![]()
The ferlin family
proteins have emerged as multi-C2 domain regulators
of calcium-triggered membrane fusion and fission events. While initially
determined to share many of the features of members of the synaptotagmin
family of calcium sensors, ferlins in more recent studies have been
found to interact directly with non-neuronal voltage-gated calcium
channels and nucleate the assembly of membrane-trafficking protein
complexes, functions that distinguish them from the more well studied
members of the synaptotagmin family. Here we highlight some of the
recent findings that have advanced our understanding of ferlins and
their functional differences with the synaptotagmin family.
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Affiliation(s)
- Colin P Johnson
- Department of Biochemistry and Biophysics, Oregon State University , Corvallis, Oregon 97331-4003, United States
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25
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Lang-Roth R, Fischer-Krall E, Kornblum C, Nürnberg G, Meschede D, Goebel I, Nürnberg P, Beutner D, Kubisch C, Walger M, Volk AE. AUNA2: A Novel Type of Non-Syndromic Slowly Progressive Auditory Synaptopathy/Auditory Neuropathy with Autosomal-Dominant Inheritance. Audiol Neurootol 2017; 22:30-40. [PMID: 28601886 DOI: 10.1159/000474929] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/08/2016] [Accepted: 03/31/2017] [Indexed: 12/17/2022] Open
Abstract
BACKGROUND Auditory synaptopathy/neuropathy (AS/AN) is a heterogeneous disorder, which may be caused by environmental factors like postnatal hyperbilirubinemia or by genetic factors. The genetic forms are subdivided into syndromic and non-syndromic types, and show different inheritance patterns with a strong preponderance of autosomal-recessive forms. To date, only a single locus for non-syndromic autosomal-dominant AS/AN (AUNA1) has been reported in a single family, in which a non-coding DIAPH3 mutation was subsequently described as causative. MATERIALS AND METHODS Here, we report detailed clinical data on a large German AS/AN family with slowly progressive postlingual hearing loss. Affected family members developed their first symptoms in their second decade. Moderate hearing loss in the fourth decade then progressed to profound hearing impairment in older family members. Comprehensive audiological and neurological tests were performed in the affected family members. Genetic testing comprised linkage analyses with polymorphic markers and a genome-wide linkage analysis using the Affymetrix GeneChip® Human Mapping 250K. RESULTS AND CONCLUSION We identified a large family with autosomal-dominant AS/AN. By means of linkage analyses, the AUNA1 locus was excluded, and putatively linked regions on chromosomal bands 12q24 and 13q34 were identified as likely carrying the second locus for autosomal-dominant AS/AN (AUNA2). AUNA2 is associated with a slowly progressive postlingual hearing loss without any evidence for additional symptoms in other organ systems.
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Affiliation(s)
- Ruth Lang-Roth
- Department of Otorhinolaryngology, Head and Neck Surgery, University of Cologne, Cologne, Germany
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26
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Strenzke N, Chakrabarti R, Al-Moyed H, Müller A, Hoch G, Pangrsic T, Yamanbaeva G, Lenz C, Pan KT, Auge E, Geiss-Friedlander R, Urlaub H, Brose N, Wichmann C, Reisinger E. Hair cell synaptic dysfunction, auditory fatigue and thermal sensitivity in otoferlin Ile515Thr mutants. EMBO J 2016; 35:2519-2535. [PMID: 27729456 DOI: 10.15252/embj.201694564] [Citation(s) in RCA: 59] [Impact Index Per Article: 7.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/15/2016] [Revised: 08/24/2016] [Accepted: 09/13/2016] [Indexed: 11/09/2022] Open
Abstract
The multi-C2 domain protein otoferlin is required for hearing and mutated in human deafness. Some OTOF mutations cause a mild elevation of auditory thresholds but strong impairment of speech perception. At elevated body temperature, hearing is lost. Mice homozygous for one of these mutations, OtofI515T/I515T, exhibit a moderate hearing impairment involving enhanced adaptation to continuous or repetitive sound stimulation. In OtofI515T/I515T inner hair cells (IHCs), otoferlin levels are diminished by 65%, and synaptic vesicles are enlarged. Exocytosis during prolonged stimulation is strongly reduced. This indicates that otoferlin is critical for the reformation of properly sized and fusion-competent synaptic vesicles. Moreover, we found sustained exocytosis and sound encoding to scale with the amount of otoferlin at the plasma membrane. We identified a 20 amino acid motif including an RXR motif, presumably present in human but not in mouse otoferlin, which reduces the plasma membrane abundance of Ile515Thr-otoferlin. Together, this likely explains the auditory synaptopathy at normal temperature and the temperature-sensitive deafness in humans carrying the Ile515Thr mutation.
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Affiliation(s)
- Nicola Strenzke
- Auditory Systems Physiology Group, Department for Otolaryngology and InnerEarLab, University Medical Center Göttingen, Göttingen, Germany .,Collaborative Research Center 889 "Cellular Mechanisms of Sensory Processing", Göttingen, Germany
| | - Rituparna Chakrabarti
- Collaborative Research Center 889 "Cellular Mechanisms of Sensory Processing", Göttingen, Germany.,Molecular Architecture of Synapses Group, Institute for Auditory Neuroscience and InnerEarLab, University Medical Center Göttingen and Max Planck Institute of Experimental Medicine, Göttingen, Germany.,Göttingen Graduate School for Neurosciences, Biophysics, and Molecular Biosciences, Göttingen, Germany
| | - Hanan Al-Moyed
- Göttingen Graduate School for Neurosciences, Biophysics, and Molecular Biosciences, Göttingen, Germany.,Molecular Biology of Cochlear Neurotransmission Group, Department for Otolaryngology and InnerEarLab, University Medical Center Göttingen, Göttingen, Germany
| | - Alexandra Müller
- Collaborative Research Center 889 "Cellular Mechanisms of Sensory Processing", Göttingen, Germany.,Göttingen Graduate School for Neurosciences, Biophysics, and Molecular Biosciences, Göttingen, Germany.,Molecular Biology of Cochlear Neurotransmission Group, Department for Otolaryngology and InnerEarLab, University Medical Center Göttingen, Göttingen, Germany
| | - Gerhard Hoch
- Institute for Auditory Neuroscience and InnerEarLab, University Medical Center Göttingen and German Primate Center, Göttingen, Germany
| | - Tina Pangrsic
- Collaborative Research Center 889 "Cellular Mechanisms of Sensory Processing", Göttingen, Germany.,Synaptic Physiology of Mammalian Vestibular Hair Cells Group, Institute for Auditory Neuroscience and InnerEarLab, University Medical Center Göttingen and Max Planck Institute of Experimental Medicine, Göttingen, Germany
| | - Gulnara Yamanbaeva
- Auditory Systems Physiology Group, Department for Otolaryngology and InnerEarLab, University Medical Center Göttingen, Göttingen, Germany.,Collaborative Research Center 889 "Cellular Mechanisms of Sensory Processing", Göttingen, Germany.,Göttingen Graduate School for Neurosciences, Biophysics, and Molecular Biosciences, Göttingen, Germany
| | - Christof Lenz
- Bioanalytical Mass Spectrometry Group, Max Planck Institute for Biophysical Chemistry, Göttingen, Germany.,Bioanalytics, Institute of Clinical Chemistry, University Medical Center Göttingen, Göttingen, Germany
| | - Kuan-Ting Pan
- Bioanalytical Mass Spectrometry Group, Max Planck Institute for Biophysical Chemistry, Göttingen, Germany
| | - Elisabeth Auge
- Auditory Systems Physiology Group, Department for Otolaryngology and InnerEarLab, University Medical Center Göttingen, Göttingen, Germany
| | - Ruth Geiss-Friedlander
- Department of Molecular Biology, University Medical Center Göttingen, Göttingen, Germany
| | - Henning Urlaub
- Collaborative Research Center 889 "Cellular Mechanisms of Sensory Processing", Göttingen, Germany.,Bioanalytical Mass Spectrometry Group, Max Planck Institute for Biophysical Chemistry, Göttingen, Germany.,Bioanalytics, Institute of Clinical Chemistry, University Medical Center Göttingen, Göttingen, Germany
| | - Nils Brose
- Collaborative Research Center 889 "Cellular Mechanisms of Sensory Processing", Göttingen, Germany.,Department of Molecular Neurobiology, Max Planck Institute of Experimental Medicine, Göttingen, Germany
| | - Carolin Wichmann
- Collaborative Research Center 889 "Cellular Mechanisms of Sensory Processing", Göttingen, Germany .,Molecular Architecture of Synapses Group, Institute for Auditory Neuroscience and InnerEarLab, University Medical Center Göttingen and Max Planck Institute of Experimental Medicine, Göttingen, Germany
| | - Ellen Reisinger
- Collaborative Research Center 889 "Cellular Mechanisms of Sensory Processing", Göttingen, Germany .,Molecular Biology of Cochlear Neurotransmission Group, Department for Otolaryngology and InnerEarLab, University Medical Center Göttingen, Göttingen, Germany.,Department of Molecular Neurobiology, Max Planck Institute of Experimental Medicine, Göttingen, Germany
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27
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Vogl C, Panou I, Yamanbaeva G, Wichmann C, Mangosing SJ, Vilardi F, Indzhykulian AA, Pangršič T, Santarelli R, Rodriguez-Ballesteros M, Weber T, Jung S, Cardenas E, Wu X, Wojcik SM, Kwan KY, Del Castillo I, Schwappach B, Strenzke N, Corey DP, Lin SY, Moser T. Tryptophan-rich basic protein (WRB) mediates insertion of the tail-anchored protein otoferlin and is required for hair cell exocytosis and hearing. EMBO J 2016; 35:2536-2552. [PMID: 27458190 DOI: 10.15252/embj.201593565] [Citation(s) in RCA: 43] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2015] [Revised: 05/29/2016] [Accepted: 06/10/2016] [Indexed: 12/21/2022] Open
Abstract
The transmembrane recognition complex (TRC40) pathway mediates the insertion of tail-anchored (TA) proteins into membranes. Here, we demonstrate that otoferlin, a TA protein essential for hair cell exocytosis, is inserted into the endoplasmic reticulum (ER) via the TRC40 pathway. We mutated the TRC40 receptor tryptophan-rich basic protein (Wrb) in hair cells of zebrafish and mice and studied the impact of defective TA protein insertion. Wrb disruption reduced otoferlin levels in hair cells and impaired hearing, which could be restored in zebrafish by transgenic Wrb rescue and otoferlin overexpression. Wrb-deficient mouse inner hair cells (IHCs) displayed normal numbers of afferent synapses, Ca2+ channels, and membrane-proximal vesicles, but contained fewer ribbon-associated vesicles. Patch-clamp of IHCs revealed impaired synaptic vesicle replenishment. In vivo recordings from postsynaptic spiral ganglion neurons showed a use-dependent reduction in sound-evoked spiking, corroborating the notion of impaired IHC vesicle replenishment. A human mutation affecting the transmembrane domain of otoferlin impaired its ER targeting and caused an auditory synaptopathy. We conclude that the TRC40 pathway is critical for hearing and propose that otoferlin is an essential substrate of this pathway in hair cells.
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Affiliation(s)
- Christian Vogl
- Institute for Auditory Neuroscience and InnerEarLab, University Medical Center Göttingen, Göttingen, Germany.,Collaborative Research Center 889, University of Göttingen, Göttingen, Germany
| | - Iliana Panou
- Institute for Auditory Neuroscience and InnerEarLab, University Medical Center Göttingen, Göttingen, Germany.,Collaborative Research Center 889, University of Göttingen, Göttingen, Germany.,Göttingen Graduate School for Neurosciences, Biophysics and Molecular Biosciences, University of Göttingen, Göttingen, Germany
| | - Gulnara Yamanbaeva
- Collaborative Research Center 889, University of Göttingen, Göttingen, Germany.,Auditory Systems Physiology Group and InnerEarLab, Department of Otolaryngology, University of Göttingen Medical Center, Göttingen, Germany
| | - Carolin Wichmann
- Collaborative Research Center 889, University of Göttingen, Göttingen, Germany.,Molecular Architecture of Synapses Group, Institute for Auditory Neuroscience and InnerEarLab, University Medical Center Göttingen, Göttingen, Germany
| | - Sara J Mangosing
- Otolaryngology Division, Department of Surgery, School of Medicine, University of California San Diego, La Jolla, CA, USA
| | - Fabio Vilardi
- Institute of Molecular Biology, University Medical Center Göttingen, Göttingen, Germany
| | - Artur A Indzhykulian
- Howard Hughes Medical Institute and Department of Neurobiology, Harvard Medical School, Boston, MA, USA
| | - Tina Pangršič
- Collaborative Research Center 889, University of Göttingen, Göttingen, Germany.,Synaptic Physiology of Mammalian Vestibular Hair Cells Junior Research Group, Institute for Auditory Neuroscience and InnerEarLab, University Medical Center Göttingen, Göttingen, Germany
| | - Rosamaria Santarelli
- Department of Neurosciences, University of Padova, Padova, Italy.,Audiology and Phoniatrics Service, Treviso Regional Hospital, Treviso, Italy
| | | | - Thomas Weber
- Institute for Auditory Neuroscience and InnerEarLab, University Medical Center Göttingen, Göttingen, Germany
| | - Sangyong Jung
- Institute for Auditory Neuroscience and InnerEarLab, University Medical Center Göttingen, Göttingen, Germany.,Synaptic Nanophysiology Group, Max Planck Institute for Biophysical Chemistry, Göttingen, Germany
| | - Elena Cardenas
- Otolaryngology Division, Department of Surgery, School of Medicine, University of California San Diego, La Jolla, CA, USA
| | - Xudong Wu
- Howard Hughes Medical Institute and Department of Neurobiology, Harvard Medical School, Boston, MA, USA
| | - Sonja M Wojcik
- Department of Molecular Neurobiology, Max-Planck-Institute for Experimental Medicine, Göttingen, Germany
| | - Kelvin Y Kwan
- W. M. Keck Center for Collaborative Neuroscience, Nelson Lab-D250, Rutgers University, Piscataway, NJ, USA
| | - Ignacio Del Castillo
- Servicio de Genetica, Hospital Universitario Ramon y Cajal, IRYCIS, Madrid, Spain.,Centro de Investigacion Biomedica en Red de Enfermedades Raras (CIBERER), Madrid, Spain
| | - Blanche Schwappach
- Institute of Molecular Biology, University Medical Center Göttingen, Göttingen, Germany
| | - Nicola Strenzke
- Collaborative Research Center 889, University of Göttingen, Göttingen, Germany.,Auditory Systems Physiology Group and InnerEarLab, Department of Otolaryngology, University of Göttingen Medical Center, Göttingen, Germany
| | - David P Corey
- Howard Hughes Medical Institute and Department of Neurobiology, Harvard Medical School, Boston, MA, USA
| | - Shuh-Yow Lin
- Otolaryngology Division, Department of Surgery, School of Medicine, University of California San Diego, La Jolla, CA, USA
| | - Tobias Moser
- Institute for Auditory Neuroscience and InnerEarLab, University Medical Center Göttingen, Göttingen, Germany .,Collaborative Research Center 889, University of Göttingen, Göttingen, Germany.,Synaptic Nanophysiology Group, Max Planck Institute for Biophysical Chemistry, Göttingen, Germany.,Center for Nanoscale Microscopy and Molecular Physiology of the Brain, University Medical Center Göttingen, Göttingen, Germany
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Rabbitt RD, Brichta AM, Tabatabaee H, Boutros PJ, Ahn J, Della Santina CC, Poppi LA, Lim R. Heat pulse excitability of vestibular hair cells and afferent neurons. J Neurophysiol 2016; 116:825-43. [PMID: 27226448 DOI: 10.1152/jn.00110.2016] [Citation(s) in RCA: 34] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/08/2016] [Accepted: 05/24/2016] [Indexed: 11/22/2022] Open
Abstract
In the present study we combined electrophysiology with optical heat pulse stimuli to examine thermodynamics of membrane electrical excitability in mammalian vestibular hair cells and afferent neurons. We recorded whole cell currents in mammalian type II vestibular hair cells using an excised preparation (mouse) and action potentials (APs) in afferent neurons in vivo (chinchilla) in response to optical heat pulses applied to the crista (ΔT ≈ 0.25°C per pulse). Afferent spike trains evoked by heat pulse stimuli were diverse and included asynchronous inhibition, asynchronous excitation, and/or phase-locked APs synchronized to each infrared heat pulse. Thermal responses of membrane currents responsible for APs in ganglion neurons were strictly excitatory, with Q10 ≈ 2. In contrast, hair cells responded with a mix of excitatory and inhibitory currents. Excitatory hair cell membrane currents included a thermoelectric capacitive current proportional to the rate of temperature rise (dT/dt) and an inward conduction current driven by ΔT An iberiotoxin-sensitive inhibitory conduction current was also evoked by ΔT, rising in <3 ms and decaying with a time constant of ∼24 ms. The inhibitory component dominated whole cell currents in 50% of hair cells at -68 mV and in 67% of hair cells at -60 mV. Responses were quantified and described on the basis of first principles of thermodynamics. Results identify key molecular targets underlying heat pulse excitability in vestibular sensory organs and provide quantitative methods for rational application of optical heat pulses to examine protein biophysics and manipulate cellular excitability.
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Affiliation(s)
- Richard D Rabbitt
- Departments of Bioengineering and Otolaryngology, University of Utah, Salt Lake City, Utah;
| | - Alan M Brichta
- School of Biomedical Sciences and Pharmacy, University of Newcastle, Callaghan, New South Wales, Australia; and
| | - Hessam Tabatabaee
- School of Biomedical Sciences and Pharmacy, University of Newcastle, Callaghan, New South Wales, Australia; and
| | - Peter J Boutros
- Department of Otolaryngology-Head and Neck Surgery, Johns Hopkins School of Medicine, Baltimore, Maryland
| | - JoongHo Ahn
- Department of Otolaryngology-Head and Neck Surgery, Johns Hopkins School of Medicine, Baltimore, Maryland
| | - Charles C Della Santina
- Department of Otolaryngology-Head and Neck Surgery, Johns Hopkins School of Medicine, Baltimore, Maryland
| | - Lauren A Poppi
- School of Biomedical Sciences and Pharmacy, University of Newcastle, Callaghan, New South Wales, Australia; and
| | - Rebecca Lim
- School of Biomedical Sciences and Pharmacy, University of Newcastle, Callaghan, New South Wales, Australia; and
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Abstract
Sensorineural hearing impairment is the most common form of hearing loss, and encompasses pathologies of the cochlea and the auditory nerve. Hearing impairment caused by abnormal neural encoding of sound stimuli despite preservation of sensory transduction and amplification by outer hair cells is known as 'auditory neuropathy'. This term was originally coined for a specific type of hearing impairment affecting speech comprehension beyond changes in audibility: patients with this condition report that they "can hear but cannot understand". This type of hearing impairment can be caused by damage to the sensory inner hair cells (IHCs), IHC ribbon synapses or spiral ganglion neurons. Human genetic and physiological studies, as well as research on animal models, have recently shown that disrupted IHC ribbon synapse function--resulting from genetic alterations that affect presynaptic glutamate loading of synaptic vesicles, Ca(2+) influx, or synaptic vesicle exocytosis--leads to hearing impairment termed 'auditory synaptopathy'. Moreover, animal studies have demonstrated that sound overexposure causes excitotoxic loss of IHC ribbon synapses. This mechanism probably contributes to hearing disorders caused by noise exposure or age-related hearing loss. This Review provides an update on recently elucidated sensory, synaptic and neural mechanisms of hearing impairment, their corresponding clinical findings, and discusses current rehabilitation strategies as well as future therapies.
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Affiliation(s)
- Tobias Moser
- Institute for Auditory Neuroscience and InnerEarLab, University Medical Center Göttingen, 37099 Göttingen, Germany
| | - Arnold Starr
- Center for Hearing Research, University of California, Irvine, California 92697, USA
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Oonk AMM, Huygen PLM, Kunst HPM, Kremer H, Pennings RJE. Features of autosomal recessive non-syndromic hearing impairment: a review to serve as a reference. Clin Otolaryngol 2016; 41:487-97. [PMID: 26474130 DOI: 10.1111/coa.12567] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 09/25/2015] [Indexed: 11/29/2022]
Abstract
OBJECTIVE Non-syndromic sensorineural hearing impairment is inherited in an autosomal recessive fashion in 75-85% of cases. To date, 61 genes with this type of inheritance have been identified as related to hearing impairment, and the genetic heterogeneity is accompanied by a large variety of clinical characteristics. Adequate counselling on a patient's hearing prognosis and rehabilitation is part of the diagnosis on the genetic cause of hearing impairment and, in addition, is important for the psychological well-being of the patient. TYPE OF REVIEW Traditional literature review. DATA SOURCE All articles describing clinical characteristics of the audiovestibular phenotypes of identified genes and related loci have been reviewed. CONCLUSION This review aims to serve as a summary and a reference for counselling purposes when a causative gene has been identified in a patient with a non-syndromic autosomal recessively inherited sensorineural hearing impairment.
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Affiliation(s)
- A M M Oonk
- Department of Otorhinolaryngology, Hearing & Genes, Radboud University Medical Center, Nijmegen, The Netherlands. .,Donders Institute for Brain Cognition and Behaviour, Radboud University Medical Center, Nijmegen, The Netherlands.
| | - P L M Huygen
- Department of Otorhinolaryngology, Hearing & Genes, Radboud University Medical Center, Nijmegen, The Netherlands
| | - H P M Kunst
- Department of Otorhinolaryngology, Hearing & Genes, Radboud University Medical Center, Nijmegen, The Netherlands.,Donders Institute for Brain Cognition and Behaviour, Radboud University Medical Center, Nijmegen, The Netherlands
| | - H Kremer
- Department of Otorhinolaryngology, Hearing & Genes, Radboud University Medical Center, Nijmegen, The Netherlands.,Nijmegen Centre for Molecular Life Sciences, Radboud University Medical Center, Nijmegen, The Netherlands.,Department of Human Genetics, Radboud University Medical Center, Nijmegen, The Netherlands
| | - R J E Pennings
- Department of Otorhinolaryngology, Hearing & Genes, Radboud University Medical Center, Nijmegen, The Netherlands.,Donders Institute for Brain Cognition and Behaviour, Radboud University Medical Center, Nijmegen, The Netherlands
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31
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Zhang Q, Lan L, Shi W, Yu L, Xie LY, Xiong F, Zhao C, Li N, Yin Z, Zong L, Guan J, Wang D, Sun W, Wang Q. Temperature sensitive auditory neuropathy. Hear Res 2016; 335:53-63. [PMID: 26778470 DOI: 10.1016/j.heares.2016.01.008] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/21/2015] [Revised: 01/10/2016] [Accepted: 01/11/2016] [Indexed: 11/29/2022]
Abstract
Temperature sensitive auditory neuropathy is a very rare and puzzling disorder. In the present study, we reported three unrelated 2 to 6 year-old children who were diagnosed as auditory neuropathy patients who complained of severe hearing loss when they had fever. Their hearing thresholds varied from the morning to the afternoon. Two of these patients' hearing improved with age, and one patient received positive results from cochlear implant. Genetic analysis revealed that these three patients had otoferlin (OTOF) homozygous or compound heterozygous mutations with the genotypes c.2975_2978delAG/c.4819C>T, c.4819C>T/c.4819C>T, or c.2382_2383delC/c.1621G>A, respectively. Our study suggests that these gene mutations may be the cause of temperature sensitive auditory neuropathy. The long term follow up results suggest that the hearing loss in this type of auditory neuropathy may recover with age.
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Affiliation(s)
- Qiujing Zhang
- Department of Otolaryngology/Head and Neck Surgery, Chinese PLA Institute of Otolaryngology, Chinese PLA General Hospital, 28 Fuxing Road, Beijing 100853, China.
| | - Lan Lan
- Department of Otolaryngology/Head and Neck Surgery, Chinese PLA Institute of Otolaryngology, Chinese PLA General Hospital, 28 Fuxing Road, Beijing 100853, China.
| | - Wei Shi
- Department of Otolaryngology/Head and Neck Surgery, Chinese PLA Institute of Otolaryngology, Chinese PLA General Hospital, 28 Fuxing Road, Beijing 100853, China.
| | - Lan Yu
- Department of Otolaryngology/Head and Neck Surgery, Chinese PLA Institute of Otolaryngology, Chinese PLA General Hospital, 28 Fuxing Road, Beijing 100853, China.
| | - Lin-Yi Xie
- Department of Otolaryngology/Head and Neck Surgery, Chinese PLA Institute of Otolaryngology, Chinese PLA General Hospital, 28 Fuxing Road, Beijing 100853, China.
| | - Fen Xiong
- Department of Otolaryngology/Head and Neck Surgery, Chinese PLA Institute of Otolaryngology, Chinese PLA General Hospital, 28 Fuxing Road, Beijing 100853, China.
| | - Cui Zhao
- Department of Otolaryngology/Head and Neck Surgery, Chinese PLA Institute of Otolaryngology, Chinese PLA General Hospital, 28 Fuxing Road, Beijing 100853, China.
| | - Na Li
- Department of Otolaryngology/Head and Neck Surgery, Chinese PLA Institute of Otolaryngology, Chinese PLA General Hospital, 28 Fuxing Road, Beijing 100853, China.
| | - Zifang Yin
- Department of Otolaryngology/Head and Neck Surgery, Chinese PLA Institute of Otolaryngology, Chinese PLA General Hospital, 28 Fuxing Road, Beijing 100853, China.
| | - Liang Zong
- Department of Otolaryngology/Head and Neck Surgery, Chinese PLA Institute of Otolaryngology, Chinese PLA General Hospital, 28 Fuxing Road, Beijing 100853, China.
| | - Jing Guan
- Department of Otolaryngology/Head and Neck Surgery, Chinese PLA Institute of Otolaryngology, Chinese PLA General Hospital, 28 Fuxing Road, Beijing 100853, China.
| | - Dayong Wang
- Department of Otolaryngology/Head and Neck Surgery, Chinese PLA Institute of Otolaryngology, Chinese PLA General Hospital, 28 Fuxing Road, Beijing 100853, China.
| | - Wei Sun
- Department of Communicative Disorders & Sciences, Center for Hearing and Deafness, University at Buffalo, The State University of New York, Buffalo, NY 14215, USA.
| | - Qiuju Wang
- Department of Otolaryngology/Head and Neck Surgery, Chinese PLA Institute of Otolaryngology, Chinese PLA General Hospital, 28 Fuxing Road, Beijing 100853, China.
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Harrison RV, Gordon KA, Papsin BC, Negandhi J, James AL. Auditory neuropathy spectrum disorder (ANSD) and cochlear implantation. Int J Pediatr Otorhinolaryngol 2015; 79:1980-7. [PMID: 26545793 DOI: 10.1016/j.ijporl.2015.10.006] [Citation(s) in RCA: 42] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/23/2015] [Revised: 10/09/2015] [Accepted: 10/11/2015] [Indexed: 10/22/2022]
Abstract
We discuss issues related to cochlear implantation in children with auditory neuropathy spectrum disorder (ANSD). We describe the varied nature of this disease category including the numerous potential causes of auditory neuropathy. The most prevalent etiology for infants with ANSD is associated with prolonged neonatal intensive care unit (NICU) stay. We discuss the potential contribution of cochlear hypoxia to this etiology. The second part of this review describes in detail our own experience at the Hospital for Sick Children in Toronto, with cochlear implantation of children diagnosed with ANSD. We outline the detection, diagnosis, and referral routes for our patients. We provide an overview of our "standard operation procedures" regarding candidacy, and discuss some of the special considerations that need to be applied to children with ANSD. This includes decisions to implant children with better audiometric thresholds that are standard in non-ANSD patients, concerns about the possibility of spontaneous remission and the appropriate timing of implantation. Finally we review an extensive published literature in outcomes after cochlear implantation (CI) in ANSD. This is not a systematic review but rather an exercise to distill out some important reoccurring themes and the general consensus of opinion to date. Our conclusion is that the hearing loss category ANSD, together with its numerous co-morbidities, is far too heterogeneous to make definitive statements about prognosis with CI.
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Affiliation(s)
- Robert V Harrison
- Department of Otolaryngology - HNS, Program in Neuroscience and Mental Health, The Hospital for Sick Children, 555 University Ave, Toronto, Ontario, Canada M5G 1X8; Department of Otolaryngology - Head and Neck Surgery, University of Toronto, 190 Elizabeth Street, Toronto, Ontario, Canada MG5 2N2.
| | - Karen A Gordon
- Department of Otolaryngology - HNS, Program in Neuroscience and Mental Health, The Hospital for Sick Children, 555 University Ave, Toronto, Ontario, Canada M5G 1X8; Department of Otolaryngology - Head and Neck Surgery, University of Toronto, 190 Elizabeth Street, Toronto, Ontario, Canada MG5 2N2
| | - Blake C Papsin
- Department of Otolaryngology - HNS, Program in Neuroscience and Mental Health, The Hospital for Sick Children, 555 University Ave, Toronto, Ontario, Canada M5G 1X8; Department of Otolaryngology - Head and Neck Surgery, University of Toronto, 190 Elizabeth Street, Toronto, Ontario, Canada MG5 2N2
| | - Jaina Negandhi
- Department of Otolaryngology - HNS, Program in Neuroscience and Mental Health, The Hospital for Sick Children, 555 University Ave, Toronto, Ontario, Canada M5G 1X8
| | - Adrian L James
- Department of Otolaryngology - HNS, Program in Neuroscience and Mental Health, The Hospital for Sick Children, 555 University Ave, Toronto, Ontario, Canada M5G 1X8; Department of Otolaryngology - Head and Neck Surgery, University of Toronto, 190 Elizabeth Street, Toronto, Ontario, Canada MG5 2N2
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33
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Abstract
Auditory neuropathy/dys-synchrony disorder affects neural responses, either directly or indirectly. Patients may demonstrate good ability to detect sound, but have significant difficulty listening in noise. Clinical auditory physiologic measures are used to characterize cochlear, eighth nerve, and brainstem function, and are needed to accurately identify this disorder. Cochlear implants provide benefit to many patients, and some patients derive benefit from amplification. This disorder can be identified and managed in infants, may have later onset, may be a part of a syndrome, and may include fluctuation in hearing ability.
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Affiliation(s)
- Linda J Hood
- Department of Hearing and Speech Sciences, Vanderbilt University, 1215 21st Avenue South, MCE South Tower, Room 8310, Nashville, TN 37232-8242, USA; School of Rehabilitation Sciences, University of Queensland, Brisbane, Queensland, Australia.
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Abstract
In 1996, a new type of bilateral hearing disorder was discerned and published almost simultaneously by Kaga et al. [1] and Starr et al. [2]. Although the pathophysiology of this disorder as reported by each author was essentially identical, Kaga used the term "auditory nerve disease" and Starr used the term "auditory neuropathy". Auditory neuropathy (AN) in adults is an acquired disorder characterized by mild-to-moderate pure-tone hearing loss, poor speech discrimination, and absence of the auditory brainstem response (ABR) all in the presence of normal cochlear outer hair cell function as indicated by normal distortion product otoacoustic emissions (DPOAEs) and evoked summating potentials (SPs) by electrocochleography (ECoG). A variety of processes and etiologies are thought to be involved in its pathophysiology including mutations of the OTOF and/or OPA1 genes. Most of the subsequent reports in the literature discuss the various auditory profiles of patients with AN [3,4] and in this report we present the profiles of an additional 17 cases of adult AN. Cochlear implants are useful for the reacquisition of hearing in adult AN although hearing aids are ineffective. In 2008, the new term of Auditory Neuropathy Spectrum Disorders (ANSD) was proposed by the Colorado Children's Hospital group following a comprehensive study of newborn hearing test results. When ABRs were absent and DPOAEs were present in particular cases during newborn screening they were classified as ANSD. In 2013, our group in the Tokyo Medical Center classified ANSD into three types by following changes in ABRs and DPOAEs over time with development. In Type I, there is normalization of hearing over time, Type II shows a change into profound hearing loss and Type III is true auditory neuropathy (AN). We emphasize that, in adults, ANSD is not the same as AN.
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Affiliation(s)
- Kimitaka Kaga
- National Institute of Sensory Organs, National Tokyo Medical Center, Japan; Center for Speech and Hearing Disorders, International University of Health and Welfare, Japan.
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35
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Santarelli R, del Castillo I, Cama E, Scimemi P, Starr A. Audibility, speech perception and processing of temporal cues in ribbon synaptic disorders due to OTOF mutations. Hear Res 2015; 330:200-12. [PMID: 26188103 DOI: 10.1016/j.heares.2015.07.007] [Citation(s) in RCA: 44] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/17/2014] [Revised: 06/21/2015] [Accepted: 07/12/2015] [Indexed: 11/26/2022]
Abstract
Mutations in the OTOF gene encoding otoferlin result in a disrupted function of the ribbon synapses with impairment of the multivesicular glutamate release. Most affected subjects present with congenital hearing loss and abnormal auditory brainstem potentials associated with preserved cochlear hair cell activities (otoacoustic emissions, cochlear microphonics [CMs]). Transtympanic electrocochleography (ECochG) has recently been proposed for defining the details of potentials arising in both the cochlea and auditory nerve in this disorder, and with a view to shedding light on the pathophysiological mechanisms underlying auditory dysfunction. We review the audiological and electrophysiological findings in children with congenital profound deafness carrying two mutant alleles of the OTOF gene. We show that cochlear microphonic (CM) amplitude and summating potential (SP) amplitude and latency are normal, consistently with a preserved outer and inner hair cell function. In the majority of OTOF children, the SP component is followed by a markedly prolonged low-amplitude negative potential replacing the compound action potential (CAP) recorded in normally-hearing children. This potential is identified at intensities as low as 90 dB below the behavioral threshold. In some ears, a synchronized CAP is superimposed on the prolonged responses at high intensity. Stimulation at high rates reduces the amplitude and duration of the prolonged potentials, consistently with their neural generation. In some children, however, the ECochG response only consists of the SP, with no prolonged potential. Cochlear implants restore hearing sensitivity, speech perception and neural CAP by electrically stimulating the auditory nerve fibers. These findings indicate that an impaired multivesicular glutamate release in OTOF-related disorders leads to abnormal auditory nerve fiber activation and a consequent impairment of spike generation. The magnitude of these effects seems to vary, ranging from no auditory nerve fiber activation to an abnormal generation of EPSPs that occasionally trigger a synchronized electrical activity, resulting in high-threshold CAPs.
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Affiliation(s)
- Rosamaria Santarelli
- Department of Neurosciences, University of Padova, Via Giustiniani 2, 35128 Padova, Italy; Audiology and Phoniatrics Service, Treviso Regional Hospital, Piazza Ospedale 1, 31100 Treviso, Italy.
| | - Ignacio del Castillo
- Servicio de Genética, Hospital Universitario Ramón y Cajal, IRYCIS, 28034 Madrid, Spain; Centro de Investigación Biomédica en Red de Enfermedades Raras (CIBERER), 28034 Madrid, Spain
| | - Elona Cama
- Department of Neurosciences, University of Padova, Via Giustiniani 2, 35128 Padova, Italy; Audiology and Phoniatrics Service, Treviso Regional Hospital, Piazza Ospedale 1, 31100 Treviso, Italy
| | - Pietro Scimemi
- Department of Neurosciences, University of Padova, Via Giustiniani 2, 35128 Padova, Italy; Audiology and Phoniatrics Service, Treviso Regional Hospital, Piazza Ospedale 1, 31100 Treviso, Italy
| | - Arnold Starr
- Department of Neurology, University of California, Irvine, CA 92697, USA
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Lepcha A, Chandran RK, Alexander M, Agustine AM, Thenmozhi K, Balraj A. Neurological associations in auditory neuropathy spectrum disorder: Results from a tertiary hospital in South India. Ann Indian Acad Neurol 2015; 18:171-80. [PMID: 26019414 PMCID: PMC4445192 DOI: 10.4103/0972-2327.150578] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/12/2014] [Revised: 03/09/2014] [Accepted: 05/08/2014] [Indexed: 01/28/2023] Open
Abstract
Aims: To find out the prevalence and types of neurological abnormalities associated in auditory neuropathy spectrum disorder in a large tertiary referral center. Settings and Design: A prospective clinical study was conducted on all patients diagnosed with auditory neuropathy spectrum disorder in the ear, nose, and throat (ENT) and neurology departments during a 17-month period. Patients with neurological abnormalities on history and examination were further assessed by a neurologist to determine the type of disorder present. Results: The frequency of auditory neuropathy spectrum disorder was 1.12%. Sixty percent were found to have neurological involvement. This included cerebral palsy in children, peripheral neuropathy (PN), spinocerebellar ataxia, hereditary motor-sensory neuropathy, spastic paresis, and ponto-bulbar palsy. Neurological lesions did not present simultaneously with hearing loss in most patients. Sixty-six percent of patients with auditory neuropathy spectrum disorder were born of consanguineous marriages. Conclusions: There is a high prevalence of neurological lesions in auditory neuropathy spectrum disorder which has to be kept in mind while evaluating such patients. Follow-up and counselling regarding the appearance of neuropathies is therefore important in such patients. A hereditary etiology is indicated in a majority of cases of auditory neuropathy spectrum disorder.
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Affiliation(s)
- Anjali Lepcha
- Department of Ear, Nose and Throat, Christian Medical College and Hospital, Vellore, Tamil Nadu, India
| | - Reni K Chandran
- Department of Otolaryngology, Head and Neck Surgery, Hamad Medical Corporation, Al Wakra Hospital, Doha, Qatar
| | - Mathew Alexander
- Department of Neurology, Christian Medical College and Hospital, Vellore, Tamil Nadu, India
| | - Ann Mary Agustine
- Department of Ear, Nose and Throat, Christian Medical College and Hospital, Vellore, Tamil Nadu, India
| | - K Thenmozhi
- Department of Ear, Nose and Throat, Christian Medical College and Hospital, Vellore, Tamil Nadu, India
| | - Achamma Balraj
- Department of Ear, Nose and Throat, Christian Medical College and Hospital, Vellore, Tamil Nadu, India
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Abstract
INTRODUCTION Mutations in the otoferlin gene are responsible for auditory neuropathy. OBJECTIVE To investigate the prevalence of mutations in the mutations in the otoferlin gene in patients with and without auditory neuropathy. METHODS This original cross-sectional case study evaluated 16 index cases with auditory neuropathy, 13 patients with sensorineural hearing loss, and 20 normal-hearing subjects. DNA was extracted from peripheral blood leukocytes, and the mutations in the otoferlin gene sites were amplified by polymerase chain reaction/restriction fragment length polymorphism. RESULTS The 16 index cases included nine (56%) females and seven (44%) males. The 13 deaf patients comprised seven (54%) males and six (46%) females. Among the 20 normal-hearing subjects, 13 (65%) were males and seven were (35%) females. Thirteen (81%) index cases had wild-type genotype (AA) and three (19%) had the heterozygous AG genotype for IVS8-2A-G (intron 8) mutation. The 5473C-G (exon 44) mutation was found in a heterozygous state (CG) in seven (44%) index cases and nine (56%) had the wild-type allele (CC). Of these mutants, two (25%) were compound heterozygotes for the mutations found in intron 8 and exon 44. All patients with sensorineural hearing loss and normal-hearing individuals did not have mutations (100%). CONCLUSION There are differences at the molecular level in patients with and without auditory neuropathy.
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Abstract
Neural disorders of the auditory nerve are associated with particular disorders of auditory perceptions dependent on processing of acoustic temporal cues. These include: (1) speech perception; (2) localizing a sound's origin in space; and (3) identifying sounds in background noise. Auditory neuropathy (AN) is a consequence of: (1) presynaptic disorders affecting inner hair cell ribbon synapses; (2) postsynaptic disorders of auditory nerve dendrites; and (3) postsynaptic disorders of auditory nerve axons. The etiologies of these disorders are diverse, similar to other cranial or peripheral neuropathies. The pathologies cause attenuated and dyssynchronous auditory nerve discharges. Therapies and management of patients with AN are reviewed.
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Affiliation(s)
- Arnold Starr
- Departments of Neurology and Neurobiology, University of California, Irvine, CA, USA.
| | - Gary Rance
- School of Audiology, University of Melbourne, Melbourne, Australia
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Evidence for genotype-phenotype correlation for OTOF mutations. Int J Pediatr Otorhinolaryngol 2014; 78:950-3. [PMID: 24746455 PMCID: PMC4066206 DOI: 10.1016/j.ijporl.2014.03.022] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/12/2013] [Revised: 03/17/2014] [Accepted: 03/18/2014] [Indexed: 11/23/2022]
Abstract
OBJECTIVES The aim of this study is to evaluate the auditory phenotype in subjects with OTOF gene mutations to describe genotype-phenotype correlations. METHODS Twenty-two affected members from three families with homozygous OTOF mutations were included. Nine subjects were evaluated audiologically with otoscopic examination, pure-tone audiometry, tympanometry with acoustic reflex testing, auditory brain stem responses, and otoacoustic emission tests. RESULTS Homozygous c.4718T>C (p.Ile1573Thr) mutation was associated with the auditory neuropathy/auditory dys-synchrony (AN/AD) phenotype and with progressive sensorineural hearing loss in four siblings in one family, while homozygous c.4467dupC (p.I1490HfsX19) was associated with severe to profound sensorineural hearing loss without AN/AD in four relatives in another family. Homozygous c.1958delC (p.Pro653LeufsX13) mutation was associated with moderate sensorineural hearing loss without AN/AD in one affected person in an additional family. CONCLUSIONS The audiological phenotype associated with different OTOF mutations appears to be consistently different suggesting the presence of a genotype-phenotype correlation.
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Abstract
OBJECTIVE To review new insights into the pathophysiology of sensorineural hearing impairment. Specifically, we address defects of the ribbon synapses between inner hair cells and spiral ganglion neurons that cause auditory synaptopathy. DATA SOURCES AND STUDY SELECTION Here, we review original publications on the genetics, animal models, and molecular mechanisms of hair cell ribbon synapses and their dysfunction. CONCLUSION Hair cell ribbon synapses are highly specialized to enable indefatigable sound encoding with utmost temporal precision. Their dysfunctions, which we term auditory synaptopathies, impair audibility of sounds to varying degrees but commonly affect neural encoding of acoustic temporal cues essential for speech comprehension. Clinical features of auditory synaptopathies are similar to those accompanying auditory neuropathy, a group of genetic and acquired disorders of spiral ganglion neurons. Genetic auditory synaptopathies include alterations of glutamate loading of synaptic vesicles, synaptic Ca influx or synaptic vesicle turnover. Acquired synaptopathies include noise-induced hearing loss because of excitotoxic synaptic damage and subsequent gradual neural degeneration. Alterations of ribbon synapses likely also contribute to age-related hearing loss.
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Ramakrishnan NA, Drescher MJ, Morley BJ, Kelley PM, Drescher DG. Calcium regulates molecular interactions of otoferlin with soluble NSF attachment protein receptor (SNARE) proteins required for hair cell exocytosis. J Biol Chem 2014; 289:8750-66. [PMID: 24478316 DOI: 10.1074/jbc.m113.480533] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022] Open
Abstract
Mutations in otoferlin, a C2 domain-containing ferlin family protein, cause non-syndromic hearing loss in humans (DFNB9 deafness). Furthermore, transmitter secretion of cochlear inner hair cells is compromised in mice lacking otoferlin. In the present study, we show that the C2F domain of otoferlin directly binds calcium (KD = 267 μM) with diminished binding in a pachanga (D1767G) C2F mouse mutation. Calcium was found to differentially regulate binding of otoferlin C2 domains to target SNARE (t-SNARE) proteins and phospholipids. C2D-F domains interact with the syntaxin-1 t-SNARE motif with maximum binding within the range of 20-50 μM Ca(2+). At 20 μM Ca(2+), the dissociation rate was substantially lower, indicating increased binding (KD = ∼10(-9)) compared with 0 μM Ca(2+) (KD = ∼10(-8)), suggesting a calcium-mediated stabilization of the C2 domain·t-SNARE complex. C2A and C2B interactions with t-SNAREs were insensitive to calcium. The C2F domain directly binds the t-SNARE SNAP-25 maximally at 100 μM and with reduction at 0 μM Ca(2+), a pattern repeated for C2F domain interactions with phosphatidylinositol 4,5-bisphosphate. In contrast, C2F did not bind the vesicle SNARE protein synaptobrevin-1 (VAMP-1). Moreover, an antibody targeting otoferlin immunoprecipitated syntaxin-1 and SNAP-25 but not synaptobrevin-1. As opposed to an increase in binding with increased calcium, interactions between otoferlin C2F domain and intramolecular C2 domains occurred in the absence of calcium, consistent with intra-C2 domain interactions forming a "closed" tertiary structure at low calcium that "opens" as calcium increases. These results suggest a direct role for otoferlin in exocytosis and modulation of calcium-dependent membrane fusion.
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Ching TYC, Day J, Dillon H, Gardner-Berry K, Hou S, Seeto M, Wong A, Zhang V. Impact of the presence of auditory neuropathy spectrum disorder (ANSD) on outcomes of children at three years of age. Int J Audiol 2013; 52 Suppl 2:S55-64. [PMID: 24350696 PMCID: PMC3869001 DOI: 10.3109/14992027.2013.796532] [Citation(s) in RCA: 36] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
Abstract
OBJECTIVE To determine the influence of the presence of auditory neuropathy spectrum disorder (ANSD) on speech, language, and psycho-social development of children at three years of age. DESIGN A population-based, longitudinal study was performed on outcomes of children with hearing impairment (LOCHI) in Australia. The demographic characteristics of the children were described, and their developmental outcomes were evaluated at three years of age. Performance of children with ANSD was compared with that of children without ANSD in the LOCHI study. STUDY SAMPLE There were 47 children with ANSD in the study sample. RESULTS Sixty-four percent of children with ANSD have hearing sensitivity loss ranging from mild to severe degree, and the remaining have profound hearing loss. At three years, 27 children used hearing aids, 19 used cochlear implants, and one child did not use any hearing device. Thirty percent of children have disabilities in addition to hearing loss. On average, there were no significant differences in performance level between children with and without ANSD. Also, the variability of scores was not significantly different between the two groups. CONCLUSIONS There was no significant difference in performance levels or variability between children with and without ANSD, both for children who use hearing aids, and children who use cochlear implants.
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Affiliation(s)
- Teresa Y. C. Ching
- National Acoustic Laboratories, Sydney, New South Wales, Australia
- The HEARing CRC, Melbourne, Victoria, Australia
| | - Julia Day
- The HEARing CRC, Melbourne, Victoria, Australia
- Australian Hearing, Melbourne, Victoria, Australia
| | - Harvey Dillon
- National Acoustic Laboratories, Sydney, New South Wales, Australia
- The HEARing CRC, Melbourne, Victoria, Australia
| | - Kirsty Gardner-Berry
- National Acoustic Laboratories, Sydney, New South Wales, Australia
- The HEARing CRC, Melbourne, Victoria, Australia
| | - Sanna Hou
- National Acoustic Laboratories, Sydney, New South Wales, Australia
- The HEARing CRC, Melbourne, Victoria, Australia
| | - Mark Seeto
- National Acoustic Laboratories, Sydney, New South Wales, Australia
- The HEARing CRC, Melbourne, Victoria, Australia
| | - Angela Wong
- National Acoustic Laboratories, Sydney, New South Wales, Australia
- The HEARing CRC, Melbourne, Victoria, Australia
| | - Vicky Zhang
- National Acoustic Laboratories, Sydney, New South Wales, Australia
- The HEARing CRC, Melbourne, Victoria, Australia
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Runge CL, Erbe CB, McNally MT, Van Dusen C, Friedland DR, Kwitek AE, Kerschner JE. A novel otoferlin splice-site mutation in siblings with auditory neuropathy spectrum disorder. Audiol Neurootol 2013; 18:374-82. [PMID: 24135434 DOI: 10.1159/000354978] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/24/2013] [Accepted: 08/12/2013] [Indexed: 11/19/2022] Open
Abstract
We characterize a novel otoferlin mutation discovered in a sibling pair diagnosed with auditory neuropathy spectrum disorder and investigate auditory nerve function through their cochlear implants. Genetic sequencing revealed a homozygous mutation at the otoferlin splice donor site of exon 28 (IVS28 + 1G>T) in both siblings. Functional investigation showed that the intronic sequence between exons 28 and 29 was retained in the mutated minigenes that were expressed in 293T cells. Auditory nerve compound action potential recovery functions in the siblings demonstrated different rates of neural recovery, with sibling AN1 showing rapid recovery (1.14 ms) and AN2 showing average recovery (0.78 ms) compared to subjects with sensorineural hearing loss (average: adults 0.71 ms, children 0.85 ms). Differences in neural recovery were consistent with speech perception differences between the siblings. Genotype information may indicate site of lesion in hearing loss; however, additional, as yet, unknown factors may impact clinical outcomes and must be considered.
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Affiliation(s)
- Christina L Runge
- Departments of Otolaryngology and Communication Sciences, Medical College of Wisconsin, Milwaukee, Wisc., USA
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Dimitrijevic A, Pratt H, Starr A. Auditory cortical activity in normal hearing subjects to consonant vowels presented in quiet and in noise. Clin Neurophysiol 2013; 124:1204-15. [DOI: 10.1016/j.clinph.2012.11.014] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/09/2011] [Revised: 11/27/2012] [Accepted: 11/28/2012] [Indexed: 11/29/2022]
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Wynne DP, Zeng FG, Bhatt S, Michalewski HJ, Dimitrijevic A, Starr A. Loudness adaptation accompanying ribbon synapse and auditory nerve disorders. ACTA ACUST UNITED AC 2013; 136:1626-38. [PMID: 23503620 DOI: 10.1093/brain/awt056] [Citation(s) in RCA: 38] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/17/2023]
Abstract
Abnormal auditory adaptation is a standard clinical tool for diagnosing auditory nerve disorders due to acoustic neuromas. In the present study we investigated auditory adaptation in auditory neuropathy owing to disordered function of inner hair cell ribbon synapses (temperature-sensitive auditory neuropathy) or auditory nerve fibres. Subjects were tested when afebrile for (i) psychophysical loudness adaptation to comfortably-loud sustained tones; and (ii) physiological adaptation of auditory brainstem responses to clicks as a function of their position in brief 20-click stimulus trains (#1, 2, 3 … 20). Results were compared with normal hearing listeners and other forms of hearing impairment. Subjects with ribbon synapse disorder had abnormally increased magnitude of loudness adaptation to both low (250 Hz) and high (8000 Hz) frequency tones. Subjects with auditory nerve disorders had normal loudness adaptation to low frequency tones; all but one had abnormal adaptation to high frequency tones. Adaptation was both more rapid and of greater magnitude in ribbon synapse than in auditory nerve disorders. Auditory brainstem response measures of adaptation in ribbon synapse disorder showed Wave V to the first click in the train to be abnormal both in latency and amplitude, and these abnormalities increased in magnitude or Wave V was absent to subsequent clicks. In contrast, auditory brainstem responses in four of the five subjects with neural disorders were absent to every click in the train. The fifth subject had normal latency and abnormally reduced amplitude of Wave V to the first click and abnormal or absent responses to subsequent clicks. Thus, dysfunction of both synaptic transmission and auditory neural function can be associated with abnormal loudness adaptation and the magnitude of the adaptation is significantly greater with ribbon synapse than neural disorders.
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Affiliation(s)
- Dwight P Wynne
- Department of Biomedical Engineering, University of California, Irvine, CA 92697, USA.
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Mahdieh N, Shirkavand A, Rabbani B, Tekin M, Akbari B, Akbari MT, Zeinali S. Screening of OTOF mutations in Iran: a novel mutation and review. Int J Pediatr Otorhinolaryngol 2012; 76:1610-5. [PMID: 22906306 DOI: 10.1016/j.ijporl.2012.07.030] [Citation(s) in RCA: 31] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/15/2012] [Revised: 07/21/2012] [Accepted: 07/27/2012] [Indexed: 10/28/2022]
Abstract
OBJECTIVE Mutations in OTOF have been reported to cause nonsyndromic hearing loss in different populations. The purpose of this study is screening of OTOF mutations in Iranian population. METHODS Thirty-eight consanguineous families affected with autosomal recessive nonsyndromic hearing loss (ARNSHL) and negative for GJB2 or GJB6 mutations were screened by autozygosity mapping and Sanger sequencing to find OTOF mutations. RESULTS A novel homozygous frameshift mutation (c.1981dupG) was found to cause hearing loss in one family and no other OTOF variants were detected in the remaining families. The affected individuals were homozygous forp. D661GfsX2 causing defect in long isoform of otoferlin. CONCLUSIONS We conclude that OTOF mutations are not the major cause of ARNSHL in the Iranian population but still may play an important role in HL; therefore evaluation the OTOF gene is of concern.
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Affiliation(s)
- Nejat Mahdieh
- Medical Genetic Group, Faculty of Medicine, Ilam University of Medical Sciences, Ilam, Iran.
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Otoferlin: a multi-C2 domain protein essential for hearing. Trends Neurosci 2012; 35:671-80. [DOI: 10.1016/j.tins.2012.08.002] [Citation(s) in RCA: 100] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/17/2012] [Revised: 07/25/2012] [Accepted: 08/13/2012] [Indexed: 12/21/2022]
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Matsunaga T, Mutai H, Kunishima S, Namba K, Morimoto N, Shinjo Y, Arimoto Y, Kataoka Y, Shintani T, Morita N, Sugiuchi T, Masuda S, Nakano A, Taiji H, Kaga K. A prevalent founder mutation and genotype-phenotype correlations ofOTOFin Japanese patients with auditory neuropathy. Clin Genet 2012; 82:425-32. [DOI: 10.1111/j.1399-0004.2012.01897.x] [Citation(s) in RCA: 56] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
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Abstracts of the British Society of Audiology annual conference (incorporating the Experimental and Clinical Short papers meetings). Int J Audiol 2012. [DOI: 10.3109/14992027.2012.653103] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
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