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Yeral C, Seneldir L, Karakoc AH, Sap A, Yilmaz O. Unusual phenotype in 35delG mutation: a case report. J Med Case Rep 2024; 18:241. [PMID: 38734626 PMCID: PMC11088767 DOI: 10.1186/s13256-024-04559-3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/25/2024] [Accepted: 04/05/2024] [Indexed: 05/13/2024] Open
Abstract
BACKGROUND Mutations in the GJB2 gene, which encodes the protein connexin 26 and is involved in inner ear homeostasis, are identified in approximately 50% of patients with autosomal recessive nonsyndromic hearing loss, making it one of the primary causes of prelingual nonsyndromic hearing loss in various populations. The 35delG mutation, one of the most common mutations of the GJB2 gene, usually causes prelingual, bilateral mild to profound, nonprogressive sensorineural hearing loss. CASE PRESENTATION We present an unusual case of an 18-year-old Turkish female with heterozygous 35delG mutation and postlingual, profound-sloping, progressive and fluctuating unilateral sensorineural hearing loss. The phenotype is different from the usual findings. CONCLUSIONS The 35delG mutation causing hearing loss may not always be reflected in the phenotype as expected and therefore may have different audiologic manifestations.
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Affiliation(s)
- Cem Yeral
- Faculty of Health Sciences, Department of Audiology, İstanbul University-Cerrahpaşa, Istanbul, Türkiye.
| | - Lutfu Seneldir
- Faculty of Medicine, Department of Otolaryngology, Istanbul Medipol University, Istanbul, Türkiye
| | - Arzu Hediye Karakoc
- Faculty of Health Sciences, Department of Audiology, Istanbul Medipol University, Istanbul, Türkiye
| | - Aleyna Sap
- Faculty of Health Sciences, Department of Audiology, Istanbul Medipol University, Istanbul, Türkiye
| | - Oguz Yilmaz
- Faculty of Health Sciences, Department of Audiology, Istanbul Medipol University, Istanbul, Türkiye
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Yun Y, Lee SY. Updates on Genetic Hearing Loss: From Diagnosis to Targeted Therapies. J Audiol Otol 2024; 28:88-92. [PMID: 38695053 PMCID: PMC11065549 DOI: 10.7874/jao.2024.00157] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/22/2024] [Revised: 03/21/2024] [Accepted: 04/04/2024] [Indexed: 05/05/2024] Open
Abstract
Sensorineural hearing loss (SNHL) is the most common sensory disorder, with a high Mendelian genetic contribution. Considering the genotypic and phenotypic heterogeneity of SNHL, the advent of next-generation sequencing technologies has revolutionized knowledge on its genomic architecture. Nonetheless, the conventional application of panel and exome sequencing in real-world practice is being challenged by the emerging need to explore the diagnostic capability of whole-genome sequencing, which enables the detection of both noncoding and structural variations. Small molecules and gene therapies represent good examples of how breakthroughs in genetic understanding can be translated into targeted therapies for SNHL. For example, targeted small molecules have been used to ameliorate autoinflammatory hearing loss caused by gain-of-function variants of NLRP3 and inner ear proteinopathy with OSBPL2 variants underlying dysfunctional autophagy. Strikingly, the successful outcomes of the first-in-human trial of OTOF gene therapy highlighted its potential in the treatment of various forms of genetic hearing loss. clustered regularly interspaced short palindromic repeats (CRISPR)-based technologies are currently being developed for site-specific genome editing to treat human genetic disorders. These advancements have led to an era of genotype- and mechanism-based precision medicine in SNHL practice.
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Affiliation(s)
- Yejin Yun
- Department of Otorhinolaryngology, Seoul National University College of Medicine, Seoul National University Hospital, Seoul, Korea
| | - Sang-Yeon Lee
- Department of Otorhinolaryngology, Seoul National University College of Medicine, Seoul National University Hospital, Seoul, Korea
- Department of Genomic Medicine, Seoul National University Hospital, Seoul, Korea
- Sensory Organ Research Institute, Seoul National University Medical Research Center, Seoul, Korea
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Reda Del Barrio S, García Fernández A, Quesada-Espinosa JF, Sánchez-Calvín MT, Gómez-Manjón I, Sierra-Tomillo O, Juárez-Rufián A, de Vergas Gutiérrez J. Genetic diagnosis of childhood sensorineural hearing loss. Acta Otorrinolaringol Esp (Engl Ed) 2024; 75:83-93. [PMID: 38224868 DOI: 10.1016/j.otoeng.2023.07.002] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/24/2023] [Accepted: 07/03/2023] [Indexed: 01/17/2024]
Abstract
INTRODUCTION Congenital/early-onset sensorineural hearing loss (SNHL) is one of the most common hereditary disorders in our environment. There is increasing awareness of the importance of an etiologic diagnosis, and genetic testing with next-generation sequencing (NGS) has the highest diagnostic yield. Our study shows the genetic results obtained in a cohort of patients with bilateral congenital/early-onset SNHL. MATERIALS AND METHODS We included 105 children with bilateral SNHL that received genetic testing between 2019 and 2022. Genetic tests were performed with whole exome sequencing, analyzing genes related to hearing loss (virtual panel with 244 genes). RESULTS 48% (50/105) of patients were genetically diagnosed. We identified pathogenic and likely pathogenic variants in 26 different genes, and the most frequently mutated genes were GJB2, USH2A and STRC. 52% (26/50) of variants identified produced non-syndromic hearing loss, 40% (20/50) produced syndromic hearing loss, and the resting 8% (4/50) could produce both non-syndromic and syndromic hearing loss. CONCLUSIONS Genetic testing plays a vital role in the etiologic diagnosis of bilateral SNHL. Our cohort shows that genetic testing with NGS has a high diagnostic yield and can provide useful information for the clinical workup of patients.
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Affiliation(s)
- Sara Reda Del Barrio
- Servicio de Otorrinolaringología, Hospital Universitario 12 de Octubre, Madrid, Spain.
| | | | | | | | - Irene Gómez-Manjón
- Servicio de Genética, Hospital Universitario 12 de Octubre, Madrid, Spain
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Jung J, Noh SH, Jo S, Song D, Kang MJ, Shin MH, Lee HJ, Pyun JC, Namkung W, Han G, Lee MG, Choi JY. Novel small molecule-mediated restoration of the surface expression and anion exchange activity of mutated pendrin causing Pendred syndrome and DFNB4. Biomed Pharmacother 2023; 167:115445. [PMID: 37690388 DOI: 10.1016/j.biopha.2023.115445] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/07/2023] [Revised: 08/28/2023] [Accepted: 09/04/2023] [Indexed: 09/12/2023] Open
Abstract
Variants in SLC26A4 (pendrin) are the most common reasons for genetic hearing loss and vestibular dysfunction in East Asians. In patients with Pendred syndrome and DFNB4 (autosomal recessive type of genetic hearing loss 4), caused by variants in SLC26A4, the hearing function is residual at birth and deteriorates over several years, with no curative treatment for these disorders. In the present study, we revealed that a novel small molecule restores the expression and function of mutant pendrin. High-throughput screening of 54,000 small molecules was performed. We observed that pendrin corrector (PC2-1) increased the surface expression and anion exchange activity of p.H723R pendrin (H723R-PDS), the most prevalent genetic variant that causes Pendred syndrome and DFNB4. Furthermore, in endogenous H723R-PDS-expressing human nasal epithelial cells, PC2-1 significantly increased the surface expression of pendrin. PC2-1 exhibited high membrane permeability in vitro and high micromolar concentrations in the cochlear perilymph in vivo. In addition, neither inhibition of Kv11.1 activity in the human ether-a-go-go-related gene assay nor cell toxicity in the cell proliferation assay was observed at a high PC2-1 concentration (30 μM). These preclinical data support the hypothesis of the druggability of mutant pendrin using the novel corrector molecule PC2-1. In conclusion, PC2-1 may be a new therapeutic molecule for ameliorating hearing loss and treating vestibular disorders in patients with Pendred syndrome or DFNB4.
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Affiliation(s)
- Jinsei Jung
- Department of Otorhinolaryngology, Graduate School of Medical Science, Brain Korea 21 Project, Yonsei University College of Medicine, Seoul 03722, Republic of Korea; Won-Sang Lee Institute for Hearing Loss, Seoul 03722, Republic of Korea
| | - Shin Hye Noh
- Severance Biomedical Science Institute, Yonsei University College of Medicine, Seoul 03722, Republic of Korea
| | - Sungwoo Jo
- College of Pharmacy, Yonsei Institute of Pharmaceutical Sciences, Yonsei University, Incheon, Republic of Korea
| | - Doona Song
- College of Pharmacy, Yonsei Institute of Pharmaceutical Sciences, Yonsei University, Incheon, Republic of Korea; Department of Integrated OMICS for Biomedical Science, Yonsei University, Seoul 03722, Republic of Korea; Translational Research Center for Protein Function Control, Department of Biotechnology, Yonsei University, Seoul 03722, Republic of Korea
| | - Min Jin Kang
- Department of Otorhinolaryngology, Graduate School of Medical Science, Brain Korea 21 Project, Yonsei University College of Medicine, Seoul 03722, Republic of Korea; Won-Sang Lee Institute for Hearing Loss, Seoul 03722, Republic of Korea
| | - Mi Hwa Shin
- Department of Otorhinolaryngology, Graduate School of Medical Science, Brain Korea 21 Project, Yonsei University College of Medicine, Seoul 03722, Republic of Korea; Won-Sang Lee Institute for Hearing Loss, Seoul 03722, Republic of Korea
| | - Hyun Jae Lee
- Otolaryngology Branch, National Institute on Deafness and Other Communication Disorders, National Institutes of Health, USA
| | - Jae-Chul Pyun
- Department of Materials Science and Engineering, Yonsei University, Seoul 03722, Republic of Korea
| | - Wan Namkung
- College of Pharmacy, Yonsei Institute of Pharmaceutical Sciences, Yonsei University, Incheon, Republic of Korea.
| | - Gyoonhee Han
- College of Pharmacy, Yonsei Institute of Pharmaceutical Sciences, Yonsei University, Incheon, Republic of Korea; Department of Integrated OMICS for Biomedical Science, Yonsei University, Seoul 03722, Republic of Korea; Translational Research Center for Protein Function Control, Department of Biotechnology, Yonsei University, Seoul 03722, Republic of Korea.
| | - Min Goo Lee
- Severance Biomedical Science Institute, Yonsei University College of Medicine, Seoul 03722, Republic of Korea; Department of Pharmacology, Graduate School of Medical Science, Brain Korea 21 Project, Republic of Korea, Seoul 03722, Republic of Korea.
| | - Jae Young Choi
- Department of Otorhinolaryngology, Graduate School of Medical Science, Brain Korea 21 Project, Yonsei University College of Medicine, Seoul 03722, Republic of Korea; Won-Sang Lee Institute for Hearing Loss, Seoul 03722, Republic of Korea.
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Yin G, Wang XH, Sun Y. Recent advances in CRISPR-Cas system for the treatment of genetic hearing loss. Am J Stem Cells 2023; 12:37-50. [PMID: 37736272 PMCID: PMC10509501] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Subscribe] [Scholar Register] [Received: 07/23/2023] [Accepted: 07/31/2023] [Indexed: 09/23/2023]
Abstract
Genetic hearing loss has emerged as a significant public health concern that demands attention. Among the various treatment strategies, gene therapy based on gene editing technology is considered the most promising approach for addressing genetic hearing loss by repairing or eliminating mutated genes. The advent of the clustered regularly interspaced short palindromic repeats (CRISPR)-Cas system has revolutionized gene therapy through its remarkable gene editing capabilities. This system has been extensively employed in mammalian gene editing and is currently being evaluated through clinical trials. Against this backdrop, this review aims to provide an overview of recent advances in utilizing the CRISPR-Cas system to treat genetic hearing loss. Additionally, we delve into the primary challenges and prospects associated with the current application of this system in addressing genetic hearing loss.
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Affiliation(s)
- Ge Yin
- Department of Otorhinolaryngology, Union Hospital, Tongji Medical College, Huazhong University of Science and TechnologyWuhan 430022, Hubei, China
| | - Xiao-Hui Wang
- Department of Otorhinolaryngology, Union Hospital, Tongji Medical College, Huazhong University of Science and TechnologyWuhan 430022, Hubei, China
| | - Yu Sun
- Department of Otorhinolaryngology, Union Hospital, Tongji Medical College, Huazhong University of Science and TechnologyWuhan 430022, Hubei, China
- Hubei Province Key Laboratory of Oral and Maxillofacial Development and RegenerationWuhan 430022, Hubei, China
- Institute of Otorhinolaryngology, Union Hospital, Tongji Medical College, Huazhong University of Science and TechnologyWuhan 430022, Hubei, China
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Friis IJ, Aaberg K, Edholm B. Causes of hearing loss and implantation age in a cohort of Danish pediatric cochlear implant recipients. Int J Pediatr Otorhinolaryngol 2023; 171:111640. [PMID: 37441990 DOI: 10.1016/j.ijporl.2023.111640] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/09/2023] [Revised: 06/14/2023] [Accepted: 06/19/2023] [Indexed: 07/15/2023]
Abstract
INTRODUCTION Sensorineural hearing loss (SNHL) is the most common birth disorder. The cause of SNHL is heterogeneous and varies in different populations. Understanding the causes of a hearing loss (HL) predict the outcome of cochlear implantation and is of great importance in understanding the mechanism of the disease and in providing the best treatment. Undiagnosed and untreated HL has a profound effect on the acquisition of early communication skills, speech, language, academic, emotional, and psychosocial development in children. OBJECTIVES To determine the cause of HL and implantation age in pediatric cochlear implant (CI) users in a Danish population. METHODS Data of 100 children (54 females and 46 males), age 0-17 years, was analyzed. All of the children were implanted during 2020-2022. RESULTS Hereditary HL was diagnosed in 44 cases (44%), with pathogenic variants in the SLC26A4 gene found in 14 cases (14%). Syndromic HL was diagnosed in 23 children (23%). Non-syndromic HL was diagnosed in 21 children (21%), where the most common genetic variation was found in the GJB2 gene. Acquired prenatal and postnatal sensory disorders TORCH risk factors were associated with HL in 25 cases (25%). Congenital CMV DNA was diagnosed in 23 samples (23%). The cause of the HL remained unknown for 31 (31%) children. In 70 (70%) of the participants the HL was diagnosed at time of newborn hearing screening (NHS). Twenty-three of the children were diagnosed with congenital severe to profound bilateral HL and were simultaneously implanted between 8 and 14 months (mean age 10.5 months). In the remaining 47 cases, the HL was progressive and the children were implanted when the HL reached the criteria for implantation. CONCLUSIONS In the current study, the major causes of HL were alterations in the SLC26A4 gene: 13% with Pendred syndrome and 1% non-syndromic. Thirty-one (31%) had HL of unknown origin and almost half of these cases had inner ear malformations (n = 16).
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Affiliation(s)
- Ida Jensen Friis
- Department of Otorhinolaryngology, Aarhus University Hospital, Aarhus C, Denmark.
| | - Kirsten Aaberg
- Department of Otorhinolaryngology, Aarhus University Hospital, Aarhus C, Denmark
| | - Bjarke Edholm
- Department of Otorhinolaryngology, Aarhus University Hospital, Aarhus C, Denmark
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Wu J, Tao Y, Deng D, Meng Z, Zhao Y. The applications of CRISPR/Cas-mediated genome editing in genetic hearing loss. Cell Biosci 2023; 13:93. [PMID: 37210555 DOI: 10.1186/s13578-023-01021-7] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/12/2022] [Accepted: 03/25/2023] [Indexed: 05/22/2023] Open
Abstract
Hearing loss (HL) can be caused by a number of different genetic factors. Non-syndromic HL refers that HL occurs as an isolated symptom in an individual, whereas syndromic HL refers that HL is associated with other symptoms or abnormalities. To date, more than 140 genes have been identified as being associated with non-syndromic HL, and approximately 400 genetic syndromes can include HL as one of the clinical symptoms. However, no gene therapeutic approaches are currently available to restore or improve hearing. Therefore, there is an urgent necessity to elucidate the possible pathogenesis of specific mutations in HL-associated genes and to investigate the promising therapeutic strategies for genetic HL. The development of the CRISPR/Cas system has revolutionized the field of genome engineering, which has become an efficacious and cost-effective tool to foster genetic HL research. Moreover, several in vivo studies have demonstrated the therapeutic efficacy of the CRISPR/Cas-mediated treatments for specific genetic HL. In this review, we briefly introduce the progress in CRISPR/Cas technique as well as the understanding of genetic HL, and then we detail the recent achievements of CRISPR/Cas technique in disease modeling and therapeutic strategies for genetic HL. Furthermore, we discuss the challenges for the application of CRISPR/Cas technique in future clinical treatments.
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Affiliation(s)
- Junhao Wu
- Department of Otorhinolaryngology-Head & Neck Surgery, West China Hospital of Sichuan University, Chengdu, 610041, China
- Department of Audiology and Speech Language Pathology, West China Hospital of Sichuan University, Chengdu, China
| | - Yong Tao
- Department of Otorhinolaryngology-Head & Neck Surgery, West China Hospital of Sichuan University, Chengdu, 610041, China
- Department of Audiology and Speech Language Pathology, West China Hospital of Sichuan University, Chengdu, China
| | - Di Deng
- Department of Otorhinolaryngology-Head & Neck Surgery, West China Hospital of Sichuan University, Chengdu, 610041, China
- Department of Audiology and Speech Language Pathology, West China Hospital of Sichuan University, Chengdu, China
| | - Zhaoli Meng
- Department of Otorhinolaryngology-Head & Neck Surgery, West China Hospital of Sichuan University, Chengdu, 610041, China.
- Department of Audiology and Speech Language Pathology, West China Hospital of Sichuan University, Chengdu, China.
| | - Yu Zhao
- Department of Otorhinolaryngology-Head & Neck Surgery, West China Hospital of Sichuan University, Chengdu, 610041, China.
- Department of Audiology and Speech Language Pathology, West China Hospital of Sichuan University, Chengdu, China.
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Mostafa BE, El Sawi MA, Sabry SM, Hassan DM, Rezk Shafik M. Genetic Screening for 35delG Mutation in Egyptian Patients with Profound Sensorineural Hearing Loss Scheduled for Cochlear Implantation: A Population-Based Study. ORL J Otorhinolaryngol Relat Spec 2021; 83:181-186. [PMID: 33756453 DOI: 10.1159/000513752] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/29/2020] [Accepted: 12/14/2020] [Indexed: 11/19/2022]
Abstract
OBJECTIVES The aim of this work was to assess the type and site of the 35delG gene mutation in patients presenting with profound SNHL and scheduled for cochlear implantation. The secondary objectives were to determine their geographical distribution throughout Egypt, screening of the parents for the mutation, and to correlate the type of mutation with clinical severity and outcomes after surgery. METHODS The study was carried out on 100 consecutive patients scheduled for cochlear implantation. Patients with syndromic hearing loss or noncongenital hearing loss (trauma, infections, and ototoxicity) were excluded. All patients were subjected to detailed history taking including geographic tagging for their origins in Egypt, imaging (CT and MRI cochlear implantation protocols), full audiological evaluation (PTA, ABR, and TEOAE), and genetic screening for GJB2 mutation using Invitrogen PCR mix and ApaI restriction enzyme (North America, CA, 10572-014). The parents of mutation-positive patients were also subjected to audiological and genetic analysis. All patients were subjected to postimplantation evaluation of hearing after 6 and 12 months. RESULTS There were 64 males and 36 females from 98 families. Ages ranged between 1.9 and 7 years (mean 3.72 years). They originated from all over Egypt but the majority came from the Giza and Cairo areas. The 35delG mutations were found in exon 2 in 31% of the cases and all were heterozygous. In the parents, 18 mothers and 13 fathers were positive but only 8 had mild to moderate SNHL. Hearing evaluation by pure tone and speech discrimination scores at 6 and 12 months showed that the 35delG children had a statistically better result compared to the children without this mutation. CONCLUSION The prevalence of the 35delG mutation in nonsyndromic children in this sample was 31% which is different from previous studies in the Egyptian population but close to the values found in other populations in the Mediterranean basin.
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Affiliation(s)
- Badr Eldin Mostafa
- Department of Otorhinolaryngology Head and Neck Surgery, Faculty of Medicine, Ain-Shams University, Cairo, Egypt,
| | - Mohammed Abdel El Sawi
- Department of Pediatrics and Medical Genetics, Faculty of Medicine, Ain-Shams University, Cairo, Egypt
| | - Sabry Magdi Sabry
- Department of Otorhinolaryngology Head and Neck Surgery, Faculty of Medicine, Ain-Shams University, Cairo, Egypt
| | - Dalia Mohammed Hassan
- Department of Otorhinolaryngology Head and Neck Surgery, Faculty of Medicine, Ain-Shams University, Cairo, Egypt
| | - Michael Rezk Shafik
- Department of Otorhinolaryngology Head and Neck Surgery, Faculty of Medicine, Ain-Shams University, Cairo, Egypt
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Na G, Choi HJ, Joo SY, Rim JH, Kim JA, Kim HY, Yu S, Jeong Y, Shin GC, Noh HE, Lee HY, Kim DH, Gee HY, Jung J, Choi JY. Heterogeneity of MYO15A variants significantly determine the feasibility of acoustic stimulation with hearing aid and cochlear implant. Hear Res 2021; 404:108227. [PMID: 33784549 DOI: 10.1016/j.heares.2021.108227] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/27/2020] [Revised: 03/08/2021] [Accepted: 03/12/2021] [Indexed: 12/15/2022]
Abstract
Autosomal recessive nonsyndromic hearing loss 3 (DFNB3) mainly leads to congenital and severe-to-profound hearing impairment, which is caused by variants in MYO15A. However, audiological heterogeneity in patients with DFNB3 hinders precision medicine in hearing rehabilitation. Here, we aimed to elucidate the heterogeneity of the auditory phenotypes of MYO15A variants according to the affected domain and the feasibilities for acoustic stimulation. We conducted whole-exome sequencing for 10 unrelated individuals from seven multiplex families with DFNB3; 11 MYO15A variants, including the novel frameshift c.900delT (p.Pro301Argfs*143) and nonsense c.4879G > T (p.Glu1627*) variants, were identified. In seven probands, residual hearing at low frequencies was significantly higher in the groups with one or two N-terminal frameshift variants in trans conformation compared to that in the group without these variants. This is consistent with the 56 individuals from the previously published reports that carried a varying number of N-terminal truncating variants in MYO15A. In addition, patients with missense variants in the second FERM domain had better hearing at low frequencies than patients without these variants. Subsequently, acoustic stimulation provided by devices such as hearing aids or cochlear implants was feasible in patients with one or two N-terminal truncating variants or a second FERM missense variant. In conclusion, N-terminal or second FERM variants in MYO15A allow the practical use of acoustic stimulation through hearing aids or electroacoustic stimulation for aural rehabilitation.
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Affiliation(s)
- Gina Na
- Department of Otorhinolaryngology, Yonsei University College of Medicine, 50-1 Yonsei-ro, Seoul, Seodaemun-gu 03722, Republic of Korea; Department of Otorhinolaryngology, Ilsan Paik Hospital, Inje University College of Medicine, Goyang, Republic of Korea
| | - Hye Ji Choi
- Department of Otorhinolaryngology, Yonsei University College of Medicine, 50-1 Yonsei-ro, Seoul, Seodaemun-gu 03722, Republic of Korea
| | - Sun Young Joo
- Department of Pharmacology, Yonsei University College of Medicine, 50-1 Yonsei-ro, Seoul, Seodaemun-gu 03722, Republic of Korea; Graduate School of Medical Science, Brain Korea 21 Project, Yonsei University College of Medicine Seoul, Republic of Korea
| | - John Hoon Rim
- Department of Pharmacology, Yonsei University College of Medicine, 50-1 Yonsei-ro, Seoul, Seodaemun-gu 03722, Republic of Korea; Graduate School of Medical Science, Brain Korea 21 Project, Yonsei University College of Medicine Seoul, Republic of Korea
| | - Jung Ah Kim
- Department of Pharmacology, Yonsei University College of Medicine, 50-1 Yonsei-ro, Seoul, Seodaemun-gu 03722, Republic of Korea; Graduate School of Medical Science, Brain Korea 21 Project, Yonsei University College of Medicine Seoul, Republic of Korea
| | - Hye-Youn Kim
- Department of Pharmacology, Yonsei University College of Medicine, 50-1 Yonsei-ro, Seoul, Seodaemun-gu 03722, Republic of Korea; Graduate School of Medical Science, Brain Korea 21 Project, Yonsei University College of Medicine Seoul, Republic of Korea
| | - Seyoung Yu
- Department of Pharmacology, Yonsei University College of Medicine, 50-1 Yonsei-ro, Seoul, Seodaemun-gu 03722, Republic of Korea; Graduate School of Medical Science, Brain Korea 21 Project, Yonsei University College of Medicine Seoul, Republic of Korea
| | - Yeonsu Jeong
- Department of Otorhinolaryngology, Yonsei University College of Medicine, 50-1 Yonsei-ro, Seoul, Seodaemun-gu 03722, Republic of Korea
| | - Geun Cheol Shin
- Department of Otorhinolaryngology, Yonsei University College of Medicine, 50-1 Yonsei-ro, Seoul, Seodaemun-gu 03722, Republic of Korea
| | - Hae Eun Noh
- Department of Otorhinolaryngology, Yonsei University College of Medicine, 50-1 Yonsei-ro, Seoul, Seodaemun-gu 03722, Republic of Korea
| | - Ho Young Lee
- Department of Otorhinolaryngology, Yonsei University College of Medicine, 50-1 Yonsei-ro, Seoul, Seodaemun-gu 03722, Republic of Korea
| | - Da Hye Kim
- Department of Otorhinolaryngology, Yonsei University College of Medicine, 50-1 Yonsei-ro, Seoul, Seodaemun-gu 03722, Republic of Korea
| | - Heon Yung Gee
- Department of Pharmacology, Yonsei University College of Medicine, 50-1 Yonsei-ro, Seoul, Seodaemun-gu 03722, Republic of Korea; Graduate School of Medical Science, Brain Korea 21 Project, Yonsei University College of Medicine Seoul, Republic of Korea.
| | - Jinsei Jung
- Department of Otorhinolaryngology, Yonsei University College of Medicine, 50-1 Yonsei-ro, Seoul, Seodaemun-gu 03722, Republic of Korea; Graduate School of Medical Science, Brain Korea 21 Project, Yonsei University College of Medicine Seoul, Republic of Korea.
| | - Jae Young Choi
- Department of Otorhinolaryngology, Yonsei University College of Medicine, 50-1 Yonsei-ro, Seoul, Seodaemun-gu 03722, Republic of Korea
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Abstract
It is estimated that at least 50% of congenital or childhood hearing loss is attributable to genetic causes. In non-syndromic hearing loss, which accounts for 70% of genetic hearing loss, approximately 80% of cases are autosomal recessive, 15% autosomal dominant, and 1-2% mitochondrial or X-linked. In addition, 30% of genetic hearing loss is syndromic. The genetic causes of hearing loss are highly heterogeneous. So far, more than 140 deafness-related genes have been discovered. Studies on those genes tremendously increased our understanding of the inner ear functions at the molecular level. It also offers important information for the patients and allows personalized and accurate genetic counseling. In many cases, genetic diagnosis of hearing loss can help to avoid unnecessary and costly clinical testing, offer prognostic information, and guide future medical management. On the other hand, a variety of gene therapeutic approaches have been developed aiming to relieve or converse the hearing loss due to genetic causes. Prevention of genetic hearing loss is feasible through prepregnancy and prenatal genetic diagnosis and counseling.
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Affiliation(s)
- Tao Yang
- Department of Otorhinolaryngology-Head and Neck Surgery, Shanghai Ninth People's Hospital, Shanghai Jiaotong University School of Medicine, Shanghai, China. .,Ear Institute, Shanghai Jiaotong University School of Medicine, Shanghai, China. .,Shanghai Key Laboratory of Translational Medicine on Ear and Nose Diseases, Shanghai, China.
| | - Luo Guo
- Key Laboratory of Hearing Medicine of NHFPC, ENT Institute and Otorhinolaryngology Department, Shanghai Engineering Research Centre of Cochlear Implant, Affiliated Eye and ENT Hospital, State Key Laboratory of Medical Neurobiology, Fudan University, Shanghai, China
| | - Longhao Wang
- Department of Otorhinolaryngology-Head and Neck Surgery, Shanghai Ninth People's Hospital, Shanghai Jiaotong University School of Medicine, Shanghai, China.,Ear Institute, Shanghai Jiaotong University School of Medicine, Shanghai, China.,Shanghai Key Laboratory of Translational Medicine on Ear and Nose Diseases, Shanghai, China
| | - Xiaoyu Yu
- Department of Otorhinolaryngology-Head and Neck Surgery, Shanghai Ninth People's Hospital, Shanghai Jiaotong University School of Medicine, Shanghai, China.,Ear Institute, Shanghai Jiaotong University School of Medicine, Shanghai, China.,Shanghai Key Laboratory of Translational Medicine on Ear and Nose Diseases, Shanghai, China
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Gardiner SA, Laing N, Mall S, Wonkam A. Perceptions of parents of children with hearing loss of genetic origin in South Africa. J Community Genet 2018; 10:325-333. [PMID: 30465126 DOI: 10.1007/s12687-018-0396-y] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/29/2018] [Accepted: 11/06/2018] [Indexed: 01/15/2023] Open
Abstract
More than 80% of people with hearing loss (HL) live in low- and middle-income countries. Up to 90% of deaf children are born to hearing parents, leading to novel parenting, communication, educational, and psychosocial experiences. Half of congenital pre-lingual HL is genetic, with a relatively high recurrence risk that may lead to specific challenges for parents of affected children. Currently, little is known of genes implicated and causative mutations for most populations who have HL in Sub-Saharan Africa, as well as genetic counseling services needs for this population. Therefore, this study aimed to explore parents' perceptions and understanding of the genetic etiology of their child's HL, in order to inform policies and services. In-depth qualitative interviews were conducted with 11 parents of children who have non-syndromic HL of putative genetic origin. Data were analyzed through the framework approach. Three salient themes emerged, namely comprehension and understanding of the cause, in which most parents were unable to identify the potential hereditary cause of their child's HL; responsibility and blame; and their perception of genetic counseling and testing. Most of the participants had positive attitudes towards genetic testing, describing that it may provide answers and that the information gained would be helpful for the future. The data could assist in understanding the challenges faced by parents, in the absence of genetic testing, emphasizing the need for accurate genetic testing to support counseling services to parents of children with HL in an African Setting.
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Affiliation(s)
- Sinead Amber Gardiner
- Division of Human Genetics, Falmouth Building, Faculty of Health Sciences, Department of Pathology, University of Cape Town, Observatory, Cape Town, 7925, South Africa
| | - Nakita Laing
- Division of Human Genetics, Groote Schuur Hospital/Red Cross War Memorial Children's Hospital, Cape Town, South Africa
| | - Sumaya Mall
- Department of Psychiatry and Mental Health, University of Cape Town, Faculty of Health Sciences, Cape Town, South Africa.,Division of Epidemiology and Biostatistics, School of Public Health, Faculty of Health Sciences, University of the Witwatersrand, Johannesburg, South Africa
| | - Ambroise Wonkam
- Division of Human Genetics, Falmouth Building, Faculty of Health Sciences, Department of Pathology, University of Cape Town, Observatory, Cape Town, 7925, South Africa.
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Leclère JC, Le Gac MS, Le Maréchal C, Ferec C, Marianowski R. GJB2 mutations: Genotypic and phenotypic correlation in a cohort of 690 hearing-impaired patients, toward a new mutation? Int J Pediatr Otorhinolaryngol 2017; 102:80-85. [PMID: 29106882 DOI: 10.1016/j.ijporl.2017.09.011] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/16/2016] [Revised: 09/10/2017] [Accepted: 09/11/2017] [Indexed: 10/18/2022]
Abstract
OBJECTIVES To analyze the clinical features of hearing impairment and to search for correlations with the genotype in patients with GJB2 mutations. DESIGN Case series. SETTING Collaborative study in referral centers, institutional practice. PATIENTS A total of 690 hearing-impaired patients were genotypically and phenotypically described. The mutations of GJB2 and GJB6 were studied. Heterozygous patients were searched for another mutation by microsatellite approach. MAIN OUTCOME MEASURES Prevalence of GJB2 mutations, microsatellite approach, hearing-impairment. RESULTS In 498 patients (72,17% of the cohort), no mutation was found. Homozygotous patients were 59 (8,55%), with 51 for c.35delG, 6 for p.M34T and 2 for GJB6. Compound heterozygous were 64 (9,28%) with 56 c.35delG-others mutations. Genotypes with biallelic non sense mutations had a high risk of severe to profound hearing impairment. It was frequently milder in compound heterozygotes than in c.35delG homozygotes. Heterozygous patients were 69 (10%) with 21 c.35delG, 20 p.M34T and 28 others mutations. We selected patients with a complete historical medical file (clinical and audiometric data). Then, we performed a microsatellite approach (multiplex PCR of short DNA fragments) to localize a new pathologic allele. Seventeen heterozygous patients were studied. Six patients (35%) showed the same haplotype. They were compound heterozygous bearing a new pathologic allele. CONCLUSION Genotype may affect deafness severity, but environmental and other genetic factors may also modulate the severity and evolution of GJB2-GJB6 deafness. A new haplotype for GJB2 is described but the exact mutation remains unknown.
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Affiliation(s)
- Jean-Christophe Leclère
- Department of Otorhinolaryngology-Head and Neck Surgery, University Hospital CHU Brest, France
| | - Marie-Suzanne Le Gac
- Department of Otorhinolaryngology-Head and Neck Surgery, University Hospital CHU Brest, France
| | | | - Claude Ferec
- Genetic Department, University Hospital CHU Brest, France
| | - Rémi Marianowski
- Department of Otorhinolaryngology-Head and Neck Surgery, University Hospital CHU Brest, France.
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Sanyelbhaa H, Kabel A, Abo El-Naga HAER, Sanyelbhaa A, Salem H. The risk ratio for development of hereditary sensorineural hearing loss in consanguineous marriage offspring. Int J Pediatr Otorhinolaryngol 2017; 101:7-10. [PMID: 28964313 DOI: 10.1016/j.ijporl.2017.07.020] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/07/2017] [Revised: 07/15/2017] [Accepted: 07/17/2017] [Indexed: 11/16/2022]
Abstract
OBJECTIVES This study aims to define the relative risk of development of hearing loss in offspring of consanguineous marriages. MATERIALS AND METHODS This is a retrospective case-control study conducted in a tertiary referral center in Jeddah, KSA. The study group included 1600 probands (848 males, 752 females), with age range 0.5-12 years (6.6 ± 3.6). The study group comprised of two equal, age and sex matched subgroups; Hearing Loss (HL) group and Normal Hearing (NH) group. The children included in the HL group should have idiopathic or non syndromic genetic sensorineural hearing loss. RESULTS The HL Group comprised 800 children with variable degrees of sensorineural hearing loss. Profound and severe degrees of hearing loss were the most prevalent degrees (P <0.05%). The prevalence of consanguineous marriage offspring in the NH group was 42.5%, while in the HL group it was 68.9% (P < 0.05). The differences between both study subgroups regarding the distribution of different degrees of parental consanguinity (first, second, double first, and first once removed cousins) were insignificant (P > 0.05). The relative risk and 95% confidence interval (RR, 95% CI) for development of hearing loss in offspring of consanguineous marriage was 1.76 (95% CI 1.57-1.97, P < 0.001). CONCLUSIONS There was 76% increased risk for consanguineous marriage progeny to develop SNHL when compared to non consanguineous progeny.
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Affiliation(s)
| | | | | | | | - Hatem Salem
- Ministry of Health, Kingdome of Saudi Arabia, Saudi Arabia
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Thatcher A, Le Prell C, Miller J, Green G. ACEMg supplementation ameliorates progressive Connexin 26 hearing loss in a child. Int J Pediatr Otorhinolaryngol 2014; 78:563-5. [PMID: 24439969 DOI: 10.1016/j.ijporl.2013.12.030] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/06/2013] [Revised: 12/18/2013] [Accepted: 12/19/2013] [Indexed: 11/28/2022]
Abstract
Mutations in the gene encoding Connexin 26 are the most common cause of genetic hearing loss. The hearing loss is typically stable but may be progressive. The reason for progression is unknown. Antioxidants have been associated with attenuation of hearing loss from other insults. One antioxidant regimen consists of beta-carotene (metabolized to vitamin A), vitamin C, vitamin E, and magnesium (ACEMg). We present a child with Connexin 26 related hearing loss who experienced progressive hearing loss over 7 years of observation. He was given ACEMg daily for 3 years, during which time his progressive hearing loss was ameliorated.
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Affiliation(s)
- Aaron Thatcher
- University of Michigan, Department of Otolaryngology, United States.
| | - Colleen Le Prell
- University of Florida, Department of Speech, Language, and Hearing Sciences, United States.
| | - Josef Miller
- University of Michigan, Department of Otolaryngology, United States.
| | - Glenn Green
- University of Michigan, Department of Otolaryngology, United States.
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