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Morales-Angulo C, Gallo-Terán J, González-Aguado R, Onecha E, Del Castillo I. Hearing loss secondary to variants in the OTOF gene. Int J Pediatr Otorhinolaryngol 2024; 186:112082. [PMID: 39265223 DOI: 10.1016/j.ijporl.2024.112082] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/04/2024] [Revised: 08/20/2024] [Accepted: 08/27/2024] [Indexed: 09/14/2024]
Abstract
OBJECTIVE Genetic variants in the OTOF gene are responsible for non-syndromic hearing loss with an autosomal recessive inheritance pattern. The objective of our work was to evaluate the clinical characteristics of patients with biallelic pathogenic variants in OTOF and their evolution after treatment. METHODS A cohort of 124 patients with prelingual hearing loss, studied from 1996 to 2023, was included in this study. A genetic analysis was conducted to identify the type and frequency of variants in the OTOF gene and their relation to the clinical characteristics of the patients. RESULTS The homozygous p. Gln829* variant in the OTOF gene was detected in 3 probands (2.4 %) of a group 124 individuals with prelingual hearing loss. Another 6 family members to a total of 9 individuals were finally included. All presented with severe/profound bilateral sensorineural hearing loss of congenital onset. Three of these individuals were diagnosed with auditory neuropathy spectrum disorder. One individual passed the OAE test during the screening program, and since he did not have risk factors for hearing loss that would warrant ABR testing, this led to a delay in his hearing loss diagnosis. Four individuals underwent cochlear implants (three bilateral) with good functional outcomes. In three of them. However, in 17 familial cases with heterozygous variants, either no hearing loss was observed or it was within the expected range for their age. CONCLUSIONS Hearing loss secondary to the p. Gln829* variant of the OTOF gene is relatively rare in our medical area. Its presence in homozygosity is the cause of severe/profound bilateral prelingual sensorineural hearing loss, responsible for auditory neuropathy with a good response to cochlear implantation.
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Affiliation(s)
- Carmelo Morales-Angulo
- Department of Otolaryngology and Head and Neck Surgery. Marqués de Valdecilla University Hospital, Santander, Spain; Cell Cycle, Stem Cell Fate and Cancer Laboratory, Institute for Research Marqués de Valdecilla (IDIVAL), 39011 Santander, Spain; Faculty of Medicine. University of Cantabria, Santander, Spain.
| | - Jaime Gallo-Terán
- Department of Radiology. Marqués de Valdecilla University Hospital, Santander, Spain
| | - Rocío González-Aguado
- Department of Otolaryngology and Head and Neck Surgery. Marqués de Valdecilla University Hospital, Santander, Spain
| | - Esther Onecha
- Department of Genetics. Marqués de Valdecilla University Hospital, Santander, Spain
| | - Ignacio Del Castillo
- Department of Genetics. Hospital Universitario Ramón y Cajal, IRYCIS, Madrid, Spain; Centro de Investigación Biomédica en Red de Enfermedades Raras (CIBERER), Madrid, Spain
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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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Naseer H, Rashid A, Majeed A, Baig ZA. Association of R1939W and P1987R variants of Otoferlin ( OTOF) gene with severe to profound nonsyndromic sensorineural hearing loss in Pakistani subjects. Pak J Med Sci 2023; 39:1456-1461. [PMID: 37680836 PMCID: PMC10480747 DOI: 10.12669/pjms.39.5.6393] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/25/2022] [Revised: 06/18/2022] [Accepted: 05/26/2023] [Indexed: 09/09/2023] Open
Abstract
Objective To find possible association of R1939W and P1987R variants of OTOF gene with severe to profound NSSHL in cochlear implant subjects. Methods It was a case control study, conducted from June 2021 to February 2022, comprising 50 cases of severe to profound NSSHL who had received cochlear implant from ENT Department, CMH Rawalpindi and 50 age-matched healthy controls from PEMH Rawalpindi. Blood samples were collected from all the subjects, followed by DNA extraction and allele-specific polymerase chain reaction, performed at Multi-disciplinary Laboratory of Department of Biochemistry and Molecular Biology, Army Medical College Rawalpindi. Statistical analysis was done using 'SPSS' and 'XLSTAT', followed by genetic analysis using 'SNPstat'. Results Mean age of the cases was 5.96 ± 4.62 years (N=50), comprising 58% males and 42% females. All had bilateral and prelingual HL. Parental consanguinity was 72%, whereas 62% cases had a positive family history of deafness. Alleles of R1939W and P1987R were not associated with NSSHL, as shown by their p values of 0.56 and 0.89 respectively. For R1939W ORs were 0.71 (dominant model) and 0.80 (overdominant model), indicating negative association with NSSHL. Regarding P1987R OR was 0.96 (log-additive model). Genotypes of both variants were not in HW Equilibrium (p <0.0001), whereas their alleles showed high LD (D'=0.92). Conclusion High percentage of parental consanguinity was observed among cochlear implant candidates. The OTOF variants R1939W and P1987R were found to have protective roles against NSSHL in study population.
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Affiliation(s)
- Hammael Naseer
- Dr. Hammael Naseer, MBBS. Department of Biochemistry and Molecular Biology, Army Medical College, National University of Medical Sciences, Rawalpindi, Pakistan
| | - Amir Rashid
- Dr. Amir Rashid, PhD. Department of Biochemistry and Molecular Biology, Army Medical College, National University of Medical Sciences, Rawalpindi, Pakistan
| | - Asifa Majeed
- Dr. Asifa Majeed, Post Doc. Department of Biochemistry and Molecular Biology, Army Medical College, National University of Medical Sciences, Rawalpindi, Pakistan
| | - Zunaira Ali Baig
- Zunaira Ali Baig, M.Phil. Department of Biochemistry and Molecular Biology, Army Medical College, National University of Medical Sciences, Rawalpindi, Pakistan
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Bukhari A, Khojah A, Marin W, Khramtsov A, Khramtsova G, Costin C, Morgan G, Ramesh P, Klein-Gitelman MS, Le Poole IC, Pachman LM. Increased Otoferlin Expression in B Cells Is Associated with Muscle Weakness in Untreated Juvenile Dermatomyositis: A Pilot Study. Int J Mol Sci 2023; 24:10553. [PMID: 37445728 PMCID: PMC10341737 DOI: 10.3390/ijms241310553] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/02/2023] [Revised: 06/15/2023] [Accepted: 06/19/2023] [Indexed: 07/15/2023] Open
Abstract
Otoferlin mRNA expression is increased in JDM patients' PBMCs and muscle compared to healthy controls. This study aims to evaluate the role of otoferlin in JDM disease pathophysiology and its association with disease activity in untreated children with JDM. A total of 26 untreated JDM (88.5% female, 92.3% white, non-Hispanic) and 15 healthy controls were included in this study. Otoferlin mRNA expression was determined by qRT-PCR before and a few months after therapy. Detailed flow cytometry of various cell surface markers and cytoplasmic otoferlin was performed to identify cells expressing otoferlin. In addition, muscle otoferlin expression was evaluated in situ in six untreated JDM patients and three healthy controls. There was a significant increase in otoferlin expression in JDM children compared to controls (Median 67.5 vs. 2.1; p = 0.001). There was a positive correlation between mRNA otoferlin expression and the following disease activity markers: disease activity scores (DAS)-total (rs = 0.62, p < 0.001); childhood myositis assessment scale (CMAS) (rs = -0.61, p = 0.002); neopterin (rs = 0.57, p = 0.004) and von Willebrand factor antigen (vWF: Ag) (rs = 0.60, p = 0.004). Most of the otoferlin-positive cells were unswitched B cells (63-99.4%), with 65-75% of them expressing plasmablast markers (CD19+, IgM+, CD38hi, CD24-). The findings of this pilot study suggest that otoferlin expression is associated with muscle weakness, making it a possible biomarker of disease activity. Additionally, B cells and plasmablasts were the primary cells expressing otoferlin.
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Affiliation(s)
- Ameera Bukhari
- College of Science, Taif University, Taif 21944, Saudi Arabia
| | - Amer Khojah
- Department of Pediatrics, College of Medicine, Umm Al-Qura University, Makkah 24381, Saudi Arabia
- Division of Pediatric Rheumatology, Ann & Robert H. Lurie Children’s Hospital of Chicago, Chicago, IL 60611, USA
| | - Wilfredo Marin
- Stanley Manne Children’s Research Institute, Ann & Robert H. Lurie Children’s Hospital of Chicago, Chicago, IL 60611, USA (G.K.)
| | - Andrey Khramtsov
- Department of Pathology, Ann & Robert H. Lurie Children’s Hospital of Chicago, Chicago, IL 60611, USA
| | - Galina Khramtsova
- Stanley Manne Children’s Research Institute, Ann & Robert H. Lurie Children’s Hospital of Chicago, Chicago, IL 60611, USA (G.K.)
| | - Christopher Costin
- Division of Pediatric Rheumatology, Ann & Robert H. Lurie Children’s Hospital of Chicago, Chicago, IL 60611, USA
- Feinberg School of Medicine, Northwestern University, Chicago, IL 60611, USA
| | - Gabrielle Morgan
- Division of Pediatric Rheumatology, Ann & Robert H. Lurie Children’s Hospital of Chicago, Chicago, IL 60611, USA
| | - Prathyaya Ramesh
- Department of Pathology, Ann & Robert H. Lurie Children’s Hospital of Chicago, Chicago, IL 60611, USA
- Department of Dermatology, Microbiology & Immunology, Northwestern University, Chicago, IL 60611, USA
| | - Marisa S. Klein-Gitelman
- Division of Pediatric Rheumatology, Ann & Robert H. Lurie Children’s Hospital of Chicago, Chicago, IL 60611, USA
- Feinberg School of Medicine, Northwestern University, Chicago, IL 60611, USA
| | - I. Caroline Le Poole
- Feinberg School of Medicine, Northwestern University, Chicago, IL 60611, USA
- Department of Dermatology, Microbiology & Immunology, Northwestern University, Chicago, IL 60611, USA
| | - Lauren M. Pachman
- Division of Pediatric Rheumatology, Ann & Robert H. Lurie Children’s Hospital of Chicago, Chicago, IL 60611, USA
- Feinberg School of Medicine, Northwestern University, Chicago, IL 60611, USA
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Rong S, Neil CR, Welch A, Duan C, Maguire S, Meremikwu IC, Meyerson M, Evans BJ, Fairbrother WG. Large-scale functional screen identifies genetic variants with splicing effects in modern and archaic humans. Proc Natl Acad Sci U S A 2023; 120:e2218308120. [PMID: 37192163 PMCID: PMC10214146 DOI: 10.1073/pnas.2218308120] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/07/2022] [Accepted: 04/12/2023] [Indexed: 05/18/2023] Open
Abstract
Humans coexisted and interbred with other hominins which later became extinct. These archaic hominins are known to us only through fossil records and for two cases, genome sequences. Here, we engineer Neanderthal and Denisovan sequences into thousands of artificial genes to reconstruct the pre-mRNA processing patterns of these extinct populations. Of the 5,169 alleles tested in this massively parallel splicing reporter assay (MaPSy), we report 962 exonic splicing mutations that correspond to differences in exon recognition between extant and extinct hominins. Using MaPSy splicing variants, predicted splicing variants, and splicing quantitative trait loci, we show that splice-disrupting variants experienced greater purifying selection in anatomically modern humans than that in Neanderthals. Adaptively introgressed variants were enriched for moderate-effect splicing variants, consistent with positive selection for alternative spliced alleles following introgression. As particularly compelling examples, we characterized a unique tissue-specific alternative splicing variant at the adaptively introgressed innate immunity gene TLR1, as well as a unique Neanderthal introgressed alternative splicing variant in the gene HSPG2 that encodes perlecan. We further identified potentially pathogenic splicing variants found only in Neanderthals and Denisovans in genes related to sperm maturation and immunity. Finally, we found splicing variants that may contribute to variation among modern humans in total bilirubin, balding, hemoglobin levels, and lung capacity. Our findings provide unique insights into natural selection acting on splicing in human evolution and demonstrate how functional assays can be used to identify candidate causal variants underlying differences in gene regulation and phenotype.
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Affiliation(s)
- Stephen Rong
- Center for Computational Molecular Biology, Brown University, Providence, RI02912
- Department of Molecular Biology, Cell Biology, and Biochemistry, Brown University, Providence, RI02912
| | - Christopher R. Neil
- Department of Molecular Biology, Cell Biology, and Biochemistry, Brown University, Providence, RI02912
| | - Anastasia Welch
- Department of Molecular Biology, Cell Biology, and Biochemistry, Brown University, Providence, RI02912
| | - Chaorui Duan
- Department of Molecular Biology, Cell Biology, and Biochemistry, Brown University, Providence, RI02912
| | - Samantha Maguire
- Department of Molecular Biology, Cell Biology, and Biochemistry, Brown University, Providence, RI02912
| | - Ijeoma C. Meremikwu
- Department of Molecular Biology, Cell Biology, and Biochemistry, Brown University, Providence, RI02912
| | - Malcolm Meyerson
- Department of Molecular Biology, Cell Biology, and Biochemistry, Brown University, Providence, RI02912
| | - Ben J. Evans
- Department of Biology, McMaster University, Hamilton, ONL8S 4K1, Canada
| | - William G. Fairbrother
- Center for Computational Molecular Biology, Brown University, Providence, RI02912
- Department of Molecular Biology, Cell Biology, and Biochemistry, Brown University, Providence, RI02912
- Hassenfeld Child Health Innovation Institute of Brown University, Providence, RI02912
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Asaad M, Mahfood M, Al Mutery A, Tlili A. Loss-of-function mutations in MYO15A and OTOF cause non-syndromic hearing loss in two Yemeni families. Hum Genomics 2023; 17:42. [PMID: 37189200 DOI: 10.1186/s40246-023-00489-1] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/27/2022] [Accepted: 05/06/2023] [Indexed: 05/17/2023] Open
Abstract
BACKGROUND Hearing loss is a rare hereditary deficit that is rather common among consanguineous populations. Autosomal recessive non-syndromic hearing loss is the predominant form of hearing loss worldwide. Although prevalent, hearing loss is extremely heterogeneous and poses a pitfall in terms of diagnosis and screening. Using next-generation sequencing has enabled a rapid increase in the identification rate of genes and variants in heterogeneous conditions, including hearing loss. We aimed to identify the causative variants in two consanguineous Yemeni families affected with hearing loss using targeted next-generation sequencing (clinical exome sequencing). The proband of each family was presented with sensorineural hearing loss as indicated by pure-tone audiometry results. RESULTS We explored variants obtained from both families, and our analyses collectively revealed the presence and segregation of two novel loss-of-function variants: a frameshift variant, c.6347delA in MYO15A in Family I, and a splice site variant, c.5292-2A > C, in OTOF in Family II. Sanger sequencing and PCR-RFLP of DNA samples from 130 deaf and 50 control individuals confirmed that neither variant was present in our in-house database. In silico analyses predicted that each variant has a pathogenic effect on the corresponding protein. CONCLUSIONS We describe two novel loss-of-function variants in MYO15A and OTOF that cause autosomal recessive non-syndromic hearing loss in Yemeni families. Our findings are consistent with previously reported pathogenic variants in the MYO15A and OTOF genes in Middle Eastern individuals and suggest their implication in hearing loss.
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Affiliation(s)
- Maria Asaad
- Department of Applied Biology, College of Sciences, University of Sharjah, Building W8 - Room 107, P.O. Box 27272, Sharjah, UAE
| | - Mona Mahfood
- Department of Applied Biology, College of Sciences, University of Sharjah, Building W8 - Room 107, P.O. Box 27272, Sharjah, UAE
| | - Abdullah Al Mutery
- Department of Applied Biology, College of Sciences, University of Sharjah, Building W8 - Room 107, P.O. Box 27272, Sharjah, UAE
- Human Genetics and Stem Cells Research Group, Research Institute of Sciences and Engineering, University of Sharjah, Sharjah, UAE
| | - Abdelaziz Tlili
- Department of Applied Biology, College of Sciences, University of Sharjah, Building W8 - Room 107, P.O. Box 27272, Sharjah, UAE.
- Human Genetics and Stem Cells Research Group, Research Institute of Sciences and Engineering, University of Sharjah, Sharjah, UAE.
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Tsuzuki N, Namba K, Saegusa C, Mutai H, Nishiyama T, Oishi N, Matsunaga T, Fujioka M, Ozawa H. Apoptosis of type I spiral ganglion neuron cells in Otof-mutant mice. Neurosci Lett 2023; 803:137178. [PMID: 36914046 DOI: 10.1016/j.neulet.2023.137178] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/29/2022] [Revised: 02/08/2023] [Accepted: 03/08/2023] [Indexed: 03/15/2023]
Abstract
Otof, which encodes otoferlin, knockout mice are considered model mice for auditory neuropathy spectrum disorder, which is characterized by an absent auditory brainstem response (ABR) despite preserved distortion product otoacoustic emission (DPOAE). Although otoferlin-deficient mice lack neurotransmitter release at the inner hair cell (IHC) synapse, it remains unclear how the Otof mutation affects spiral ganglions. Thus, we used Otof-mutant mice carrying the Otoftm1a(KOMP)Wtsi allele (Otoftm1a) and analyzed spiral ganglion neurons (SGNs) in Otoftm1a/tm1a mice by immunolabeling type Ⅰ SGNs (SGN-Ⅰ) and type II SGNs (SGN-II). We also examined apoptotic cells in SGNs. Four-week-old Otoftm1a/tm1a mice had an absent ABR but normal DPOAEs. The number of SGNs was significantly lower in Otoftm1a/tm1a mice on postnatal day 7 (P7), P14, and P28 compared with that of wild-type mice. Moreover, significantly more apoptotic SGNs were observed in Otoftm1a/tm1a mice than in wild-type mice on P7, P14, and P28. SGN-IIs were not significantly reduced in Otoftm1a/tm1a mice on P7, P14, and P28. No apoptotic SGN-IIs were observed under our experimental conditions. In summary, Otoftm1a/tm1a mice showed a reduction in SGNs accompanied by apoptosis of SGN-Ⅰs even before the onset of hearing. We speculate that the reduction in SGNs with apoptosis is a secondary defect caused by a lack of otoferlin in IHCs. Appropriate glutamatergic synaptic inputs may be important for the survival of SGNs.
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Affiliation(s)
- Nobuyoshi Tsuzuki
- Department of Otolaryngology, Head and Neck Surgery, Keio University School of Medicine, 35, Shinanomachi, Shinjuku, Tokyo 160-8582, Japan; Division of Hearing and Balance Research, National Institute of Sensory Organs, National Hospital Organization Tokyo Medical Center, 2-5-1, Higashigaoka, Meguro, Tokyo 152-8902, Japan; Department of Otolaryngology, National Hospital Organization Tokyo Medical Center, 2-5-1, Higashigaoka, Meguro, Tokyo 152-8902, Japan.
| | - Kazunori Namba
- Division of Hearing and Balance Research, National Institute of Sensory Organs, National Hospital Organization Tokyo Medical Center, 2-5-1, Higashigaoka, Meguro, Tokyo 152-8902, Japan
| | - Chika Saegusa
- Department of Otolaryngology, Head and Neck Surgery, Keio University School of Medicine, 35, Shinanomachi, Shinjuku, Tokyo 160-8582, Japan; Department of Molecular Genetics, Kitasato University School of Medicine, 1-15-1, Kitasato, Minami-ku, Sagamihara, Kanagawa 252-0374, Japan.
| | - Hideki Mutai
- Division of Hearing and Balance Research, National Institute of Sensory Organs, National Hospital Organization Tokyo Medical Center, 2-5-1, Higashigaoka, Meguro, Tokyo 152-8902, Japan.
| | - Takanori Nishiyama
- Department of Otolaryngology, Head and Neck Surgery, Keio University School of Medicine, 35, Shinanomachi, Shinjuku, Tokyo 160-8582, Japan
| | - Naoki Oishi
- Department of Otolaryngology, Head and Neck Surgery, Keio University School of Medicine, 35, Shinanomachi, Shinjuku, Tokyo 160-8582, Japan.
| | - Tatsuo Matsunaga
- Division of Hearing and Balance Research, National Institute of Sensory Organs, National Hospital Organization Tokyo Medical Center, 2-5-1, Higashigaoka, Meguro, Tokyo 152-8902, Japan; Department of Otolaryngology, National Hospital Organization Tokyo Medical Center, 2-5-1, Higashigaoka, Meguro, Tokyo 152-8902, Japan.
| | - Masato Fujioka
- Department of Otolaryngology, Head and Neck Surgery, Keio University School of Medicine, 35, Shinanomachi, Shinjuku, Tokyo 160-8582, Japan; Department of Molecular Genetics, Kitasato University School of Medicine, 1-15-1, Kitasato, Minami-ku, Sagamihara, Kanagawa 252-0374, Japan; Clinical and Translational Research Center, Keio University School of Medicine, 35, Shinanomachi, Shinjuku, Tokyo 160-8582, Japan.
| | - Hiroyuki Ozawa
- Department of Otolaryngology, Head and Neck Surgery, Keio University School of Medicine, 35, Shinanomachi, Shinjuku, Tokyo 160-8582, Japan
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Calcium signaling and genetic rare diseases: An auditory perspective. Cell Calcium 2023; 110:102702. [PMID: 36791536 DOI: 10.1016/j.ceca.2023.102702] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/14/2022] [Revised: 02/01/2023] [Accepted: 02/02/2023] [Indexed: 02/07/2023]
Abstract
Deafness is a highly heterogeneous disorder which stems, for 50%, from genetic origins. Sensory transduction relies mainly on sensory hair cells of the cochlea, in the inner ear. Calcium is key for the function of these cells and acts as a fundamental signal transduction. Its homeostasis depends on three factors: the calcium influx, through the mechanotransduction channel at the apical pole of the hair cell as well as the voltage-gated calcium channel at the base of the cells; the calcium buffering via Ca2+-binding proteins in the cytoplasm, but also in organelles such as mitochondria and the reticulum endoplasmic mitochondria-associated membranes with specialized proteins; and the calcium extrusion through the Ca-ATPase pump, located all over the plasma membrane. In addition, the synaptic transmission to the central nervous system is also controlled by calcium. Genetic studies of inherited deafness have tremendously helped understand the underlying molecular pathways of calcium signaling. In this review, we discuss these different factors in light of the associated genetic diseases (syndromic and non-syndromic deafness) and the causative genes.
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[Hereditary hearing loss]. HNO 2023; 71:131-142. [PMID: 36526931 DOI: 10.1007/s00106-022-01254-x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 11/02/2022] [Indexed: 12/23/2022]
Abstract
Understanding the genetic basis of hearing loss is becoming increasingly relevant, as 50-70% of congenital hearing loss is hereditary and postlingual hearing loss is also often of hereditary origin. To date, more than 220 genes for hearing loss have been identified and more than 600 syndromes with hearing loss described. This review article explains the classification of genetic hearing loss into syndromic versus non-syndromic forms and the modes of inheritance involved. Some of the most common syndromes (Usher, Pendred, Jervell-Lange-Nielsen, Waardenburg, branchiootorenal, and Alport syndrome) are introductorily described. New sequencing technologies have significantly expanded the diagnostic options for genetic hearing loss and made them more accessible. This text aims to encourage initiation of genetic diagnosis in hearing-impaired patients with suspected hereditary genesis in order to provide the best possible counseling for affected individuals and their families.
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Kim KS, Koo HY, Bok J. Alternative splicing in shaping the molecular landscape of the cochlea. Front Cell Dev Biol 2023; 11:1143428. [PMID: 36936679 PMCID: PMC10018040 DOI: 10.3389/fcell.2023.1143428] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/13/2023] [Accepted: 02/16/2023] [Indexed: 03/06/2023] Open
Abstract
The cochlea is a complex organ comprising diverse cell types with highly specialized morphology and function. Until now, the molecular underpinnings of its specializations have mostly been studied from a transcriptional perspective, but accumulating evidence points to post-transcriptional regulation as a major source of molecular diversity. Alternative splicing is one of the most prevalent and well-characterized post-transcriptional regulatory mechanisms. Many molecules important for hearing, such as cadherin 23 or harmonin, undergo alternative splicing to produce functionally distinct isoforms. Some isoforms are expressed specifically in the cochlea, while some show differential expression across the various cochlear cell types and anatomical regions. Clinical phenotypes that arise from mutations affecting specific splice variants testify to the functional relevance of these isoforms. All these clues point to an essential role for alternative splicing in shaping the unique molecular landscape of the cochlea. Although the regulatory mechanisms controlling alternative splicing in the cochlea are poorly characterized, there are animal models with defective splicing regulators that demonstrate the importance of RNA-binding proteins in maintaining cochlear function and cell survival. Recent technological breakthroughs offer exciting prospects for overcoming some of the long-standing hurdles that have complicated the analysis of alternative splicing in the cochlea. Efforts toward this end will help clarify how the remarkable diversity of the cochlear transcriptome is both established and maintained.
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Affiliation(s)
- Kwan Soo Kim
- Department of Anatomy, Yonsei University College of Medicine, Seoul, Republic of Korea
- Brain Korea 21 Project for Medical Science, Yonsei University College of Medicine, Seoul, Republic of Korea
| | - Hei Yeun Koo
- Department of Anatomy, Yonsei University College of Medicine, Seoul, Republic of Korea
| | - Jinwoong Bok
- Department of Anatomy, Yonsei University College of Medicine, Seoul, Republic of Korea
- Brain Korea 21 Project for Medical Science, Yonsei University College of Medicine, Seoul, Republic of Korea
- Department of Otorhinolaryngology, Yonsei University College of Medicine, Seoul, Republic of Korea
- *Correspondence: Jinwoong Bok,
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Balan JR, Jaisinghani P. Effect of Sensory Modality on Reaction Time in Individuals with Auditory Neuropathy Spectrum Disorder. JOURNAL OF COMMUNICATION DISORDERS 2022; 100:106278. [PMID: 36343389 DOI: 10.1016/j.jcomdis.2022.106278] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/30/2021] [Revised: 10/27/2022] [Accepted: 10/31/2022] [Indexed: 06/16/2023]
Abstract
PURPOSE To investigate and compare the reaction time of individuals with auditory neuropathy in three modalities, auditory, visual, and audio-visual. The reaction time of individuals with auditory neuropathy was also compared with those with normal hearing. The relationship between reaction time across modalities and the duration of hearing loss in auditory neuropathy was also investigated. METHODS AND MATERIALS The reaction time of adults with auditory neuropathy and those with normal hearing was measured in the three modalities using the Choice reaction time task. RESULTS The auditory neuropathy group significantly had a longer reaction time than the normal hearing in all modalities. The trend of the mean reaction time differed across groups. Further, a significant difference in reaction time of the auditory neuropathy group was noted between auditory and visual mode, auditory and audio-visual mode. However, no significant difference between visual and audio-visual modalities was noted in reaction time. CONCLUSION Significantly longer reaction time in auditory neuropathy is presumed to have resulted from neural conduction delay and impaired processing. The auditory neuropathy group can utilize visual cues for faster processing, and the study recommends an audio-visual mode for their management. In addition, the duration of hearing loss in auditory neuropathy had no relationship with reaction time across all modalities.
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Affiliation(s)
- Jithin Raj Balan
- The University of Texas at Austin, Moody College of Communication, Austin, Texas.
| | - Priyanka Jaisinghani
- Department of Communication Sciences and Disorders, Baylor University, Waco, Texas.
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Elsayed O, Al‐Shamsi A. Mutation spectrum of non-syndromic hearing loss in the UAE, a retrospective cohort study and literature review. Mol Genet Genomic Med 2022; 10:e2052. [PMID: 36056583 PMCID: PMC9651598 DOI: 10.1002/mgg3.2052] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/05/2022] [Revised: 06/23/2022] [Accepted: 08/15/2022] [Indexed: 12/14/2022] Open
Abstract
BACKGROUND Hearing loss (HL) is a heterogeneous condition that causes partial or complete hearing impairment. Hundreds of variants in >60 genes have been reported to be associated with Hereditary HL (HHL), variants of the GJB2 gene are the most common cause of congenital SNHL, with >100 variants reported. The HHL prevalence is thought to be high in the Arab population; however, the genetic epidemiology of HHL among Emirati populations is understudied. AIMS To shed light on the mutational spectrum of NSHL in Emirati patients seen in the genetic clinic over 10 years and to capture founder mutation(s) if any were identified. METHODS Retrospective chart review of all Emirati patients assessed by clinical geneticists due to NSHL during the period between January 2010 to December 2020. Genetic tests were done based on clinical phenotypes of the patient and family history including targeted mutation testing, next-generation sequencing, or whole-exome sequencing (solo or trio). The authors did literature reviews using PubMed for all previously reported articles related to NSHL genes from UAE. RESULTS A total of 162 patients with HL, were evaluated during the period between January 2010 to December 2020. There were 82 patients with NSHL, and only 72 patients who completed the genetic evaluations were included in this retrospective study. Among the studied group, 42 (51.2%) were males and 40 (48.78%) were females. The youngest patient was 2 years old and the oldest patient was 50 years old. Consanguinity was documented in 76 patients (92.68%). A total of 14 mutations reported here are novel (23/72 i.e., 31.9%). Twelve missense mutations, 6 nonsense mutations, 6 frameshift mutations, 2 in-frame deletion mutations, and 1 splice site mutation was found. Variants in the GJB2 gene are the most commonly identified cause of NSHL, with c.35delG being the most followed by c.506G > A. The second commonly found variant is c.934C > G (p.Arg312Gly) in the CDC14A gene, found in 9 patients. This was followed by variants in OTOF and SLC26A4 genes, found in 8 patients, respectively. Chromosomal microdeletions encompassing genes causing NSHL were found in 3 patients. No mitochondrial mutations were found in this study group. A total of 11 previous reports about Emirati patients with NSHL were reviewed, with a total of 35 patients. CONCLUSION Emirati patients with NSHL have several mutations, most notably missense mutations. Novel mutations are worth further testing and represent the area for future researches.
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Affiliation(s)
- Omnia Elsayed
- Pediatrics DepartmentTawam HospitalAl AinUnited Arab Emirates
| | - Aisha Al‐Shamsi
- Genetic Division, Pediatrics DepartmentTawam HospitalAl AinUnited Arab Emirates
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13
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Mutai H, Momozawa Y, Kamatani Y, Nakano A, Sakamoto H, Takiguchi T, Nara K, Kubo M, Matsunaga T. Whole exome analysis of patients in Japan with hearing loss reveals high heterogeneity among responsible and novel candidate genes. Orphanet J Rare Dis 2022; 17:114. [PMID: 35248088 PMCID: PMC8898489 DOI: 10.1186/s13023-022-02262-4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/10/2021] [Accepted: 02/20/2022] [Indexed: 11/16/2022] Open
Abstract
Background Heterogeneous genetic loci contribute to hereditary hearing loss; more than 100 deafness genes have been identified, and the number is increasing. To detect pathogenic variants in multiple deafness genes, in addition to novel candidate genes associated with hearing loss, whole exome sequencing (WES), followed by analysis prioritizing genes categorized in four tiers, were applied.
Results Trios from families with non-syndromic or syndromic hearing loss (n = 72) were subjected to WES. After segregation analysis and interpretation according to American College of Medical Genetics and Genomics guidelines, candidate pathogenic variants in 11 previously reported deafness genes (STRC, MYO15A, CDH23, PDZD7, PTPN11, SOX10, EYA1, MYO6, OTOF, OTOG, and ZNF335) were identified in 21 families. Discrepancy between pedigree inheritance and genetic inheritance was present in one family. In addition, eight genes (SLC12A2, BAIAP2L2, HKDC1, SVEP1, CACNG1, GTPBP4, PCNX2, and TBC1D8) were screened as single candidate genes in 10 families. Conclusions Our findings demonstrate that four-tier assessment of WES data is efficient and can detect novel candidate genes associated with hearing loss, in addition to pathogenic variants of known deafness genes. Supplementary Information The online version contains supplementary material available at 10.1186/s13023-022-02262-4.
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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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15
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Mukherjee D, Meng X, Kao JPY, Kanold PO. Impaired Hearing and Altered Subplate Circuits During the First and Second Postnatal Weeks of Otoferlin-Deficient Mice. Cereb Cortex 2021; 32:2816-2830. [PMID: 34849612 DOI: 10.1093/cercor/bhab383] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/11/2021] [Revised: 09/23/2021] [Accepted: 09/25/2021] [Indexed: 02/01/2023] Open
Abstract
Sensory deprivation from the periphery impacts cortical development. Otoferlin deficiency leads to impaired cochlear synaptic transmission and is associated with progressive hearing loss in adults. However, it remains elusive how sensory deprivation due to otoferlin deficiency impacts the early development of the auditory cortex (ACX) especially before the onset of low threshold hearing. To test that, we performed in vivo imaging of the ACX in awake mice lacking otoferlin (Otof-/-) during the first and second postnatal weeks and found that spontaneous and sound-driven cortical activity were progressively impaired. We then characterized the effects on developing auditory cortical circuits by performing in vitro recordings from subplate neurons (SPN), the first primary targets of thalamocortical inputs. We found that in Otof-/- pups, SPNs received exuberant connections from excitatory and inhibitory neurons. Moreover, as a population, SPNs showed higher similarity with respect to their circuit topology in the absence of otoferlin. Together, our results show that otoferlin deficiency results in impaired hearing and has a powerful influence on cortical connections and spontaneous activity in early development even before complete deafness. Therefore, peripheral activity has the potential to sculpt cortical structures from the earliest ages, even before hearing impairment is diagnosed.
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Affiliation(s)
- Didhiti Mukherjee
- Department of Biomedical Engineering, Johns Hopkins University, Baltimore, MD 21205, USA.,Department of Biology, University of Maryland, College Park, MD 20742, USA
| | - Xiangying Meng
- Department of Biomedical Engineering, Johns Hopkins University, Baltimore, MD 21205, USA.,Department of Biology, University of Maryland, College Park, MD 20742, USA
| | - Joseph P Y Kao
- Center for Biomedical Engineering and Technology, and Department of Physiology, University of Maryland School of Medicine, Baltimore, MD 21201, USA
| | - Patrick O Kanold
- Department of Biomedical Engineering, Johns Hopkins University, Baltimore, MD 21205, USA.,Department of Biology, University of Maryland, College Park, MD 20742, USA.,Kavli Neuroscience Discovery Institute, Johns Hopkins University, Baltimore, MD 21205, USA
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16
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Mutations in LOXHD1 gene can cause auditory neuropathy spectrum disorder. OTOLARYNGOLOGY CASE REPORTS 2021; 21. [PMID: 35875410 PMCID: PMC9307087 DOI: 10.1016/j.xocr.2021.100367] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
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17
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Comprehensive functional network analysis and screening of deleterious pathogenic variants in non-syndromic hearing loss causative genes. Biosci Rep 2021; 41:230001. [PMID: 34714320 PMCID: PMC8559308 DOI: 10.1042/bsr20211865] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/05/2021] [Revised: 10/12/2021] [Accepted: 10/15/2021] [Indexed: 11/17/2022] Open
Abstract
Hearing loss (HL) is a significant public health problem and causes the most frequent congenital disability in developed societies. The genetic analysis of non-syndromic hearing loss (NSHL) may be considered as a complement to the existent plethora of diagnostic modalities available. The present study focuses on exploring more target genes with respective non-synonymous single nucleotide polymorphisms (nsSNPs) involved in the development of NSHL. The functional network analysis and variant study have successfully been carried out from the gene pool retrieved from reported research articles of the last decade. The analyses have been done through STRING. According to predicted biological processes, various variant analysis tools have successfully classified the NSHL causative genes and identified the deleterious nsSNPs, respectively. Among the predicted pathogenic nsSNPs with rsIDs rs80356586 (I515T), rs80356596 (L1011P), rs80356606 (P1987R) in OTOF have been reported in NSHL earlier. The rs121909642 (P722S), rs267606805 (P722H) in FGFR1, rs121918506 (E565A) and rs121918509 (A628T, A629T) in FGFR2 have not been reported in NSHL yet, which should be clinically experimented in NSHL. This also indicates this variant's novelty as its association in NSHL. The findings and the analyzed data have delivered some vibrant genetic pathogenesis of NSHL. These data might be used in the diagnostic and prognostic purposes in non-syndromic congenitally deaf children.
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18
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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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Kim SY, Lee S, Seo GH, Kim BJ, Oh DY, Han JH, Park MK, Lee SM, Kim B, Yi N, Kim NJ, Koh DH, Hwang S, Keum C, Choi BY. Powerful use of automated prioritization of candidate variants in genetic hearing loss with extreme etiologic heterogeneity. Sci Rep 2021; 11:19476. [PMID: 34593925 PMCID: PMC8484668 DOI: 10.1038/s41598-021-99007-3] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/04/2021] [Accepted: 08/17/2021] [Indexed: 01/02/2023] Open
Abstract
Variant prioritization of exome sequencing (ES) data for molecular diagnosis of sensorineural hearing loss (SNHL) with extreme etiologic heterogeneity poses a significant challenge. This study used an automated variant prioritization system (“EVIDENCE”) to analyze SNHL patient data and assess its diagnostic accuracy. We performed ES of 263 probands manifesting mild to moderate or higher degrees of SNHL. Candidate variants were classified according to the 2015 American College of Medical Genetics guidelines, and we compared the accuracy, call rates, and efficiency of variant prioritizations performed manually by humans or using EVIDENCE. In our in silico panel, 21 synthetic cases were successfully analyzed by EVIDENCE. In our cohort, the ES diagnostic yield for SNHL by manual analysis was 50.19% (132/263) and 50.95% (134/263) by EVIDENCE. EVIDENCE processed ES data 24-fold faster than humans, and the concordant call rate between humans and EVIDENCE was 97.72% (257/263). Additionally, EVIDENCE outperformed human accuracy, especially at discovering causative variants of rare syndromic deafness, whereas flexible interpretations that required predefined specific genotype–phenotype correlations were possible only by manual prioritization. The automated variant prioritization system remarkably facilitated the molecular diagnosis of hearing loss with high accuracy and efficiency, fostering the popularization of molecular genetic diagnosis of SNHL.
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Affiliation(s)
- So Young Kim
- Department of Otorhinolaryngology-Head and Neck Surgery, CHA Bundang Medical Center, CHA University, Seongnam, Republic of Korea
| | - Seungmin Lee
- Department of Otorhinolaryngology-Head and Neck Surgery, Seoul National University Bundang Hospital, Seongnam, Republic of Korea.,R&D Center, ENCell Co. Ltd, Seoul, Republic of Korea
| | - Go Hun Seo
- 3billion, Inc., Seoul, Republic of Korea
| | - Bong Jik Kim
- Department of Otolaryngology-Head and Neck Surgery, Chungnam National University Sejong Hospital, College of Medicine, Chungnam National University, Daejeon, Republic of Korea
| | - Doo Yi Oh
- Department of Otorhinolaryngology-Head and Neck Surgery, Seoul National University Bundang Hospital, Seongnam, Republic of Korea
| | - Jin Hee Han
- Department of Otorhinolaryngology-Head and Neck Surgery, Seoul National University Bundang Hospital, Seongnam, Republic of Korea
| | - Moo Kyun Park
- Department of Otorhinolaryngology, Seoul National University College of Medicine, Seoul, Republic of Korea
| | - So Min Lee
- Department of Otorhinolaryngology-Head and Neck Surgery, CHA Bundang Medical Center, CHA University, Seongnam, Republic of Korea
| | - Bonggi Kim
- Department of Otorhinolaryngology-Head and Neck Surgery, Seoul National University Bundang Hospital, Seongnam, Republic of Korea
| | - Nayoung Yi
- Department of Otorhinolaryngology-Head and Neck Surgery, Seoul National University Bundang Hospital, Seongnam, Republic of Korea
| | - Namju Justin Kim
- Department of Biological Sciences, Vanderbilt University, Nashville, USA
| | - Doo Hyun Koh
- Department of Biomedical Science, The Graduate School, CHA University, Seongnam, Republic of Korea
| | - Sohyun Hwang
- Department of Biomedical Science, The Graduate School, CHA University, Seongnam, Republic of Korea.,Department of Pathology, CHA University, CHA Bundang Medical Center, Seongnam, Republic of Korea
| | | | - Byung Yoon Choi
- Department of Otorhinolaryngology-Head and Neck Surgery, Seoul National University Bundang Hospital, Seongnam, Republic of Korea.
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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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21
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The natural history of OTOF-related auditory neuropathy spectrum disorders: a multicenter study. Hum Genet 2021; 141:853-863. [PMID: 34424407 DOI: 10.1007/s00439-021-02340-w] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/30/2021] [Accepted: 08/07/2021] [Indexed: 10/20/2022]
Abstract
Pathogenic variations in the OTOF gene are a common cause of hearing loss. To refine the natural history and genotype-phenotype correlations of OTOF-related auditory neuropathy spectrum disorders (ANSD), audiograms and distortion product otoacoustic emissions (DPOAEs) were collected from a diverse cohort of individuals diagnosed with OTOF-related ANSD by comprehensive genetic testing and also reported in the literature. Comparative analysis was undertaken to define genotype-phenotype relationships using a Monte Carlo algorithm. 67 audiograms and 25 DPOAEs from 49 unique individuals positive for OTOF-related ANSD were collected. 51 unique OTOF pathogenic variants were identified of which 21 were missense and 30 were loss of function (LoF; nonsense, splice-site, copy number variants, and indels). There was a statistically significant difference in low, middle, and high frequency hearing thresholds between missense/missense and LoF/missense genotypes as compared to LoF/LoF genotypes (average hearing threshold for low, middle and high frequencies 70.9, 76.0, and 73.4 dB vs 88.5, 95.6, and 94.7 dB) via Tukey's test with age as a co-variate (P = 0.0180, 0.0327, and 0.0347, respectively). Hearing declined during adolescence with missense/missense and LoF/missense genotypes, with an annual mid-frequency threshold deterioration of 0.87 dB/year and 1.87 dB/year, respectively. 8.5% of frequencies measured via DPOAE were lost per year in individuals with serial tests. Audioprofiling of OTOF-related ANSD suggests significantly worse hearing with LoF/LoF genotypes. The unique pattern of variably progressive OTOF-related autosomal recessive ANSD may be amenable to gene therapy in selected clinical scenarios.
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22
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Cox A, Tolkach Y, Stein J, Kristiansen G, Ritter M, Ellinger J. Otoferlin is a prognostic biomarker in patients with clear cell renal cell carcinoma: A systematic expression analysis. Int J Urol 2021; 28:424-431. [PMID: 33465825 DOI: 10.1111/iju.14486] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/10/2020] [Accepted: 12/08/2020] [Indexed: 12/16/2022]
Abstract
OBJECTIVES To comprehensively investigate the role of otoferlin as a prognostic and diagnostic biomarker in clear cell renal cell carcinoma. METHODS Three independent cohorts were used to study otoferlin in clear cell renal cell carcinoma: The Cancer Genome Atlas cohort (messenger ribonucleic acid expression; clear cell renal cell carcinoma n = 514, normal renal tissue n = 81); study validation cohort (messenger ribonucleic acid expression; clear cell renal cell carcinoma n = 79, normal renal tissue n = 44); and immunohistochemistry cohort (protein expression; clear cell renal cell carcinoma n = 142, normal renal tissue n = 30). Otoferlin gene expressions were extracted from The Cancer Genome Atlas database or determined using quantitative real-time polymerase chain reaction, respectively. Protein expression was assessed using immunohistochemistry staining against otoferlin on tissue microarrays. Correlations between otoferlin messenger ribonucleic acid/protein expression and clinicopathological data/patient survival were statistically tested. RESULTS Otoferlin messenger ribonucleic acid expression was significantly upregulated in clear cell renal cell carcinoma compared with normal renal tissue. High expression levels correlated with advanced stage, higher grade and metastatic tumors, accompanied by independent prognostic significance for overall and cancer-specific survival. In contrast, otoferlin protein expression was downregulated in tumor tissue. Although, high otoferlin expression in clear cell renal cell carcinoma was positively correlated with histological grading and independently predictive of a shortened progression-free survival. CONCLUSION Our data suggest otoferlin as an indicator of tumor aggressiveness and as a prognostic biomarker for patients with clear cell renal cell carcinoma, leading to the conclusion that otoferlin could promote the malignancy of clear cell renal cell carcinoma.
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Affiliation(s)
- Alexander Cox
- Department of Urology, University Hospital Bonn, Bonn, Germany
| | - Yuri Tolkach
- Institute of Pathology, University Hospital Bonn, Bonn, Germany.,Institute of Pathology, University Hospital Cologne, Cologne, Germany
| | - Johannes Stein
- Department of Urology, University Hospital Bonn, Bonn, Germany
| | | | - Manuel Ritter
- Department of Urology, University Hospital Bonn, Bonn, Germany
| | - Jörg Ellinger
- Department of Urology, University Hospital Bonn, Bonn, Germany
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Souissi A, Ben Said M, Ben Ayed I, Elloumi I, Bouzid A, Mosrati MA, Hasnaoui M, Belcadhi M, Idriss N, Kamoun H, Gharbi N, Gibriel AA, Tlili A, Masmoudi S. Novel pathogenic mutations and further evidence for clinical relevance of genes and variants causing hearing impairment in Tunisian population. J Adv Res 2021; 31:13-24. [PMID: 34194829 PMCID: PMC8240103 DOI: 10.1016/j.jare.2021.01.005] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/24/2020] [Revised: 12/14/2020] [Accepted: 01/07/2021] [Indexed: 12/22/2022] Open
Abstract
Introduction Hearing impairment (HI) is characterized by complex genetic heterogeneity. The evolution of next generation sequencing, including targeted enrichment panels, has revolutionized HI diagnosis. Objectives In this study, we investigated genetic causes in 22 individuals with non-GJB2 HI. Methods We customized a HaloplexHS kit to include 30 genes known to be associated with autosomal recessive nonsyndromic HI (ARNSHI) and Usher syndrome in North Africa. Results In accordance with the ACMG/AMP guidelines, we report 11 pathogenic variants; as follows; five novel variants including three missense (ESRRB-Tyr295Cys, MYO15A-Phe2089Leu and MYO7A-Tyr560Cys) and two nonsense (USH1C-Gln122Ter and CIB2-Arg104Ter) mutations; two previously reported mutations (OTOF-Glu57Ter and PNPT1-Glu475Gly), but first time identified among Tunisian families; and four other identified mutations namely WHRN-Gly808AspfsX11, SLC22A4-Cys113Tyr and two MYO7A compound heterozygous splice site variants that were previously described in Tunisia. Pathogenic variants in WHRN and CIB2 genes, in patients with convincing phenotype ruling out retinitis pigmentosa, provide strong evidence supporting their association with ARNSHI. Moreover, we shed lights on the pathogenic implication of mutations in PNPT1 gene in auditory function providing new evidence for its association with ARNSHI. Lack of segregation of a previously identified causal mutation OTOA-Val603Phe further supports its classification as variant of unknown significance. Our study reports absence of otoacoustic emission in subjects using bilateral hearing aids for several years indicating the importance of screening genetic alteration in OTOF gene for proper management of those patients. Conclusion In conclusion, our findings do not only expand the spectrum of HI mutations in Tunisian patients, but also improve our knowledge about clinical relevance of HI causing genes and variants.
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Affiliation(s)
- Amal Souissi
- Laboratory of Molecular and Cellular Screening Processes, Center of Biotechnology of Sfax, University of Sfax, Tunisia
| | - Mariem Ben Said
- Laboratory of Molecular and Cellular Screening Processes, Center of Biotechnology of Sfax, University of Sfax, Tunisia
| | - Ikhlas Ben Ayed
- Medical Genetic Department, University Hedi Chaker Hospital of Sfax, Tunisia
- Faculty of Medicine of Sfax, University of Sfax, Tunisia
| | - Ines Elloumi
- Laboratory of Molecular and Cellular Screening Processes, Center of Biotechnology of Sfax, University of Sfax, Tunisia
| | - Amal Bouzid
- Laboratory of Molecular and Cellular Screening Processes, Center of Biotechnology of Sfax, University of Sfax, Tunisia
| | - Mohamed Ali Mosrati
- Laboratory of Molecular and Cellular Screening Processes, Center of Biotechnology of Sfax, University of Sfax, Tunisia
| | - Mehdi Hasnaoui
- Department of Otorhinolaryngology, Taher Sfar University Hospital of Mahdia, Tunisia
| | - Malek Belcadhi
- Laboratory of Molecular and Cellular Screening Processes, Center of Biotechnology of Sfax, University of Sfax, Tunisia
| | - Nabil Idriss
- Department of Otorhinolaryngology, Taher Sfar University Hospital of Mahdia, Tunisia
| | - Hassen Kamoun
- Medical Genetic Department, University Hedi Chaker Hospital of Sfax, Tunisia
- Faculty of Medicine of Sfax, University of Sfax, Tunisia
| | - Nourhene Gharbi
- Medical Genetic Department, University Hedi Chaker Hospital of Sfax, Tunisia
- Faculty of Medicine of Sfax, University of Sfax, Tunisia
| | - Abdullah A. Gibriel
- Biochemistry and Molecular Biology Department, Faculty of Pharmacy. The British University in Egypt (BUE) Cairo, Egypt
| | - Abdelaziz Tlili
- Department of Applied Biology, College of Sciences, University of Sharjah, Sharjah, United Arab Emirates
- Human Genetics and Stem Cell Laboratory, Research Institute of Sciences and Engineering, University of Sharjah, Sharjah, United Arab Emirates
| | - Saber Masmoudi
- Laboratory of Molecular and Cellular Screening Processes, Center of Biotechnology of Sfax, University of Sfax, Tunisia
- Corresponding author at: Laboratory of Molecular and Cellular Screening Processes, Centre of Biotechnology of Sfax, Sidi Mansour road Km 6, BP “1177”, 3018 Sfax, Tunisia.
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Auditory Neuropathy Spectrum Disorder (ANSD)-Clinical Characteristics and Pathogenic Variant Analysis of Three Nonsyndromic Deafness Families. BIOMED RESEARCH INTERNATIONAL 2020; 2020:8843539. [PMID: 33426078 PMCID: PMC7772035 DOI: 10.1155/2020/8843539] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 10/01/2020] [Revised: 11/23/2020] [Accepted: 12/12/2020] [Indexed: 12/15/2022]
Abstract
Objective To analyze the phenotypic features and pathogenic variants of three unrelated families presenting with nonsyndromic auditory neuropathy spectrum disorder (ANSD). Methods Three recruited families that were affected by congenital deafness were clinically evaluated, including a detailed family history and audiological and radiological examination. The peripheral blood of all patients and their parents was collected for DNA extraction, and then, the exonic and flanking regions were enriched and sequenced using targeted capture and high-throughput sequencing technology. Bioinformatics analyses and the Sanger sequencing were carried out to screen and validate candidate pathogenic variants. The pathogenicity of candidate variants was evaluated by an approach that was based on the standards and guidelines for interpreting genetic variants as proposed by the American College of Medical Genetics and Genomics (ACMG). Results Four patients in three families were diagnosed as nonsyndromic ANSD, and all exhibited OTOF gene mutations. Among them, two individuals in family 1 (i.e., fam 1-II-2 and fam 1-II-3) carried homozygous variants c.[2688del];[2688del] (NM_194248.3). Two individuals from family 2 (fam 2-II-1) and family 3 (fam 3-II-4) carried compound heterozygous variants c.[4960G>A];[1469C>G] and c.[2675A>G];[2977_2978del], respectively. Conclusions Three unrelated pedigrees with ANSD were caused by pathogenic variants in the OTOF gene. Five mutations were found and included c.2688del, c.2675A>G, c.2977_2978del, c.4960G>A, and c.1469C>G, of which the first two are novel and expanded mutational spectrum of the OTOF gene, thus having important implications for genetic counseling of the family.
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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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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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West AN, Kuan EC, Peng KA. Identification of Perinatal Risk Factors for Auditory Neuropathy Spectrum Disorder. Laryngoscope 2020; 131:671-674. [PMID: 32609896 DOI: 10.1002/lary.28904] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/30/2020] [Revised: 06/02/2020] [Accepted: 06/10/2020] [Indexed: 11/09/2022]
Abstract
OBJECTIVES/HYPOTHESIS To identify medical risk factors associated with auditory neuropathy spectrum disorder (ANSD). STUDY DESIGN Retrospective case-control study. METHODS During a 2-year period (2013-2014) patients with newly diagnosed ANSD were identified at a tertiary care facility. Twenty-two patients (n = 22) were identified aged 0.5 to 8.1 years. There were 15 males and seven females. Sixteen had bilateral, four had left-sided, and two had right-sided ANSD. Two age-matched, side-matched, and gender-matched control groups were then collected. The first group was 22 normal-hearing children (n = 22). The second was 22 children with sensorineural hearing loss (SNHL) (n = 22) who did not meet the criteria for ANSD. The chart of each subject was reviewed for the following five-predictor variables: prematurity, low birth weight, jaundice, use of mechanical ventilation, and administration of ototoxic medications. Analysis of variance was performed to analyze the prevalence of perinatal risk factors among the three groups. Multivariate linear regression was then applied. RESULTS When comparing the ANSD group to both the normal-hearing and SNHL groups, the subjects with ANSD had statistically significant higher rates of prematurity, low birth weight, jaundice, and mechanical ventilation. Multiple regression analysis was performed to identify predictors of ANSD compared to each control group individually. Jaundice in the first month of life approached significance when comparing the ANSD group to the normal-hearing group, and was the only medical risk factor found to be statistically significant when comparing the ANSD group to the SNHL group. CONCLUSIONS A history of neonatal hyperbilirubinemia was significantly more common in children with ANSD compared to children with severe SNHL. LEVEL OF EVIDENCE 3 Laryngoscope, 131:671-674, 2021.
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Affiliation(s)
- Alisha N West
- Department of Head and Neck Surgery, David Geffen School of Medicine at University of California Los Angeles, Los Angeles, California, U.S.A
| | - Edward C Kuan
- Department of Otolaryngology-Head and Neck Surgery, University of California, Irvine, Irvine, California, U.S.A
| | - Kevin A Peng
- House Ear Institute, University of Southern California, Los Angeles, California, U.S.A
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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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29
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Zheng D, Liu X. Cochlear Implantation Outcomes in Patients With OTOF Mutations. Front Neurosci 2020; 14:447. [PMID: 32508568 PMCID: PMC7253664 DOI: 10.3389/fnins.2020.00447] [Citation(s) in RCA: 18] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/06/2019] [Accepted: 04/09/2020] [Indexed: 01/26/2023] Open
Abstract
Auditory neuropathy is a special type of hearing loss caused by dysfunction of the synapse of the inner hair cells, the auditory nerve, and/or the auditory nerve itself. For patients with auditory neuropathy who have severe to profound hearing loss or failed auditory skills development with hearing-aids, cochlear implantation (CI) serves as the only possible effective treatment. It is accepted that the exact sites of lesion causing auditory neuropathy determine the CI performance. Mutations in the OTOF gene were the first identified and the most common cause of congenital auditory neuropathy. The site of lesion in patients with auditory neuropathy caused by biallelic OTOF mutations (OTOF-related auditory neuropathy) is presumed to be presynaptic, leaving auditory nerve function intact. Thus, OTOF-related auditory neuropathy is expected to have good CI performances. In this review, we describe the CI outcomes in patients with OTOF mutations. We will focus on whether biallelic OTOF mutations are ideal indications for CI in patients with auditory neuropathy. Also, the factors that may still influence the CI outcomes in patients with OTOF mutations are discussed.
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Affiliation(s)
- Dandan Zheng
- Department of Otorhinolaryngology, 2nd Affiliated Hospital, School of Medicine, Zhejiang University, Hangzhou, China
| | - Xiao Liu
- Department of Otorhinolaryngology, 2nd Affiliated Hospital, School of Medicine, Zhejiang University, Hangzhou, China
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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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Case report of two children with auditory neuropathy spectrum disorder related to a neurofascin (NFASC) gene variant. Int J Pediatr Otorhinolaryngol 2020; 131:109863. [PMID: 31945734 DOI: 10.1016/j.ijporl.2020.109863] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/03/2019] [Revised: 01/05/2020] [Accepted: 01/05/2020] [Indexed: 11/24/2022]
Abstract
We present a case of two siblings born to nonconsanguineous parents that presented with hypotonia, respiratory insufficiency, and auditory neuropathy spectrum disorder (ANSD) correlated with NFASC (MIM: 609145) and the homozygous loss of function variant p.P924RfsX35. This appears to be the first two reported cases of NFASC correlated with ANSD. NFASC encodes for neurofascin which plays an important role in the formation, function and maintenance of axon initial segments and nodes of Ranvier. Due to the rarity of this gene variation, reports are sparse in the literature leading to delays in diagnosis which can impact patient's language acquisition and spoken language skills.
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Kuchay RAH, Mir YR, Zeng X, Hassan A, Namba K, Tekin M. Novel OTOF pathogenic variant segregating with non-syndromic hearing loss in a consanguineous family from tribal Rajouri in Jammu and Kashmir. Int J Pediatr Otorhinolaryngol 2020; 130:109831. [PMID: 31875531 DOI: 10.1016/j.ijporl.2019.109831] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/04/2019] [Revised: 12/11/2019] [Accepted: 12/14/2019] [Indexed: 11/17/2022]
Abstract
BACKGROUND Hereditary hearing loss is characterized by a very high genetic heterogeneity. The OTOF (Locus: DFNB9), encoding otoferlin, is reported to be one of the major causes of non-syndromic hearing loss, and is also reported to be the most common cause of non-syndromic recessive auditory neuropathy spectrum disorder. METHODS In this study, whole exome sequencing was employed for detection of novel pathogenic variant that segregates with autosomal recessive nonsyndromic hearing loss in a tribal family from Rajouri, Jammu and Kashmir. Proband was a 9-year-old male born to first-cousin parents and presented with sensorineural hearing loss since birth. Family resides in an area with high consanguinity and lack of basic health care facilities including genetic counselling services. RESULTS We report a novel OTOF pathogenic variant NM_194248.2:c.4249_4250insG (p.Ser1417CysfsTer4) co-segregating with hearing loss in this family and not present in any public databases. CONCLUSIONS Our findings not only extend the geographical and mutational spectrum of autosomal recessive nonsyndromic hearing loss but also support the need for introducing genetic counselling services to rural and tribal areas in India with high consanguinity.
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Affiliation(s)
- Raja A H Kuchay
- Department of Biotechnology, Baba Ghulam Shah Badshah University, Rajouri, J&K, India.
| | - Yaser Rafiq Mir
- Department of Biotechnology, Baba Ghulam Shah Badshah University, Rajouri, J&K, India
| | - Xue Zeng
- Department of Genetics, Yale School of Medicine, New Haven, CT, USA
| | - Asima Hassan
- Department of Ophthalmology, Government Medical College, Srinagar, J&K, India
| | - Kazunori Namba
- Division of Hearing and Balance Research, National Institute of Sensory Organs, National Hospital Organization Tokyo Medical Center, Japan
| | - Mustafa Tekin
- John P. Hussman Institute for Human Genomics, University of Miami Miller School of Medicine, Miami, FL, 33136, USA
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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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Deterioration in Distortion Product Otoacoustic Emissions in Auditory Neuropathy Patients With Distinct Clinical and Genetic Backgrounds. Ear Hear 2019; 40:184-191. [PMID: 29688962 DOI: 10.1097/aud.0000000000000586] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/17/2022]
Abstract
OBJECTIVES Auditory neuropathy (AN) is a clinical disorder characterized by the absence of auditory brainstem response and presence of otoacoustic emissions. A gradual loss of otoacoustic emissions has been reported for some cases of AN. Such cases could be diagnosed as cochlear hearing loss and lead to misunderstanding of the pathology when patients first visit clinics after the loss of otoacoustic emissions. The purpose of this study was to investigate the time course of changes in distortion product otoacoustic emissions (DPOAEs) in association with patients' genetic and clinical backgrounds, including the use of hearing aids. DESIGN DPOAE measurements from 31 patients with AN were assessed. Genetic analyses for GJB2, OTOF, and mitochondrial m.1555A> G and m.3243A> G mutations were conducted for all cases, and the analyses for CDH23 and OPA1 were conducted for the selected cases. Patients who were younger than 10 years of age at the time of AN diagnosis were designated as the pediatric AN group (22 cases), and those who were 18 years of age or older were designated as the adult AN group (9 cases). DPOAE was measured at least twice in all patients. The response rate for DPOAEs was defined and analyzed. RESULTS The pediatric AN group comprised 10 patients with OTOF mutations, 1 with GJB2 mutations, 1 with OPA1 mutation, and 10 with indefinite causes. Twelve ears (27%) showed no change in DPOAE, 20 ears (46%) showed a decrease in DPOAE, and 12 ears (27%) lost DPOAE. Loss of DPOAE occurred in one ear (2%) at 0 years of age and four ears (9%) at 1 year of age. The time courses of DPOAEs in patients with OTOF mutations were divided into those with early loss and those with no change, indicating that the mechanism for deterioration of DPOAEs includes not only the OTOF mutations but also other common modifier factors. Most, but not all, AN patients who used hearing aids showed deterioration of DPOAEs after the start of using hearing aids. A few AN patients also showed deterioration of DPOAEs before using hearing aids. The adult AN group comprised 2 patients with OPA1 mutations, 2 with OTOF mutations, and 5 with indefinite causes. Four ears (22%) showed no change in DPOAE, 13 ears (72%) showed a decrease, and one ear (6%) showed a loss of DPOAE. Although the ratio of DPOAE decrease was higher in the adult AN group than in the pediatric AN group, the ratio of DPOAE loss was lower in the adult AN group. DPOAE was not lost in all four ears with OPA1 mutations and in all four ears with OTOF mutations in the adult group. CONCLUSIONS DPOAE was decreased or lost in approximately 70% of pediatric and about 80% of adult AN patients. Eleven percent of pediatric AN patients lost DPOAEs by 1 year of age. Genetic factors were thought to have influenced the time course of DPOAEs in the pediatric AN group. In most adult AN patients, DPOAE was rarely lost regardless of the genetic cause.
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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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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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37
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El-Badry MM, Gamal R, Fawzy A. Evaluation of saccular and inferior vestibular nerve function in children with auditory neuropathy spectrum disorder. Eur Arch Otorhinolaryngol 2018; 275:2925-2931. [PMID: 30259131 DOI: 10.1007/s00405-018-5149-3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/14/2018] [Accepted: 09/24/2018] [Indexed: 10/28/2022]
Abstract
PURPOSE The aim of the current work was to evaluate the function of the saccule and inferior vestibular nerve in children with auditory neuropathy spectrum disorder (ANSD) by recording the cervical-evoked myogenic potentials (C-VEMP) on those children and to compare C-VEMP results in ANSD children of pre-lingual onset to those in ANSD children of post-lingual onset. METHODS The study included 38 ANSD children of pre-lingual onset, 16 ANSD children of post-lingual onset, and 20 control children. All participant children were subjected to C-VEMP testing using 500 Hz tone burst stimuli. RESULTS The vast majority of ANSD children of pre-lingual onset (35 out of 38; 92.1%) had bilateral intact C-VEMP response with C-VEMP parameters (amplitude, asymmetric ratio, latency, and inter-aural latency difference) that were not statistically different than those in the control children. Only three children had bilateral absent C-VEMP response. On the other hand, the majority of ANSD children of post-lingual onset (11 out of 16; 68.75%) had bilateral absent C-VEMP response. The remaining five children had bilateral intact C-VEMP response with C-VEMP parameters that were not statistically different than those in the control children. CONCLUSIONS The pathology of ANSD spares the saccule and inferior vestibular nerve in the vast majority of ANSD children of pre-lingual onset, while it involves them in the majority of ANSD of post-lingual onset reflecting different site(s) of lesion between the two ANSD categories. Such results have important clinical implications as regards to the management of ANSD in children.
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Affiliation(s)
| | - Reham Gamal
- Audio-Vestibular Unit, Minia University, Minia, Egypt
| | - Amira Fawzy
- Audio-Vestibular Unit, Minia University, Minia, Egypt
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38
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Hosoya M, Minami SB, Enomoto C, Matsunaga T, Kaga K. Elongated EABR wave latencies observed in patients with auditory neuropathy caused by OTOF mutation. Laryngoscope Investig Otolaryngol 2018; 3:388-393. [PMID: 30410993 PMCID: PMC6209615 DOI: 10.1002/lio2.210] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/03/2017] [Accepted: 07/30/2018] [Indexed: 11/06/2022] Open
Abstract
Objectives We sought to determine how the pathology altered electrically evoked auditory brainstem responses (EABRs) in patients with hearing loss by evaluating EABRs in auditory neuropathy patients with OTOF mutations comparing with various types of congenital deafness. Methods We included 15 patients with congenital hearing loss, grouped according to pathology: OTOF mutations (n = 4), GJB2 mutations (n = 4), SLC26A4 mutations (n = 4), or cytomegalovirus infections (n = 3). EABRs were recorded when patients underwent cochlear implantation surgery. We evaluated the latencies and amplitudes of the recorded EABRs and compared them statistically between four groups. Results The EABR latencies of Wave III and Wave V, and of the interval between them, were significantly longer in the OTOF mutation group than in the GJB2 and SLC26A4 mutation groups (Wave III) and in all three other groups (Wave V and Wave III-V latency); amplitudes were not significantly different between groups. Conclusions Our results suggest OTOF mutations cause delayed (or slowed) postsynaptic neurotransmission, although the presumed mechanism involved reduced presynaptic transmission between hair cells and spiral ganglion neurons. Level of Evidence Mainly a case report.
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Affiliation(s)
| | | | | | - Tatsuo Matsunaga
- Laboratory of Auditory Disorders and Division of Hearing and Balance Research Tokyo Japan.,Medical Genetics Center; National Institute of Sensory Organs, National Tokyo Medical Center Tokyo Japan
| | - Kimitaka Kaga
- National Institute of Sensory Organs Tokyo Japan.,Center for Speech and Hearing Disorders International University of Health and Welfare Tokyo Japan
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39
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Xia H, Huang X, Xu H, Guo Y, Hu P, Deng X, Yang Z, Liu A, Deng H. An OTOF Frameshift Variant Associated with Auditory Neuropathy Spectrum Disorder. Curr Genomics 2018; 19:370-374. [PMID: 30065612 PMCID: PMC6030853 DOI: 10.2174/1389202919666171113152951] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/21/2015] [Revised: 06/13/2016] [Accepted: 06/18/2016] [Indexed: 11/28/2022] Open
Abstract
Background: Auditory Neuropathy Spectrum Disorder (ANSD) is manifested as impairment of auditory nerve activity but preservation of the outer hair cell function. Objective: This study was to detect the disease-causing gene and variant(s) in a Chinese ANSD family. Methods: A four-generation consanguineous Chinese ANSD family and 200 unrelated healthy controls were enrolled. Exome sequencing and Sanger sequencing were applied to identify the genetic basis for ANSD in this family. Results: Exome sequencing detected a c.1236delC variant of the otoferlin gene in an apparently homozygous state. Sanger sequencing confirmed that the variant co-segregating with the phenotype of hearing impairments in this family. The variant was not detected in 200 healthy controls. The c.1236delC alteration may result in a truncated otoferlin missing the C2C-C2F domains and the C-terminal transmembrane domain, and thus severely damages Ca2+-dependent synaptic vesicle fusion and targeting function of the otoferlin. Conclusion: Our study suggested that the c.1236delC alteration in the otoferlin gene may be the disease-causing variant in this family, and also shed new light on genetic counseling to this ANSD family.
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Affiliation(s)
- Hong Xia
- Center for Experimental Medicine and Department of Neurology, The Third Xiangya Hospital, Central South University, Changsha, China.,Department of Emergency, The Third Xiangya Hospital, Central South University, Changsha, China
| | - Xiangjun Huang
- Department of General Surgery, The First Hospital of Hunan University of Chinese Medicine, Changsha, China
| | - Hongbo Xu
- Center for Experimental Medicine and Department of Neurology, The Third Xiangya Hospital, Central South University, Changsha, China
| | - Yi Guo
- Center for Experimental Medicine and Department of Neurology, The Third Xiangya Hospital, Central South University, Changsha, China.,Department of Medical Information, Information Security and Big Data Research Institute, Central South University, Changsha, China
| | - Pengzhi Hu
- Center for Experimental Medicine and Department of Neurology, The Third Xiangya Hospital, Central South University, Changsha, China.,Department of Radiology, The Third Xiangya Hospital, Central South University, Changsha, China
| | - Xiong Deng
- Center for Experimental Medicine and Department of Neurology, The Third Xiangya Hospital, Central South University, Changsha, China
| | - Zhijian Yang
- Center for Experimental Medicine and Department of Neurology, The Third Xiangya Hospital, Central South University, Changsha, China
| | - An Liu
- Department of Otolaryngology-Head Neck Surgery, The Third Xiangya Hospital, Central South University, Changsha, China
| | - Hao Deng
- Center for Experimental Medicine and Department of Neurology, The Third Xiangya Hospital, Central South University, Changsha, China
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40
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Cheng Y, Nakamura M, Matsunaga T, Kaga K. A case of auditory neuropathy revealed by OTOF gene mutation analysis in a junior high school girl. J Otol 2018; 12:202-206. [PMID: 29937857 PMCID: PMC6002630 DOI: 10.1016/j.joto.2017.07.002] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/27/2017] [Revised: 07/06/2017] [Accepted: 07/11/2017] [Indexed: 11/16/2022] Open
Abstract
Objective Congenital auditory neuropathy (AN) affects hearing and speech development. The degree of hearing difficulty in congenital AN varies as a function of pathology at the inner ear hair cell (IHC) synapses or the auditory nerve. We report a case of a Chinese girl with AN revealed by OTOF (otoferlin) gene mutation analysis who had only a mild hearing loss. Patient A 13-year-old Chinese girl was diagnosed as having congenital AN on the basis of OTOF gene mutation analysis. She manifest a mild sensorineural hearing loss with 50% maximum monosyllable speech discrimination rate, normal DPOAEs (distortion product otoacoustic emissions) beyond ambient noise levels, only SPs (summating potentials) evoked during ECoG (electrocochleography) and absent ABRs (auditory evoked brainstem responses) bilaterally to clicks presented at 100 dBnHL. She was able to effectively communicate with others by speech reading owing to her mild hearing loss. Moreover, bilateral hearing aids helped her to communicate. Conclusions Our patient was demonstrated to have a mutation on the OTOF gene. Nevertheless, she was able to communicate using auditory visual speech reading in spite of a mild auditory threshold elevation probably due to partial pathology at the IHC synapses or in the auditory nerve.
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Affiliation(s)
- Ying Cheng
- National Institute of Sensory Organs, Tokyo Medical Center, Japan.,The Department of Otolaryngology Head and Neck Surgery in the Second Affiliated Hospital of Xi'an Jiaotong University, Shaanxi Province, PR China
| | - Masako Nakamura
- National Institute of Sensory Organs, Tokyo Medical Center, Japan
| | - Tatsuo Matsunaga
- National Institute of Sensory Organs, Tokyo Medical Center, Japan
| | - Kimitaka Kaga
- National Institute of Sensory Organs, Tokyo Medical Center, Japan
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41
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Pandey N, Rashid T, Jalvi R, Sharma M, Rangasayee R, Andrabi KI, Anand A. Mutations in OTOF, CLDN14 & SLC26A4 genes as major causes of hearing impairment in Dhadkai village, Jammu & Kashmir, India. Indian J Med Res 2018; 146:489-497. [PMID: 29434063 PMCID: PMC5819031 DOI: 10.4103/ijmr.ijmr_635_15] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/04/2022] Open
Abstract
Background & objectives: A high incidence of hearing impairment is reported from the village of Dhadkai in the State of Jammu and Kashmir, India. Prevalence of endogamy in this community suggested a common genetic basis for the disorder. A genetic study was undertaken to ascertain the basis for the high incidence of hearing impairment in this region. Methods: In a two-step approach to identify the causative mutation/s, a whole-genome-based linkage analysis of an extended family of 45 members was carried out, which included 23 affected and 22 unaffected members. Mutational analysis for the candidate deafness genes helped reveal causative mutations in the family. In addition, seven deafness-causing genes, Cx26, SLC26A4, CLDN14, TMPRSS3, TMC1, TMIE and USH1C, were analyzed in smaller families with hearing impairment. Results: In the 45-member extended family, the critical chromosomal region mapped to 2p24-p22. The c.2122C>T (p.R708X) mutation in OTOF in 2p24-p22was identified as being the causal change. Linkage to 2p24-p22 locus was not observed in a particular branch of this extended family. Analysis of seven known deafness-causing genes in this branch revealed a mutation, c.254T>A (p.V85D), in CLDN14. Among seven small families unrelated to the 45-member extended family, hearing loss was attributable to p.R708X in OTOF in three families and to p.V85D in CLDN14 in one family; a new mutation c.1668T>A (p.Y556X) SLC26A4 was identified in two families and the causative change could not be identified in one family. Interpretation & conclusions: This study suggested considerable genetic heterogeneity in the causation of hearing loss in Dhadkai. Recessive mutations were observed in at least three genes causing hearing loss: OTOF (p.R708X), SLC26A4 (p.Y556X) and CLDN14 (p.V85D). Mutation p.R708X appeared to be the major cause of hearing impairment in Dhadkai.
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Affiliation(s)
- Nishtha Pandey
- Molecular Biology & Genetics Unit, Jawaharlal Nehru Centre for Advanced Scientific Research; Centre for Human Genetics, Bengaluru, India
| | - Tabassum Rashid
- Department of Biotechnology, The University of Kashmir, Srinagar, India
| | - Rajeev Jalvi
- Department of Audiology, Ali Yavar Jung National Institute for the Hearing Handicapped, Mumbai, India
| | - Meenakshi Sharma
- Molecular Biology & Genetics Unit, Jawaharlal Nehru Centre for Advanced Scientific Research, Bengaluru, India
| | - Raghunath Rangasayee
- Department of Audiology, Ali Yavar Jung National Institute for the Hearing Handicapped, Mumbai, India
| | | | - Anuranjan Anand
- Molecular Biology & Genetics Unit, Jawaharlal Nehru Centre for Advanced Scientific Research, Bengaluru, India
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42
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Jain RK, Pingle SK, Tumane RG, Thakkar LR, Jawade AA, Barapatre A, Trivedi M. Cochlear Proteins Associated with Noise-induced Hearing Loss: An Update. Indian J Occup Environ Med 2018; 22:60-73. [PMID: 30319226 PMCID: PMC6176698 DOI: 10.4103/ijoem.ijoem_43_18] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022] Open
Abstract
Noise-induced hearing loss (NIHL) is one of the major occupational disease that has influence on the quality of life of mining workers. Several reports suggest NIHL is attributed to noise exposure at workplace and approximately 16% of hearing loss is due to it. NIHL occurs as a result of exposure to high-level noise (>85 dB) in the workplace. Noise disrupts proteins present in the micromachinery of the ear that is required for mechano-electric transduction of sound waves. High-level noise exposure can lead to hearing impairment owing to mechanical and metabolic exhaustion in cochlea, the major organ responsible for resilience of sound. Several key proteins of cochlea include tectorial membrane, inner hair cells, outer hair cells, and stereocilia are damaged due to high-level noise exposure. Numerous studies conducted in animals have shown cochlear proteins involvement in NIHL, but the pertinent literature remains limited in humans. Detection of proteins and pathways perturbed within the micromachinery of the ear after excessive sound induction leads toward the early identification of hearing loss. The situation insisted to present this review as an update on cochlear proteins associated with NIHL after an extensive literature search using several electronic databases which help to understand the pathophysiology of NIHL.
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Affiliation(s)
- Ruchika K Jain
- Department of Biochemistry, National Institute of Miners' Health JNARDDC Campus, Wadi, Nagpur, Maharashtra, India
| | - Shubhangi K Pingle
- Department of Biochemistry, National Institute of Miners' Health JNARDDC Campus, Wadi, Nagpur, Maharashtra, India
| | - Rajani G Tumane
- Department of Biochemistry, National Institute of Miners' Health JNARDDC Campus, Wadi, Nagpur, Maharashtra, India
| | - Lucky R Thakkar
- National Centre for Microbial Resources, National Centre for Cell Science, University of Pune Campus, Pune, Maharashtra, India
| | - Aruna A Jawade
- Department of Biochemistry, National Institute of Miners' Health JNARDDC Campus, Wadi, Nagpur, Maharashtra, India
| | - Anand Barapatre
- Department of Biochemistry, National Institute of Miners' Health JNARDDC Campus, Wadi, Nagpur, Maharashtra, India
| | - Minal Trivedi
- B. K. Birla College of Science, Arts & Commerce (Autonomous), Kalyan, Maharashtra, India
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Han KH, Oh DY, Lee S, Lee C, Han JH, Kim MY, Park HR, Park MK, Kim NKD, Lee J, Yi E, Kim JM, Kim JW, Chae JH, Oh SH, Park WY, Choi BY. ATP1A3 mutations can cause progressive auditory neuropathy: a new gene of auditory synaptopathy. Sci Rep 2017; 7:16504. [PMID: 29184165 PMCID: PMC5705773 DOI: 10.1038/s41598-017-16676-9] [Citation(s) in RCA: 37] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/03/2017] [Accepted: 11/16/2017] [Indexed: 12/21/2022] Open
Abstract
The etiologies and prevalence of sporadic, postlingual-onset, progressive auditory neuropathy spectrum disorder (ANSD) have rarely been documented. Thus, we aimed to evaluate the prevalence and molecular etiologies of these cases. Three out of 106 sporadic progressive hearing losses turned out to manifest ANSD. Through whole exome sequencing and subsequent bioinformatics analysis, two out of the three were found to share a de novo variant, p.E818K of ATP1A3, which had been reported to cause exclusively CAPOS (cerebellar ataxia, areflexia, pes cavus, optic atrophy, and sensorineural hearing loss) syndrome. However, hearing loss induced by CAPOS has never been characterized to date. Interestingly, the first proband did not manifest any features of CAPOS, except subclinical areflexia; however, the phenotypes of second proband was compatible with that of CAPOS, making this the first reported CAPOS allele in Koreans. This ANSD phenotype was compatible with known expression of ATP1A3 mainly in the synapse between afferent nerve and inner hair cells. Based on this, cochlear implantation (CI) was performed in the first proband, leading to remarkable benefits. Collectively, the de novo ATP1A3 variant can cause postlingual-onset auditory synaptopathy, making this gene a significant contributor to sporadic progressive ANSD and a biomarker ensuring favorable short-term CI outcomes.
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Affiliation(s)
- Kyu-Hee Han
- Department of Otorhinolaryngology, National Medical Center, Seoul, Korea
| | - Doo-Yi Oh
- Department of Otorhinolaryngology, Seoul National University Bundang Hospital, Seongnam, Korea
| | - Seungmin Lee
- Department of Otorhinolaryngology, Seoul National University Bundang Hospital, Seongnam, Korea
| | - Chung Lee
- Samsung Genome Institute, Samsung Medical Center, Seoul, Korea.,Department of Health Sciences and Technology, Samsung Advanced Institute for Health Sciences and Technology, Sungkyunkwan University, Seoul, Korea
| | - Jin Hee Han
- Department of Otorhinolaryngology, Seoul National University Bundang Hospital, Seongnam, Korea
| | - Min Young Kim
- Department of Otorhinolaryngology, Seoul National University Bundang Hospital, Seongnam, Korea
| | - Hye-Rim Park
- Department of Otorhinolaryngology, Seoul National University Bundang Hospital, Seongnam, Korea
| | - Moo Kyun Park
- Department of Otorhinolaryngology, Seoul National University Hospital, Seoul, Korea
| | - Nayoung K D Kim
- Samsung Genome Institute, Samsung Medical Center, Seoul, Korea
| | - Jaekwang Lee
- Division of Functional Food Research, Korea Food Research Institute (KFRI), Seongnam, Korea
| | - Eunyoung Yi
- College of Pharmacy and Natural Medicine Research Institute, Mokpo National University, Muan, Korea
| | - Jong-Min Kim
- Department of Neurology, Seoul National University Bundang Hospital, Seongnam, Korea
| | - Jeong-Whun Kim
- Department of Otorhinolaryngology, Seoul National University Bundang Hospital, Seongnam, Korea
| | - Jong-Hee Chae
- Department of Pediatrics, Pediatric Clinical Neuroscience Center, Seoul National University Children's Hospital, Seoul, Korea
| | - Seung Ha Oh
- Department of Otorhinolaryngology, Seoul National University Hospital, Seoul, Korea
| | - Woong-Yang Park
- Samsung Genome Institute, Samsung Medical Center, Seoul, Korea.,Department of Health Sciences and Technology, Samsung Advanced Institute for Health Sciences and Technology, Sungkyunkwan University, Seoul, Korea.,Department of Molecular Cell Biology, School of Medicine, Sungkyunkwan University, Seoul, Korea
| | - Byung Yoon Choi
- Department of Otorhinolaryngology, Seoul National University Bundang Hospital, Seongnam, Korea.
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44
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Alkowari MK, Vozzi D, Bhagat S, Krishnamoorthy N, Morgan A, Hayder Y, Logendra B, Najjar N, Gandin I, Gasparini P, Badii R, Girotto G, Abdulhadi K. Targeted sequencing identifies novel variants involved in autosomal recessive hereditary hearing loss in Qatari families. Mutat Res 2017; 800-802:29-36. [PMID: 28501645 DOI: 10.1016/j.mrfmmm.2017.05.001] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/16/2017] [Revised: 04/11/2017] [Accepted: 05/03/2017] [Indexed: 06/07/2023]
Abstract
Hereditary hearing loss is characterized by a very high genetic heterogeneity. In the Qatari population the role of GJB2, the worldwide HHL major player, seems to be quite limited compared to Caucasian populations. In this study we analysed 18 Qatari families affected by non-syndromic hearing loss using a targeted sequencing approach that allowed us to analyse 81 genes simultaneously. Thanks to this approach, 50% of these families (9 out of 18) resulted positive for the presence of likely causative alleles in 6 different genes: CDH23, MYO6, GJB6, OTOF, TMC1 and OTOA. In particular, 4 novel alleles were detected while the remaining ones were already described to be associated to HHL in other ethnic groups. Molecular modelling has been used to further investigate the role of novel alleles identified in CDH23 and TMC1 genes demonstrating their crucial role in Ca2+ binding and therefore possible functional role in proteins. Present study showed that an accurate molecular diagnosis based on next generation sequencing technologies might largely improve molecular diagnostics outcome leading to benefits for both genetic counseling and definition of recurrence risk.
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Affiliation(s)
- Moza K Alkowari
- Division of Experimental Genetics, Sidra Medical and Research Centre, Doha, Qatar
| | - Diego Vozzi
- Medical Genetics, Institute for Maternal and Child Health - IRCCS "Burlo Garofolo", Trieste, Italy
| | | | - Navaneethakrishnan Krishnamoorthy
- Division of Experimental Genetics, Sidra Medical and Research Centre, Doha, Qatar; Heart Science Centre, National Heart and Lung Institute, Imperial College London, United Kingdom
| | - Anna Morgan
- Medical Genetics, Institute for Maternal and Child Health - IRCCS "Burlo Garofolo", Trieste, Italy; Medical Sciences, Chirurgical and Health Department, University of Trieste, Trieste, Italy
| | | | | | | | - Ilaria Gandin
- Medical Genetics, Institute for Maternal and Child Health - IRCCS "Burlo Garofolo", Trieste, Italy
| | - Paolo Gasparini
- Medical Genetics, Institute for Maternal and Child Health - IRCCS "Burlo Garofolo", Trieste, Italy; Medical Sciences, Chirurgical and Health Department, University of Trieste, Trieste, Italy
| | - Ramin Badii
- Molecular Genetics Laboratory, HMC, Doha, Qatar
| | - Giorgia Girotto
- Medical Genetics, Institute for Maternal and Child Health - IRCCS "Burlo Garofolo", Trieste, Italy; Medical Sciences, Chirurgical and Health Department, University of Trieste, Trieste, Italy.
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45
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Riggs WJ, Roche JP, Giardina CK, Harris MS, Bastian ZJ, Fontenot TE, Buchman CA, Brown KD, Adunka OF, Fitzpatrick DC. Intraoperative Electrocochleographic Characteristics of Auditory Neuropathy Spectrum Disorder in Cochlear Implant Subjects. Front Neurosci 2017; 11:416. [PMID: 28769753 PMCID: PMC5515907 DOI: 10.3389/fnins.2017.00416] [Citation(s) in RCA: 35] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/04/2017] [Accepted: 07/04/2017] [Indexed: 11/13/2022] Open
Abstract
Auditory neuropathy spectrum disorder (ANSD) is characterized by an apparent discrepancy between measures of cochlear and neural function based on auditory brainstem response (ABR) testing. Clinical indicators of ANSD are a present cochlear microphonic (CM) with small or absent wave V. Many identified ANSD patients have speech impairment severe enough that cochlear implantation (CI) is indicated. To better understand the cochleae identified with ANSD that lead to a CI, we performed intraoperative round window electrocochleography (ECochG) to tone bursts in children (n = 167) and adults (n = 163). Magnitudes of the responses to tones of different frequencies were summed to measure the "total response" (ECochG-TR), a metric often dominated by hair cell activity, and auditory nerve activity was estimated visually from the compound action potential (CAP) and auditory nerve neurophonic (ANN) as a ranked "Nerve Score". Subjects identified as ANSD (45 ears in children, 3 in adults) had higher values of ECochG-TR than adult and pediatric subjects also receiving CIs not identified as ANSD. However, nerve scores of the ANSD group were similar to the other cohorts, although dominated by the ANN to low frequencies more than in the non-ANSD groups. To high frequencies, the common morphology of ANSD cases was a large CM and summating potential, and small or absent CAP. Common morphologies in other groups were either only a CM, or a combination of CM and CAP. These results indicate that responses to high frequencies, derived primarily from hair cells, are the main source of the CM used to evaluate ANSD in the clinical setting. However, the clinical tests do not capture the wide range of neural activity seen to low frequency sounds.
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Affiliation(s)
- William J Riggs
- Department of Otolaryngology/Head and Neck Surgery, Ohio State University College of MedicineColumbus, OH, United States
| | - Joseph P Roche
- Lab Department of Otolaryngology/Head and Neck Surgery, University of Wisconsin School of MedicineMadison, WI, United States
| | - Christopher K Giardina
- Department of Otolaryngology/Head and Neck Surgery, The University of North Carolina at Chapel Hill School of MedicineChapel Hill, NC, United States
| | - Michael S Harris
- Department of Otolaryngology/Head and Neck Surgery, Ohio State University College of MedicineColumbus, OH, United States
| | - Zachary J Bastian
- Department of Otolaryngology/Head and Neck Surgery, The University of North Carolina at Chapel Hill School of MedicineChapel Hill, NC, United States
| | - Tatyana E Fontenot
- Department of Otolaryngology/Head and Neck Surgery, The University of North Carolina at Chapel Hill School of MedicineChapel Hill, NC, United States
| | - Craig A Buchman
- Department of Otolaryngology/Head and Neck Surgery, Washington University School of Medicine in St. LouisSt. Louis, MO, United States
| | - Kevin D Brown
- Department of Otolaryngology/Head and Neck Surgery, The University of North Carolina at Chapel Hill School of MedicineChapel Hill, NC, United States
| | - Oliver F Adunka
- Department of Otolaryngology/Head and Neck Surgery, Ohio State University College of MedicineColumbus, OH, United States
| | - Douglas C Fitzpatrick
- Department of Otolaryngology/Head and Neck Surgery, The University of North Carolina at Chapel Hill School of MedicineChapel Hill, NC, United States
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46
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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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Tang F, Ma D, Wang Y, Qiu Y, Liu F, Wang Q, Lu Q, Shi M, Xu L, Liu M, Liang J. Novel compound heterozygous mutations in the OTOF Gene identified by whole-exome sequencing in auditory neuropathy spectrum disorder. BMC MEDICAL GENETICS 2017; 18:35. [PMID: 28335750 PMCID: PMC5364697 DOI: 10.1186/s12881-017-0400-0] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 11/14/2016] [Accepted: 03/14/2017] [Indexed: 11/16/2022]
Abstract
Background Many hearing-loss diseases are demonstrated to have Mendelian inheritance caused by mutations in single gene. However, many deaf individuals have diseases that remain genetically unexplained. Auditory neuropathy is a sensorineural deafness in which sounds are able to be transferred into the inner ear normally but the transmission of the signals from inner ear to auditory nerve and brain is injured, also known as auditory neuropathy spectrum disorder (ANSD). The pathogenic mutations of the genes responsible for the Chinese ANSD population remain poorly understood. Methods A total of 127 patients with non-syndromic hearing loss (NSHL) were enrolled in Guangxi Zhuang Autonomous Region. A hereditary deafness gene mutation screening was performed to identify the mutation sites in four deafness-related genes (GJB2, GJB3, 12S rRNA, and SLC26A4). In addition, whole-exome sequencing (WES) was applied to explore unappreciated mutation sites in the cases with the singularity of its phenotype. Results Well-characterized mutations were found in only 8.7% (11/127) of the patients. Interestingly, two mutations in the OTOF gene were identified in two affected siblings with ANSD from a Chinese family, including one nonsense mutation c.1273C > T (p.R425X) and one missense mutation c.4994 T > C (p.L1665P). Furthermore, we employed Sanger sequencing to confirm the mutations in each subject. Two compound heterozygous mutations in the OTOF gene were observed in the two affected siblings, whereas the two parents and unaffected sister were heterozygous carriers of c.1273C > T (father and sister) and c.4994 T > C (mother). The nonsense mutation p.R425X, contributes to a premature stop codon, may result in a truncated polypeptide, which strongly suggests its pathogenicity for ANSD. The missense mutation p.L1665P results in a single amino acid substitution in a highly conserved region. Conclusions Two mutations in the OTOF gene in the Chinese deaf population were recognized for the first time. These findings not only extend the OTOF gene mutation spectrum for ANSD but also indicate that whole-exome sequencing is an effective approach to clarify the genetic characteristics in non-syndromic ANSD patients. Electronic supplementary material The online version of this article (doi:10.1186/s12881-017-0400-0) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- Fengzhu Tang
- Department of Otolaryngology, The People's Hospital of Guangxi Zhuang Autonomous Region, 6 Taoyuan Road, Nanning, 530021, China
| | - Dengke Ma
- CapitalBio Technology Co., Ltd., Building C, Block 88 Kechuang 6th Street, Yizhuang Biomedical Park, Beijing Economic- Technological Development Area, Beijing, 101111, China
| | - Yulan Wang
- CapitalBio Technology Co., Ltd., Building C, Block 88 Kechuang 6th Street, Yizhuang Biomedical Park, Beijing Economic- Technological Development Area, Beijing, 101111, China
| | - Yuecai Qiu
- CapitalBio Technology Co., Ltd., Building C, Block 88 Kechuang 6th Street, Yizhuang Biomedical Park, Beijing Economic- Technological Development Area, Beijing, 101111, China
| | - Fei Liu
- Research Center of Medical Sciences, The People's Hospital of Guangxi Zhuang Autonomous Region, 6 Taoyuan Road, Nanning, 530021, China
| | - Qingqing Wang
- CapitalBio Technology Co., Ltd., Building C, Block 88 Kechuang 6th Street, Yizhuang Biomedical Park, Beijing Economic- Technological Development Area, Beijing, 101111, China
| | - Qiutian Lu
- Department of Otolaryngology, The People's Hospital of Guangxi Zhuang Autonomous Region, 6 Taoyuan Road, Nanning, 530021, China
| | - Min Shi
- Department of Otolaryngology, The People's Hospital of Guangxi Zhuang Autonomous Region, 6 Taoyuan Road, Nanning, 530021, China
| | - Liang Xu
- Department of Otolaryngology, The People's Hospital of Guangxi Zhuang Autonomous Region, 6 Taoyuan Road, Nanning, 530021, China
| | - Min Liu
- Department of Otolaryngology, The People's Hospital of Guangxi Zhuang Autonomous Region, 6 Taoyuan Road, Nanning, 530021, China
| | - Jianping Liang
- Department of Otolaryngology, The People's Hospital of Guangxi Zhuang Autonomous Region, 6 Taoyuan Road, Nanning, 530021, China.
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Harris SL, Kazmierczak M, Pangršič T, Shah P, Chuchvara N, Barrantes-Freer A, Moser T, Schwander M. Conditional deletion of pejvakin in adult outer hair cells causes progressive hearing loss in mice. Neuroscience 2017; 344:380-393. [PMID: 28089576 DOI: 10.1016/j.neuroscience.2016.12.055] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/16/2016] [Revised: 12/27/2016] [Accepted: 12/29/2016] [Indexed: 10/20/2022]
Abstract
Mutations in the Pejvakin (Pjvk) gene cause autosomal recessive hearing loss DFNB59 with audiological features of auditory neuropathy spectrum disorder (ANSD) or cochlear dysfunction. The precise mechanisms underlying the variable clinical phenotypes of DFNB59 remain unclear. Here, we demonstrate that mice with conditional ablation of the Pjvk gene in all sensory hair cells or only in outer hair cells (OHCs) show similar auditory phenotypes with early-onset profound hearing loss. By contrast, loss of Pjvk in adult OHCs causes a slowly progressive hearing loss associated with OHC degeneration and delayed loss of inner hair cells (IHCs), indicating a primary role for pejvakin in regulating OHC function and survival. Consistent with this model, synaptic transmission at the IHC ribbon synapse is largely unaffected in sirtaki mice that carry a C-terminal deletion mutation in Pjvk. Using the C-terminal domain of pejvakin as bait, we identified in a cochlear cDNA library ROCK2, an effector for the small GTPase Rho, and the scaffold protein IQGAP1, involved in modulating actin dynamics. Both ROCK2 and IQGAP1 associate via their coiled-coil domains with pejvakin. We conclude that pejvakin is required to sustain OHC activity and survival in a cell-autonomous manner likely involving regulation of Rho signaling.
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Affiliation(s)
- Suzan L Harris
- Department of Cell Biology and Neuroscience, Rutgers the State University of New Jersey, Piscataway, NJ 08854, United States
| | - Marcin Kazmierczak
- Department of Cell Biology and Neuroscience, Rutgers the State University of New Jersey, Piscataway, NJ 08854, United States
| | - Tina Pangršič
- Institute for Auditory Neuroscience and InnerEarLab, University Medical Center Göttingen, 37099 Göttingen, Germany; Collaborative Research Center 889, University of Göttingen, 37099 Göttingen, Germany
| | - Prahar Shah
- Department of Cell Biology and Neuroscience, Rutgers the State University of New Jersey, Piscataway, NJ 08854, United States
| | - Nadiya Chuchvara
- Department of Cell Biology and Neuroscience, Rutgers the State University of New Jersey, Piscataway, NJ 08854, United States
| | - Alonso Barrantes-Freer
- Institute for Auditory Neuroscience and InnerEarLab, University Medical Center Göttingen, 37099 Göttingen, Germany; Collaborative Research Center 889, University of Göttingen, 37099 Göttingen, Germany
| | - Tobias Moser
- Institute for Auditory Neuroscience and InnerEarLab, University Medical Center Göttingen, 37099 Göttingen, Germany; Collaborative Research Center 889, University of Göttingen, 37099 Göttingen, Germany
| | - Martin Schwander
- Department of Cell Biology and Neuroscience, Rutgers the State University of New Jersey, Piscataway, NJ 08854, United States.
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Affiliation(s)
- Karen B Avraham
- Department of Human Molecular Genetics & Biochemistry, Sackler Faculty of Medicine and Sagol School of Neuroscience, Tel Aviv University, Tel Aviv, Israel
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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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