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Sansović I, Meašić AM, Bobinec A, Morožin Pohovski L, Odak L, Vulin K, Lozić B, Kero M, Huljev Frković S, Pušeljić S. Spectrum of genetic variants in 306 patients with non-syndromic hearing loss from Croatia. Croat Med J 2024; 65:198-208. [PMID: 38868966 PMCID: PMC11157262] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/26/2024] [Accepted: 05/17/2024] [Indexed: 06/14/2024] Open
Abstract
AIM To determine the spectrum and frequency of disease-causing variants in patients with non-syndromic hearing loss (NSHL) and to investigate the diagnostic yield of the applied genetic methods. METHODS The study enrolled 306 unrelated patients with childhood-onset, mild-to-profound NSHL referred to Children's Hospital Zagreb for genetic testing between March 2006 and October 2023. The GJB2 variants were analyzed with the multiplex ligation-dependent probe amplification method and Sanger sequencing of the coding region of the GJB2 gene. In 21 patients negative for GJB2 biallelic variants, clinical exome sequencing (CES) was performed. RESULTS Among 234 disease-associated GJB2 alleles detected, 19 were clinically relevant, of which 18 were reported as pathogenic/likely pathogenic. The c.35delG variant accounted for 73.5% of the mutated alleles. More than half of the patients with biallelic GJB2 variants (64/110, 58.2%) were 35delG homozygotes. Seventeen non-GJB2 variants were found in 10 genes (TECTA, NOG, SLC26A4, PCDH15, TMPRSS3, USH2A, GATA3, MYO15A, SOX10, COL2A1) in 11 participants, and 5 variants (in TECTA, NOG, PCDH15, and SOX10) were novel (29.4%). CONCLUSION We were able to elucidate the genetic cause of hearing loss in 121 patients, with an overall diagnostic rate of 39.5%. The c.35delG was the most common variant. CES allowed us to diagnose almost half of the patients with HL; to distinguish NSHL from the syndromic form of HL in cases where the phenotype was unclear or where symptoms were absent from an early age; and to discover novel variants.
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Affiliation(s)
- Ivona Sansović
- Ivona Sansović, Children's Hospital Zagreb, University of Zagreb, School of Medicine, Department of Medical and Laboratory Genetics, Endocrinology and Diabetology, Klaićeva 16, 10000 Zagreb, Croatia,
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Chen PY, Yang TW, Tseng YS, Tsai CY, Yeh CS, Lee YH, Lin PH, Lin TC, Wu YJ, Yang TH, Chiang YT, Hsu JSJ, Hsu CJ, Chen PL, Chou CF, Wu CC. Machine learning-based longitudinal prediction for GJB2-related sensorineural hearing loss. Comput Biol Med 2024; 176:108597. [PMID: 38763069 DOI: 10.1016/j.compbiomed.2024.108597] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/12/2023] [Revised: 05/09/2024] [Accepted: 05/10/2024] [Indexed: 05/21/2024]
Abstract
BACKGROUND Recessive GJB2 variants, the most common genetic cause of hearing loss, may contribute to progressive sensorineural hearing loss (SNHL). The aim of this study is to build a realistic predictive model for GJB2-related SNHL using machine learning to enable personalized medical planning for timely intervention. METHOD Patients with SNHL with confirmed biallelic GJB2 variants in a nationwide cohort between 2005 and 2022 were included. Different data preprocessing protocols and computational algorithms were combined to construct a prediction model. We randomly divided the dataset into training, validation, and test sets at a ratio of 72:8:20, and repeated this process ten times to obtain an average result. The performance of the models was evaluated using the mean absolute error (MAE), which refers to the discrepancy between the predicted and actual hearing thresholds. RESULTS We enrolled 449 patients with 2184 audiograms available for deep learning analysis. SNHL progression was identified in all models and was independent of age, sex, and genotype. The average hearing progression rate was 0.61 dB HL per year. The best MAE for linear regression, multilayer perceptron, long short-term memory, and attention model were 4.42, 4.38, 4.34, and 4.76 dB HL, respectively. The long short-term memory model performed best with an average MAE of 4.34 dB HL and acceptable accuracy for up to 4 years. CONCLUSIONS We have developed a prognostic model that uses machine learning to approximate realistic hearing progression in GJB2-related SNHL, allowing for the design of individualized medical plans, such as recommending the optimal follow-up interval for this population.
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Affiliation(s)
- Pey-Yu Chen
- Department of Otolaryngology, MacKay Memorial Hospital, Taipei, Taiwan; Department of Audiology and Speech-Language Pathology, Mackay Medical College, New Taipei City, Taiwan; Department of Otolaryngology, National Taiwan University Hospital, Taipei, Taiwan
| | - Ta-Wei Yang
- Graduate Institute of Networking and Multimedia, National Taiwan University, Taipei, Taiwan
| | - Yi-Shan Tseng
- Department of Computer Science & Information Engineering, National Taiwan University, Taipei, Taiwan
| | - Cheng-Yu Tsai
- Department of Otolaryngology, National Taiwan University Hospital, Taipei, Taiwan; Graduate Institute of Medical Genomics and Proteomics, National Taiwan University College of Medicine, Taipei, Taiwan
| | - Chiung-Szu Yeh
- Department of Computer Science & Information Engineering, National Taiwan University, Taipei, Taiwan
| | - Yen-Hui Lee
- Department of Otolaryngology, National Taiwan University Biomedical Park Hospital, Hsinchu County, Taiwan; Department of Otolaryngology, National Taiwan University Hospital Hsin-Chu Branch, Hsinchu City, Taiwan; Hearing and Speech Center, National Taiwan University Hospital, Taipei, Taiwan
| | - Pei-Hsuan Lin
- Department of Otolaryngology, National Taiwan University Hospital, Taipei, Taiwan; Graduate Institute of Clinical Medicine, College of Medicine, National Taiwan University, Taipei, Taiwan
| | - Ting-Chun Lin
- Department of Computer Science & Information Engineering, National Taiwan University, Taipei, Taiwan
| | - Yu-Jen Wu
- Department of Computer Science & Information Engineering, National Taiwan University, Taipei, Taiwan
| | - Ting-Hua Yang
- Department of Otolaryngology, National Taiwan University Hospital, Taipei, Taiwan
| | - Yu-Ting Chiang
- Department of Otolaryngology, National Taiwan University Hospital, Taipei, Taiwan; Graduate Institute of Medical Genomics and Proteomics, National Taiwan University College of Medicine, Taipei, Taiwan
| | - Jacob Shu-Jui Hsu
- Graduate Institute of Medical Genomics and Proteomics, National Taiwan University College of Medicine, Taipei, Taiwan
| | - Chuan-Jen Hsu
- Department of Otolaryngology, National Taiwan University Hospital, Taipei, Taiwan; Department of Otorhinolaryngology-Head and Neck Surgery, Taichung Tzu Chi Hospital, Buddhist Tzu Chi Medical Foundation, Taichung, Taiwan; School of Medicine, Tzu Chi University, Hualien, Taiwan
| | - Pei-Lung Chen
- Graduate Institute of Medical Genomics and Proteomics, National Taiwan University College of Medicine, Taipei, Taiwan; Department of Medical Genetics, National Taiwan University Hospital, Taipei, Taiwan
| | - Chen-Fu Chou
- Department of Computer Science & Information Engineering, National Taiwan University, Taipei, Taiwan
| | - Chen-Chi Wu
- Department of Otolaryngology, National Taiwan University Hospital, Taipei, Taiwan; Department of Medical Genetics, National Taiwan University Hospital, Taipei, Taiwan; Department of Medical Research, National Taiwan University Hospital Hsin-Chu Branch, Hsin-Chu, Taiwan.
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Yen TT, Chen IC, Cho S, Chang TG, Shih KH, Hua MW, Li JL, Hsu CY, Hsiao TH, Chen YM. GJB2 p.V37I Mutation Associated With Moderate Nonsyndromic Hearing Loss in an Adult Taiwanese Population. Ear Hear 2023; 44:1423-1429. [PMID: 37271870 DOI: 10.1097/aud.0000000000001384] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/06/2023]
Abstract
BACKGROUND Gap junction protein beta 2 ( GJB2 ) p.V37I mutations are the most important hereditary cause of sensorineural hearing loss (SNHL) in Taiwan. Hearing outcomes are associated with hearing levels at baseline and the duration of follow-up. However, the audiological features of GJB2 p.V37I mutations in the adult population are unknown. The objectives of the present study were to investigate the audiological features, progression rate, and allele frequency of GJB2 p.V37I mutations among an adult Taiwanese population. METHODS Subjects of this case-control study were chosen from 13,580 participants of the Taiwan Precision Medicine Initiative. The genetic variations of GJB2 p.V37I were determined by polymerase chain reaction. We analyzed existing pure-tone threshold data from 38 individuals who were homozygous or compound heterozygotes for GJB2 p.V37I, 129 who were heterozygotes, and 602 individuals who were wild-type. Phenome-wide association studies (PheWAS) analysis was also performed to identify phenotypes associated with GJB2 p.V37I. RESULTS The minor allele frequency of GJB2 p.V37I was 0.92% in our study population. The mean hearing level of participants with a p.V37I mutation indicated moderate to severe hearing loss with 38.2% ± 22.3% binaural hearing impairment. GJB2 p.V37I was associated with an increased risk of hearing disability (odds ratio: 21.46, 95% confidence interval: 8.62 to 53.44, p < 0.001) in an autosomal recessive pattern. In addition, PheWAS discovered a significant association between GJB2 p.V37I and fracture of the humerus. GJB2 p.V37I is a pathogenic and prevalent variant of SNHL among the adult population. CONCLUSIONS The present study recommends patients with known GJB2 p.V37I mutations receive regular audiometric evaluation and genetic counseling. Early assistive listening device intervention is suggested to improve the quality of hearing.
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Affiliation(s)
- Ting-Ting Yen
- Department of Otolaryngology, Taichung Veterans General Hospital, Taichung, Taiwan
- School of Medicine, College of Medicine, National Yang-Ming Chiao Tung University, Taipei, Taiwan
| | - I-Chieh Chen
- Department of Medical Research, Taichung Veterans General Hospital, Taichung, Taiwan
| | - Sudi Cho
- Department of Neurobiology, Physiology and Behavior, College of Biological Sciences, University of California, Davis, California, USA
| | - Ting-Gang Chang
- Department of Psychiatry, Taichung Veterans General Hospital, Taichung, Taiwan
- Department of Psychology, School of Psychology,Chung Shan Medical University, Taichung, Taiwan
- Department of Post-Baccalaureate Medicine, College of Medicine, National Chung Hsing University, Taichung, Taiwan
| | - Kai-Hsiang Shih
- Department of Otolaryngology, Taichung Veterans General Hospital, Taichung, Taiwan
| | - Men-Wei Hua
- Department of Otolaryngology, Taichung Veterans General Hospital, Taichung, Taiwan
| | - Jui-Lin Li
- Department of Otolaryngology, Taichung Veterans General Hospital, Taichung, Taiwan
| | - Chiann-Yi Hsu
- Department of Medical Research, Taichung Veterans General Hospital, Taichung, Taiwan
| | - Tzu-Hung Hsiao
- Department of Medical Research, Taichung Veterans General Hospital, Taichung, Taiwan
- Department of Public Health, College of Medicine, Fu Jen Catholic University, New Taipei City, Taiwan
- Institute of Genomics and Bioinformatics, College of Life Sciences, National Chung Hsing University, Taichung, Taiwan
| | - Yi-Ming Chen
- School of Medicine, College of Medicine, National Yang-Ming Chiao Tung University, Taipei, Taiwan
- Department of Medical Research, Taichung Veterans General Hospital, Taichung, Taiwan
- Division of Allergy, Immunology, and Rheumatology, Department of Internal Medicine, Taichung Veterans General Hospital, Taichung, Taiwan
- Department of Post-Baccalaureate Medicine, College of Medicine, National Chung Hsing University, Taichung, Taiwan
- Ph.D. Program in Translational Medicine and Rong Hsing Research Center for Translational Medicine, College of Life Sciences, National Chung Hsing University, Taiwan
- Precision Medicine Research Center, College of Medicine, College of Medicine, National Chung Hsing University, Taichung, Taiwan
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Pshennikova VG, Teryutin FM, Cherdonova AM, Borisova TV, Solovyev AV, Romanov GP, Morozov IV, Bondar AA, Posukh OL, Fedorova SA, Barashkov NA. The GJB2 (Cx26) Gene Variants in Patients with Hearing Impairment in the Baikal Lake Region (Russia). Genes (Basel) 2023; 14:genes14051001. [PMID: 37239361 DOI: 10.3390/genes14051001] [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: 03/25/2023] [Revised: 04/22/2023] [Accepted: 04/25/2023] [Indexed: 05/28/2023] Open
Abstract
The GJB2 (Cx26) gene pathogenic variants are associated with autosomal recessive deafness type 1A (DFNB1A, OMIM #220290). Direct sequencing of the GJB2 gene among 165 hearing-impaired individuals living in the Baikal Lake region of Russia identified 14 allelic variants: pathogenic/likely pathogenic-nine variants, benign-three variants, unclassified-one variant, and one novel variant. The contribution of the GJB2 gene variants to the etiology of hearing impairment (HI) in the total sample of patients was 15.8% (26 out of 165) and significantly differed in patients of different ethnicity (5.1% in Buryat patients and 28.9% in Russian patients). In patients with DFNB1A (n = 26), HIs were congenital/early onset (92.3%), symmetric (88.5%), sensorineural (100.0%), and variable in severity (moderate-11.6%, severe-26.9% or profound-61.5%). The reconstruction of the SNP haplotypes with three frequent GJB2 pathogenic variants (c.-23+1G>A, c.35delG or c.235delC), in comparison with previously published data, supports a major role of the founder effect in the expansion of the c.-23+1G>A and c.35delG variants around the world. Comparative analysis of the haplotypes with c.235delC revealed one major haplotype G A C T (97.5%) in Eastern Asians (Chinese, Japanese and Korean patients) and two haplotypes, G A C T (71.4%) and G A C C (28.6%), in Northern Asians (Altaians, Buryats and Mongols). The variable structure of the c.235delC-haplotypes in Northern Asians requires more studies to expand our knowledge about the origin of this pathogenic variant.
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Affiliation(s)
- Vera G Pshennikova
- Laboratory of Molecular Genetics, Yakut Science Centre of Complex Medical Problems, Yaroslavskogo 6/3, 677019 Yakutsk, Russia
| | - Fedor M Teryutin
- Laboratory of Molecular Genetics, Yakut Science Centre of Complex Medical Problems, Yaroslavskogo 6/3, 677019 Yakutsk, Russia
| | - Alexandra M Cherdonova
- Laboratory of Molecular Biology, Institute of Natural Sciences, M.K. Ammosov North-Eastern Federal University, Kulakovskogo 46, 677010 Yakutsk, Russia
| | - Tuyara V Borisova
- Laboratory of Molecular Biology, Institute of Natural Sciences, M.K. Ammosov North-Eastern Federal University, Kulakovskogo 46, 677010 Yakutsk, Russia
| | - Aisen V Solovyev
- Laboratory of Molecular Biology, Institute of Natural Sciences, M.K. Ammosov North-Eastern Federal University, Kulakovskogo 46, 677010 Yakutsk, Russia
| | - Georgii P Romanov
- Laboratory of Molecular Biology, Institute of Natural Sciences, M.K. Ammosov North-Eastern Federal University, Kulakovskogo 46, 677010 Yakutsk, Russia
| | - Igor V Morozov
- Novosibirsk State University, 630090 Novosibirsk, Russia
- Institute of Chemical Biology and Fundamental Medicine, Siberian Branch of the Russian Academy of Sciences, 630090 Novosibirsk, Russia
| | - Alexander A Bondar
- Institute of Chemical Biology and Fundamental Medicine, Siberian Branch of the Russian Academy of Sciences, 630090 Novosibirsk, Russia
| | - Olga L Posukh
- Novosibirsk State University, 630090 Novosibirsk, Russia
- Federal Research Center Institute of Cytology and Genetics, Siberian Branch of the Russian Academy of Sciences, 630090 Novosibirsk, Russia
| | - Sardana A Fedorova
- Laboratory of Molecular Genetics, Yakut Science Centre of Complex Medical Problems, Yaroslavskogo 6/3, 677019 Yakutsk, Russia
- Laboratory of Molecular Biology, Institute of Natural Sciences, M.K. Ammosov North-Eastern Federal University, Kulakovskogo 46, 677010 Yakutsk, Russia
| | - Nikolay A Barashkov
- Laboratory of Molecular Genetics, Yakut Science Centre of Complex Medical Problems, Yaroslavskogo 6/3, 677019 Yakutsk, Russia
- Laboratory of Molecular Biology, Institute of Natural Sciences, M.K. Ammosov North-Eastern Federal University, Kulakovskogo 46, 677010 Yakutsk, Russia
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Riza AL, Alkhzouz C, Farcaș M, Pîrvu A, Miclea D, Mihuț G, Pleșea RM, Ștefan D, Drodar M, Lazăr C, Study OBOTHINT, Study OBOTFUSE, Ioana M, Popp R. Non-Syndromic Hearing Loss in a Romanian Population: Carrier Status and Frequent Variants in the GJB2 Gene. Genes (Basel) 2022; 14:69. [PMID: 36672810 PMCID: PMC9858611 DOI: 10.3390/genes14010069] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/17/2022] [Revised: 12/16/2022] [Accepted: 12/22/2022] [Indexed: 12/28/2022] Open
Abstract
The genetic causes of autosomal recessive nonsyndromic hearing loss (ARNSHL) are heterogeneous and highly ethnic-specific. We describe GJB2 (connexin 26) variants and carrier frequencies as part of our study and summarize previously reported ones for the Romanian population. In total, 284 unrelated children with bilateral congenital NSHL were enrolled between 2009 and 2018 in northwestern Romania. A tiered diagnostic approach was used: all subjects were tested for c.35delG, c.71G>A and deletions in GJB6 (connexin 30) using PCR-based methods. Furthermore, 124 cases undiagnosed at this stage were analyzed by multiplex-ligation-dependent probe amplifications (MLPA), probe mix P163, and sequencing of GJB2 exon 2. Targeted allele-specific PCR/restriction fragment length polymorphism (RFLP) established definite ethio-pathogenical diagnosis for 72/284 (25.35%) of the cohort. Out of the 124 further analyzed, in 12 cases (9.67%), we found compound heterozygous point mutations in GJB2. We identified one case of deletion of exon 1 of the WFS1 (wolframin) gene. Carrier status evaluation used Illumina Infinium Global Screening Array (GSA) genotyping: the HINT cohort-416 individuals in northwest Romania, and the FUSE cohort-472 individuals in southwest Romania. GSA variants yielded a cumulated risk allele presence of 0.0284. A tiered diagnostic approach may be efficient in diagnosing ARNSHL. The summarized contributions to Romanian descriptive epidemiology of ARNSHL shows that pathogenic variants in the GJB2 gene are frequent among NSHL cases and have high carrier rates, especially for c.35delG and c.71G>A. These findings may serve in health strategy development.
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Affiliation(s)
- Anca-Lelia Riza
- Regional Centre of Medical Genetics Dolj, Emergency County Hospital Craiova, 200642 Craiova, Romania
- Laboratory of Human Genomics, University of Medicine and Pharmacy of Craiova, 200638 Craiova, Romania
| | - Camelia Alkhzouz
- First Pediatric Department, “Iuliu Hatieganu” University of Medicine and Pharmacy, 400012 Cluj-Napoca, Romania
- Clinical Emergency Hospital for Children, 400394 Cluj-Napoca, Romania
| | - Marius Farcaș
- Molecular Sciences Department, “Iuliu Hatieganu” University of Medicine and Pharmacy, 400012 Cluj-Napoca, Romania
| | - Andrei Pîrvu
- Regional Centre of Medical Genetics Dolj, Emergency County Hospital Craiova, 200642 Craiova, Romania
- Laboratory of Human Genomics, University of Medicine and Pharmacy of Craiova, 200638 Craiova, Romania
| | - Diana Miclea
- First Pediatric Department, “Iuliu Hatieganu” University of Medicine and Pharmacy, 400012 Cluj-Napoca, Romania
- Clinical Emergency Hospital for Children, 400394 Cluj-Napoca, Romania
| | - Gheorghe Mihuț
- ENT Department, Clinical Emergency Hospital for Children, 400394 Cluj-Napoca, Romania
| | - Răzvan-Mihail Pleșea
- Regional Centre of Medical Genetics Dolj, Emergency County Hospital Craiova, 200642 Craiova, Romania
- Laboratory of Human Genomics, University of Medicine and Pharmacy of Craiova, 200638 Craiova, Romania
| | - Delia Ștefan
- Molecular Sciences Department, “Iuliu Hatieganu” University of Medicine and Pharmacy, 400012 Cluj-Napoca, Romania
| | - Mihaela Drodar
- Laboratory of Human Genomics, University of Medicine and Pharmacy of Craiova, 200638 Craiova, Romania
| | - Călin Lazăr
- First Pediatric Department, “Iuliu Hatieganu” University of Medicine and Pharmacy, 400012 Cluj-Napoca, Romania
- Clinical Emergency Hospital for Children, 400394 Cluj-Napoca, Romania
| | | | | | - Mihai Ioana
- Regional Centre of Medical Genetics Dolj, Emergency County Hospital Craiova, 200642 Craiova, Romania
- Laboratory of Human Genomics, University of Medicine and Pharmacy of Craiova, 200638 Craiova, Romania
| | - Radu Popp
- Molecular Sciences Department, “Iuliu Hatieganu” University of Medicine and Pharmacy, 400012 Cluj-Napoca, Romania
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Predictors of Early Language Outcomes in Children with Connexin 26 Hearing Loss across Three Countries. CHILDREN 2022; 9:children9070990. [PMID: 35883974 PMCID: PMC9324687 DOI: 10.3390/children9070990] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 05/30/2022] [Revised: 06/28/2022] [Accepted: 06/28/2022] [Indexed: 11/16/2022]
Abstract
GJB2-associated hearing loss (GJB2-HL) is the most common genetic cause of hearing loss in children. However, little is known about the clinical characteristics and early language outcomes in population-oriented samples including children with different degrees of hearing loss. Insight into these characteristics are relevant for the counselling of parents. Our sample consisted of 66 children at approximately 2 years of age (17–32 months) with bilateral hearing loss due to GJB2 from three population-based cohorts in Austria, Australia and the Netherlands. Predictors of early vocabulary, including demographic, audiological, genetic and intervention variables and the role of medical comorbidities and nonverbal cognition were examined. The vocabulary scores of children with GJB2-HL were approximately 0.7 standard deviations (SDs) below the norms of children with typical hearing. Age at access to family-centered early intervention and first-born position among siblings predicted language outcomes, whereas the degree of hearing loss and genetic subtype were not significantly correlated with expressive vocabulary. In children with GJB2-HL, early access to family-centered early intervention significantly affected language outcomes at the age of two.
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Dia Y, Adadey SM, Diop JPD, Aboagye ET, Ba SA, De Kock C, Ly CAT, Oluwale OG, Sène ARG, Sarr PD, Diallo BK, Diallo RN, Wonkam A. GJB2 Is a Major Cause of Non-Syndromic Hearing Impairment in Senegal. BIOLOGY 2022; 11:795. [PMID: 35625523 PMCID: PMC9138795 DOI: 10.3390/biology11050795] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 04/26/2022] [Revised: 05/16/2022] [Accepted: 05/17/2022] [Indexed: 11/29/2022]
Abstract
This study aimed to investigate GJB2 (MIM: 121011) and GJB6 (MIM: 604418) variants associated with familial non-syndromic hearing impairment (HI) in Senegal. We investigated a total of 129 affected and 143 unaffected individuals from 44 multiplex families by segregating autosomal recessive non-syndromic HI, 9 sporadic HI cases of putative genetic origin, and 148 control individuals without personal or family history of HI. The DNA samples were screened for GJB2 coding-region variants and GJB6-D3S1830 deletions. The mean age at the medical diagnosis of the affected individuals was 2.93 ± 2.53 years [range: 1−15 years]. Consanguinity was present in 40 out of 53 families (75.47%). Variants in GJB2 explained HI in 34.1% (n = 15/44) of multiplex families. A bi-allelic pathogenic variant, GJB2: c.94C>T: p.(Arg32Cys) accounted for 25% (n = 11/44 families) of familial cases, of which 80% (n = 12/15) were consanguineous. Interestingly, the previously reported “Ghanaian” founder variant, GJB2: c.427C>T: p.(Arg143Trp), accounted for 4.5% (n = 2/44 families) of the families investigated. Among the normal controls, the allele frequency of GJB2: c.94C>T and GJB2: c.427C>T was estimated at 1% (2/148 ∗ 2) and 2% (4/148 ∗ 2), respectively. No GJB6-D3S1830 deletion was identified in any of the HI patients. This is the first report of a genetic investigation of HI in Senegal, and suggests that GJB2: c.94C>T: p.(Arg32Cys) and GJB2: c.427C>T: p.(Arg143Trp) should be tested in clinical practice for congenital HI in Senegal.
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Affiliation(s)
- Yacouba Dia
- Division of Human Genetics, Faculty of Medicine, Pharmacy and Odontology, University Cheikh Anta Diop (UCAD), Dakar 10700, Senegal; (Y.D.); (J.P.D.D.); (S.A.B.); (C.A.T.L.); (A.R.G.S.); (P.D.S.), (R.N.D.)
| | - Samuel Mawuli Adadey
- Division of Human Genetics, Faculty of Health Sciences, University of Cape Town, Cape Town 7925, South Africa; (S.M.A.); (E.T.A.); (C.D.K.); (O.G.O.)
- West African Centre for Cell Biology of Infectious Pathogens (WACCBIP), University of Ghana, Legon, Accra P.O. Box LG 54, Ghana
| | - Jean Pascal Demba Diop
- Division of Human Genetics, Faculty of Medicine, Pharmacy and Odontology, University Cheikh Anta Diop (UCAD), Dakar 10700, Senegal; (Y.D.); (J.P.D.D.); (S.A.B.); (C.A.T.L.); (A.R.G.S.); (P.D.S.), (R.N.D.)
| | - Elvis Twumasi Aboagye
- Division of Human Genetics, Faculty of Health Sciences, University of Cape Town, Cape Town 7925, South Africa; (S.M.A.); (E.T.A.); (C.D.K.); (O.G.O.)
| | - Seydi Abdoul Ba
- Division of Human Genetics, Faculty of Medicine, Pharmacy and Odontology, University Cheikh Anta Diop (UCAD), Dakar 10700, Senegal; (Y.D.); (J.P.D.D.); (S.A.B.); (C.A.T.L.); (A.R.G.S.); (P.D.S.), (R.N.D.)
| | - Carmen De Kock
- Division of Human Genetics, Faculty of Health Sciences, University of Cape Town, Cape Town 7925, South Africa; (S.M.A.); (E.T.A.); (C.D.K.); (O.G.O.)
| | - Cheikh Ahmed Tidjane Ly
- Division of Human Genetics, Faculty of Medicine, Pharmacy and Odontology, University Cheikh Anta Diop (UCAD), Dakar 10700, Senegal; (Y.D.); (J.P.D.D.); (S.A.B.); (C.A.T.L.); (A.R.G.S.); (P.D.S.), (R.N.D.)
| | - Oluwafemi Gabriel Oluwale
- Division of Human Genetics, Faculty of Health Sciences, University of Cape Town, Cape Town 7925, South Africa; (S.M.A.); (E.T.A.); (C.D.K.); (O.G.O.)
| | - Andrea Regina Gnilane Sène
- Division of Human Genetics, Faculty of Medicine, Pharmacy and Odontology, University Cheikh Anta Diop (UCAD), Dakar 10700, Senegal; (Y.D.); (J.P.D.D.); (S.A.B.); (C.A.T.L.); (A.R.G.S.); (P.D.S.), (R.N.D.)
| | - Pierre Diaga Sarr
- Division of Human Genetics, Faculty of Medicine, Pharmacy and Odontology, University Cheikh Anta Diop (UCAD), Dakar 10700, Senegal; (Y.D.); (J.P.D.D.); (S.A.B.); (C.A.T.L.); (A.R.G.S.); (P.D.S.), (R.N.D.)
| | - Bay Karim Diallo
- Department of Oto-Rhino-Laryngology, Albert Royer Children’s Hospital, Dakar 10700, Senegal;
| | - Rokhaya Ndiaye Diallo
- Division of Human Genetics, Faculty of Medicine, Pharmacy and Odontology, University Cheikh Anta Diop (UCAD), Dakar 10700, Senegal; (Y.D.); (J.P.D.D.); (S.A.B.); (C.A.T.L.); (A.R.G.S.); (P.D.S.), (R.N.D.)
| | - Ambroise Wonkam
- Division of Human Genetics, Faculty of Health Sciences, University of Cape Town, Cape Town 7925, South Africa; (S.M.A.); (E.T.A.); (C.D.K.); (O.G.O.)
- McKusick-Nathans Institute and Department of Genetic Medicine, Johns-Hopskins University School of Medicine, Baltimore, MD 21205, USA
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Stepanova AA, Ismagilova OR, Galeeva NM, Markova TG, Tavartkiladze GA, Kvlividze O, Polyakov AV. Molecular Genetic Study of the Causes of Nonsyndromic Sensorineural Hearing Loss in Patients from Georgia. RUSS J GENET+ 2022. [DOI: 10.1134/s1022795422050106] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
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9
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Connexin Mutations and Hereditary Diseases. Int J Mol Sci 2022; 23:ijms23084255. [PMID: 35457072 PMCID: PMC9027513 DOI: 10.3390/ijms23084255] [Citation(s) in RCA: 15] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/05/2022] [Revised: 04/04/2022] [Accepted: 04/09/2022] [Indexed: 02/01/2023] Open
Abstract
Inherited diseases caused by connexin mutations are found in multiple organs and include hereditary deafness, congenital cataract, congenital heart diseases, hereditary skin diseases, and X-linked Charcot–Marie–Tooth disease (CMT1X). A large number of knockout and knock-in animal models have been used to study the pathology and pathogenesis of diseases of different organs. Because the structures of different connexins are highly homologous and the functions of gap junctions formed by these connexins are similar, connexin-related hereditary diseases may share the same pathogenic mechanism. Here, we analyze the similarities and differences of the pathology and pathogenesis in animal models and find that connexin mutations in gap junction genes expressed in the ear, eye, heart, skin, and peripheral nerves can affect cellular proliferation and differentiation of corresponding organs. Additionally, some dominant mutations (e.g., Cx43 p.Gly60Ser, Cx32 p.Arg75Trp, Cx32 p.Asn175Asp, and Cx32 p.Arg142Trp) are identified as gain-of-function variants in vivo, which may play a vital role in the onset of dominant inherited diseases. Specifically, patients with these dominant mutations receive no benefits from gene therapy. Finally, the complete loss of gap junctional function or altered channel function including permeability (ions, adenosine triphosphate (ATP), Inositol 1,4,5-trisphosphate (IP3), Ca2+, glucose, miRNA) and electric activity are also identified in vivo or in vitro.
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Molina Romero M, Yoldi Chaure A, Gañán Parra M, Navas Bastida P, del Pico Sánchez JL, Vaquero Argüelles Á, de la Fuente Vaquero P, Ramírez López JP, Castilla Alcalá JA. Probability of high-risk genetic matching with oocyte and semen donors: complete gene analysis or genotyping test? J Assist Reprod Genet 2022; 39:341-355. [PMID: 35091964 PMCID: PMC8956772 DOI: 10.1007/s10815-021-02381-0] [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: 03/29/2021] [Accepted: 12/17/2021] [Indexed: 02/03/2023] Open
Abstract
PURPOSE To estimate the probability of high-risk genetic matching when assisted reproductive techniques (ART) are applied with double gamete donation, following an NGS carrier test based on a complete study of the genes concerned. We then determine the results that would have been obtained if the genotyping tests most widely used in Spanish gamete banks had been applied. METHODS In this descriptive observational study, 1818 gamete donors were characterised by NGS. The pathogenic variants detected were analysed to estimate the probability of high-risk genetic matching and to determine the results that would have been obtained if the three most commonly used genotyping tests in ART had been applied. RESULTS The probability of high-risk genetic matching with gamete donation, screened by NGS and complete gene analysis, was 5.5%, versus the 0.6-2.7% that would have been obtained with the genotyping test. A total of 1741 variants were detected, including 607 different variants, of which only 22.6% would have been detected by all three genotyping tests considered and 44.7% of which would not have been detected by any of these tests. CONCLUSION Our study highlights the considerable heterogeneity of the genotyping tests, which present significant differences in their ability to detect pathogenic variants. The complete study of the genes by NGS considerably reduces reproductive risks when genetic matching is performed with gamete donors. Accordingly, we recommend that carrier screening in gamete donors be carried out using NGS and a complete study with nontargeted analysis of the variants of the screened genes.
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Affiliation(s)
- Marta Molina Romero
- CEIFER Biobanco - NextClinics, Calle Maestro Bretón, 1, 18004 Granada, Spain
| | | | | | | | | | | | | | | | - José Antonio Castilla Alcalá
- CEIFER Biobanco - NextClinics, Calle Maestro Bretón, 1, 18004 Granada, Spain ,U. Reproducción, UGC Obstetricia y Ginecología, HU Virgen de Las Nieves, Granada, Spain ,Instituto de Investigación Biosanitaria Ibs.Granada, Granada, Spain
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11
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Abstract
Hearing loss (HL) is an etiologically heterogeneous disorder that affects around 5% of the world's population. There has been an exponential increase in the identification of genes and variants responsible for hereditary HL over recent years. Iran, a country located in the Middle East, has a high prevalence of consanguineous marriages, so heterogeneous diseases such as HL are more common. Comprehensive studies using different strategies from linkage analysis to next-generation sequencing, especially exome-sequencing, have achieved significant success in identifying possible pathogens in deaf Iranian families. About 12% of non-syndromic autosomal recessive HL genes investigated to date, were first identified in families from Iran. Variations of 56 genes have been observed in families with NSHL in Iran. Variants in GJB2, SLC26A4, MYO15A, MYO7A, CDH23, and TMC1 account for 16.5%, 16.25%, 13.5%, 9.35%, 6.9% and 4.92%, cases of NSHL, respectively. In summary, there are also different diagnostic rates between studies conducted in Iran. In the comprehensive investigations conducted by the Genetic Research Center of the University of Social Welfare and Rehabilitation Sciences over the past 20 years, the overall diagnosis rate is about 80% while there are other studies with lower diagnostic rates which could reflect differences in project designs, sampling, and accuracy and validity of the methods used. Furthermore, there are several syndromic HHLs in Iran including, Waardenburg syndrome, BOR syndrome, Brown-Vialetto-Van Laere syndrome, Wolfram syndrome, among which Pendred and Usher syndromes are well-studied. These results are of importance for further investigation and elucidation of the molecular basis of HHL in Iran.
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12
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Preimplantation Genetic Diagnosis in Hereditary Hearing Impairment. Diagnostics (Basel) 2021; 11:diagnostics11122395. [PMID: 34943631 PMCID: PMC8700639 DOI: 10.3390/diagnostics11122395] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/21/2021] [Revised: 12/16/2021] [Accepted: 12/16/2021] [Indexed: 01/19/2023] Open
Abstract
Sensorineural hearing impairment is a common sensory deficit in children and more than 50% of these cases are caused by genetic etiologies, that is, hereditary hearing impairment (HHI). Recent advances in genomic medicine have revolutionized the diagnostics of, and counseling for, HHI, including preimplantation genetic diagnosis (PGD), thus providing parents-to-be with better reproductive choices. Over the past decade, we have performed PGD using the amplification refractory mutation system quantitative polymerase chain reaction (ARMS-qPCR) technique in 11 couples with a history of HHI, namely eight with GJB2 variants, one with OTOF variants, one with SLC26A4 variants, and one with an MITF variant. We demonstrated that PGD can be successfully applied to HHI of different inheritance modes, namely autosomal dominant or recessive, and phenotypes, namely syndromic or non-syndromic HHI. However, certain ethical concerns warrant scrutiny before PGD can be widely applied to at-risk couples with a history of HHI.
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13
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Arias S, Paradisi I, Hernández A, Kanzler D. Undescribed GJB2 c.35dupG homozygous prelingual distinguished from c.35delG homozygous/compound heterozygous deafs, dwelling a German ancestry Venezuelan isolate. EGYPTIAN JOURNAL OF MEDICAL HUMAN GENETICS 2021. [DOI: 10.1186/s43042-021-00159-8] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022] Open
Abstract
Abstract
Background
Among ten hearing-impaired (HI) families mostly of German descent dwelling the Venezuelan isolate Colonia Tovar, which were initially studied several decades ago to assess the etiology of their profound/prelingual nonsyndromic deafness phenotype, an undescribed genotype/phenotype was found. Forty-eight subjects, including 8 of the still living 143 originally searched with audiograms 4 decades ago, were retested and their DNA collected. A genomic search of 27 loci involved in HI was performed on a randomly chosen prelingual deaf patient. Subsequently, GJB2 sequencing was performed in all subjects from each pedigree. Haplotypes were constructed with five intragenic GJB2 SNPs (rs117685390, rs7994748, rs2274084, rs2274083, and rs3751385). Audiograms performed along 5 decades were compared to evaluate age-related hearing loss in the different genotypes found in the population.
Results
Three prelingual deaf siblings, having the highest recorded symmetrical hearing loss of all the known affected in the isolate, carried the very rare mutation c.35dupG (p.V13Cfs*35) at GJB2 in a homozygous condition. Two additional GJB2 mutations were identified (p.W77R and c.35delG) in the isolate. Allelic disequilibrium in both c.35dupG and p.W77R carriers (with in-phase haplotype T;T;G;A;C) were found, although not so in the 2 other found c.35delG independent haplotypes. A compound heterozygote in trans (c.35delG/c.35dupG) was audiometrically distinguishable from both the c.35dupG and c.35delG homozygotes.
Conclusions
A relatively higher frequency of mutation of c.35dupG found than elsewhere was retrospectively inferred for the ancient population of the Kaiserstuhl region in Germany, having an opposite epidemiological situation to the one found with the contiguous and very frequent c.35delG. Haplotype analysis suggests founder phenomena and independent occurrence, hundreds of generations back in Caucasoid populations for both mutations.
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14
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Murtaza M, Zargar MH, Ali O, Khan IS, Ali MN. Spectrum and frequency of connexin 26 & connexin 30 gene mutations in patients with congenital hearing loss from Ladakh India. Meta Gene 2021. [DOI: 10.1016/j.mgene.2021.100960] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022] Open
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Hosoya M, Fujioka M, Nara K, Morimoto N, Masuda S, Sugiuchi T, Katsunuma S, Takagi A, Morita N, Ogawa K, Kaga K, Matsunaga T. Investigation of the hearing levels of siblings affected by a single GJB2 variant: Possibility of genetic modifiers. Int J Pediatr Otorhinolaryngol 2021; 149:110840. [PMID: 34293626 DOI: 10.1016/j.ijporl.2021.110840] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/19/2021] [Revised: 05/25/2021] [Accepted: 07/11/2021] [Indexed: 11/25/2022]
Abstract
OBJECTIVE Variants in GJB2 can cause autosomal recessive deafness (DFNB1). There is evidence for genotype-phenotype correlations of GJB2 variants; however, several genotypes can cause varying levels of hearing loss likely attributable to differences in genetic or environmental background. As siblings share approximately 50% of their genetic background and usually have a common environmental background, analysis of phenotypes of siblings with a specific GJB2 variant may reveal factors relevant to phenotypic variation. There have been no previous analyses of differences in hearing among siblings carrying a single GJB2 genotype. Here, we investigated hearing differences between siblings with a single GJB2 variant, which can cause various levels of hearing loss. METHODS We examined hearing levels in 16 pairs of siblings homozygous for the c.235delC variant of GJB2. Differences in hearing acuity between sibling pairs were detected by auditory evaluation. RESULTS Average differences in acoustic threshold >30 dB were observed between five pairs of siblings, whereas the remaining 11 pairs had average threshold values within approximately 10 dB of one another. Hearing loss varied from moderate to profound. CONCLUSION Our results indicate that auditory acuity associated with homozygosity for GJB2 c.235delC can vary in degree; however, in approximately 70% of younger siblings, it was approximately the same as that in the first child, despite a diverse spectrum of hearing loss among different families. These results suggest that differences in genetic background may modify the phenotype associated with homozygous GJB2 c.235delC.
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Affiliation(s)
- Makoto Hosoya
- Department of Otorhinolaryngology, Head and Neck Surgery, School of Medicine, Keio University, 35 Shinanomachi, Shinjuku-ku, Tokyo, 160-8582, Japan
| | - Masato Fujioka
- Department of Otorhinolaryngology, Head and Neck Surgery, School of Medicine, Keio University, 35 Shinanomachi, Shinjuku-ku, Tokyo, 160-8582, Japan
| | - Kiyomitsu Nara
- Division of Hearing and Balance Research, National Institute of Sensory Organs, National Hospital Organization Tokyo Medical Center, 2-5-1 Higashigaoka, Meguro-ku, Tokyo, 152-8902, Japan
| | - Noriko Morimoto
- Department of Otorhinolaryngology, National Center for Child Health and Development, 2-10-1 Okura, Setagaya-ku, Tokyo, 157-8535, Japan
| | - Sawako Masuda
- Department of Otorhinolaryngology, National Hospital Organization Mie National Hospital, 357 Osato-Kubota, Tsu, Mie, 514-0125, Japan
| | - Tomoko Sugiuchi
- Department of Otorhinolaryngology, Kanto Rosai Hospital, 1-1 Kizukisumiyoshi-cho, Nakahara-ku, Kawasaki-shi, Kanagawa, 211-8510, Japan
| | - Sayaka Katsunuma
- Department of Otorhinolaryngology, Hyogo Prefectural Kobe Children's Hospital, 1-6-7 Minatojima-minamimachi, Chuo-ku, Kobe-shi, Hyogo, 650-0047, Japan
| | - Akira Takagi
- Department of Otorhinolaryngology, Shizuoka General Hospital, 4-27-1 Kita Ando Aoi-ku, Shizuoka-shi, Shizuoka, 420-8527, Japan
| | - Noriko Morita
- Department of Otorhinolaryngology, Teikyo University Hospital, 2-11-1 Kaga, Itabashi-Ku, Tokyo, 173-8606, Japan; Department of Otorhinolaryngology, Kobari General Hospital, 29-1 Yokouchi, Noda, Chiba, 278-8501, Japan
| | - Kaoru Ogawa
- Department of Otorhinolaryngology, Head and Neck Surgery, School of Medicine, Keio University, 35 Shinanomachi, Shinjuku-ku, Tokyo, 160-8582, Japan
| | - Kimitaka Kaga
- Division of Hearing and Balance Research, National Institute of Sensory Organs, National Hospital Organization Tokyo Medical Center, 2-5-1 Higashigaoka, Meguro-ku, Tokyo, 152-8902, Japan
| | - Tatsuo Matsunaga
- Division of Hearing and Balance Research, National Institute of Sensory Organs, National Hospital Organization Tokyo Medical Center, 2-5-1 Higashigaoka, Meguro-ku, Tokyo, 152-8902, Japan; Medical Genetics Center, National Hospital Organization Tokyo Medical Center, 2-5-1 Higashigaoka, Meguro-ku, Tokyo, 152-8902, Japan.
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Resmerita I, Cozma RS, Popescu R, Radulescu LM, Panzaru MC, Butnariu LI, Caba L, Ilie OD, Gavril EC, Gorduza EV, Rusu C. Genetics of Hearing Impairment in North-Eastern Romania-A Cost-Effective Improved Diagnosis and Literature Review. Genes (Basel) 2020; 11:genes11121506. [PMID: 33333757 PMCID: PMC7765194 DOI: 10.3390/genes11121506] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/30/2020] [Revised: 12/05/2020] [Accepted: 12/12/2020] [Indexed: 12/17/2022] Open
Abstract
Background: We have investigated the main genetic causes for non-syndromic hearing impairment (NSHI) in the hearing impairment individuals from the North-Eastern Romania and proposed a cost-effective diagnosis protocol. Methods: MLPA followed by Sanger Sequencing were used for all 291 patients included in this study. Results: MLPA revealed abnormal results in 141 cases (48.45%): 57 (40.5%) were c.35delG homozygous, 26 (18.44%) were c.35delG heterozygous, 14 (9.93%) were compound heterozygous and 16 (11.35%) had other types of variants. The entire coding region of GJB2 was sequenced and out of 150 patients with normal results at MLPA, 29.33% had abnormal results: variants in heterozygous state: c.71G>A (28%), c.457G>A (20%), c.269T>C (12%), c.109G>A (12%), c.100A>T (12%), c.551G>C (8%). Out of 26 patients with c.35delG in heterozygous state, 38.46% were in fact compound heterozygous. Conclusions: We identified two variants: c.109G>A and c.100A>T that have not been reported in any study from Romania. MLPA is an inexpensive, rapid and reliable technique that could be a cost-effective diagnosis method, useful for patients with hearing impairment. It can be adaptable for the mutation spectrum in every population and followed by Sanger sequencing can provide a genetic diagnosis for patients with different degrees of hearing impairment.
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Affiliation(s)
- Irina Resmerita
- Department of Medical Genetics, Faculty of Medicine, “Grigore T. Popa” University of Medicine and Pharmacy, University Street, No 16, 700115 Iasi, Romania; (R.P.); (M.C.P.); (L.I.B.); (L.C.); (E.-C.G.); (E.V.G.); (C.R.)
- Correspondence: or (I.R.); (R.S.C.); Tel.: +40-0741195689 (I.R.)
| | - Romica Sebastian Cozma
- Department of Otorhinolaryngology, Faculty of Medicine, “Grigore T. Popa” University of Medicine and Pharmacy, University Street, No 16, 700115 Iasi, Romania;
- Correspondence: or (I.R.); (R.S.C.); Tel.: +40-0741195689 (I.R.)
| | - Roxana Popescu
- Department of Medical Genetics, Faculty of Medicine, “Grigore T. Popa” University of Medicine and Pharmacy, University Street, No 16, 700115 Iasi, Romania; (R.P.); (M.C.P.); (L.I.B.); (L.C.); (E.-C.G.); (E.V.G.); (C.R.)
| | - Luminita Mihaela Radulescu
- Department of Otorhinolaryngology, Faculty of Medicine, “Grigore T. Popa” University of Medicine and Pharmacy, University Street, No 16, 700115 Iasi, Romania;
| | - Monica Cristina Panzaru
- Department of Medical Genetics, Faculty of Medicine, “Grigore T. Popa” University of Medicine and Pharmacy, University Street, No 16, 700115 Iasi, Romania; (R.P.); (M.C.P.); (L.I.B.); (L.C.); (E.-C.G.); (E.V.G.); (C.R.)
| | - Lacramioara Ionela Butnariu
- Department of Medical Genetics, Faculty of Medicine, “Grigore T. Popa” University of Medicine and Pharmacy, University Street, No 16, 700115 Iasi, Romania; (R.P.); (M.C.P.); (L.I.B.); (L.C.); (E.-C.G.); (E.V.G.); (C.R.)
| | - Lavinia Caba
- Department of Medical Genetics, Faculty of Medicine, “Grigore T. Popa” University of Medicine and Pharmacy, University Street, No 16, 700115 Iasi, Romania; (R.P.); (M.C.P.); (L.I.B.); (L.C.); (E.-C.G.); (E.V.G.); (C.R.)
| | - Ovidiu-Dumitru Ilie
- Department of Biology, Faculty of Biology, “Alexandru Ioan Cuza” University, Carol I Avenue, No 20A, 700505 Iasi, Romania;
| | - Eva-Cristiana Gavril
- Department of Medical Genetics, Faculty of Medicine, “Grigore T. Popa” University of Medicine and Pharmacy, University Street, No 16, 700115 Iasi, Romania; (R.P.); (M.C.P.); (L.I.B.); (L.C.); (E.-C.G.); (E.V.G.); (C.R.)
| | - Eusebiu Vlad Gorduza
- Department of Medical Genetics, Faculty of Medicine, “Grigore T. Popa” University of Medicine and Pharmacy, University Street, No 16, 700115 Iasi, Romania; (R.P.); (M.C.P.); (L.I.B.); (L.C.); (E.-C.G.); (E.V.G.); (C.R.)
| | - Cristina Rusu
- Department of Medical Genetics, Faculty of Medicine, “Grigore T. Popa” University of Medicine and Pharmacy, University Street, No 16, 700115 Iasi, Romania; (R.P.); (M.C.P.); (L.I.B.); (L.C.); (E.-C.G.); (E.V.G.); (C.R.)
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Differences in hearing levels between siblings with hearing loss caused by GJB2 mutations. Auris Nasus Larynx 2020; 47:938-942. [DOI: 10.1016/j.anl.2020.05.008] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/22/2019] [Revised: 05/11/2020] [Accepted: 05/18/2020] [Indexed: 11/23/2022]
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Buonfiglio P, Bruque CD, Luce L, Giliberto F, Lotersztein V, Menazzi S, Paoli B, Elgoyhen AB, Dalamón V. GJB2 and GJB6 Genetic Variant Curation in an Argentinean Non-Syndromic Hearing-Impaired Cohort. Genes (Basel) 2020; 11:E1233. [PMID: 33096615 PMCID: PMC7589744 DOI: 10.3390/genes11101233] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/18/2020] [Revised: 10/08/2020] [Accepted: 10/13/2020] [Indexed: 12/13/2022] Open
Abstract
Genetic variants in GJB2 and GJB6 genes are the most frequent causes of hereditary hearing loss among several deaf populations worldwide. Molecular diagnosis enables proper genetic counseling and medical prognosis to patients. In this study, we present an update of testing results in a cohort of Argentinean non-syndromic hearing-impaired individuals. A total of 48 different sequence variants were detected in genomic DNA from patients referred to our laboratory. They were manually curated and classified based on the American College of Medical Genetics and Genomics/Association for Molecular Pathology ACMG/AMP standards and hearing-loss-gene-specific criteria of the ClinGen Hearing Loss Expert Panel. More than 50% of sequence variants were reclassified from their previous categorization in ClinVar. These results provide an accurately interpreted set of variants to be taken into account by clinicians and the scientific community, and hence, aid the precise genetic counseling to patients.
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Affiliation(s)
- Paula Buonfiglio
- Laboratorio de Fisiología y Genética de la Audición, Instituto de Investigaciones en Ingeniería Genética y Biología Molecular “Dr. Héctor N. Torres”, Consejo Nacional de Investigaciones Científicas y Técnicas—INGEBI/CONICET, C1428ADN Ciudad Autónoma de Buenos Aires, Argentina; (P.B.); (A.B.E.)
| | - Carlos D. Bruque
- Centro Nacional de Genética Médica, ANLIS-Malbrán, C1425 Ciudad Autónoma de Buenos Aires, Argentina;
- Instituto de Biología y Medicina Experimental, Consejo Nacional de Investigaciones Científicas y Técnicas—IBYME/CONICET, C1428ADN Ciudad Autónoma de Buenos Aires, Argentina
| | - Leonela Luce
- Laboratorio de Distrofinopatías, Cátedra de Genética, Facultad de Farmacia y Bioquímica, Universidad de Buenos Aires, C1113AAD Ciudad Autónoma de Buenos Aires, Argentina; (L.L.); (F.G.)
- Instituto de Inmunología, Genética y Metabolismo—INIGEM/CONICET, Universidad de Buenos Aires, C1113AAD Ciudad Autónoma de Buenos Aires, Argentina
| | - Florencia Giliberto
- Laboratorio de Distrofinopatías, Cátedra de Genética, Facultad de Farmacia y Bioquímica, Universidad de Buenos Aires, C1113AAD Ciudad Autónoma de Buenos Aires, Argentina; (L.L.); (F.G.)
- Instituto de Inmunología, Genética y Metabolismo—INIGEM/CONICET, Universidad de Buenos Aires, C1113AAD Ciudad Autónoma de Buenos Aires, Argentina
| | - Vanesa Lotersztein
- Servicio de Genética, Hospital Militar Central “Dr. Cosme Argerich”, C1426 Ciudad Autónoma de Buenos Aires, Argentina;
| | - Sebastián Menazzi
- Servicio de Genética, Hospital de Clínicas “José de San Martín”, C1120AAR Ciudad Autónoma de Buenos Aires, Argentina;
| | - Bibiana Paoli
- Servicio de Otorrinolaringología Infantil, Hospital de Clínicas “José de San Martín”, C1120AAR Ciudad Autónoma de Buenos Aires, Argentina;
| | - Ana Belén Elgoyhen
- Laboratorio de Fisiología y Genética de la Audición, Instituto de Investigaciones en Ingeniería Genética y Biología Molecular “Dr. Héctor N. Torres”, Consejo Nacional de Investigaciones Científicas y Técnicas—INGEBI/CONICET, C1428ADN Ciudad Autónoma de Buenos Aires, Argentina; (P.B.); (A.B.E.)
- Departamento de Farmacología, Facultad de Medicina, Universidad de Buenos Aires, C1121ABG Ciudad Autónoma de Buenos Aires, Argentina
| | - Viviana Dalamón
- Laboratorio de Fisiología y Genética de la Audición, Instituto de Investigaciones en Ingeniería Genética y Biología Molecular “Dr. Héctor N. Torres”, Consejo Nacional de Investigaciones Científicas y Técnicas—INGEBI/CONICET, C1428ADN Ciudad Autónoma de Buenos Aires, Argentina; (P.B.); (A.B.E.)
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Küçük Kurtulgan H, Altuntaş EE, Yıldırım ME, Özdemir Ö, Bağcı B, Sezgin İ. The Analysis of GJB2, GJB3, and GJB6 Gene Mutations in Patients with Hereditary Non-Syndromic Hearing Loss Living in Sivas. J Int Adv Otol 2020; 15:373-378. [PMID: 31846914 DOI: 10.5152/iao.2019.5401] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022] Open
Abstract
OBJECTIVES The aim of the present study was to investigate the presence of GJB2, GJB3, and GJB6 gene mutations in non-syndromic sensorineural hearing loss (NSHL) cases living in Sivas region, to provide appropriate genetic counseling for cases who were found to have mutation, and to contribute to decrease the frequency of mutant allele in the next generation and plan treatment and rehabilitation with early diagnosis. MATERIALS AND METHODS The study included 53 unrelated cases that were diagnosed with congenital NSHL between June 2009 and March 2010. Multiplex ligation-dependent probe amplification method was used for genotyping of GJB2, GJB3, and GJB6 gene mutations. RESULTS Heterozygous 35delG variant was determined in 1.9% (n=1) of cases, homozygous 35delG in 15.1% (n=8), heterozygous IVS1+1G>A mutation in 1.9% (n=1), compound heterozygous in 3.8% (n=2), and homozygous IVS1+1G>A variant in 3.8% (n=2). None of the cases had mutation in GJB3 and GJB6 genes. Mutated allele frequencies in the present study were found to be 17.9% for 35delG and 6.6% for IVS1+1G>A. CONCLUSION The present study showed that 35delG mutation is the most common variant in the Sivas region, and that IVS1+1G>A mutation should be investigated in hearing loss. Another result of the present study was that genetic analyzes would allow early diagnosis of hearing impairments particularly when infants whose parents have consanguinity do not pass the newborn hearing screening.
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Affiliation(s)
- Hande Küçük Kurtulgan
- Department of Medical Genetics, Cumhuriyet University School of Medicine, Sivas, Turkey
| | | | - Malik Ejder Yıldırım
- Department of Medical Genetics, Cumhuriyet University School of Medicine, Sivas, Turkey
| | - Öztürk Özdemir
- Department of Medical Genetics, Çanakkale 18 Mart University, Çanakkale, Turkey
| | - Binnur Bağcı
- Department of Nutrition and Dietetics, Cumhuriyet University School of Medicine, Sivas, Turkey
| | - İlhan Sezgin
- Department of Medical Genetics, Cumhuriyet University School of Medicine, Sivas, Turkey
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Davcheva Chakar M, Bozhinovski G, Shukarova Stefanovska E, Trajkov D. Concurrent genetic and standard screening test for hearing reduction. MAKEDONSKO FARMACEVTSKI BILTEN 2020. [DOI: 10.33320/maced.pharm.bull.2020.66.02.004] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Reduction of hearing is the most common sensory impairment among newborns with an incidence of 1-3 per 1000 births. Introduction of an Auditory Newborn screening program allows early identification of hearing impairment. Mainly, congenital hearing loss in early childhood is a result of genetic changes. Due to high frequency of GJB2 pathogenic variants, its molecular characterization among sensorineural hearing reduction cases is already conducted as a routine analysis in many countries. The aim of this study is to show our initial results in the effort to determine whether genetic screening along with the standard hearing screening in newborns is justified. Otoacoustic emission (OAE) method was conducted in 223 newborns at risk of hearing impairment. Among them, 7 did not pass the test in both ears while 9 exhibited one-sided hearing loss. In all 7 children with indication of profound bilateral deafness, the diagnosis was confirmed using auditory brainstem response. Genetic screening of GJB2 gene was performed in 6 of them. Genetic analysis of GJB2 revealed homozygous state of the most common pathogenic variant 35delG in 3 (50%) of the analyzed infants. In the remaining 3 no pathogenic variant was determined. The results indicate that performing auditory OAE together with genetic screening is justified. In newborns who have not passed the hearing screening test and have profound hearing loss, without other syndrome traits, screening for mutations of GJB2 gene should be conducted. Genetic screening enables establishment of early definite diagnosis for deafness and helps in conducting adequate therapy providing timely rehabilitation and social inclusion of deaf child.
Key words: hearing loss, genetic screening, auditory screening, GJB2 gene
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Affiliation(s)
- Marina Davcheva Chakar
- University Clinic of Otorhinolaryngology, Faculty of Medicine, Ss. Cyril and Methodius University, Vodnjanska 17, 1000 Skopje, Republic of North Macedonia
| | - Gjorgji Bozhinovski
- Research Centre for Genetic Engineering and Biotechnology “Georgi D. Efremov”, Macedonian Academy of Science and Art, Boulevard Krste Petkov Misirkov, 1000 Skopje, Republic of North Macedonia
| | - Emilija Shukarova Stefanovska
- Research Centre for Genetic Engineering and Biotechnology “Georgi D. Efremov”, Macedonian Academy of Science and Art, Boulevard Krste Petkov Misirkov, 1000 Skopje, Republic of North Macedonia
| | - Dejan Trajkov
- Institute of Immunobiology and Human Genetics, Faculty of Medicine, Ss. Cyril and Methodius University, 50. Divizija 6a, 1000 Skopje, Republic of North Macedonia
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Gibriel AA, Abou-Elew MH, Masmoudi S. Analysis of p.Gly12Valfs*2, p.Trp24* and p.Trp77Arg mutations in GJB2 and p.Arg81Gln variant in LRTOMT among non syndromic hearing loss Egyptian patients: implications for genetic diagnosis. Mol Biol Rep 2019; 46:2139-2145. [PMID: 30730013 DOI: 10.1007/s11033-019-04667-0] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/12/2018] [Accepted: 01/30/2019] [Indexed: 11/28/2022]
Abstract
Hearing loss (HL) is a global sensory disorder that affects children and deprives them from their rights to enjoy standard social and educational levels. Although hundreds of genetic mutations across several genes have been linked to HL, very limited studies are available on Egyptian population which has high rate of consanguinity and HL. The frequency of the p.Gly12Valfs*2, p.Trp24* and p.Trp77Arg mutations in GJB2 along with the p.Arg81Gln variant in LRTOMT gene was investigated in Egyptian patients. 103 non-syndromic HL (NSHL) Egyptian patients and 100 control subjects were recruited in this study. PCR-RFLP and Direct sequencing were performed to screen and confirm presence/absence of those mutations in Egyptian population. The p.Gly12Valfs*2 mutation was found in eight patients (7.8%) (six homozygous and two heterozygous) with an allele frequency of 6.8%. The p.Trp24* and p.Trp77Arg were absent in both HL patients and controls. Another one patient had the heterozygous variant for p.Arg81Gln in LRTOMT gene. This study reports, for the first time, the presence of a heterozygous change for the p.Arg81Gln in LRTOMT gene in one Egyptian patient. The p.Gly12Valfs*2 mutation, but not the p.Trp24* nor the p.Trp77Arg, in GJB2 is the most frequent variant among Egyptian patients and would therefore be recommended for genetic counseling and diagnosis.
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Affiliation(s)
- Abdullah A Gibriel
- Biochemistry and Molecular Biology Department, Faculty of Pharmacy, The British University in Egypt (BUE), P.O. Box 259, 11728, Cairo, Egypt.
| | - Maha H Abou-Elew
- Otorhinolaryngology Department, Audio-Vestibular Unit, Faculty of Medicine, Kasr Al-Aini El-Manial University Hospital, Cairo University, Giza, Egypt
| | - Saber Masmoudi
- Laboboratoire Procédés de Criblage Moléculaire et Cellulaire, Centre de Biotechnologie de Sfax, Université de Sfax, Sfax, Tunisia
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Albano JMR, Mussini N, Toriano R, Facelli JC, Ferraro MB, Pickholz M. Calcium interactions with Cx26 hemmichannel: Spatial association between MD simulations biding sites and variant pathogenicity. Comput Biol Chem 2018; 77:331-342. [PMID: 30466042 DOI: 10.1016/j.compbiolchem.2018.11.004] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/21/2018] [Revised: 07/08/2018] [Accepted: 11/08/2018] [Indexed: 01/23/2023]
Abstract
Connexinophaties are a collective of diseases related to connexin channels and hemichannels. In particular many Cx26 alterations are strongly associated to human deafness. Calcium plays an important role on this structures regulation. Here, using calcium as a probe, extensive atomistic Molecular Dynamics simulations were performed on the Cx26 hemichannel embedded in a lipid bilayer. Exploring different initial conditions and calcium concentration, simulation reached ∼4 μs. Several analysis were carried out in order to reveal the calcium distribution and localization, such as electron density profiles, density maps and distance time evolution, which is directly associated to the interaction energy. Specific amino acid interactions with calcium and their stability were capture within this context. Few of these sites such as, GLU42, GLU47, GLY45 and ASP50, were already suggested in the literature. Besides, we identified novel calcium biding sites: ASP2, ASP117, ASP159, GLU114, GLU119, GLU120 and VAL226. To the best of our knowledge, this is the first time that these sites are reported within this context. Furthermore, since various pathologies involving the Cx26 hemichannel are associated with pathogenic variants in the corresponding CJB2 gene, using ClinVar, we were able to spatially associate the 3D positions of the identified calcium binding sites within the framework of this work with reported pathogenic variants in the CJB2 gene. This study presents a first step on finding associations between molecular features and pathological variants of the Cx26 hemichannel.
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Affiliation(s)
- Juan M R Albano
- Facultad de Ciencias Exactas y Naturales, Departamento de Física, Universidad de Buenos Aires, Argentina; CONICET- Universidad de Buenos Aires, IFIBA, Buenos Aires, Argentina
| | - Nahuel Mussini
- Facultad de Ciencias Exactas y Naturales, Departamento de Física, Universidad de Buenos Aires, Argentina; CONICET- Universidad de Buenos Aires, IFIBA, Buenos Aires, Argentina
| | - Roxana Toriano
- Facultad de Medicina, Departamento de Ciencias Fisiológicas, Laboratorio de Biomembranas, Buenos Aires, Argentina; CONICET - Universidad de Buenos Aires, IFIBIO Houssay, Buenos Aires, Argentina
| | - Julio C Facelli
- Department of Biomedical Informatics, The University of Utah, 421 Wakara Way, Suite 140, Salt Lake City, UT 84108, USA.
| | - Marta B Ferraro
- Facultad de Ciencias Exactas y Naturales, Departamento de Física, Universidad de Buenos Aires, Argentina; CONICET- Universidad de Buenos Aires, IFIBA, Buenos Aires, Argentina
| | - Mónica Pickholz
- Facultad de Ciencias Exactas y Naturales, Departamento de Física, Universidad de Buenos Aires, Argentina; CONICET- Universidad de Buenos Aires, IFIBA, Buenos Aires, Argentina
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Kecskeméti N, Szönyi M, Gáborján A, Küstel M, Milley GM, Süveges A, Illés A, Kékesi A, Tamás L, Molnár MJ, Szirmai Á, Gál A. Analysis of GJB2 mutations and the clinical manifestation in a large Hungarian cohort. Eur Arch Otorhinolaryngol 2018; 275:2441-2448. [PMID: 30094485 DOI: 10.1007/s00405-018-5083-4] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/01/2018] [Accepted: 07/31/2018] [Indexed: 11/25/2022]
Abstract
PURPOSE Pathogenic variants of the gap junction beta 2 (GJB2) gene are responsible for about 50% of hereditary non-syndromic sensorineural hearing loss (NSHL). In this study, we report mutation frequency and phenotype comparison of different GJB2 gene alterations in Hungarian NSHL patients. METHODS The total coding region of the GJB2 gene was analyzed with Sanger or NGS sequencing for 239 patients with NSHL and 160 controls. RESULTS Homozygous and compound heterozygous GJB2 mutations were associated with early onset serious clinical phenotype in 28 patients. In 24 patients, two deletion or nonsense mutations were detected in individuals with mainly prelingual NSHL. In compound heterozygous cases, a combination of deletion and missense mutations associated with milder postlingual NSHL. A further 25 cases harbored single heterozygous GJB2 mutations mainly associated with later onset, milder clinical phenotype. The most common mutation was the c.35delG deletion, with 12.6% allele frequency. The hearing loss was more severe in the prelingual groups. CONCLUSION The mutation frequency of GJB2 in the investigated cohort is lower than in other European cohorts. The most serious cases were associated with homozygous and compound heterozygous mutations. In our cohort the hearing impairment and age of onset was not altered between in cases with only one heterozygous GJB2 mutation and wild type genotype, which may exclude the possibility of autosomal dominant inheritance. In early onset, severe to profound hearing loss cases, if the GJB2 analysis results in only one heterozygous alteration further next generation sequencing is highly recommended.
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Affiliation(s)
- Nóra Kecskeméti
- Institute of Genomic Medicine and Rare Disorders, Semmelweis University, Tömö utca 25-29, Budapest, 1083, Hungary
- Department of Otorhinolaryngology, Head and Neck Surgery, Semmelweis University, Szigony utca 36, Budapest, 1083, Hungary
| | - Magdolna Szönyi
- Department of Otorhinolaryngology, Head and Neck Surgery, Semmelweis University, Szigony utca 36, Budapest, 1083, Hungary
| | - Anita Gáborján
- Department of Otorhinolaryngology, Head and Neck Surgery, Semmelweis University, Szigony utca 36, Budapest, 1083, Hungary
| | - Marianna Küstel
- Department of Otorhinolaryngology, Head and Neck Surgery, Semmelweis University, Szigony utca 36, Budapest, 1083, Hungary
| | - György Máté Milley
- Institute of Genomic Medicine and Rare Disorders, Semmelweis University, Tömö utca 25-29, Budapest, 1083, Hungary
| | - Anna Süveges
- Institute of Genomic Medicine and Rare Disorders, Semmelweis University, Tömö utca 25-29, Budapest, 1083, Hungary
| | - Anett Illés
- Institute of Genomic Medicine and Rare Disorders, Semmelweis University, Tömö utca 25-29, Budapest, 1083, Hungary
| | - Anna Kékesi
- Institute of Genomic Medicine and Rare Disorders, Semmelweis University, Tömö utca 25-29, Budapest, 1083, Hungary
| | - László Tamás
- Department of Otorhinolaryngology, Head and Neck Surgery, Semmelweis University, Szigony utca 36, Budapest, 1083, Hungary
| | - Mária Judit Molnár
- Institute of Genomic Medicine and Rare Disorders, Semmelweis University, Tömö utca 25-29, Budapest, 1083, Hungary
| | - Ágnes Szirmai
- Department of Otorhinolaryngology, Head and Neck Surgery, Semmelweis University, Szigony utca 36, Budapest, 1083, Hungary
| | - Anikó Gál
- Institute of Genomic Medicine and Rare Disorders, Semmelweis University, Tömö utca 25-29, Budapest, 1083, Hungary.
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Plevova P, Tvrda P, Paprskarova M, Turska P, Kantorova B, Mrazkova E, Zapletalova J. Genetic Aetiology of Nonsyndromic Hearing Loss in Moravia-Silesia. MEDICINA-LITHUANIA 2018; 54:medicina54020028. [PMID: 30344259 PMCID: PMC6037260 DOI: 10.3390/medicina54020028] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Subscribe] [Scholar Register] [Received: 03/28/2018] [Revised: 05/01/2018] [Accepted: 05/02/2018] [Indexed: 11/16/2022]
Abstract
BACKGROUND AND OBJECTIVE Hearing loss is the most common sensory deficit in humans. The aim of this study was to clarify the genetic aetiology of nonsyndromic hearing loss in the Moravian-Silesian population of the Czech Republic. PATIENTS AND METHODS This study included 200 patients (93 males, 107 females, mean age 16.9 years, ranging from 4 months to 62 years) with nonsyndromic sensorineural hearing loss. We screened all patients for mutations in GJB2 and the large deletion del(GJB6-D13S1830). We performed further screening for additional genes (SERPINB6, TMIE, COCH, ESPN, ACTG1, KCNQ4, and GJB3) with Sanger sequencing on a subset of patients that were negative for GJB2 mutations. RESULTS We detected biallelic GJB2 mutations in 44 patients (22%). Among these patients, 63.6%, 9.1% and 2.3% exhibited homozygous c.35delG, p.Trp24*, and p.Met34Thr mutations, respectively. The remaining 25% of these patients exhibited compound heterozygous c.35delG, c.-23+1G>A, p.Trp24*, p.Val37Ile, p.Met34Thr, p.Leu90Pro, c.235delC, c.313_326del14, p.Ser139Asn, and p.Gly147Leu mutations. We found a monoallelic GJB2 mutation in 12 patients (6.6%). We found no pathogenic mutations in the other tested genes. Conclusions: One fifth of our cohort had deafness related to GJB2 mutations. The del(GJB6-D13S1830), SERPINB6, TMIE, COCH, ESPN, ACTG1, GJB3, and KCNQ4 mutations were infrequently associated with deafness in the Moravian-Silesian population. Therefore, we suggest that del(GJB6-D13S1830) testing should be performed only when patients with deafness carry the monoallelic GJB2 mutation.
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Affiliation(s)
- Pavlina Plevova
- Department of Medical Genetics, University Hospital Ostrava, 17. listopadu 1790, 708 52 Ostrava, Czech Republic.
| | - Petra Tvrda
- Department of Medical Genetics, University Hospital Ostrava, 17. listopadu 1790, 708 52 Ostrava, Czech Republic.
| | - Martina Paprskarova
- Department of Medical Genetics, University Hospital Ostrava, 17. listopadu 1790, 708 52 Ostrava, Czech Republic.
| | - Petra Turska
- Department of Medical Genetics, University Hospital Ostrava, 17. listopadu 1790, 708 52 Ostrava, Czech Republic.
| | - Barbara Kantorova
- Department of Medical Genetics, University Hospital Ostrava, 17. listopadu 1790, 708 52 Ostrava, Czech Republic.
| | - Eva Mrazkova
- Department of Epidemiology and Public Health, Faculty of Medicine, University of Ostrava, Syllabova 19, 703 00 Ostrava, Zábřeh, Czech Republic.
- Department of Otorhinolaryngology, Hospital of Havířov, Dělnická 1132/24, 736 01 Havířov, Czech Republic.
| | - Jana Zapletalova
- Department of Medical Biophysics, Faculty of Medicine and Dentistry, Palacky University Olomouc, Hnevotinska 3, 775 15 Olomouc, Czech Republic.
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Shi X, Zhang Y, Qiu S, Zhuang W, Yuan N, Sun T, Gao J, Qiao Y, Liu K. A Novel GJB2 compound heterozygous mutation c.257C>G (p.T86R)/c.176del16 (p.G59A fs*18) causes sensorineural hearing loss in a Chinese family. J Clin Lab Anal 2018; 32:e22444. [PMID: 29665173 DOI: 10.1002/jcla.22444] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/14/2017] [Accepted: 03/07/2018] [Indexed: 11/07/2022] Open
Abstract
OBJECTIVE To investigate whether a novel compound heterozygous mutations c.257C>G (p.T86R)/c.176del16 (p.G59A fs*18) in GJB2 result in hearing loss. METHODS Allele-specific PCR-based universal array (ASPUA) screening and sequence analysis were applied to identify these mutations. 3D model was built to perform molecular dynamics (MD) simulation to verify the susceptibility of the mutations. Furthermore, WT- and Mut-GJB2 DNA fragments, containing the mutation of c.257C>G and c.176del16 were respectively cloned and transfected into HEK293 and spiral ganglion neuron cell (SGNs) by lenti-virus delivery system to indicate the subcellular localization of the WT- and Mut-CX26 protein. RESULTS A novel compound heterozygous mutation c.257C>G (p.T86R)/c.176del16 (p.G59A fs*18) in GJB2 was identified in a Chinese family, in which 4 siblings with profound hearing loss, but the fifth child is normal. By ASPUA screening and sequencing, a compound heterozygote mutations in GJB2 c.257C>G (p.T86R)/c.176del16 (p.G59A fs*18) were identified in these four deaf children, each of the mutated GJB2 gene were inherited from their parents. There is no mutation of GJB2 gene identified in the normal child. Besides, the compound heterozygous mutation GJB2 c.257C>G (p.T86R)/c.176del16 (p.G59A fs*18) could lead to the alterations of the subcellular localization of each corresponding mutated CX26 protein and could cause the hearing loss, which has been predicted by MD simulation and verified in both 293T and SGNs cell line. CONCLUSION The c.257C>G (p.T86R)/c.176del16 (p.G59A fs*18) compound mutations in GJB2 detected in this study are novel, and which may be associated with hearing loss in this Chinese family.
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Affiliation(s)
- Xi Shi
- The Institute of Audiology and Balance science of Xuzhou Medical University, Xuzhou, China
- Department of Otolaryngology-Head and Neck Surgery, Beijing Friendship Hospital, Capital Medical University, Beijing, China
| | - Yan Zhang
- Department of Otolaryngology-Head and neck surgery, The first Hospital of JiLin University, Changchun, China
| | - Shiwei Qiu
- The Institute of Audiology and Balance science of Xuzhou Medical University, Xuzhou, China
| | - Wei Zhuang
- Clinical Hearing Center of Affliated Hospital of Xuzhou Medical University, Xuzhou, China
| | - Na Yuan
- The Institute of Audiology and Balance science of Xuzhou Medical University, Xuzhou, China
| | - Tiantian Sun
- The Institute of Audiology and Balance science of Xuzhou Medical University, Xuzhou, China
| | - Jian Gao
- Jiangsu Key Laboratory of New Drug Research and Clinical Pharmacy, Xuzhou Medical University, Xuzhou, China
| | - Yuehua Qiao
- Clinical Hearing Center of Affliated Hospital of Xuzhou Medical University, Xuzhou, China
| | - Ke Liu
- Department of Otolaryngology-Head and Neck Surgery, Beijing Friendship Hospital, Capital Medical University, Beijing, China
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Tlili A, Fahd Al Mutery A, Mahfood M, Kamal Eddine Ahmad Mohamed W, Bajou K. Identification of a novel frameshift mutation in the ILDR1 gene in a UAE family, mutations review and phenotype genotype correlation. PLoS One 2017; 12:e0185281. [PMID: 28945813 PMCID: PMC5612695 DOI: 10.1371/journal.pone.0185281] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/09/2017] [Accepted: 09/08/2017] [Indexed: 12/17/2022] Open
Abstract
Autosomal recessive non-syndromic hearing loss is one of the most common monogenic diseases. It is characterized by high allelic and locus heterogeneities that make a precise diagnosis difficult. In this study, whole-exome sequencing was performed for an affected patient allowing us to identify a new frameshift mutation (c.804delG) in the Immunoglobulin-Like Domain containing Receptor-1 (ILDR1) gene. Direct Sanger sequencing and segregation analysis were performed for the family pedigree. The mutation was homozygous in all affected siblings but heterozygous in the normal consanguineous parents. The present study reports a first ILDR1 gene mutation in the UAE population and confirms that the whole-exome sequencing approach is a robust tool for the diagnosis of monogenic diseases with high levels of allelic and locus heterogeneity. In addition, by reviewing all reported ILDR1 mutations, we attempt to establish a genotype phenotype correlation to explain the phenotypic variability observed at low frequencies.
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Affiliation(s)
- 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
- * E-mail:
| | - Abdullah Fahd Al Mutery
- Department of Applied Biology, College of Sciences, University of Sharjah, Sharjah, United Arab Emirates
| | - Mona Mahfood
- Department of Applied Biology, College of Sciences, University of Sharjah, Sharjah, United Arab Emirates
| | | | - Khalid Bajou
- 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
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Pan J, Xu P, Tang W, Cui Z, Feng M, Wang C. Mutation analysis of common GJB2, SCL26A4 and 12S rRNA genes among 380 deafness patients in northern China. Int J Pediatr Otorhinolaryngol 2017; 98:39-42. [PMID: 28583500 DOI: 10.1016/j.ijporl.2017.04.018] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/20/2016] [Revised: 04/06/2017] [Accepted: 04/10/2017] [Indexed: 10/19/2022]
Abstract
OBJECTIVES The molecular etiology of nonsyndromic deafness in Chinese population has not been investigated systematically, our study is aim to investigate the molecular etiology of nonsyndromic deafness patients from Northern China (Heilongjiang province), in order to provide genetic test and counseling to families. METHODS 380 unrelated patients with hearing loss who attended to the Department of Otolaryngology, The Fourth Affiliated Hospital of Harbin Medical University were enrolled to our study. All patients were diagnosed with nonsyndromic deafness by audiologic evaluation, 202 normal-hearing individuals were taken as controls. Mutations in three common deafness-causing genes (GJB2, SLC26A4 and 12S rRNA) were screened by direct sequencing. RESULTS Mutations (homozygote or compound heterozygote) in GJB2 accounted for 8.9% (34/380) of the patients, mutations in SLC26A4 accounted for 10.0% (38/380) of the patients screened. Only one case was found to carry 12S rRNA 1555A > G (1/380, 0.26%). Five types of mutations in GJB2 were identified, GJB2 235delC was the most prevalent mutation in our patient group (76/380, 20.0%), followed by 299-300delAT with a frequency of 7.4% (28/380). Two types of mutations in SLC26A4 were detected in our patient group (IVS7-2A > G and 2168A > G). IVS7-2A > G was identified in 27 patients (27/380, 7.1%) and 2168A > G was identified in 14 patients (14/380, 3.7%). CONCLUSIONS Our results demonstrate that 19.2% patients with nonsyndromic deafness were caused by mutations in three common deafness genes (GJB2, SLC26A4 and 12S rRNA) in our northern China patient group. GJB2 235delC was the most prevalent mutation, same as in the most Asian populations. These data enrich the database of deafness mutations and provide the standard for clinical diagnose, treatment and genetic counseling in Northern China population.
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Affiliation(s)
- Jing Pan
- Department of Laboratory, The Fourth Affiliated Hospital of Harbin Medical University, 37 Yiyuan Street, Harbin, 150001, Heilongjiang province, China.
| | - Ping Xu
- Department of Otolaryngology Head and Neck Surgery, The Fourth Affiliated Hospital of Harbin Medical University, 37 Yiyuan Street, Harbin, 150001, Heilongjiang province, China.
| | - Weibo Tang
- Department of Angiosis, The Provincial Hospital of Heilongjiang, 82 Zhongshan Road, Harbin, 150001, Heilongjiang province, China.
| | - Zhongtao Cui
- Department of Otolaryngology Head and Neck Surgery, The Fourth Affiliated Hospital of Harbin Medical University, 37 Yiyuan Street, Harbin, 150001, Heilongjiang province, China.
| | - Miao Feng
- Department of Otolaryngology Head and Neck Surgery, The Fourth Affiliated Hospital of Harbin Medical University, 37 Yiyuan Street, Harbin, 150001, Heilongjiang province, China.
| | - Chunying Wang
- Department of Otolaryngology Head and Neck Surgery, The Fourth Affiliated Hospital of Harbin Medical University, 37 Yiyuan Street, Harbin, 150001, Heilongjiang province, China.
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Parzefall T, Lucas T, Koenighofer M, Ramsebner R, Frohne A, Czeiger S, Baumgartner WD, Schoefer C, Gstoettner W, Frei K. The role of alternative GJB2 transcription in screening for neonatal sensorineural deafness in Austria. Acta Otolaryngol 2017; 137:356-360. [PMID: 27827000 DOI: 10.1080/00016489.2016.1249946] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/20/2022]
Abstract
CONCLUSION Alterations within a novel putative Exon 1a within the gap junction beta 2 (GJB2) gene may play a role in the development of genetic hearing impairment in Austria. OBJECTIVES Mutations in the GJB2 gene are the most common cause of hereditary sensorineural deafness. Genome-wide screening for alternative transcriptional start sites in the human genome has revealed the presence of an additional GJB2 exon (E1a). This study tested the hypothesis of whether alternative GJB2 transcription involving E1a may play a role in the development of congenital sensorineural deafness in Austria. METHODS GJB2 E1a and flanking regions were sequenced in randomized normal hearing control subjects and three different patient groups with non-syndromic hearing impairment (NSHI), and bioinformatic analysis was performed. Statistical analysis of disease association was carried out using the Cochran-Armitage test for trend. RESULTS A single change 2410 bp proximal to the translational start site (c.-2410T > C, rs7994748, NM_004004.5:c.-23 + 792T > C) was found to be significantly associated with the common c.35delG GJB2 mutation (p = .009). c.35delG in combination with c.-2410CC occurred at a 6.9-fold increased frequency compared to the control group. Additionally, one patient with idiopathic congenital hearing loss was found to be homozygous c.-2410CC.
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Affiliation(s)
- Thomas Parzefall
- Department of Otorhinolaryngology, Medical University of Vienna, Austria
| | - Trevor Lucas
- Department for Cell- and Developmental Biology, Medical University of Vienna, Austria
| | - Martin Koenighofer
- Department of Otorhinolaryngology, Medical University of Vienna, Austria
| | - Reinhard Ramsebner
- Department of Otorhinolaryngology, Medical University of Vienna, Austria
| | - Alexandra Frohne
- Department for Cell- and Developmental Biology, Medical University of Vienna, Austria
| | - Shelly Czeiger
- Department for Cell- and Developmental Biology, Medical University of Vienna, Austria
| | | | - Christian Schoefer
- Department for Cell- and Developmental Biology, Medical University of Vienna, Austria
| | | | - Klemens Frei
- Department of Otorhinolaryngology, Medical University of Vienna, Austria
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30
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GJB2 mutations in Turkish patients with nonsyndromic hearing loss. Meta Gene 2016. [DOI: 10.1016/j.mgene.2016.10.006] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022] Open
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31
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Guidelines for aetiological investigation into mild to moderate bilateral permanent childhood hearing impairment. HEARING BALANCE AND COMMUNICATION 2016. [DOI: 10.1080/21695717.2016.1208999] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/20/2023]
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Mehta D, Noon SE, Schwartz E, Wilkens A, Bedoukian EC, Scarano I, Crenshaw EB, Krantz ID. Outcomes of evaluation and testing of 660 individuals with hearing loss in a pediatric genetics of hearing loss clinic. Am J Med Genet A 2016; 170:2523-30. [PMID: 27480936 DOI: 10.1002/ajmg.a.37855] [Citation(s) in RCA: 34] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/18/2016] [Accepted: 07/07/2016] [Indexed: 11/11/2022]
Abstract
Hearing loss is a relatively common condition in children, occurring in approximately 2 out of every 1,000 births with approximately 50% of reported diagnoses having a primary genetic etiology. Given the prevalence and genetic component of hearing loss, coupled with a trend toward early diagnosis with the institution of universal newborn hearing screening, The Genetics of Hearing Loss Clinic was established at The Children's Hospital of Philadelphia to manage the diagnosis, testing, and genetic counseling for individuals and families. This paper described a cohort of 660 individuals with a diagnosis of hearing loss evaluated between July 2008 and July 2015 in the Genetics of Hearing Loss Clinic. To elucidate the cause of hearing loss in this cohort for better management and prognostication, testing included single nucleotide polymorphism chromosomal microarray, hearing loss next generation sequencing panel, and additional clinical tests inclusive of thyroid and renal function studies, temporal bone magnetic resonance imaging, and electrocardiogram. Of those evaluated, most had bilateral sensorineural hearing loss, occurring in 489/660 (74%). Additionally, 612/660 (93%) of patients presented with a nonsyndromic form of hearing loss (no other observed clinical findings at the time of exam), of which pathogenic mutations in GJB2 were most prevalent. Of the individuals with syndromic manifestations (48/660), Usher and Waardenburg syndrome were most commonly observed. A family history of hearing loss (first degree relative) was present in 12.6% of families with available information. Through molecular analyses, clinical examination, and laboratory testing, a definitive etiologic diagnosis was established in 157/660 (23.8%) of individuals. © 2016 Wiley Periodicals, Inc.
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Affiliation(s)
- Devanshi Mehta
- Division of Human Genetics, The Children's Hospital of Philadelphia, Philadelphia, Pennsylvania
| | - Sarah E Noon
- Division of Human Genetics, The Children's Hospital of Philadelphia, Philadelphia, Pennsylvania
| | - Emily Schwartz
- Division of Human Genetics, The Children's Hospital of Philadelphia, Philadelphia, Pennsylvania
| | - Alisha Wilkens
- Division of Human Genetics, The Children's Hospital of Philadelphia, Philadelphia, Pennsylvania
| | - Emma C Bedoukian
- Division of Human Genetics, The Children's Hospital of Philadelphia, Philadelphia, Pennsylvania
| | - Irene Scarano
- Division of Human Genetics, The Children's Hospital of Philadelphia, Philadelphia, Pennsylvania
| | - E Bryan Crenshaw
- Center for Childhood Communication, The Children's Hospital of Philadelphia, Philadelphia, Pennsylvania.,Department of Otorhinolaryngology: Head and Neck Surgery, Perelman School of Medicine at the University of Pennsylvania, Philadelphia, Pennsylvania
| | - Ian D Krantz
- Division of Human Genetics, The Children's Hospital of Philadelphia, Philadelphia, Pennsylvania. .,The Perelman School of Medicine at the University of Pennsylvania, Philadelphia, Pennsylvania.
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García IE, Prado P, Pupo A, Jara O, Rojas-Gómez D, Mujica P, Flores-Muñoz C, González-Casanova J, Soto-Riveros C, Pinto BI, Retamal MA, González C, Martínez AD. Connexinopathies: a structural and functional glimpse. BMC Cell Biol 2016; 17 Suppl 1:17. [PMID: 27228968 PMCID: PMC4896260 DOI: 10.1186/s12860-016-0092-x] [Citation(s) in RCA: 34] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022] Open
Abstract
Mutations in human connexin (Cx) genes have been related to diseases, which we termed connexinopathies. Such hereditary disorders include nonsyndromic or syndromic deafness (Cx26, Cx30), Charcot Marie Tooth disease (Cx32), occulodentodigital dysplasia and cardiopathies (Cx43), and cataracts (Cx46, Cx50). Despite the clinical phenotypes of connexinopathies have been well documented, their pathogenic molecular determinants remain elusive. The purpose of this work is to identify common/uncommon patterns in channels function among Cx mutations linked to human diseases. To this end, we compiled and discussed the effect of mutations associated to Cx26, Cx32, Cx43, and Cx50 over gap junction channels and hemichannels, highlighting the function of the structural channel domains in which mutations are located and their possible role affecting oligomerization, gating and perm/selectivity processes.
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Affiliation(s)
- Isaac E García
- Centro Interdisciplinario de Neurociencia de Valparaíso, Instituto de Neurociencia, Facultad de Ciencias, Universidad de Valparaíso, Valparaíso, Chile
| | - Pavel Prado
- Centro Interdisciplinario de Neurociencia de Valparaíso, Instituto de Neurociencia, Facultad de Ciencias, Universidad de Valparaíso, Valparaíso, Chile
| | - Amaury Pupo
- Centro Interdisciplinario de Neurociencia de Valparaíso, Instituto de Neurociencia, Facultad de Ciencias, Universidad de Valparaíso, Valparaíso, Chile
| | - Oscar Jara
- Centro Interdisciplinario de Neurociencia de Valparaíso, Instituto de Neurociencia, Facultad de Ciencias, Universidad de Valparaíso, Valparaíso, Chile
| | - Diana Rojas-Gómez
- Centro Interdisciplinario de Neurociencia de Valparaíso, Instituto de Neurociencia, Facultad de Ciencias, Universidad de Valparaíso, Valparaíso, Chile
| | - Paula Mujica
- Centro Interdisciplinario de Neurociencia de Valparaíso, Instituto de Neurociencia, Facultad de Ciencias, Universidad de Valparaíso, Valparaíso, Chile
| | - Carolina Flores-Muñoz
- Centro Interdisciplinario de Neurociencia de Valparaíso, Instituto de Neurociencia, Facultad de Ciencias, Universidad de Valparaíso, Valparaíso, Chile
| | - Jorge González-Casanova
- Centro Interdisciplinario de Neurociencia de Valparaíso, Instituto de Neurociencia, Facultad de Ciencias, Universidad de Valparaíso, Valparaíso, Chile
| | - Carolina Soto-Riveros
- Centro Interdisciplinario de Neurociencia de Valparaíso, Instituto de Neurociencia, Facultad de Ciencias, Universidad de Valparaíso, Valparaíso, Chile
| | - Bernardo I Pinto
- Centro Interdisciplinario de Neurociencia de Valparaíso, Instituto de Neurociencia, Facultad de Ciencias, Universidad de Valparaíso, Valparaíso, Chile
| | - Mauricio A Retamal
- Centro de Fisiología Celular e Integrativa, Facultad de Medicina, Clínica Alemana Universidad del Desarrollo, Santiago, Chile
| | - Carlos González
- Centro Interdisciplinario de Neurociencia de Valparaíso, Instituto de Neurociencia, Facultad de Ciencias, Universidad de Valparaíso, Valparaíso, Chile
| | - Agustín D Martínez
- Centro Interdisciplinario de Neurociencia de Valparaíso, Instituto de Neurociencia, Facultad de Ciencias, Universidad de Valparaíso, Valparaíso, Chile.
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Dalamón VK, Buonfiglio P, Larralde M, Craig P, Lotersztein V, Choate K, Pallares N, Diamante V, Elgoyhen AB. Connexin 26 (GJB2) mutation in an Argentinean patient with keratitis-ichthyosis-deafness (KID) syndrome: a case report. BMC MEDICAL GENETICS 2016; 17:37. [PMID: 27141831 PMCID: PMC4855445 DOI: 10.1186/s12881-016-0298-y] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 09/02/2015] [Accepted: 04/22/2016] [Indexed: 11/20/2022]
Abstract
Background Keratitis-Ichthyosis-Deafness (KID) syndrome is a rare condition characterized by pre-lingual sensorineural deafness with skin hyperkeratinization. The primary cause of the disease is a loss-of-function mutation in the GJB2 gene. Mutations in Argentinean patients have not been described. Case presentation We studied a 2 year-old boy with bilateral congenital sensorineural deafness with dry skin over the entire body, hypotrichosis of the scalp, thin and light-blond hair. Analysis of the GJB2 gene nucleotide sequence revealed the substitution of guanine-148 by adenine predicted to result in an Asp50Asn amino acid substitution. Conclusion This is the first KID report in a patient from Argentina. This de novo mutation proved to be the cause of keratitis-ichthyosis-deafness syndrome (KID-syndrome) in the patient, and has implications in medical genetic practice.
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Affiliation(s)
- Viviana Karina Dalamón
- Instituto de Investigaciones en Ingeniería Genética y Biología Molecular "Dr. Héctor Torres"-(INGEBI), Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET), Vuelta de Obligado 2490. (1428) Ciudad Autónoma de Buenos Aires, Buenos Aires, Argentina.
| | - Paula Buonfiglio
- Instituto de Investigaciones en Ingeniería Genética y Biología Molecular "Dr. Héctor Torres"-(INGEBI), Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET), Vuelta de Obligado 2490. (1428) Ciudad Autónoma de Buenos Aires, Buenos Aires, Argentina
| | - Margarita Larralde
- Servicio de Dermatología Pediátrica, Hospital Ramos Mejía, Ciudad Autonoma de Buenos Aires, Argentina.,Departamento de Dermatología, Hospital Alemán, Ciudad Autonoma de Buenos Aires, Argentina
| | - Patricio Craig
- Departamento de Química Biológica e Instituto de Química y Fisicoquímica Biológicas, Universidad de Buenos Aires, Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET), Ciudad Autonoma de Buenos Aires, Argentina
| | - Vanesa Lotersztein
- Servicio de Genética, Hospital de Clínicas "José de San Martín", Ciudad Autonoma de Buenos Aires, Argentina
| | - Keith Choate
- Dermatology Yale University School of Medicine, New Haven, USA
| | - Norma Pallares
- Instituto Superior de Implantes Cocleares "Dr. Vicente Diamante", Ciudad Autonoma de Buenos Aires, Argentina
| | - Vicente Diamante
- Instituto Superior de Implantes Cocleares "Dr. Vicente Diamante", Ciudad Autonoma de Buenos Aires, Argentina
| | - Ana Belén Elgoyhen
- Instituto de Investigaciones en Ingeniería Genética y Biología Molecular "Dr. Héctor Torres"-(INGEBI), Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET), Vuelta de Obligado 2490. (1428) Ciudad Autónoma de Buenos Aires, Buenos Aires, Argentina.,Departamento de Farmacología, Facultad de Medicina, Universidad de Buenos Aires, Ciudad Autonoma de Buenos Aires, Argentina
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ACEMg Diet Supplement Modifies Progression of Hereditary Deafness. Sci Rep 2016; 6:22690. [PMID: 26965868 PMCID: PMC4786814 DOI: 10.1038/srep22690] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/23/2015] [Accepted: 02/19/2016] [Indexed: 11/08/2022] Open
Abstract
Dietary supplements consisting of beta-carotene (precursor to vitamin A), vitamins C and E and the mineral magnesium (ACEMg) can be beneficial for reducing hearing loss due to aminoglycosides and overstimulation. This regimen also slowed progression of deafness for a boy with GJB2 (CONNEXIN 26) mutations. To assess the potential for treating GJB2 and other forms of hereditary hearing loss with ACEMg, we tested the influence of ACEMg on the cochlea and hearing of mouse models for two human mutations: GJB2, the leading cause of childhood deafness, and DIAPH3, a cause of auditory neuropathy. One group of mice modeling GJB2 (Gjb2-CKO) received ACEMg diet starting shortly after they were weaned (4 weeks) until 16 weeks of age. Another group of Gjb2-CKO mice received ACEMg in utero and after weaning. The ACEMg diet was given to mice modeling DIAPH3 (Diap3-Tg) after weaning (4 weeks) until 12 weeks of age. Control groups received food pellets without the ACEMg supplement. Hearing thresholds measured by auditory brainstem response were significantly better for Gjb2-CKO mice fed ACEMg than for the control diet group. In contrast, Diap3-Tg mice displayed worse thresholds than controls. These results indicate that ACEMg supplementation can influence the progression of genetic hearing loss.
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Burke WF, Warnecke A, Schöner-Heinisch A, Lesinski-Schiedat A, Maier H, Lenarz T. Prevalence and audiological profiles of GJB2 mutations in a large collective of hearing impaired patients. Hear Res 2016; 333:77-86. [PMID: 26778469 DOI: 10.1016/j.heares.2016.01.006] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/18/2015] [Revised: 01/07/2016] [Accepted: 01/13/2016] [Indexed: 11/28/2022]
Abstract
Mutations in the GJB2 gene are known to represent the commonest cause of hereditary and congenital hearing loss. In this study, a complete sequencing of the GJB2 gene in a cohort of 506 patients from a single, large cochlear implant program in Europe was performed. Audiological testing for those patients who could actively participate was performed using pure tone audiometry (PTA). Those unable to undergo PTA were measured using click-auditory brainstem response (ABR). Data analysis was performed to determine genotype-phenotype correlations of the mutational status vs. audiological profiles and vs. age at the time of presentation. An overall prevalence of biallelic mutations of 13.4% was found for the total collective. When subsets of younger patients were examined, the prevalence increased to 27% of those up to age 18 and 35% of those up to age 5 at the time of testing, respectively. This increase was found to be highly significant (p < 0.001). Analysis of the mean PTA thresholds revealed a strong correlation between allele combination status and mean PTA (p = 0.021). The prevalence of simple heterozygotes was found to be approximately 10.1%, which is around 3.3 times the value expected in the general population. As GJB2 follows a recessive pattern of inheritance, the question arises as to why such a large fraction of simple heterozygotes was observed among the hearing impaired patients included in this study.
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Affiliation(s)
- W F Burke
- Department of Otolaryngology, Hannover Medical School, Hannover, Germany; Cluster of Excellence, Hearing4All, Germany.
| | - A Warnecke
- Department of Otolaryngology, Hannover Medical School, Hannover, Germany; Cluster of Excellence, Hearing4All, Germany
| | - A Schöner-Heinisch
- Institute for Human Genetics, Hannover Medical School, Hannover, Germany
| | | | - H Maier
- Department of Otolaryngology, Hannover Medical School, Hannover, Germany; Cluster of Excellence, Hearing4All, Germany
| | - T Lenarz
- Department of Otolaryngology, Hannover Medical School, Hannover, Germany; Cluster of Excellence, Hearing4All, Germany
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Cascella R, Strafella C, Gambardella S, Longo G, Borgiani P, Sangiuolo F, Novelli G, Giardina E. Two molecular assays for the rapid and inexpensive detection ofGJB2andGJB6mutations. Electrophoresis 2016; 37:860-4. [DOI: 10.1002/elps.201500346] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/24/2015] [Revised: 11/25/2015] [Accepted: 11/30/2015] [Indexed: 11/11/2022]
Affiliation(s)
- Raffaella Cascella
- Department of Biomedicine and Prevention, School of Medicine; University of Rome “Tor Vergata,”; Rome Italy
- Emotest Laboratory; Pozzuoli Italy
| | - Claudia Strafella
- Department of Biomedicine and Prevention, School of Medicine; University of Rome “Tor Vergata,”; Rome Italy
| | | | - Giuliana Longo
- Department of Biomedicine and Prevention, School of Medicine; University of Rome “Tor Vergata,”; Rome Italy
| | - Paola Borgiani
- Department of Biomedicine and Prevention, School of Medicine; University of Rome “Tor Vergata,”; Rome Italy
| | - Federica Sangiuolo
- Department of Biomedicine and Prevention, School of Medicine; University of Rome “Tor Vergata,”; Rome Italy
| | - Giuseppe Novelli
- Department of Biomedicine and Prevention, School of Medicine; University of Rome “Tor Vergata,”; Rome Italy
| | - Emiliano Giardina
- Department of Biomedicine and Prevention, School of Medicine; University of Rome “Tor Vergata,”; Rome Italy
- Molecular Genetics Laboratory UILDM; Santa Lucia Foundation; Rome Italy
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38
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Teryutin FM, Barashkov NA, Kunel'skaya NL, Pshennikova VG, Solov'ev AV. [The audiological analysis in the patients homozygous for the c.-23+1G>A mutation in the GJB2 gene presenting with the loss of hearing in Yakutiya]. Vestn Otorinolaringol 2016; 81:19-24. [PMID: 26977562 DOI: 10.17116/otorino201681119-24] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/05/2023]
Abstract
In the course of previous investigations carried out in the Republic of Sakha (Yakutiya), we have identified the main molecular-genetic factor responsible for the hereditary impairment of hearing among the indigenous population (mostly the Yakuts).The disease was shown to be attributable to the c.-23+1G>A mutation localized in the splice donor site (exon 1) of the GJB2 (Cx26) gene. The present study involved the comprehensive audiological analysis of the patients homozygous for the c.-23+1G>A mutation in the GJB2 gene based on the results of the study of a large sample of the patients residing in Yakutiya. All individuals with the GJB2 genotype c.-23+1G>A/c.-23-1G>A (n=108) at the mean age of 14.32±4.7 years (all ethnic Yakuts)were examined with the use oftonal threshold audiometry for air conduction testing at the frequencies of 0.25, 0.5, 1.0, 2.0, 4.0, and 8.0 kHz and bone conduction testing at the frequencies of 0.25, 0.5, 1.0, and 4.0 with a step of 5.0 dB.The results of the ASSR test were used whenever tonal threshold audiometry proved impracticable The data obtained in the study characterize the allelic form of the disease associated with the GJB2 genotype c.-23+1G>A/c.-23-1G>A as the congenital bilateral symmetric (90.1%), sensorineural (90.1%) form of hearing impairment of variable severity (from grade 1 to complete deafness) with the «flat» audiological profile (median slope not more than 5.0 dB in the extended frequency range (EFR) of 0.5, 1.0, 2.0, and 4.0, kHz). It is concluded that the results of the audiological analysis performed in the present study give evidence of relatively homogeneous but variable in terms of severity impairment of hearing in the patients homozygous for the c.-23+1G>A mutation in the GJB2 (Cx26) gene. It may serve as a positive prognostic sign to be used in the development and prescription of hearing aids.
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Affiliation(s)
- F M Teryutin
- Yakutsk Research Centre of Complex Medical Problems, Yakutsk, Russia, 677010; M.K. AmosovInstitute of Natural Sciences, North-Eastern Federal University, Yakutsk, Russia, 677010
| | - N A Barashkov
- Yakutsk Research Centre of Complex Medical Problems, Yakutsk, Russia, 677010; M.K. AmosovInstitute of Natural Sciences, North-Eastern Federal University, Yakutsk, Russia, 677010
| | - N L Kunel'skaya
- L.I. Sverzhevsky Research Institute of Clinical Otorhinolaryngology, Moscow Health Department, Moscow, Russia, 117152
| | - V G Pshennikova
- Yakutsk Research Centre of Complex Medical Problems, Yakutsk, Russia, 677010; M.K. AmosovInstitute of Natural Sciences, North-Eastern Federal University, Yakutsk, Russia, 677010
| | - A V Solov'ev
- M.K. AmosovInstitute of Natural Sciences, North-Eastern Federal University, Yakutsk, Russia, 677010
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Mutation spectrum of autosomal recessive non-syndromic hearing loss in central Iran. Int J Pediatr Otorhinolaryngol 2015; 79:1892-5. [PMID: 26409293 DOI: 10.1016/j.ijporl.2015.08.039] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/17/2015] [Revised: 08/25/2015] [Accepted: 08/27/2015] [Indexed: 01/05/2023]
Abstract
OBJECTIVE To identify the spectrum of mutations in connexin 26 gene and frequency of two deletions in connexin 30 gene in central Iran. METHODS After extraction of DNA from 300 blood samples, connexin 26 gene coding region was amplified using specific primers. PCR products were used for bidirectional sequencing. Multiplex PCR was used for detection of del(GJB6-D13S1830) and del(GJB6-D13S1854) in the GJB6 gene. RESULTS Eighteen different mutations including two novel variants in GJB2 gene were detected. The GJB2 mutations were observed in 23.3% of all the subjects. In addition, none of the deaf patients carried the del(GJB6-D13S1830) and del(GJB6-D13S1854) in the GJB6 gene. The 35delG mutation was the most common mutation, accounting for 32.65% of the mutant alleles. CONCLUSION The present study indicates that mutations in the GJB2 gene particularly 35delG are important causes for ARNSHL. 60% of the patients were heterozygous carriers. Thus, further investigation is needed to detect the genetic cause of hearing loss in patients with mono allelic mutations in the coding region of GJB2.
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The controversial p.Met34Thr variant in GJB2 gene: Two siblings, one genotype, two phenotypes. Int J Pediatr Otorhinolaryngol 2015; 79:1316-9. [PMID: 26117665 DOI: 10.1016/j.ijporl.2015.05.041] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/08/2015] [Revised: 05/27/2015] [Accepted: 05/31/2015] [Indexed: 01/02/2023]
Abstract
INTRODUCTION Recent advances in molecular genetics have increased the identification of genes and mutations responsible for inherited forms of hearing loss (HL), enabling early detection of these cases. Approximately, 60% of early-onset HL cases are due to genetic causes, of which 70% are non-syndromic. Of these, 75-80% are inherited in an autosomal recessive pattern (DFNB). Mutations in GJB2 gene, coding for connexin 26 (Cx26), are the major cause of autosomal recessive hereditary HL, but some GJB2 mutations are yet of unclear or controversial significance. OBJECTIVES The aim of the present study was to identify the etiology of hearing loss, and correlate genotype-phenotype, in two Portuguese siblings with profound and moderate non-syndromic sensorineural bilateral HL. MATERIAL AND METHODS The affected subjects and their parents underwent audiological and genetic study. Molecular analysis of GJB2 gene was performed, searching for mutations in the coding region and receptor splicing site by automated sequencing. RESULTS The onset and the degree of HL were different in the two affected subjects. However, the same GJB2 genotype [p.Met34Thr]+[p.Arg184Pro] was identified in both siblings. The c.551G>C (p.Arg184Pro) and c.101T>C (p.Met34Thr) missense variants were inherited from the father and mother, respectively, both heterozygous carriers of these variants. CONCLUSION The clinical and genetic data here presented suggest that the non-syndromic sensorineural HL of these two Portuguese siblings might be due to the presence of p.Met34Thr and p.Arg184Pro variants in compound heterozygosity. If so, p.Met34Thr variant could have function as a hypomorphic allele that may cause HL depending on the opposing GJB2 allele. The observed phenotypic variability may not, however, be solely explained by variable expression of this genotype. A putative modifier gene or mutations in another HL-associated gene could probably be contributing to the severe HL in one of the siblings.
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Adhikary B, Ghosh S, Paul S, Bankura B, Pattanayak AK, Biswas S, Maity B, Das M. Spectrum and frequency of GJB2, GJB6 and SLC26A4 gene mutations among nonsyndromic hearing loss patients in eastern part of India. Gene 2015; 573:239-45. [PMID: 26188157 DOI: 10.1016/j.gene.2015.07.050] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/03/2014] [Revised: 07/08/2015] [Accepted: 07/14/2015] [Indexed: 11/16/2022]
Abstract
Genetically caused nonsyndromic hearing loss is highly heterogeneous. Inspite of this large heterogeneity, mutations in the genes GJB2, GJB6 and SLC26A4 are major contributors. The mutation spectrum of these genes varies among different ethnic groups. Only a handful of studies focused on the altered genetic signature of these genes in different demographic regions of India but never focused on the eastern part of the country. Our study for the first time aimed to characterize the mutation profile of these genes in hearing loss patients of West Bengal state, India. Mutations in GJB2, GJB6 and SLC26A4 genes were screened by bidirectional sequencing from 215 congenital nonsyndromic hearing loss patients. Radiological diagnosis was performed in patients with SLC26A4 mutations by temporal bone CT scan. The study revealed that 4.65% and 6.97% patients had monoallelic and biallelic GJB2 mutations respectively. Six mutations were identified, p.W24X being the most frequent one accounting for 71.05% of the mutated alleles. Mutations in GJB6 including the previously identified deletion mutation (GJB6-D13S1830) were not identified in our study. Further, no patients harbored biallelic mutations in the SLC26A4 gene or the common inner ear malformation Enlarged Vestibular Aqueduct (EVA). The mutation profile of GJB2 in our study is distinct from other parts of India, suggesting that the mutation spectrum of this gene varies with ethnicity and geographical origin. The absence of GJB6 mutations and low frequency of SLC26A4 mutations suggest that additional genetic factors may also contribute to this disease.
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Affiliation(s)
- Bidisha Adhikary
- Department of Zoology, University of Calcutta, 35 Ballygunge Circular Road, Kolkata 700 019, West Bengal, India
| | - Sudakshina Ghosh
- Department of Zoology, University of Calcutta, 35 Ballygunge Circular Road, Kolkata 700 019, West Bengal, India
| | - Silpita Paul
- Department of Zoology, University of Calcutta, 35 Ballygunge Circular Road, Kolkata 700 019, West Bengal, India
| | - Biswabandhu Bankura
- Department of Zoology, University of Calcutta, 35 Ballygunge Circular Road, Kolkata 700 019, West Bengal, India
| | - Arup Kumar Pattanayak
- Department of Zoology, University of Calcutta, 35 Ballygunge Circular Road, Kolkata 700 019, West Bengal, India
| | - Subhradev Biswas
- Department of E.N.T., Institute of Post Graduate Medical Education & Research, 244 A J C Bose Road, Kolkata 700 020, West Bengal, India
| | - Biswanath Maity
- Department of Zoology, University of Calcutta, 35 Ballygunge Circular Road, Kolkata 700 019, West Bengal, India
| | - Madhusudan Das
- Department of Zoology, University of Calcutta, 35 Ballygunge Circular Road, Kolkata 700 019, West Bengal, India.
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Amorini M, Romeo P, Bruno R, Galletti F, Di Bella C, Longo P, Briuglia S, Salpietro C, Rigoli L. Prevalence of Deafness-Associated Connexin-26 (GJB2) and Connexin-30 (GJB6) Pathogenic Alleles in a Large Patient Cohort from Eastern Sicily. Ann Hum Genet 2015; 79:341-349. [PMID: 26096904 DOI: 10.1111/ahg.12120] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/19/2014] [Accepted: 03/24/2015] [Indexed: 11/28/2022]
Abstract
Mutations in the gene encoding the gap junction protein connexin 26 (GJB2) and connexin 30 (GJB6) have been shown to be a major contributor to prelingual, sensorineural, nonsyndromic deafness. The aim of this study was to characterize and establish the prevalence of GJB2 and GJB6 gene alterations in 196 patients affected by sensorineural, nonsyndromic hearing loss, from Eastern Sicily. We performed sequence analysis of GJB2 and identified sequence variants in 68 out of 196 patients (34.7%); (28 homozygous for c.35delG, 22 compound heterozygous and 11 with only one variant allele). We found 12 different allelic variants, the most prevalent being c.35delG, which was found on 89 chromosomes (65.5%), followed by other alleles with different frequencies (p.E47X, c.-23+1G>A, p.L90P, p.R184W, p.M34T, c.167delT, p.R127H, p.M163V, p.V153I, p.W24X, and p.T8M). Importantly, for the first time we present the frequency and spectrum of GJB2 mutations in NSHL patients from Eastern Sicily. No alterations were found in the GJB6 gene, confirming that alterations in this gene are uncommon in our geographic area. Note that 65.3% and 23.5% of our patients, respectively were found to be negative or carriers by GJB2 molecular screening. This emphasizes the need to broaden the genetic analysis to other genes involved in hearing loss.
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Affiliation(s)
- Maria Amorini
- Department of Paediatrics, University of Messina, Italy
| | | | - Rocco Bruno
- Department of Experimental Medical-Surgery, Specialist and Odontostomatological Science, Otorhinolaringology and Auditory Microsurgery Unit, University of Messina, Italy
| | - Francesco Galletti
- Department of Experimental Medical-Surgery, Specialist and Odontostomatological Science, Otorhinolaringology and Auditory Microsurgery Unit, University of Messina, Italy
| | | | - Patrizia Longo
- Department of Experimental Medical-Surgery, Specialist and Odontostomatological Science, Otorhinolaringology and Auditory Microsurgery Unit, University of Messina, Italy
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Kim SY, Kim AR, Han KH, Kim MY, Jeon EH, Koo JW, Oh SH, Choi BY. Residual Hearing in DFNB1 Deafness and Its Clinical Implication in a Korean Population. PLoS One 2015; 10:e0125416. [PMID: 26061264 PMCID: PMC4464755 DOI: 10.1371/journal.pone.0125416] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/27/2014] [Accepted: 03/23/2015] [Indexed: 11/19/2022] Open
Abstract
Introduction The contribution of Gap junction beta-2 protein (GJB2) to the genetic load of deafness and its mutation spectra vary among different ethnic groups. Objective In this study, the mutation spectrum and audiologic features of patients with GJB2 mutations were evaluated with a specific focus on residual hearing. Methods An initial cohort of 588 subjects from 304 families with varying degrees of hearing loss were collected at the otolaryngology clinics of Seoul National University Hospital and Seoul National University Bundang Hospital from September 2010 through January 2014. GJB2 sequencing was carried out for 130 probands with sporadic or autosomal recessive non syndromic hearing loss. The audiograms were evaluated in the GJB2 mutants. Results Of the 130 subjects, 22 (16.9%) were found to carry at least one mutant allele of GJB2. The c.235delC mutation was shown to have the most common allele frequency (39.0%) among GJB2 mutations, followed by p.R143W (26.8%) and p.V37I (9.8%). Among those probands without the p.V37I allele in a trans configuration who showed some degree of residual hearing, the mean air conduction thresholds at 250 and 500 Hz were 57 dB HL and 77.8 dB HL, respectively. The c.235delC mutation showed a particularly wide spectrum of hearing loss, from mild to profound and significantly better hearing thresholds at 250 Hz and 2k Hz than in the non-p.V37I and non-235delC nonsyndromic hearing loss and deafness 1(DFNB1) subjects. Conclusion Despite its reputation as the cause of severe to profound deafness, c.235delC, the most frequent DFNB1 mutation in our cohort, caused a wide range of hearing loss with some residual hearing in low frequencies. This finding can be of paramount help for prediction of low frequency hearing thresholds in very young DFNB1 patients and highlights the importance of soft surgery for cochlear implantation in these patients.
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Affiliation(s)
- So Young Kim
- Department of Otorhinolaryngology-Head and Neck Surgery, Seoul National University Hospital, Seoul National University College of Medicine, Seoul, Korea
| | - Ah Reum Kim
- Department of Otorhinolaryngology-Head and Neck Surgery, Seoul National University Hospital, Seoul National University College of Medicine, Seoul, Korea
| | - Kyu Hee Han
- Department of Otorhinolaryngology-Head and Neck Surgery, National Medical Center, Seoul, Korea
| | - Min Young Kim
- Department of Otorhinolaryngology-Head and Neck Surgery, Seoul National University Bundang Hospital, Seoul National University College of Medicine, Seongnam, Korea
| | - Eun-Hee Jeon
- Department of Otorhinolaryngology-Head and Neck Surgery, Seoul National University Bundang Hospital, Seoul National University College of Medicine, Seongnam, Korea
| | - Ja-Won Koo
- Department of Otorhinolaryngology-Head and Neck Surgery, Seoul National University Bundang Hospital, Seoul National University College of Medicine, Seongnam, Korea
- Sensory Organ Research Institute, Seoul National University Medical Research Center, Seoul, Korea
| | - Seung Ha Oh
- Department of Otorhinolaryngology-Head and Neck Surgery, Seoul National University Hospital, Seoul National University College of Medicine, Seoul, Korea
- Sensory Organ Research Institute, Seoul National University Medical Research Center, Seoul, Korea
| | - Byung Yoon Choi
- Department of Otorhinolaryngology-Head and Neck Surgery, Seoul National University Bundang Hospital, Seoul National University College of Medicine, Seongnam, Korea
- Sensory Organ Research Institute, Seoul National University Medical Research Center, Seoul, Korea
- * E-mail:
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Zheng J, Ying Z, Cai Z, Sun D, He Z, Gao Y, Zhang T, Zhu Y, Chen Y, Guan MX. GJB2 Mutation Spectrum and Genotype-Phenotype Correlation in 1067 Han Chinese Subjects with Non-Syndromic Hearing Loss. PLoS One 2015; 10:e0128691. [PMID: 26043044 PMCID: PMC4456361 DOI: 10.1371/journal.pone.0128691] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/13/2015] [Accepted: 04/29/2015] [Indexed: 11/17/2022] Open
Abstract
Mutations in Gap Junction Beta 2 (GJB2) have been reported to be a major cause of non-syndromic hearing loss in many populations worldwide. The spectrums and frequencies of GJB2 variants vary substantially among different ethnic groups, and the genotypes among these populations remain poorly understood. In the present study, we carried out a systematic and extended mutational screening of GJB2 gene in 1067 Han Chinese subjects with non-syndromic hearing loss, and the resultant GJB2 variants were evaluated by phylogenetic, structural and bioinformatic analysis. A total of 25 (23 known and 2 novel) GJB2 variants were identified, including 6 frameshift mutations, 1 nonsense mutation, 16 missense mutations and 2 silent mutations. In this cohort, c.235delC is the most frequently observed pathogenic mutation. The phylogenetic, structural and bioinformatic analysis showed that 2 novel variants c.127G>T (p.V43L), c.293G>C (p.R98P) and 2 known variants c. 107T>C (p.L36P) and c.187G>T (p.V63L) are localized at highly conserved amino acids. In addition, these 4 mutations are absent in 203 healthy individuals, therefore, they are probably the most likely candidate pathogenic mutations. In addition, 66 (24 novel and 42 known) genotypes were identified, including 6 homozygotes, 20 compound heterozygotes, 18 single heterozygotes, 21 genotypes harboring only polymorphism(s) and the wild type genotype. Among these, 153 (14.34%) subjects were homozygous for pathogenic mutations, 63 (5.91%) were compound heterozygotes, and 157 (14.71%) carried single heterozygous mutation. Furthermore, 65.28% (141/216) of these cases with two pathogenic mutations exhibited profound hearing loss. These data suggested that mutations in GJB2 gene are responsible for approximately 34.96% of non-syndromic hearing loss in Han Chinese population from Zhejiang Province in eastern China. In addition, our results also strongly supported the idea that other factors such as alterations in regulatory regions, additional genes, and environmental factors may contribute to the clinical manifestation of deafness.
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Affiliation(s)
- Jing Zheng
- Institute of Genetics, School of Medicine, Zhejiang University, Hangzhou, China
| | - Zhengbiao Ying
- Department of Otolaryngology, Wenling People’s Hospital, Wenzhou Medical University, Taizhou, China
| | - Zhaoyang Cai
- Department of Otolaryngology, Wenling People’s Hospital, Wenzhou Medical University, Taizhou, China
| | - Dongmei Sun
- Department of Laboratory Medicine, Jinhua Municipal Central Hospital, Jinhua, China
| | - Zheyun He
- Attardi Institute of Mitochondrial Biomedicine, School of Laboratory Medicine and Life Sciences, Wenzhou Medical University, Wenzhou, China
| | - Yinglong Gao
- Attardi Institute of Mitochondrial Biomedicine, School of Laboratory Medicine and Life Sciences, Wenzhou Medical University, Wenzhou, China
| | - Ting Zhang
- Department of Otolaryngology, Wenling People’s Hospital, Wenzhou Medical University, Taizhou, China
| | - Yi Zhu
- Department of Otolaryngology, the First Affiliated Hospital, Wenzhou Medical University, Wenzhou, China
| | - Ye Chen
- Institute of Genetics, School of Medicine, Zhejiang University, Hangzhou, China
- Collaborative Innovation Center for Diagnosis and Treatment of Infectious Diseases, Zhejiang University, Hangzhou, China
| | - Min-Xin Guan
- Institute of Genetics, School of Medicine, Zhejiang University, Hangzhou, China
- Collaborative Innovation Center for Diagnosis and Treatment of Infectious Diseases, Zhejiang University, Hangzhou, China
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Zonta F, Girotto G, Buratto D, Crispino G, Morgan A, Abdulhadi K, Alkowari M, Badii R, Gasparini P, Mammano F. The p.Cys169Tyr variant of connexin 26 is not a polymorphism. Hum Mol Genet 2015; 24:2641-8. [PMID: 25628337 PMCID: PMC4383868 DOI: 10.1093/hmg/ddv026] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/10/2014] [Accepted: 01/21/2015] [Indexed: 12/31/2022] Open
Abstract
Mutations in the GJB2 gene, which encodes the gap junction protein connexin 26 (Cx26), are the primary cause of hereditary prelingual hearing impairment. Here, the p.Cys169Tyr missense mutation of Cx26 (Cx26C169Y), previously classified as a polymorphism, has been identified as causative of severe hearing loss in two Qatari families. We have analyzed the effect of this mutation using a combination of confocal immunofluorescence microscopy and molecular dynamics simulations. At the cellular level, our results show that the mutant protein fails to form junctional channels in HeLa transfectants despite being correctly targeted to the plasma membrane. At the molecular level, this effect can be accounted for by disruption of the disulfide bridge that Cys169 forms with Cys64 in the wild-type structure (Cx26WT). The lack of the disulfide bridge in the Cx26C169Y protein causes a spatial rearrangement of two important residues, Asn176 and Thr177. In the Cx26WT protein, these residues play a crucial role in the intra-molecular interactions that permit the formation of an intercellular channel by the head-to-head docking of two opposing hemichannels resident in the plasma membrane of adjacent cells. Our results elucidate the molecular pathogenesis of hereditary hearing loss due to the connexin mutation and facilitate the understanding of its role in both healthy and affected individuals.
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Affiliation(s)
- Francesco Zonta
- Dipartimento di Fisica e Astronomia 'G. Galilei', Università di Padova, 35131 Padova, Italy
| | - Giorgia Girotto
- Department of Medical, Surgical and Health Sciences, University of Trieste, 34100 Trieste, Italy
| | - Damiano Buratto
- Dipartimento di Fisica e Astronomia 'G. Galilei', Università di Padova, 35131 Padova, Italy
| | - Giulia Crispino
- Dipartimento di Fisica e Astronomia 'G. Galilei', Università di Padova, 35131 Padova, Italy, Istituto Veneto di Medicina Molecolare, Fondazione per la Ricerca Biomedica Avanzata, 35129 Padova, Italy
| | - Anna Morgan
- Department of Medical, Surgical and Health Sciences, University of Trieste, 34100 Trieste, Italy
| | - Khalid Abdulhadi
- Audiology and Balance Unit, National Program for Early Detection of Hearing Loss, WH, Hamad Medical Corporation (HMC) Doha, Doha, Qatar
| | - Moza Alkowari
- Molecular Genetics Laboratory, Department of Laboratory of Medicine and Pathology, Hamad Medical Corporation (HMC), Doha, Qatar
| | - Ramin Badii
- Molecular Genetics Laboratory, Department of Laboratory of Medicine and Pathology, Hamad Medical Corporation (HMC), Doha, Qatar
| | - Paolo Gasparini
- Department of Medical, Surgical and Health Sciences, University of Trieste, 34100 Trieste, Italy, Medical Genetics, Institute for Maternal and Child Health-IRCCS 'Burlo Garofolo', Trieste, Italy and
| | - Fabio Mammano
- Dipartimento di Fisica e Astronomia 'G. Galilei', Università di Padova, 35131 Padova, Italy, Istituto Veneto di Medicina Molecolare, Fondazione per la Ricerca Biomedica Avanzata, 35129 Padova, Italy, CNR Institute of Cell Biology and Neurobiology, 00015 Monterotondo, Rome, Italy
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Lang-Roth R. Hearing impairment and language delay in infants: Diagnostics and genetics. GMS CURRENT TOPICS IN OTORHINOLARYNGOLOGY, HEAD AND NECK SURGERY 2014; 13:Doc05. [PMID: 25587365 PMCID: PMC4273166 DOI: 10.3205/cto000108] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
This overview study provides information on important phoniatric and audiological aspects of early childhood hearing and language development with the aim of presenting diagnostic and therapeutic approaches. The article first addresses the universal newborn hearing screening that has been implemented in Germany for all infants since January 2009. The process of newborn hearing screening from the maternity ward to confirmation diagnostics is presented in accordance with a decision by the Federal Joint Committee (G-BA). The second topic is pediatric audiology diagnostics. Following confirmation of a permanent early childhood hearing disorder, the search for the cause plays an important role. Hereditary hearing disorders and intrauterine cytomegalovirus (CMV) infection, probably the most common cause of an acquired hearing disorder, are discussed and compared with the most common temporary hearing disorder, otitis media with effusion, which in some cases is severe enough to be relevant for hearing and language development and therefore requires treatment. The third topic covered in this article is speech and language development in the first 3 years of life, which is known today to be crucial for later language development and learning to read and write. There is a short overview and introduction to modern terminology, followed by the abnormalities and diagnostics of early speech and language development. Only some aspects of early hearing and language development are addressed here. Important areas such as the indication for a cochlear implant in the first year of life or because of unilateral deafness are not included due to their complexity.
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Affiliation(s)
- Ruth Lang-Roth
- Department of Otorhinolaryngology, Cologne University Hospital. Köln, Germany
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Beck C, Pérez-Álvarez JC, Sigruener A, Haubner F, Seidler T, Aslanidis C, Strutz J, Schmitz G. Identification and genotype/phenotype correlation of mutations in a large German cohort with hearing loss. Eur Arch Otorhinolaryngol 2014; 272:2765-76. [PMID: 25214170 DOI: 10.1007/s00405-014-3157-5] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/08/2013] [Accepted: 06/15/2014] [Indexed: 12/25/2022]
Abstract
The prevalence of hearing impairment is estimated as approximately 1 on 1,000 newborn children. To assess a higher mutation detection rate in individuals with hearing loss a three-step mutation screening program consisting of GJB2 in first line, then GJB1, GJB3 and GJB6 (second step) and if tested negative or heterozygote, testing of GJA1, GJB4, SLC26A4 and PJVK (third) was performed. Audiograms were derived from all patients to characterize audiological features of GJB2 mutations especially. In 59 patients (31.3%) of the 188 probands, the hearing impairment was due to GJB2 mutations, 45 (23.9%) of these being homozygous for 35delG mutation and 14 (7.4%) compound heterozygous for GJB2 mutations in the coding region of exon 2 whereas no significant sequence variation was found in exon 1. In 22 (11.7%) additional patients a single recessive mutation in GJB2, GJB3, GJB6 and SLC26A4 without a second mutation on the other allele was identified, making genetic counseling difficult. Our study showed significant difference in hearing loss degree in the patients with GJB2-mutations. Forty-five (45.5%) GJB2-cases were identified in 99 individuals diagnosed with severe to profound hearing loss, 14 (17.7%) GJB2-cases were identified in 79 individuals with moderate deafness whereas no clear GJB2 mutation was found in 10 patients with mild hearing loss (p < 0.001). Revealing a high variability of hearing levels in identical genotypes (even intrafamilial), a significant genotype-phenotype correlation could not be established. Based on the identified mutations spectrum and frequencies, speaking mostly of GJB2, a step by step screening for mutations can be devised and in addition may lead to a better stratification of patients for specific therapeutical approaches.
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Affiliation(s)
- Christopher Beck
- Institute for Clinical Chemistry and Laboratory Medicine, University Hospital Regensburg, Franz-Josef-Strauß-Allee 11, 93053, Regensburg, Germany
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Hearing impairment in Estonia: an algorithm to investigate genetic causes in pediatric patients. Adv Med Sci 2014; 58:419-28. [PMID: 24222258 DOI: 10.2478/ams-2013-0001] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
PURPOSE The present study was initiated to establish the etiological causes of early onset hearing loss (HL) among Estonian children between 2000-2009. METHODS The study group consisted of 233 probands who were first tested with an arrayed primer extension assay, which covers 199 mutations in 7 genes (GJB2, GJB6, GJB3, SLC26A4, SLC26A5 genes, and two mitochondrial genes - 12S rRNA, tRNASer(UCN)). From probands whose etiology of HL remained unknown, DNA analysis of congenital cytomegalovirus (CMV) infection and G-banded karyotype and/or chromosomal microarray analysis (CMA) were performed. RESULTS In 110 (47%) cases, the etiology of HL was genetic and in 5 (2%) congenital CMV infection was diagnosed. We found mutations with clinical significance in GJB2 (100 children, 43%) and in 2 mitochondrial genes (2 patients, 1%). A single mutation in SLC26A4 gene was detected in 5 probands (2.2%) and was considered diagnostic. In 4 probands a heterozygous IVS2-2A>G change in the SLC26A5 gene was found. We did not find any instances of homozygosity for this splice variant in the probands. CMA identified in 4 probands chromosomal regions with the loss of one allele. In 2 of them we were able to conclude that the found abnormalities are definitely pathogenic (12q13.3-q14.2 and 17q22-23.2 microdeletion), but the pathogenity of 2 other findings (3p26.2 and 1p33 microdeletion) remained unknown. CONCLUSION This practical diagnostic algorithm confirmed the etiology of early onset HL for 115 Estonian patients (49%). This algorithm may be generalized to other populations for clinical application.
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Identification of D179H, a novel missense GJB2 mutation in a Western Sicily family. Eur Arch Otorhinolaryngol 2014; 271:1457-61. [DOI: 10.1007/s00405-013-2613-y] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/21/2013] [Accepted: 06/19/2013] [Indexed: 10/26/2022]
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Salvago P, Martines E, La Mattina E, Mucia M, Sammarco P, Sireci F, Martines F. Distribution and phenotype of GJB2 mutations in 102 Sicilian patients with congenital non syndromic sensorineural hearing loss. Int J Audiol 2014; 53:558-63. [PMID: 24793888 DOI: 10.3109/14992027.2014.905717] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
Abstract
OBJECTIVE To evaluate the frequency of GJB2 mutations and their correlation with phenotype in Sicilian non-syndromic sensorineural hearing loss (NSHL) patients. DESIGN Sequencing of the coding region, basal promoter, exon 1, and donor splice site of the GJB2 gene; screening for the presence of the two common GJB6 deletions. STUDY SAMPLE A cohort of 102 Sicilian NSHL patients. RESULTS Fifteen different mutations in GJB2 and seventeen different genotypes were detected. No GJB6 mutations were found. The hearing impairment was profound in the 64.72% of probands (mean PTA0.25-4 kHz of 88.82 ± 26.52 dB HL). A total of 81.37% of patients harboured at least one c.35delG allele; c.167delT and c.-23 + 1G> A were identified in 10.78% and the 9.8% of patients respectively; c.35delG homozygotes presented more severe hearing impairment (75.59% of profound hearing loss) and a higher mean PTA0.25-4 kHz (96.79 ± 21.11 dB HL) with respect to c.35delG/non-c.35delG and c.35delG/Wt patients (P < 0.05). CONCLUSIONS This work underlines the role of c.35delG, c.167delT and c.-23 + 1G> A as the most frequent causes of NSHL in Sicily. The c.35delG frequency found is similar to those reported in other populations of the Mediterranean area. The analysis of genetic and audiologic data confirmed a variability in the phenotype associated to a single genotype.
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Affiliation(s)
- Pietro Salvago
- * Dipartimento di Biomedicina Sperimentale e Neuroscienze Cliniche, (BioNeC), Sezione di Otorinolaringoiatria, Università degli Studi di Palermo , Palermo , Italy
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