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Posukh OL, Maslova EA, Danilchenko VY, Zytsar MV, Orishchenko KE. Functional Consequences of Pathogenic Variants of the GJB2 Gene (Cx26) Localized in Different Cx26 Domains. Biomolecules 2023; 13:1521. [PMID: 37892203 PMCID: PMC10604905 DOI: 10.3390/biom13101521] [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: 09/15/2023] [Revised: 10/08/2023] [Accepted: 10/10/2023] [Indexed: 10/29/2023] Open
Abstract
One of the most common forms of genetic deafness has been predominantly associated with pathogenic variants in the GJB2 gene, encoding transmembrane protein connexin 26 (Cx26). The Cx26 molecule consists of an N-terminal domain (NT), four transmembrane domains (TM1-TM4), two extracellular loops (EL1 and EL2), a cytoplasmic loop, and a C-terminus (CT). Pathogenic variants in the GJB2 gene, resulting in amino acid substitutions scattered across the Cx26 domains, lead to a variety of clinical outcomes, including the most common non-syndromic autosomal recessive deafness (DFNB1A), autosomal dominant deafness (DFNA3A), as well as syndromic forms combining hearing loss and skin disorders. However, for rare and poorly documented variants, information on the mode of inheritance is often lacking. Numerous in vitro studies have been conducted to elucidate the functional consequences of pathogenic GJB2 variants leading to amino acid substitutions in different domains of Cx26 protein. In this work, we summarized all available data on a mode of inheritance of pathogenic GJB2 variants leading to amino acid substitutions and reviewed published information on their functional effects, with an emphasis on their localization in certain Cx26 domains.
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Affiliation(s)
- Olga L. Posukh
- Federal Research Center Institute of Cytology and Genetics, Siberian Branch of the Russian Academy of Sciences, 630090 Novosibirsk, Russia; (E.A.M.); (V.Y.D.); (M.V.Z.); (K.E.O.)
- Novosibirsk State University, 630090 Novosibirsk, Russia
| | - Ekaterina A. Maslova
- Federal Research Center Institute of Cytology and Genetics, Siberian Branch of the Russian Academy of Sciences, 630090 Novosibirsk, Russia; (E.A.M.); (V.Y.D.); (M.V.Z.); (K.E.O.)
- Novosibirsk State University, 630090 Novosibirsk, Russia
| | - Valeriia Yu. Danilchenko
- Federal Research Center Institute of Cytology and Genetics, Siberian Branch of the Russian Academy of Sciences, 630090 Novosibirsk, Russia; (E.A.M.); (V.Y.D.); (M.V.Z.); (K.E.O.)
- Novosibirsk State University, 630090 Novosibirsk, Russia
| | - Marina V. Zytsar
- Federal Research Center Institute of Cytology and Genetics, Siberian Branch of the Russian Academy of Sciences, 630090 Novosibirsk, Russia; (E.A.M.); (V.Y.D.); (M.V.Z.); (K.E.O.)
| | - Konstantin E. Orishchenko
- Federal Research Center Institute of Cytology and Genetics, Siberian Branch of the Russian Academy of Sciences, 630090 Novosibirsk, Russia; (E.A.M.); (V.Y.D.); (M.V.Z.); (K.E.O.)
- Novosibirsk State University, 630090 Novosibirsk, Russia
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Sharma N, Kumari D, Panigrahi I, Khetarpal P. A systematic review of the monogenic causes of Non-Syndromic Hearing Loss (NSHL) and discussion of Current Diagnosis and Treatment options. Clin Genet 2023; 103:16-34. [PMID: 36089522 DOI: 10.1111/cge.14228] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/26/2022] [Revised: 09/02/2022] [Accepted: 09/06/2022] [Indexed: 12/13/2022]
Abstract
Hearing impairment is one of the most widespread inheritable sensory disorder affecting at least 1 in every 1000 born. About two-third of hereditary hearing loss (HHL) disorders are non-syndromic. To provide comprehensive update of monogenic causes of non-syndromic hearing loss (NSHL), literature search has been carried out with appropriate keywords in the following databases-PubMed, Google Scholar, Cochrane library, and Science Direct. Out of 2214 papers, 271 papers were shortlisted after applying inclusion and exclusion criterion. Data extracted from selected papers include information about gene name, identified pathogenic variants, ethnicity of the patient, age of onset, gender, title, authors' name, and year of publication. Overall, pathogenic variants in 98 different genes have been associated with NSHL. These genes have important role to play during early embryonic development in ear structure formation and hearing development. Here, we also review briefly the recent information about diagnosis and treatment approaches. Understanding pathogenic genetic variants are helpful in the management of affected and may offer targeted therapies in future.
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Affiliation(s)
- Nandita Sharma
- Department of Human Genetics and Molecular Medicine, School of Health Sciences, Central University of Punjab, Bathinda, India
| | - Divya Kumari
- Department of Pediatrics Medicine, Post Graduate Institute of Medical Education and Research, Chandigarh, India
| | - Inusha Panigrahi
- Department of Pediatrics Medicine, Post Graduate Institute of Medical Education and Research, Chandigarh, India
| | - Preeti Khetarpal
- Department of Human Genetics and Molecular Medicine, School of Health Sciences, Central University of Punjab, Bathinda, India
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Jiang H, Niu Y, Qu L, Huang X, Zhu X, Tang G. A novel compound heterozygous mutation in the GJB2 gene is associated with non-syndromic hearing loss in a Chinese family. Biosci Trends 2019; 12:470-475. [PMID: 30473554 DOI: 10.5582/bst.2018.01156] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
Abstract
Autosomal recessive (AR) non-syndromic hearing loss (NSHL) is the most common form of hereditary deafness. Mutations in the gap junction protein beta 2 (GJB2) gene encoding connexin 26 (Cx26) account for about 50% of cases of ARNSHL. In the current study, a combination of exome sequencing and Sanger sequencing in a Chinese Dong family with ARNSHL allowed identification of a novel compound heterozygous mutation c.240G>C(p. Q80H)/C.109G>A(p.V37I) in exon 2 of the GJB2 gene, which co-segregated with the disease phenotype in this family and was not evident in 100 healthy controls. Bioinformatic analysis revealed that the two mutations in the GJB2 gene were probably pathogenic. Results indicated that the compound heterozygous variants, p.Q80H and p.V37I, in the GJB2 gene are associated with ARNSHL. The Q80H variant was initially identified in patients of Dong Chinese origin with NSHL. The current results broaden the spectrum of GJB2 mutations responsible for NSHL and have important implications for molecular diagnosis, treatment, and genetic counseling for this family.
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Affiliation(s)
- Haiou Jiang
- Department of Cellular Biology and Genetics, Hunan Provincial Key Laboratory of Dong Medicine, Hunan University of Medicine
| | - Youya Niu
- Department of Cellular Biology and Genetics, Hunan Provincial Key Laboratory of Dong Medicine, Hunan University of Medicine
| | - Lingfeng Qu
- Department of Cellular Biology and Genetics, Hunan Provincial Key Laboratory of Dong Medicine, Hunan University of Medicine
| | - Xueshuang Huang
- Department of Cellular Biology and Genetics, Hunan Provincial Key Laboratory of Dong Medicine, Hunan University of Medicine
| | - Xinlong Zhu
- Department of Cellular Biology and Genetics, Hunan Provincial Key Laboratory of Dong Medicine, Hunan University of Medicine
| | - Genyun Tang
- Department of Cellular Biology and Genetics, Hunan Provincial Key Laboratory of Dong Medicine, Hunan University of Medicine
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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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Shi X, Qiu S, Yan F, Shi L, Xuan Y, Zhuang W, Bei Y, Yao H, Yuan N, Yang S, Qiao Y. Polymorphism of the 86th amino acid in CX26 protein and hereditary deafness. J Otol 2016; 11:84-87. [PMID: 29937815 PMCID: PMC6002600 DOI: 10.1016/j.joto.2016.05.004] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/26/2016] [Revised: 05/17/2016] [Accepted: 05/17/2016] [Indexed: 11/24/2022] Open
Abstract
Objective To investigate the membrane localization function of the CX26 protein when its 86th amino acid is Thr, Ser or Arg, and its relations to deafness. Methods CX26-GFP protein with either Thr, Ser or Arg as the 86th amino acid was expressed in mouse SGN cells via the GFP fusion type lenti-virus expression system. The membrane localization of the fusion protein was observed under a fluorescence microscope. Results The mutated protein of CX26 T86S was localized to cell membrane and form gap conjunction structures, showing no difference to the wild type CX26 protein (with Thr as the 86th amino acid). However, the gap conjunction structure disappeared when the mutation was CX26 T86A. Conclusion These results indicate that the CX26 T86R mutation may be a cause of hearing loss, but CX26 T86S as a non-pathogenic polymorphism mutation does not affect functions of the CX26 protein. The results are in accordance with the results of clinical screening.
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Affiliation(s)
- Xi Shi
- Institute of Audiology and Balance Science, Xuzhou Medical University, Xuzhou 221004, China
| | - Shiwei Qiu
- Institute of Audiology and Balance Science, Xuzhou Medical University, Xuzhou 221004, China
| | - Fendong Yan
- Institute of Audiology and Balance Science, Xuzhou Medical University, Xuzhou 221004, China
| | - Lizhang Shi
- Institute of Audiology and Balance Science, Xuzhou Medical University, Xuzhou 221004, China
| | - Yili Xuan
- Institute of Audiology and Balance Science, Xuzhou Medical University, Xuzhou 221004, China
| | - Wei Zhuang
- Institute of Audiology and Balance Science, Xuzhou Medical University, Xuzhou 221004, China
| | - Yingli Bei
- Institute of Audiology and Balance Science, Xuzhou Medical University, Xuzhou 221004, China
| | - Hanli Yao
- Institute of Audiology and Balance Science, Xuzhou Medical University, Xuzhou 221004, China
| | - Na Yuan
- Institute of Audiology and Balance Science, Xuzhou Medical University, Xuzhou 221004, China
| | - Shiming Yang
- Department of Otolaryngology-Head & Neck Surgery, Institute of Otolaryngology of PLA, Chinese PLA General Hospital, Beijing 100853, China
| | - Yuehua Qiao
- Clinical Hearing Center, Affiliated Hospital of Xuzhou Medical University, Xuzhou 221006, China
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Molecular Impairment Mechanisms of Novel OPA1 Mutations Predicted by Molecular Modeling in Patients With Autosomal Dominant Optic Atrophy and Auditory Neuropathy Spectrum Disorder. Otol Neurotol 2016; 37:394-402. [PMID: 26905822 DOI: 10.1097/mao.0000000000000978] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
HYPOTHESIS Different missense mutations of the optic atrophy 1 gene (OPA1) identified in optic atrophy patients with auditory neuropathy spectrum disorder (ANSD) induce functional impairment through different molecular mechanisms. BACKGROUND OPA1 is the gene responsible for autosomal dominant optic atrophy (ADOA), but some of its mutations are also associated with ANSD. OPA1 is a member of the GTPase family of proteins and plays a key role in the maintenance of mitochondrial activities that are dependent on dimer formation of the protein. There are many reports of OPA1 mutations, but the molecular mechanisms of their functional impairments are unclear. METHODS The sequences of coding regions in OPA1 were analyzed from blood samples of ADOA patients with ANSD. Molecular modeling of the protein's ability to form dimers and its GTP-binding ability were conducted to study the effects of structural changes in OPA1 caused by two identified mutations and their resultant effects on protein function. RESULTS Two heterozygous mutations, p.T414P (c.1240A>C) and p.T540P (c.1618A>C), located in the GTPase and middle domains of OPA1, respectively, were identified in two patients. Molecular modeling indicated decreased dimer formation caused by destabilization of the association structure of the p.T414P mutant, and decreased GTP-binding caused by destabilization of the binding site structure in the p.T540P mutant. CONCLUSION These two different conformational changes might result in decreased GTPase activities that trigger ADOA associated with ANSD, and are likely to be associated with mild clinical features. Molecular modeling would provide useful information in clinical practice.
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