1
|
Aldè M, Cantarella G, Zanetti D, Pignataro L, La Mantia I, Maiolino L, Ferlito S, Di Mauro P, Cocuzza S, Lechien JR, Iannella G, Simon F, Maniaci A. Autosomal Dominant Non-Syndromic Hearing Loss (DFNA): A Comprehensive Narrative Review. Biomedicines 2023; 11:1616. [PMID: 37371710 DOI: 10.3390/biomedicines11061616] [Citation(s) in RCA: 9] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/07/2023] [Revised: 05/26/2023] [Accepted: 05/29/2023] [Indexed: 06/29/2023] Open
Abstract
Autosomal dominant non-syndromic hearing loss (HL) typically occurs when only one dominant allele within the disease gene is sufficient to express the phenotype. Therefore, most patients diagnosed with autosomal dominant non-syndromic HL have a hearing-impaired parent, although de novo mutations should be considered in all cases of negative family history. To date, more than 50 genes and 80 loci have been identified for autosomal dominant non-syndromic HL. DFNA22 (MYO6 gene), DFNA8/12 (TECTA gene), DFNA20/26 (ACTG1 gene), DFNA6/14/38 (WFS1 gene), DFNA15 (POU4F3 gene), DFNA2A (KCNQ4 gene), and DFNA10 (EYA4 gene) are some of the most common forms of autosomal dominant non-syndromic HL. The characteristics of autosomal dominant non-syndromic HL are heterogenous. However, in most cases, HL tends to be bilateral, post-lingual in onset (childhood to early adulthood), high-frequency (sloping audiometric configuration), progressive, and variable in severity (mild to profound degree). DFNA1 (DIAPH1 gene) and DFNA6/14/38 (WFS1 gene) are the most common forms of autosomal dominant non-syndromic HL affecting low frequencies, while DFNA16 (unknown gene) is characterized by fluctuating HL. A long audiological follow-up is of paramount importance to identify hearing threshold deteriorations early and ensure prompt treatment with hearing aids or cochlear implants.
Collapse
Affiliation(s)
- Mirko Aldè
- Department of Clinical Sciences and Community Health, University of Milan, 20090 Milan, Italy
- Department of Specialist Surgical Sciences, Fondazione IRCCS Ca' Granda Ospedale Maggiore Policlinico, 20090 Milan, Italy
- Otology Study Group of the Young-Otolaryngologists of the International Federations of Oto-Rhino-Laryngological Societies (YO-IFOS), 75000 Paris, France
| | - Giovanna Cantarella
- Department of Clinical Sciences and Community Health, University of Milan, 20090 Milan, Italy
- Department of Specialist Surgical Sciences, Fondazione IRCCS Ca' Granda Ospedale Maggiore Policlinico, 20090 Milan, Italy
| | - Diego Zanetti
- Department of Clinical Sciences and Community Health, University of Milan, 20090 Milan, Italy
- Department of Specialist Surgical Sciences, Fondazione IRCCS Ca' Granda Ospedale Maggiore Policlinico, 20090 Milan, Italy
| | - Lorenzo Pignataro
- Department of Clinical Sciences and Community Health, University of Milan, 20090 Milan, Italy
- Department of Specialist Surgical Sciences, Fondazione IRCCS Ca' Granda Ospedale Maggiore Policlinico, 20090 Milan, Italy
| | - Ignazio La Mantia
- Department of Medical, Surgical Sciences and Advanced Technologies G.F. Ingrassia, University of Catania, 95123 Catania, Italy
| | - Luigi Maiolino
- Department of Medical, Surgical Sciences and Advanced Technologies G.F. Ingrassia, University of Catania, 95123 Catania, Italy
| | - Salvatore Ferlito
- Department of Medical, Surgical Sciences and Advanced Technologies G.F. Ingrassia, University of Catania, 95123 Catania, Italy
| | - Paola Di Mauro
- Department of Medical, Surgical Sciences and Advanced Technologies G.F. Ingrassia, University of Catania, 95123 Catania, Italy
| | - Salvatore Cocuzza
- Department of Medical, Surgical Sciences and Advanced Technologies G.F. Ingrassia, University of Catania, 95123 Catania, Italy
| | - Jérôme René Lechien
- Otology Study Group of the Young-Otolaryngologists of the International Federations of Oto-Rhino-Laryngological Societies (YO-IFOS), 75000 Paris, France
| | - Giannicola Iannella
- Otology Study Group of the Young-Otolaryngologists of the International Federations of Oto-Rhino-Laryngological Societies (YO-IFOS), 75000 Paris, France
| | - Francois Simon
- Otology Study Group of the Young-Otolaryngologists of the International Federations of Oto-Rhino-Laryngological Societies (YO-IFOS), 75000 Paris, France
| | - Antonino Maniaci
- Otology Study Group of the Young-Otolaryngologists of the International Federations of Oto-Rhino-Laryngological Societies (YO-IFOS), 75000 Paris, France
- Department of Medical, Surgical Sciences and Advanced Technologies G.F. Ingrassia, University of Catania, 95123 Catania, Italy
| |
Collapse
|
2
|
Progression of KCNQ4 related genetic hearing loss: a narrative review. JOURNAL OF BIO-X RESEARCH 2021. [DOI: 10.1097/jbr.0000000000000112] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022] Open
|
3
|
Salah M, de Varebeke SJ, Fransen E, Topsakal V, Van Camp G, Van Rompaey V. Predictive Sensitivity and Concordance of Machine-learning Tools for Diagnosing DFNA9 in a Large Series of p.Pro51Ser Variant Carriers in the COCH-gene. Otol Neurotol 2021; 42:671-677. [PMID: 33492061 DOI: 10.1097/mao.0000000000003028] [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: 11/25/2022]
Abstract
OBJECTIVE In this study we aimed to evaluate the predictive cross-sectional sensitivity and longitudinal concordance of a machine-learning algorithm in a series of genetically confirmed p.(Pro51Ser) variant carriers (DFNA9). STUDY DESIGN Cross-sectional study. SETTING Tertiary and secondary referral center. PATIENTS Audiograms of 111 subjects with the p.(Pro51Ser) mutation in the COCH-gene were analyzed cross-sectionally. A subset of 17 subjects with repeated audiograms were used for longitudinal analysis. INTERVENTIONS All audiological thresholds were run through the web-based AudioGene v4.0 software. MAIN OUTCOME MEASURES Sensitivity for accurate prediction of DFNA9 for cross-sectional data and concordance of correct prediction for longitudinal auditory data. RESULTS DFNA9 was predicted with a sensitivity of 93.7% in a series of 222 cross-sectionally collected audiological thresholds (76.1% as first gene locus). When using the hearing thresholds of the best ear, the sensitivity was 94.6%. The sensitivity was significantly higher in DFNA9 patients aged younger than 40 and aged 60 years or older, compared to the age group of 40 to 59 years, with resp. 97.6% (p < 0.0001) and 98.8% (p < 0.0001) accurate predictions. An average concordance of 91.6% was found to show the same response in all successive longitudinal audiometric data per patient. CONCLUSIONS Audioprofiling software can accurately predict DFNA9 in an area with a high prevalence of confirmed carriers of the p.(Pro51Ser) variant in the COCH-gene. This algorithm yields high promises for helping clinicians in directing genetic testing in case of a strong family history of progressive hearing loss, especially for very young and old carriers.
Collapse
Affiliation(s)
- Mahadi Salah
- Department Otorhinolaryngology and Head and Neck Surgery, Jessa Hospital, Hasselt
- Department of Otorhinolaryngology, University Hospital Antwerp
| | - Sebastien Janssens de Varebeke
- Department Otorhinolaryngology and Head and Neck Surgery, Jessa Hospital, Hasselt
- Department of Translational Neurosciences, Faculty of Medicine and Health Sciences
| | - Erik Fransen
- StatUa Center for Statistics
- Center for medical genetics, University of Antwerp, Edegem, Belgium
| | - Vedat Topsakal
- Department of Otorhinolaryngology, University Hospital Antwerp
- Department of Translational Neurosciences, Faculty of Medicine and Health Sciences
| | - Guy Van Camp
- Center for medical genetics, University of Antwerp, Edegem, Belgium
| | - Vincent Van Rompaey
- Department of Otorhinolaryngology, University Hospital Antwerp
- Department of Translational Neurosciences, Faculty of Medicine and Health Sciences
| |
Collapse
|
4
|
Molecular basis and restoration of function deficiencies of Kv7.4 variants associated with inherited hearing loss. Hear Res 2020; 388:107884. [PMID: 31995783 DOI: 10.1016/j.heares.2020.107884] [Citation(s) in RCA: 14] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/22/2019] [Revised: 12/12/2019] [Accepted: 12/31/2019] [Indexed: 11/20/2022]
Abstract
Deafness non-syndromic autosomal dominant 2 (DFNA2) is characterized by symmetric, predominantly high-frequency sensorineural hearing loss that is progressive across all frequencies. The disease is associated with variants of a potassium voltage-gated channel subfamily Q member 4 gene, KCNQ4 (Kv7.4). Here, we studied nine recently identified Kv7.4 variants in DFNA2 pedigrees, including V230E, E260K, D262V, Y270H, W275R, G287R, P291L, P291S and S680F. We proved that the variant S680F did not alter the channel function while the other eight variants resulted in function deficiencies. We further proved that the two variants E260K and P291S showed reduced cell membrane expressions while the other seven variants showed moderate cell surface expressions. Thus, trafficking deficiency is not a common mechanism underlying channel dysfunction. Next, we studied two variants, V230E and G287R, using molecular dynamics simulation. We showed that V230E stabilized Kv7.4 channel in the closed state by forming an additional hydrogen bond with a basic residue K325, while G287R distorted the selectivity filter and blocked the pore region of Kv7.4 channel. Moreover, by co-expressing wild-type (WT) and variant proteins in vitro, we demonstrated that the heterogeneous Kv7.4 channel currents were reduced compared to the WT channel currents and the reduction could be rescued by a Kv7.4 opener retigabine. Our study provided the underlying mechanisms and suggested a potential alternative therapeutic approach for DFNA2.
Collapse
|
5
|
Runge CL, Indap A, Zhou Y, Kent JW, King E, Erbe CB, Cole R, Littrell J, Merath K, James R, Rüschendorf F, Kerschner JE, Marth G, Hübner N, Göring HHH, Friedland DR, Kwok WM, Olivier M. Association of TMTC2 With Human Nonsyndromic Sensorineural Hearing Loss. JAMA Otolaryngol Head Neck Surg 2017; 142:866-72. [PMID: 27311106 DOI: 10.1001/jamaoto.2016.1444] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Abstract
IMPORTANCE Sensorineural hearing loss (SNHL) is commonly caused by conditions that affect cochlear structures or the auditory nerve, and the genes identified as causing SNHL to date only explain a fraction of the overall genetic risk for this debilitating disorder. It is likely that other genes and mutations also cause SNHL. OBJECTIVE To identify a candidate gene that causes bilateral, symmetric, progressive SNHL in a large multigeneration family of Northern European descent. DESIGN, SETTING, AND PARTICIPANTS In this prospective genotype and phenotype study performed from January 1, 2006, through April 1, 2016, a 6-generation family of Northern European descent with 19 individuals having reported early-onset hearing loss suggestive of an autosomal dominant inheritance were studied at a tertiary academic medical center. In addition, 179 unrelated adult individuals with SNHL and 186 adult individuals reporting nondeafness were examined. MAIN OUTCOMES AND MEASURES Sensorineural hearing loss. RESULTS Nine family members (5 women [55.6%]) provided clinical audiometric and medical records that documented hearing loss. The hearing loss is characterized as bilateral, symmetric, progressive SNHL that reached severe to profound loss in childhood. Audiometric configurations demonstrated a characteristic dip at 1000 to 2000 Hz. All affected family members wear hearing aids or have undergone cochlear implantation. Exome sequencing and linkage and association analyses identified a fully penetrant sequence variant (rs35725509) on chromosome 12q21 (logarithm of odds, 3.3) in the TMTC2 gene region that segregates with SNHL in this family. This gene explains the SNHL occurrence in this family. The variant is also associated with SNHL in a cohort of 363 unrelated individuals (179 patients with confirmed SNHL and 184 controls, P = 7 × 10-4). CONCLUSIONS AND RELEVANCE A previously uncharacterized gene, TMTC2, has been identified as a candidate for causing progressive SNHL in humans. This finding identifies a novel locus that causes autosomal dominant SNHL and therefore a more detailed understanding of the genetic basis of SNHL. Because TMTC2 has not been previously reported to regulate auditory function, the discovery reveals a potentially new, uncharacterized mechanism of hearing loss.
Collapse
Affiliation(s)
- Christina L Runge
- Department of Otolaryngology and Communication Sciences, Medical College of Wisconsin, Milwaukee
| | - Amit Indap
- Department of Biology, Boston College, Chestnut Hill, Massachusetts
| | - Yifan Zhou
- Department of Pharmacology and Toxicology, Medical College of Wisconsin, Milwaukee
| | - Jack W Kent
- Department of Genetics, Texas Biomedical Research Institute, San Antonio
| | - Ericka King
- Department of Otolaryngology and Communication Sciences, Medical College of Wisconsin, Milwaukee
| | - Christy B Erbe
- Department of Otolaryngology and Communication Sciences, Medical College of Wisconsin, Milwaukee
| | - Regina Cole
- Biotechnology and Bioengineering Center, Medical College of Wisconsin, Milwaukee
| | - Jack Littrell
- Biotechnology and Bioengineering Center, Medical College of Wisconsin, Milwaukee
| | - Kate Merath
- Biotechnology and Bioengineering Center, Medical College of Wisconsin, Milwaukee
| | - Roland James
- Biotechnology and Bioengineering Center, Medical College of Wisconsin, Milwaukee
| | | | - Joseph E Kerschner
- Department of Otolaryngology and Communication Sciences, Medical College of Wisconsin, Milwaukee
| | - Gabor Marth
- Department of Human Genetics, University of Utah School of Medicine, Salt Lake City
| | - Norbert Hübner
- Max Delbrück Center for Molecular Medicine, Berlin-Buch, Germany
| | - Harald H H Göring
- Department of Genetics, Texas Biomedical Research Institute, San Antonio
| | - David R Friedland
- Department of Otolaryngology and Communication Sciences, Medical College of Wisconsin, Milwaukee
| | - Wai-Meng Kwok
- Department of Pharmacology and Toxicology, Medical College of Wisconsin, Milwaukee8Department of Anesthesiology, Medical College of Wisconsin, Milwaukee
| | - Michael Olivier
- Department of Genetics, Texas Biomedical Research Institute, San Antonio5Biotechnology and Bioengineering Center, Medical College of Wisconsin, Milwaukee
| |
Collapse
|
6
|
Huang B, Liu Y, Gao X, Xu J, Dai P, Zhu Q, Yuan Y. A novel pore-region mutation, c.887G > A (p.G296D) in KCNQ4, causing hearing loss in a Chinese family with autosomal dominant non-syndromic deafness 2. BMC MEDICAL GENETICS 2017; 18:36. [PMID: 28340560 PMCID: PMC5366164 DOI: 10.1186/s12881-017-0396-5] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 08/16/2016] [Accepted: 03/08/2017] [Indexed: 11/10/2022]
Abstract
BACKGROUND Hereditary non-syndromic hearing loss is the most common inherited sensory defect in humans. The KCNQ4 channel belongs to a family of potassium ion channels that play crucial roles in physiology and disease. Mutations in KCNQ4 underlie deafness non-syndromic autosomal dominant 2, a subtype of autosomal dominant, progressive, high-frequency hearing loss. METHODS A six-generation Chinese family from Hebei Province with autosomal dominantly inherited, sensorineural, postlingual, progressive hearing loss was enrolled in this study. Mutation screening of 129 genes associated with hearing loss was performed in five family members by next-generation sequencing (NGS). We also carried out variant analysis on DNA from 531 Chinese individuals with normal hearing as controls. RESULTS This family exhibits postlingual, progressive, symmetrical, bilateral, non-syndromic sensorineural hearing loss. NGS, bioinformatic analysis, and Sanger sequencing confirmed the co-segregation of a novel mutation [c.887G > A (p.G296D)] in KCNQ4 with the disease phenotype in this family. This mutation leads to a glycine-to-aspartic acid substitution at position 296 in the pore region of the KCNQ4 channel. This mutation affects a highly conserved glutamic acid. NGS is a highly efficient tool for identifying gene mutations causing heritable disease. CONCLUSIONS Progressive hearing loss is common in individuals with KCNQ4 mutations. NGS together with Sanger sequencing confirmed that the five affected members of this Chinese family inherited a missense mutation, c.887G > A (p.G296D), in exon 6 of KCNQ4. Our results increase the number of identified KCNQ4 mutations.
Collapse
Affiliation(s)
- Bangqing Huang
- Department of Otolaryngology, Chinese PLA General Hospital, Beijing, 100853, China.,Department of Otolaryngology, Hainan Branch of PLA General Hospital, Sanya, 572013, China
| | - Yanping Liu
- Department of Otorhinolaryngology, General Hospital of the Rocket Force, Beijing, 100088, China
| | - Xue Gao
- Department of Otolaryngology, Chinese PLA General Hospital, Beijing, 100853, China.,Department of Otorhinolaryngology, General Hospital of the Rocket Force, Beijing, 100088, China
| | - Jincao Xu
- Department of Otorhinolaryngology, General Hospital of the Rocket Force, Beijing, 100088, China
| | - Pu Dai
- Department of Otolaryngology, Chinese PLA General Hospital, Beijing, 100853, China.
| | - Qingwen Zhu
- Department of Otolaryngology, The Second Hospital Of Hebei Medical University, Shijiazhuang, 050018, China.
| | - Yongyi Yuan
- Department of Otolaryngology, Chinese PLA General Hospital, Beijing, 100853, China.
| |
Collapse
|
7
|
The diagnostic yield of whole-exome sequencing targeting a gene panel for hearing impairment in The Netherlands. Eur J Hum Genet 2016; 25:308-314. [PMID: 28000701 DOI: 10.1038/ejhg.2016.182] [Citation(s) in RCA: 89] [Impact Index Per Article: 11.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/12/2016] [Revised: 10/19/2016] [Accepted: 11/22/2016] [Indexed: 12/12/2022] Open
Abstract
Hearing impairment (HI) is genetically heterogeneous which hampers genetic counseling and molecular diagnosis. Testing of several single HI-related genes is laborious and expensive. In this study, we evaluate the diagnostic utility of whole-exome sequencing (WES) targeting a panel of HI-related genes. Two hundred index patients, mostly of Dutch origin, with presumed hereditary HI underwent WES followed by targeted analysis of an HI gene panel of 120 genes. We found causative variants underlying the HI in 67 of 200 patients (33.5%). Eight of these patients have a large homozygous deletion involving STRC, OTOA or USH2A, which could only be identified by copy number variation detection. Variants of uncertain significance were found in 10 patients (5.0%). In the remaining 123 cases, no potentially causative variants were detected (61.5%). In our patient cohort, causative variants in GJB2, USH2A, MYO15A and STRC, and in MYO6 were the leading causes for autosomal recessive and dominant HI, respectively. Segregation analysis and functional analyses of variants of uncertain significance will probably further increase the diagnostic yield of WES.
Collapse
|
8
|
Dai ZY, Sun BC, Huang SS, Yuan YY, Zhu YH, Su Y, Dai P. Correlation analysis of phenotype and genotype of GJB2 in patients with non-syndromic hearing loss in China. Gene 2015; 570:272-6. [PMID: 26095810 DOI: 10.1016/j.gene.2015.06.038] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/28/2015] [Revised: 06/11/2015] [Accepted: 06/12/2015] [Indexed: 11/18/2022]
Abstract
BACKGROUND Disease-associated mutations in GJB2 gene are one of the major reasons that can cause non-syndromic sensorineural hearing loss (NSHL). GJB2 gene deafness has various clinical phenotypes. This study aims to analyze characteristics and relationships of clinical phenotypes through analyzing 1481 NSHL cases and 190 GJB2 deafness patients (with dual gene mutations). PATIENTS AND METHODS All the patients diagnosed as deaf disease molecular diagnostics were obtained from the people's liberation army general hospital from March 2007 to March 2011. The accession number of GJB2 was NM_004004 in GenBank, and sequence alignment and annotation were performed using GeneTool software. RESULTS In NSHL patients, mutated allele frequency in GJB2 was 20.57%, and the preponderant type was c.235delC (11.84%) followed by c.109G>A (3.75%). Mutation rate of double allelic gene was 16.18%, including 8.43% of homozygous mutation rate and 7.75% of recombination heterozygosis mutation. Moreover, auditory threshold of GJB2 biallelic marker was associated with ages of onset, while no significant correlation was detected with disease time and whether the inner ear malformation. Similar clinical phenotype could be detected between patients with c.109G>A dual gene mutation and dual gene mutation. However, in the aspect of hearing impairment, the phenomenon of pathopoiesia caused by mutation of c.109G>A was poorer than the other mutations, and even near those patients without pathogenic mutations. CONCLUSION Our study further shows the definite relationship of clinical phenotype and genotype in GJB2 gene correlated deafness, and these results can provide basis for revealing pathogenesis, gene diagnosis and consult of deafness. The level of evidence in the study is level 4 (case series).
Collapse
Affiliation(s)
- Zhi-Yao Dai
- Department of Otolaryngology, The First Affiliated Hospital of PLA General Hospital, Beijing 100048, China
| | - Bao-Chun Sun
- Department of Otolaryngology, The First Affiliated Hospital of PLA General Hospital, Beijing 100048, China
| | - Sha-Sha Huang
- Department of Otolaryngology, Head & Neck Surgery, Chinese PLA General Hospital, Beijing 100853, China
| | - Yong-Yi Yuan
- Department of Otolaryngology, Head & Neck Surgery, Chinese PLA General Hospital, Beijing 100853, China
| | - Yu-Hua Zhu
- Department of Otolaryngology, Head & Neck Surgery, Chinese PLA General Hospital, Beijing 100853, China
| | - Yu Su
- Department of Otolaryngology, Head & Neck Surgery, Chinese PLA General Hospital, Beijing 100853, China
| | - Pu Dai
- Department of Otolaryngology, Head & Neck Surgery, Chinese PLA General Hospital, Beijing 100853, China.
| |
Collapse
|
9
|
Wang H, Zhao Y, Yi Y, Gao Y, Liu Q, Wang D, Li Q, Lan L, Li N, Guan J, Yin Z, Han B, Zhao F, Zong L, Xiong W, Yu L, Song L, Yi X, Yang L, Petit C, Wang Q. Targeted high-throughput sequencing identifies pathogenic mutations in KCNQ4 in two large Chinese families with autosomal dominant hearing loss. PLoS One 2014; 9:e103133. [PMID: 25116015 PMCID: PMC4130520 DOI: 10.1371/journal.pone.0103133] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/16/2014] [Accepted: 06/27/2014] [Indexed: 11/18/2022] Open
Abstract
Autosomal dominant non-syndromic hearing loss (ADNSHL) is highly heterogeneous, among them, KCNQ4 is one of the most frequent disease-causing genes. More than twenty KCNQ4 mutations have been reported, but none of them were detected in Chinese mainland families. In this study, we identified a novel KCNQ4 mutation in a five generation Chinese family with 84 members and a known KCNQ4 mutation in a six generation Chinese family with 66 members. Mutation screening of 30 genes for ADNSHL was performed in the probands from thirty large Chinese families with ADNSHL by targeted region capture and high-throughput sequencing. The candidate variants and the co-segregation of the phenotype were verified by polymerase chain reaction (PCR) amplification and Sanger sequencing in all ascertained family members. Then we identified a novel KCNQ4 mutation p.W275R in exon 5 and a known KCNQ4 mutation p.G285S in exon 6 in two large Chinese ADNSHL families segregating with post-lingual high frequency-involved and progressive sensorineural hearing loss. This is the first report of KCNQ4 mutation in Chinese mainland families. KCNQ4, a member of voltage-gated potassium channel family, is likely to be a common gene in Chinese patients with ADNSHL. The results also support that the combination of targeted enrichment and high-throughput sequencing is a valuable molecular diagnostic tool for autosomal dominant hereditary deafness.
Collapse
Affiliation(s)
- Hongyang Wang
- Institute of Otolaryngology, Chinese PLA General Hospital, Medical School of Chinese PLA, Beijing, China
| | - Yali Zhao
- Institute of Otolaryngology, Chinese PLA General Hospital, Medical School of Chinese PLA, Beijing, China
| | | | - Yun Gao
- Institute of Otolaryngology, Chinese PLA General Hospital, Medical School of Chinese PLA, Beijing, China
| | - Qiong Liu
- Institute of Otolaryngology, Chinese PLA General Hospital, Medical School of Chinese PLA, Beijing, China
| | - Dayong Wang
- Institute of Otolaryngology, Chinese PLA General Hospital, Medical School of Chinese PLA, Beijing, China
| | - Qian Li
- Institute of Otolaryngology, Chinese PLA General Hospital, Medical School of Chinese PLA, Beijing, China
| | - Lan Lan
- Institute of Otolaryngology, Chinese PLA General Hospital, Medical School of Chinese PLA, Beijing, China
| | - Na Li
- Institute of Otolaryngology, Chinese PLA General Hospital, Medical School of Chinese PLA, Beijing, China
| | - Jing Guan
- Institute of Otolaryngology, Chinese PLA General Hospital, Medical School of Chinese PLA, Beijing, China
| | - Zifang Yin
- Institute of Otolaryngology, Chinese PLA General Hospital, Medical School of Chinese PLA, Beijing, China
| | - Bing Han
- Institute of Otolaryngology, Chinese PLA General Hospital, Medical School of Chinese PLA, Beijing, China
| | - Feifan Zhao
- Institute of Otolaryngology, Chinese PLA General Hospital, Medical School of Chinese PLA, Beijing, China
| | - Liang Zong
- Institute of Otolaryngology, Chinese PLA General Hospital, Medical School of Chinese PLA, Beijing, China
| | - Wenping Xiong
- Institute of Otolaryngology, Chinese PLA General Hospital, Medical School of Chinese PLA, Beijing, China
| | - Lan Yu
- Institute of Otolaryngology, Chinese PLA General Hospital, Medical School of Chinese PLA, Beijing, China
| | | | - Xin Yi
- BGI-Tianjin, Tianjin, China
| | | | - Christine Petit
- Unité de Génétique et Physiologie de l'Audition, Institut Pasteur, Paris, France
- UMRS 1120, Institut National de la Santé et de la Recherche Médicale (INSERM), Paris, France
- Université Pierre et Marie Curie (Paris VI), Paris, France
- Collège de France, Paris, France
| | - Qiuju Wang
- Institute of Otolaryngology, Chinese PLA General Hospital, Medical School of Chinese PLA, Beijing, China
- * E-mail:
| |
Collapse
|
10
|
Maljevic S, Lerche H. Potassium channel genes and benign familial neonatal epilepsy. PROGRESS IN BRAIN RESEARCH 2014; 213:17-53. [DOI: 10.1016/b978-0-444-63326-2.00002-8] [Citation(s) in RCA: 77] [Impact Index Per Article: 7.7] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
|
11
|
Gao Y, Yechikov S, Vázquez AE, Chen D, Nie L. Impaired surface expression and conductance of the KCNQ4 channel lead to sensorineural hearing loss. J Cell Mol Med 2013; 17:889-900. [PMID: 23750663 PMCID: PMC3729637 DOI: 10.1111/jcmm.12080] [Citation(s) in RCA: 31] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/28/2013] [Accepted: 03/29/2013] [Indexed: 01/21/2023] Open
Abstract
KCNQ4, a voltage-gated potassium channel, plays an important role in maintaining cochlear ion homoeostasis and regulating hair cell membrane potential, both essential for normal auditory function. Mutations in the KCNQ4 gene lead to DFNA2, a subtype of autosomal dominant non-syndromic deafness that is characterized by progressive sensorineural hearing loss across all frequencies. Despite recent advances in the identification of pathogenic KCNQ4 mutations, the molecular aetiology of DFNA2 remains unknown. We report here that decreased cell surface expression and impaired conductance of the KCNQ4 channel are two mechanisms underlying hearing loss in DFNA2. In HEK293T cells, a dramatic decrease in cell surface expression was detected by immunofluorescent microscopy and confirmed by Western blot for the pathogenic KCNQ4 mutants L274H, W276S, L281S, G285C, G285S, G296S and G321S, while their overall cellular levels remained normal. In addition, none of these mutations affected tetrameric assembly of KCNQ4 channels. Consistent with these results, all mutants showed strong dominant-negative effects on the wild-type (WT) channel function. Most importantly, overexpression of HSP90β, a key component of the molecular chaperone network that controls the KCNQ4 biogenesis, significantly increased cell surface expression of the KCNQ4 mutants L281S, G296S and G321S. KCNQ4 surface expression was restored or considerably improved in HEK293T cells mimicking the heterozygous condition of these mutations in DFNA2 patients. Finally, our electrophysiological studies demonstrated that these mutations directly compromise the conductance of the KCNQ4 channel, since no significant change in KCNQ4 current was observed after KCNQ4 surface expression was restored or improved.
Collapse
Affiliation(s)
- Yanhong Gao
- Department of Otolaryngology, University of California Davis, Davis, CA, USA
| | | | | | | | | |
Collapse
|
12
|
Abdelfatah N, McComiskey DA, Doucette L, Griffin A, Moore SJ, Negrijn C, Hodgkinson KA, King JJ, Larijani M, Houston J, Stanton SG, Young TL. Identification of a novel in-frame deletion in KCNQ4 (DFNA2A) and evidence of multiple phenocopies of unknown origin in a family with ADSNHL. Eur J Hum Genet 2013; 21:1112-9. [PMID: 23443030 DOI: 10.1038/ejhg.2013.5] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/05/2012] [Revised: 12/12/2012] [Accepted: 12/28/2012] [Indexed: 11/09/2022] Open
Abstract
Autosomal dominant sensorineural hearing loss (ADSNHL) is extremely genetically heterogeneous, making it difficult to molecularly diagnose. We identified a multiplex (n=28 affected) family from the genetic isolate of Newfoundland, Canada with variable SNHL and used a targeted sequencing approach based on population-specific alleles in WFS1, TMPRSS3 and PCDH15; recurrent mutations in GJB2 and GJB6; and frequently mutated exons of KCNQ4, COCH and TECTA. We identified a novel, in-frame deletion (c.806_808delCCT: p.S269del) in the voltage-gated potassium channel KCNQ4 (DFNA2), which in silico modeling predicts to disrupt multimerization of KCNQ4 subunits. Surprisingly, 10/23 deaf relatives are non-carriers of p.S269del. Further molecular characterization of the DFNA2 locus in deletion carriers ruled out the possibility of a pathogenic mutation other than p.S269del at the DFNA2A/B locus and linkage analysis showed significant linkage to DFNA2 (maximum LOD=3.3). Further support of genetic heterogeneity in family 2071 was revealed by comparisons of audio profiles between p.S269del carriers and non-carriers suggesting additional and as yet unknown etiologies. We discuss the serious implications that genetic heterogeneity, in this case observed within a single family, has on molecular diagnostics and genetic counseling.
Collapse
Affiliation(s)
- Nelly Abdelfatah
- Discipline of Genetics, Faculty of Medicine, Memorial University, St John's, Newfoundland and Labrador, Canada
| | | | | | | | | | | | | | | | | | | | | | | |
Collapse
|
13
|
Gao Y, Yechikov S, Vazquez AE, Chen D, Nie L. Distinct roles of molecular chaperones HSP90α and HSP90β in the biogenesis of KCNQ4 channels. PLoS One 2013; 8:e57282. [PMID: 23431407 PMCID: PMC3576372 DOI: 10.1371/journal.pone.0057282] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/09/2012] [Accepted: 01/21/2013] [Indexed: 01/30/2023] Open
Abstract
Loss-of-function mutations in the KCNQ4 channel cause DFNA2, a subtype of autosomal dominant non-syndromic deafness that is characterized by progressive sensorineural hearing loss. Previous studies have demonstrated that the majority of the pathogenic KCNQ4 mutations lead to trafficking deficiency and loss of KCNQ4 currents. Over the last two decades, various strategies have been developed to rescue trafficking deficiency of pathogenic mutants; the most exciting advances have been made by manipulating activities of molecular chaperones involved in the biogenesis and quality control of the target protein. However, such strategies have not been established for KCNQ4 mutants and little is known about the molecular chaperones governing the KCNQ4 biogenesis. To identify KCNQ4-associated molecular chaperones, a proteomic approach was used in this study. As a result, two major molecular chaperones, HSP70 and HSP90, were identified and then confirmed by reciprocal co-immunoprecipitation assays, suggesting that the HSP90 chaperone pathway might be involved in the KCNQ4 biogenesis. Manipulating chaperone expression further revealed that two different isoforms of HSP90, the inducible HSP90α and the constitutive HSP90β, had opposite effects on the cellular level of the KCNQ4 channel; that HSP40, HSP70, and HOP, three key components of the HSP90 chaperone pathway, were crucial in facilitating KCNQ4 biogenesis. In contrast, CHIP, a major E3 ubiquitin ligase, had an opposite effect. Collectively, our data suggest that HSP90α and HSP90β play key roles in controlling KCNQ4 homeostasis via the HSP40-HSP70-HOP-HSP90 chaperone pathway and the ubiquitin-proteasome pathway. Most importantly, we found that over-expression of HSP90β significantly improved cell surface expression of the trafficking-deficient, pathogenic KCNQ4 mutants L274H and W276S. KCNQ4 surface expression was restored by HSP90β in cells mimicking heterozygous conditions of the DFNA2 patients, even though it was not sufficient to rescue the function of KCNQ4 channels.
Collapse
Affiliation(s)
- Yanhong Gao
- Department of Otolaryngology, University of California Davis, Davis, California, United States of America
| | - Sergey Yechikov
- Department of Otolaryngology, University of California Davis, Davis, California, United States of America
| | - Ana E. Vazquez
- Department of Otolaryngology, University of California Davis, Davis, California, United States of America
- * E-mail: (AEV); (LN)
| | - Dongyang Chen
- Department of Otolaryngology, University of California Davis, Davis, California, United States of America
| | - Liping Nie
- Department of Otolaryngology, University of California Davis, Davis, California, United States of America
- * E-mail: (AEV); (LN)
| |
Collapse
|
14
|
Abstract
The purpose of this review is to assess the current literature on deafness nonsyndromic autosomal dominant 2 (DFNA2) hearing loss and the mutations linked to this disorder. Hearing impairment, particularly nonsyndromic hearing loss, affects multiple families across the world. After the identification of the DFNA2 locus on chromosome 1p34, multiple pathogenic mutations in two genes (GJB3 and KCNQ4) have been reported. The overwhelming majority of pathogenic mutations linked to this form of nonsyndromic hearing loss have been identified in the KCNQ4 gene encoding a voltage-gated potassium channel. It is believed that KCNQ4 channels are present in outer hair cells and possibly inner hair cells and the central auditory pathway. This form of hearing loss is both phenotypically and genetically heterogeneous and there are still DFNA2 pedigrees that have not been associated with changes in either GJB3 or KCNQ4, suggesting that a possible third gene exists at this locus. Further studies of the DFNA2 locus will lead to a better understanding of progressive hearing loss and provide a better means of early detection and treatment.
Collapse
Affiliation(s)
- Laura M Dominguez
- Department of Otolaryngology, Head and Neck Surgery, Virginia Commonwealth University, Richmond, VA
| | - Kelley M Dodson
- Department of Otolaryngology, Head and Neck Surgery, Virginia Commonwealth University, Richmond, VA
| |
Collapse
|
15
|
Leitner MG, Feuer A, Ebers O, Schreiber DN, Halaszovich CR, Oliver D. Restoration of ion channel function in deafness-causing KCNQ4 mutants by synthetic channel openers. Br J Pharmacol 2012; 165:2244-59. [PMID: 21951272 DOI: 10.1111/j.1476-5381.2011.01697.x] [Citation(s) in RCA: 33] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/09/2023] Open
Abstract
BACKGROUND AND PURPOSE DFNA2 is a frequent hereditary hearing disorder caused by loss-of-function mutations in the voltage-gated potassium channel KCNQ4 (Kv7.4). KCNQ4 mediates the predominant K(+) conductance, I(K,n) , of auditory outer hair cells (OHCs), and loss of KCNQ4 function leads to degeneration of OHCs resulting in progressive hearing loss. Here we explore the possible recovery of channel activity of mutant KCNQ4 induced by synthetic KCNQ channel openers. EXPERIMENTAL APPROACH Whole cell patch clamp recordings were performed on CHO cells transiently expressing KCNQ4 wild-type (wt) and DFNA2-relevant mutants, and from acutely isolated OHCs. KEY RESULTS Various known KCNQ channel openers robustly enhanced KCNQ4 currents. The strongest potentiation was observed with a combination of zinc pyrithione plus retigabine. A similar albeit less pronounced current enhancement was observed with native I(K,n) currents in rat OHCs. DFNA2 mutations located in the channel's pore region abolished channel function and these mutant channels were completely unresponsive to channel openers. However, the function of a DFNA2 mutation located in the proximal C-terminus was restored by the combined application of both openers. Co-expression of wt and KCNQ4 pore mutants suppressed currents to barely detectable levels. In this dominant-negative situation, channel openers essentially restored currents back to wt levels, most probably through strong activation of only the small fraction of homomeric wt channels. CONCLUSIONS AND IMPLICATIONS Our data suggest that by stabilizing the KCNQ4-mediated conductance in OHCs, chemical channel openers can protect against OHC degeneration and progression of hearing loss in DFNA2.
Collapse
Affiliation(s)
- Michael G Leitner
- Department of Neurophysiology, Philipps-University Marburg, Marburg, Germany
| | | | | | | | | | | |
Collapse
|
16
|
Namba K, Mutai H, Kaneko H, Hashimoto S, Matsunaga T. In silico modeling of the pore region of a KCNQ4 missense mutant from a patient with hearing loss. BMC Res Notes 2012; 5:145. [PMID: 22420747 PMCID: PMC3374714 DOI: 10.1186/1756-0500-5-145] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/28/2011] [Accepted: 03/15/2012] [Indexed: 11/16/2022] Open
Abstract
Background Mutation of the voltage-gated potassium channel KCNQ4 causes DFNA2-type nonsyndromic autosomal dominant sensorineural hearing loss. KCNQ4 is expressed predominantly in the auditory sensory outer hair cells, which are critical for sound amplification. Results We sequenced KCNQ4 from Japanese patients with sensorineural hearing loss, and identified a novel missense mutation encoding a Tyr270His located at the N-terminus of the highly conserved pore helix sequence. As this patient was not accessible to us and information about them was limited, we used molecular modeling to investigate whether this novel mutation is hypothetically pathogenic. A careful examination of an in silico structural model of the KCNQ4 pore region revealed that the Tyr270His mutation caused an alteration in the electrostatic surface potential of the pore helix. Conclusion We propose two possible means by which the Tyr270His mutation causes hearing loss: a positively charged His270 side chain might enhance the helix dipole moment of the pore helix, thereby destabilizing the helix and/or the pore region, or it might disturb transport of K+ through the channel by electrostatic repulsion.
Collapse
Affiliation(s)
- Kazunori Namba
- Laboratory of Auditory Disorders, National Institute of Sensory Organs, National Tokyo Medical Center, Tokyo, Japan
| | | | | | | | | |
Collapse
|
17
|
Mahboubi H, Dwabe S, Fradkin M, Kimonis V, Djalilian HR. Genetics of hearing loss: where are we standing now? Eur Arch Otorhinolaryngol 2012; 269:1733-45. [PMID: 22218850 DOI: 10.1007/s00405-011-1910-6] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/06/2011] [Accepted: 12/27/2011] [Indexed: 01/23/2023]
Abstract
Hearing loss (HL) is the most common sensory impairment and is caused by a broad range of inherited to environmental causes. Inherited HL consists 50-60% of all HL cases. The inherited form of HL is further classified to different categories. More than 300 syndromes and 40 genes have been identified to result in different levels of HL. Although several diagnostic or screening tests have been developed, yet there are controversies around their use.
Collapse
Affiliation(s)
- Hossein Mahboubi
- Department of Otolaryngology Head and Neck Surgery, University of California, Irvine, 101 The City Drive South, Bldg 56, Suite 500, Rt 81, Orange, CA 92868, USA
| | | | | | | | | |
Collapse
|
18
|
de Heer AMR, Schraders M, Oostrik J, Hoefsloot L, Huygen PLM, Cremers CWRJ. Audioprofile-directed successful mutation analysis in a DFNA2/KCNQ4 (p.Leu274His) family. Ann Otol Rhinol Laryngol 2011; 120:243-8. [PMID: 21585154 DOI: 10.1177/000348941112000405] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
Abstract
OBJECTIVES We undertook to show that in a family with nonsyndromic autosomal dominant sensorineural hearing loss, genetic analysis can be successful when there is a match with a specific DFNA audioprofile. We also provide an update of relevant DFNA2/KCNQ4 audioprofiles and report the results of automatic audioprofile analysis using the Internet program AudioGene. METHODS Audiometric data and blood samples were obtained from the family W08-0384. Based on the audiograms of the affected participants, mutation analysis of KCNQ4 was started. Original audiometric threshold data were collected for all identified KCNQ4-related DFNA2 families. The Internet computer program AudioGene, recently developed for automatic audioprofile analysis, was accessed. RESULTS The family's audioprofile and the program AudioGene predicted the DFNA2/KCNQ4 locus. Mutation analysis of KCNQ4 revealed a c.821T>A (p.Leu274His) mutation of the KCNQ4 gene. This mutation has been previously identified in a Dutch family. Genetic analysis revealed a common haplotype in these two families over a region including the KCNQ4 gene. CONCLUSIONS Familiarity with the audioprofiles of DFNA traits may lead to successful mutation analysis of the gene involved, even in a small family in which genetic linkage analysis is not an option. Alternatively, the specially developed program AudioGene can be accessed on the Internet to perform automatic audioprofile analysis of a family's (audiological) phenotype.
Collapse
Affiliation(s)
- Anne-Martine R de Heer
- Department of Otorhinolaryngology-Raboud University Nijmegen Medical Center, Clinical Neuroscience Donders Center for Brain, Cognition and Behavior, Nijmegen, The Netherlands
| | | | | | | | | | | |
Collapse
|
19
|
Kim HJ, Lv P, Sihn CR, Yamoah EN. Cellular and molecular mechanisms of autosomal dominant form of progressive hearing loss, DFNA2. J Biol Chem 2010; 286:1517-27. [PMID: 20966080 DOI: 10.1074/jbc.m110.179010] [Citation(s) in RCA: 31] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/23/2023] Open
Abstract
Despite advances in identifying deafness genes, determination of the underlying cellular and functional mechanisms for auditory diseases remains a challenge. Mutations of the human K(+) channel hKv7.4 lead to post-lingual progressive hearing loss (DFNA2), which affects world-wide population with diverse racial backgrounds. Here, we have generated the spectrum of point mutations in the hKv7.4 that have been identified as diseased mutants. We report that expression of five point mutations in the pore region, namely L274H, W276S, L281S, G285C, and G296S, as well as the C-terminal mutant G321S in the heterologous expression system, yielded non-functional channels because of endoplasmic reticulum retention of the mutant channels. We mimicked the dominant diseased conditions by co-expressing the wild-type and mutant channels. As compared with expression of wild-type channel alone, the blend of wild-type and mutant channel subunits resulted in reduced currents. Moreover, the combinatorial ratios of wild type:mutant and the ensuing current magnitude could not be explained by the predictions of a tetrameric channel and a dominant negative effect of the mutant subunits. The results can be explained by the dependence of cell surface expression of the mutant on the wild-type subunit. Surprisingly, a transmembrane mutation F182L, which has been identified in a pre-lingual progressive hearing loss patient in Taiwan, yielded cell surface expression and functional features that were similar to that of the wild type, suggesting that this mutation may represent redundant polymorphism. Collectively, these findings provide traces of the cellular mechanisms for DFNA2.
Collapse
Affiliation(s)
- Hyo Jeong Kim
- Department of Anesthesiology and Pain Medicine, Program in Communication Science, School of Medicine, University of California, Davis, California 95618, USA
| | | | | | | |
Collapse
|
20
|
Baek JI, Park HJ, Park K, Choi SJ, Lee KY, Yi JH, Friedman TB, Drayna D, Shin KS, Kim UK. Pathogenic effects of a novel mutation (c.664_681del) in KCNQ4 channels associated with auditory pathology. Biochim Biophys Acta Mol Basis Dis 2010; 1812:536-43. [PMID: 20832469 DOI: 10.1016/j.bbadis.2010.09.001] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/14/2010] [Revised: 08/31/2010] [Accepted: 09/02/2010] [Indexed: 01/16/2023]
Abstract
Hearing loss is a common communication disorder caused by various environmental and genetic factors. Hereditary hearing loss is very heterogeneous, and most of such cases involve sensorineural defects in the auditory pathway. There are currently 57 known autosomal dominant non-syndromic hearing loss (DFNA) loci, and the causative genes have been identified at 22 of these loci. In the present study, we performed a genome-wide linkage analysis in a Korean family segregating autosomal dominant hearing loss. We observed linkage on chromosome 1p34, and at this locus, we detected a novel mutation consisting of an 18 nucleotide deletion in exon 4 of the KCNQ4 gene, which encodes a voltage-gated potassium channel. We carried out a functional in vitro study to analyze the effects of this mutation (c.664_681del) along with two previously described KCNQ4 mutations, p.W276S and p.G285C. Although the c.664_681del mutation is located in the intercellular loop and the two previously described mutations, p.W276S and p.G285C, are located in the pore region, all mutants inhibit normal channel function by a dominant negative effect. Our analysis indicates that the intercellular loop is as significant as the pore region as a potential site of pathogenic effects on KCNQ4 channel function.
Collapse
Affiliation(s)
- Jeong-In Baek
- Department of Biology, College of Natural Sciences, Kyungpook National University, Daegu, 702-701, South Korea
| | | | | | | | | | | | | | | | | | | |
Collapse
|
21
|
Maljevic S, Wuttke TV, Seebohm G, Lerche H. KV7 channelopathies. Pflugers Arch 2010; 460:277-88. [PMID: 20401729 DOI: 10.1007/s00424-010-0831-3] [Citation(s) in RCA: 87] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/09/2010] [Revised: 03/16/2010] [Accepted: 03/17/2010] [Indexed: 01/02/2023]
Abstract
KV7 voltage-gated potassium channels, encoded by the KCNQ gene family, have caught increasing interest of the scientific community for their important physiological roles, which are emphasized by the fact that four of the five so far identified members are related to different hereditary diseases. Furthermore, these channels prove to be attractive pharmacological targets for treating diseases characterized by membrane hyperexcitability. KV7 channels are expressed in brain, heart, thyroid gland, pancreas, inner ear, muscle, stomach, and intestines. They give rise to functionally important potassium currents, reduction of which results in pathologies such as long QT syndrome, diabetes, neonatal epilepsy, neuromyotonia, or progressive deafness. Here, we summarize some key traits of KV7 channels and review how their molecular deficiencies could explain diverse disease phenotypes. We also assess the therapeutic potential of KV7 channels; in particular, how the activation of KV7 channels by the compounds retigabine and R-L3 may be useful for treatment of epilepsy or cardiac arrhythmia.
Collapse
Affiliation(s)
- Snezana Maljevic
- Department of Neurology and Epileptology, Center for Neurology, Hertie Institute for Clinical Brain Research, University Hospital Tübingen, Hoppe-Seyler-Str. 3, 72076, Tübingen, Germany
| | | | | | | |
Collapse
|
22
|
KCNQ4 mutations associated with nonsyndromic progressive sensorineural hearing loss. Curr Opin Otolaryngol Head Neck Surg 2009; 16:441-4. [PMID: 18797286 DOI: 10.1097/moo.0b013e32830f4aa3] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
PURPOSE OF REVIEW This article provides an update on the current progress in identification of KCNQ4 mutations responsible for DFNA2, a subtype of autosomal dominant nonsyndromic progressive hearing loss. RECENT FINDINGS Hearing loss in pateints with DFNA2 usually start at high frequencies in their 20s and 30s, and then progress to more than 60 dB in less than 10 years, with middle and low frequencies often affected as well. To date, eight missense mutations and two deletions of the KCNQ4 gene have been identified in patients with DFNA2 with various clinical phenotypes. In general, missense mutations are associated with younger-onset and all-frequency hearing loss, whereas deletion mutations are underlying later-onset and pure high-frequency hearing loss. The etiology of DFNA2 remains largely unknown at this point, even though the degeneration of cochlear outer hair cells, caused by dysfunction of KCNQ4 channels, might be one of the underlying mechanisms. SUMMARY During the last decade, significant progress has been made in identifying KCNQ4 mutations in patients with DFNA2. Elucidation of the pathogenic effect of these mutations will help to gain insights into the molecular mechanisms of hearing and hearing loss, which, in turn, will facilitate informative genetic counseling, early diagnosis, and even treatment of hearing loss.
Collapse
|
23
|
Hilgert N, Smith RJH, Van Camp G. Forty-six genes causing nonsyndromic hearing impairment: which ones should be analyzed in DNA diagnostics? Mutat Res 2008; 681:189-196. [PMID: 18804553 DOI: 10.1016/j.mrrev.2008.08.002] [Citation(s) in RCA: 334] [Impact Index Per Article: 20.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/10/2008] [Revised: 08/04/2008] [Accepted: 08/22/2008] [Indexed: 10/21/2022]
Abstract
Hearing impairment is the most common sensory disorder, present in 1 of every 500 newborns. With 46 genes implicated in nonsyndromic hearing loss, it is also an extremely heterogeneous trait. Here, we categorize for the first time all mutations reported in nonsyndromic deafness genes, both worldwide and more specifically in Caucasians. The most frequent genes implicated in autosomal recessive nonsyndromic hearing loss are GJB2, which is responsible for more than half of cases, followed by SLC26A4, MYO15A, OTOF, CDH23 and TMC1. None of the genes associated with autosomal dominant nonsyndromic hearing loss accounts for a preponderance of cases, although mutations are somewhat more frequently reported in WFS1, KCNQ4, COCH and GJB2. Only a minority of these genes is currently included in genetic diagnostics, the selection criteria typically reflecting: (1) high frequency as a cause of deafness (i.e. GJB2); (2) association with another recognisable feature (i.e. SLC26A4 and enlarged vestibular aqueduct); or (3) a recognisable audioprofile (i.e. WFS1). New and powerful DNA sequencing technologies have been developed over the past few years, but have not yet found their way into DNA diagnostics. Implementing these technologies is likely to happen within the next 5 years, and will cause a breakthrough in terms of power and cost efficiency. It will become possible to analyze most - if not all - deafness genes, as opposed to one or a few genes currently. This ability will greatly improve DNA diagnostics, provide epidemiological data on gene-based mutation frequencies, and reveal novel genotype-phenotype correlations.
Collapse
Affiliation(s)
- Nele Hilgert
- Department of Medical Genetics, University of Antwerp (UA), Universiteitsplein 1, B-2610 Antwerp, Belgium
| | - Richard J H Smith
- Department of Otolaryngology-Head and Neck Surgery, University of Iowa, Iowa city, IA 52242, USA
| | - Guy Van Camp
- Department of Medical Genetics, University of Antwerp (UA), Universiteitsplein 1, B-2610 Antwerp, Belgium.
| |
Collapse
|
24
|
Mencía A, González-Nieto D, Modamio-Høybjør S, Etxeberría A, Aránguez G, Salvador N, Del Castillo I, Villarroel A, Moreno F, Barrio L, Moreno-Pelayo MA. A novel KCNQ4 pore-region mutation (p.G296S) causes deafness by impairing cell-surface channel expression. Hum Genet 2007; 123:41-53. [PMID: 18030493 DOI: 10.1007/s00439-007-0447-7] [Citation(s) in RCA: 42] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2007] [Accepted: 11/09/2007] [Indexed: 01/08/2023]
Abstract
Mutations in the potassium channel gene KCNQ4 underlie DFNA2, a subtype of autosomal dominant progressive, high-frequency hearing loss. Based on a phenotype-guided mutational screening we have identified a novel mutation c.886G>A, leading to the p.G296S substitution in the pore region of KCNQ4 channel. The possible impact of this mutation on total KCNQ4 protein expression, relative surface expression and channel function was investigated. When the G296S mutant was expressed in Xenopus oocytes, electrophysiological recordings did not show voltage-activated K(+) currents. The p.G296S mutation impaired KCNQ4 channel activity in two manners. It greatly reduced surface expression and, secondarily, abolished channel function. The deficient expression at the cell surface membrane was further confirmed in non-permeabilized NIH-3T3 cells transfected with the mutant KCNQ4 tagged with the hemagglutinin epitope in the extracellular S1-S2 linker. Co-expression of mutant and wild type KCNQ4 in oocytes was performed to mimic the heterozygous condition of the p.G296S mutation in the patients. The results showed that the G296S mutant exerts a strong dominant-negative effect on potassium currents by reducing the wild type KCNQ4 channel expression at the cell surface. This is the first study to identify a trafficking-dependent dominant mechanism for the loss of KCNQ4 channel function in DFNA2.
Collapse
Affiliation(s)
- Angeles Mencía
- Unidad de Genética Molecular, Hospital Ramón y Cajal, Carretera de Colmenar Km 9, 28034, Madrid, Spain
| | | | | | | | | | | | | | | | | | | | | |
Collapse
|
25
|
Meyer NC, Nishimura CJ, McMordie S, Smith RJH. Audioprofiling identifiesTECTAandGJB2-related deafness segregating in a single extended pedigree. Clin Genet 2007; 72:130-7. [PMID: 17661817 DOI: 10.1111/j.1399-0004.2007.00828.x] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
An audioprofile displays phenotypic data from several audiograms on a single graph that share a common genotype. In this report, we describe the application of audioprofiling to a large family in which a genome-wide screen failed to identify a deafness locus. Analysis of audiograms by audioprofiling suggested that two persons with hearing impairment had a different deafness genotype. On this basis, we reassigned affectation status and identified a p.Cys1837Arg autosomal dominant mutation in alpha-tectorin segregating in all family members except two persons, who segregated autosomal recessive deafness caused by p.Val37Ile and p.Leu90Pro mutations in Connexin 26. One nuclear family in the extended pedigree segregates both dominant and recessive non-syndromic hearing loss.
Collapse
Affiliation(s)
- N C Meyer
- Department of Otolaryngology, Carver College of Medicine, The University of Iowa, Iowa City, IA 52242, USA
| | | | | | | |
Collapse
|
26
|
Santos RLP, Häfner FM, Huygen PL, Linder TE, Schinzel AA, Spillmann T, Leal SM. Phenotypic characterization of DFNA24: prelingual progressive sensorineural hearing impairment. Audiol Neurootol 2006; 11:269-75. [PMID: 16717440 PMCID: PMC2923580 DOI: 10.1159/000093525] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/02/2005] [Accepted: 03/24/2006] [Indexed: 11/19/2022] Open
Abstract
This article describes the hearing impairment (HI) phenotype which segregates in a large multi-generation Swiss-German family with autosomal dominant nonsyndromic HI. The locus segregating within this pedigree is located on chromosome 4q35-qter and is designated as DFNA24. For this pedigree, audiometric data on 25 hearing-impaired family members are available. It was demonstrated that within this kindred the HI is sensorineural, bilateral, prelingual in onset, and progressive throughout life. Age-related typical audiograms depict steeply down-sloping curves, with moderate high-frequency HI at birth, then steady progression to moderate HI in the low frequencies, severe HI at mid-frequencies and profound HI at high frequencies by age 70. Annual threshold deterioration was approximately 0.5 dB/year at 1-2 kHz after correction for presbycusis.
Collapse
Affiliation(s)
- Regie Lyn P. Santos
- Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, Tex., USA
- Genetic Epidemiology Unit, Department of Epidemiology and Biostatistics, Erasmus MC Rotterdam, Rotterdam, The Netherlands
| | - Franziska M. Häfner
- Department of Otorhinolaryngology and Head and Neck Surgery, University Hospital of Zurich, Zurich
| | - Patrick L.M. Huygen
- Department of Otorhinolaryngology, University Medical Centre St. Radboud Nijmegen, Nijmegen
| | - Thomas E. Linder
- Department of Otorhinolaryngology and Head and Neck Surgery, Cantonal Hospital of Lucerne, Lucerne, Switzerland
| | | | - Thomas Spillmann
- Department of Otorhinolaryngology and Head and Neck Surgery, University Hospital of Zurich, Zurich
| | - Suzanne M. Leal
- Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, Tex., USA
| |
Collapse
|
27
|
Kamada F, Kure S, Kudo T, Suzuki Y, Oshima T, Ichinohe A, Kojima K, Niihori T, Kanno J, Narumi Y, Narisawa A, Kato K, Aoki Y, Ikeda K, Kobayashi T, Matsubara Y. A novel KCNQ4 one-base deletion in a large pedigree with hearing loss: implication for the genotype-phenotype correlation. J Hum Genet 2006; 51:455-460. [PMID: 16596322 DOI: 10.1007/s10038-006-0384-7] [Citation(s) in RCA: 31] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/18/2005] [Accepted: 01/23/2006] [Indexed: 10/24/2022]
Abstract
Autosomal-dominant, nonsyndromic hearing impairment is clinically and genetically heterogeneous. We encountered a large Japanese pedigree in which nonsyndromic hearing loss was inherited in an autosomal-dominant fashion. A genome-wide linkage study indicated linkage to the DFNA2 locus on chromosome 1p34. Mutational analysis of KCNQ4 encoding a potassium channel revealed a novel one-base deletion in exon 1, c.211delC, which generated a profoundly truncated protein without transmembrane domains (p.Q71fsX138). Previously, six missense mutations and one 13-base deletion, c.211_223del, had been reported in KCNQ4. Patients with the KCNQ4 missense mutations had younger-onset and more profound hearing loss than patients with the 211_223del mutation. In our current study, 12 individuals with the c.211delC mutation manifested late-onset and pure high-frequency hearing loss. Our results support the genotype-phenotype correlation that the KCNQ4 deletions are associated with later-onset and milder hearing impairment than the missense mutations. The phenotypic difference may be caused by the difference in pathogenic mechanisms: haploinsufficiency in deletions and dominant-negative effect in missense mutations.
Collapse
Affiliation(s)
- Fumiaki Kamada
- Department of Medical Genetics, Tohoku University School of Medicine, 1-1 Seiryo-machi, Aoba-ku, Sendai 980-8574, Japan
- 21st COE Program "Comprehensive Research and Education Center for Planning of Drug Development and Clinical Evaluation", Tohoku University, Sendai, Japan
| | - Shigeo Kure
- Department of Medical Genetics, Tohoku University School of Medicine, 1-1 Seiryo-machi, Aoba-ku, Sendai 980-8574, Japan.
- 21st COE Program "Comprehensive Research and Education Center for Planning of Drug Development and Clinical Evaluation", Tohoku University, Sendai, Japan.
| | - Takayuki Kudo
- Department of Medical Genetics, Tohoku University School of Medicine, 1-1 Seiryo-machi, Aoba-ku, Sendai 980-8574, Japan
| | - Yoichi Suzuki
- Department of Medical Genetics, Tohoku University School of Medicine, 1-1 Seiryo-machi, Aoba-ku, Sendai 980-8574, Japan
| | - Takeshi Oshima
- Department of Otorhinolaryngology, Head and Neck Surgery, Tohoku University School of Medicine, Sendai, Japan
| | - Akiko Ichinohe
- Department of Medical Genetics, Tohoku University School of Medicine, 1-1 Seiryo-machi, Aoba-ku, Sendai 980-8574, Japan
| | - Kanako Kojima
- Department of Medical Genetics, Tohoku University School of Medicine, 1-1 Seiryo-machi, Aoba-ku, Sendai 980-8574, Japan
| | - Tetsuya Niihori
- Department of Medical Genetics, Tohoku University School of Medicine, 1-1 Seiryo-machi, Aoba-ku, Sendai 980-8574, Japan
| | - Junko Kanno
- Department of Medical Genetics, Tohoku University School of Medicine, 1-1 Seiryo-machi, Aoba-ku, Sendai 980-8574, Japan
| | - Yoko Narumi
- Department of Medical Genetics, Tohoku University School of Medicine, 1-1 Seiryo-machi, Aoba-ku, Sendai 980-8574, Japan
| | - Ayumi Narisawa
- Department of Medical Genetics, Tohoku University School of Medicine, 1-1 Seiryo-machi, Aoba-ku, Sendai 980-8574, Japan
| | - Kumi Kato
- Department of Medical Genetics, Tohoku University School of Medicine, 1-1 Seiryo-machi, Aoba-ku, Sendai 980-8574, Japan
- 21st COE Program "Comprehensive Research and Education Center for Planning of Drug Development and Clinical Evaluation", Tohoku University, Sendai, Japan
| | - Yoko Aoki
- Department of Medical Genetics, Tohoku University School of Medicine, 1-1 Seiryo-machi, Aoba-ku, Sendai 980-8574, Japan
- 21st COE Program "Comprehensive Research and Education Center for Planning of Drug Development and Clinical Evaluation", Tohoku University, Sendai, Japan
| | - Katsuhisa Ikeda
- Department of Otorhinolaryngology, Head and Neck Surgery, Tohoku University School of Medicine, Sendai, Japan
| | - Toshimitsu Kobayashi
- Department of Otorhinolaryngology, Head and Neck Surgery, Tohoku University School of Medicine, Sendai, Japan
| | - Yoichi Matsubara
- Department of Medical Genetics, Tohoku University School of Medicine, 1-1 Seiryo-machi, Aoba-ku, Sendai 980-8574, Japan
- 21st COE Program "Comprehensive Research and Education Center for Planning of Drug Development and Clinical Evaluation", Tohoku University, Sendai, Japan
| |
Collapse
|
28
|
Beisel KW, Rocha-Sanchez SM, Morris KA, Nie L, Feng F, Kachar B, Yamoah EN, Fritzsch B. Differential expression of KCNQ4 in inner hair cells and sensory neurons is the basis of progressive high-frequency hearing loss. J Neurosci 2005; 25:9285-93. [PMID: 16207888 PMCID: PMC6725753 DOI: 10.1523/jneurosci.2110-05.2005] [Citation(s) in RCA: 97] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
Abstract
Human KCNQ4 mutations known as DFNA2 cause non-syndromic, autosomal-dominant, progressive high-frequency hearing loss in which the cellular and molecular basis is unclear. We provide immunofluorescence data showing that Kcnq4 expression in the adult cochlea has both longitudinal (base to apex) and radial (inner to outer hair cells) gradients. The most intense labeling is in outer hair cells at the apex and in inner hair cells as well as spiral ganglion neurons at the base. Spatiotemporal expression studies show increasing intensity of KCNQ4 protein labeling from postnatal day 21 (P21) to P120 mice that is most apparent in inner hair cells of the middle turn. We have identified four alternative splice variants of Kcnq4 in mice. The alternative use of exons 9-11 produces three transcript variants (v1-v3), whereas the fourth variant (v4) skips all three exons; all variants have the same amino acid sequence at the C termini. Both reverse transcription-PCR and quantitative PCR analyses demonstrate that these variants have differential expression patterns along the length of the mouse organ of Corti and spiral ganglion neurons. Our expression data suggest that the primary defect leading to high-frequency loss in DFNA2 patients may be attributable to high levels of the dysfunctional Kcnq4_v3 variant in the spiral ganglion and inner hair cells in the basal hook region. Progressive hearing loss associated with aging may result from an increasing mutational load expansion toward the apex in inner hair cells and spiral ganglion neurons.
Collapse
MESH Headings
- Animals
- Animals, Newborn
- Blotting, Northern/methods
- Cochlea/cytology
- Exons
- Ganglia, Spinal/cytology
- Gene Expression/physiology
- Gene Expression Regulation, Developmental/physiology
- Hair Cells, Auditory, Inner/metabolism
- Hearing Loss, High-Frequency/genetics
- Hearing Loss, High-Frequency/metabolism
- KCNQ Potassium Channels/genetics
- KCNQ Potassium Channels/metabolism
- Mice
- Mice, Inbred Strains
- Neurons, Afferent/metabolism
- RNA Splicing/genetics
Collapse
Affiliation(s)
- Kirk W Beisel
- Department of Biomedical Sciences, Creighton University, Omaha, Nebraska 68178, USA.
| | | | | | | | | | | | | | | |
Collapse
|