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Lezirovitz K, Mingroni-Netto RC. Genetic etiology of non-syndromic hearing loss in Latin America. Hum Genet 2021; 141:539-581. [PMID: 34652575 DOI: 10.1007/s00439-021-02354-4] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/18/2021] [Accepted: 08/23/2021] [Indexed: 12/16/2022]
Abstract
Latin America comprises all countries from South and Central America, in addition to Mexico. It is characterized by a complex mosaic of regions with heterogeneous genetic profiles regarding the geographical origin of the ancestors and proportions of admixture between the Native American, European and African components. In the first years following the findings of the role of the GJB2/GJB6 genes in the etiology of hearing loss, most scientific investigations about the genetics of hearing loss in Latin America focused on assessing the frequencies of pathogenic variants in these genes. More recently, modern techniques allowed researchers in Latin America to make exciting contributions to the finding of new candidate genes, novel mechanisms of inheritance in previously known genes, and characterize a wide diversity of variants, many of them unique to Latin America. This review aimed to provide a general landscape of the genetic studies about non-syndromic hearing loss in Latin America and their main scientific contributions. It allows the conclusion that, although there are similar contributions of some genes, such as GJB2/GJB6, when compared to European and North American countries, Latin American populations revealed some peculiarities that indicate the need for tailored strategies of screening and diagnosis to specific geographic regions.
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Affiliation(s)
- Karina Lezirovitz
- Laboratório de Otorrinolaringologia/LIM32, Faculdade de Medicina, Hospital das Clínicas, Universidade de São Paulo, São Paulo, SP, Brazil.
| | - Regina Célia Mingroni-Netto
- Departamento de Genética e Biologia Evolutiva, Centro de Pesquisas sobre o Genoma Humano e Células-Tronco, Instituto de Biociências, Universidade de São Paulo, São Paulo, Brazil
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Lin Y, Yu F, Jiao Y, Zhou F. Variations in the Mutational Spectrum in Nonsyndromic Hearing Impairment: A study of the Special Schools for the Deaf in Southern China. J Int Adv Otol 2020; 15:247-252. [PMID: 31347505 DOI: 10.5152/iao.2019.6512] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
OBJECTIVES To explore the characteristics of variations in patients with nonsyndromic hearing impairment (NSHI) in Southern China to supply a theoretical basis for screening, intervention, and prevention. MATERIALS AND METHODS A total of 634 hearing-impaired students from the special schools for the deaf and 220 normal-hearing individuals in South China were tested using an allele-specific polymerase chain reaction-based universal array, and the screened SLC26A4 mutation carrier was examined using computed tomography. The pathogenesis of deafness was analyzed using pathography and objective hearing tests. RESULTS In total, 151 patients with NSHI carried pathogenic mutations in the screening chip, and the carrier rate was 23.82% (151/634) in the studied population. Of the 151 screened carriers, 65 (10.25%) patients harbored homozygous or homoplasmy mutated genes associated with autosomal recessive hearing loss; 36 (5.68%) patients with mutant alleles were homozygous for the GJB2 c.235delC mutation and 27 (4.26%) were heterozygous. Furthermore, 18 (2.84%) patients were homozygous with mutant alleles for the SLC26A4 c.919-2A>G mutation and 43 (6.78%) were heterozygous; 7 (1.10%) patients were homoplasmy mutation carriers of MT-RNR1 gene. There was 1 SLC26A4 c.919-2A>G and 1 GJB2 c.235delC heterozygous mutant allele in the group of 220 normal-hearing individuals. CONCLUSION GJB2 and SLC26A4 were much more prevalent than MT-RNR1 and GJB3 in South China according to this gene chip. Minuscule differences in the mutation spectrum or prevalence of GJB2 c.235delC and SLC26A4 c.919-2A>G were found in our study; furthermore, a relatively high incidence of variations was observed among these individuals with NSHI.
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Affiliation(s)
- Ying Lin
- Department of Otolaryngology-Head and Neck Surgery, Guangzhou Otorhinolaryngology Head and Neck Surgery Hospital, Guangzhou Medical University, Guangzhou, China
| | - Feng Yu
- Department of Otolaryngology-Head and Neck Surgery, Guangzhou Otorhinolaryngology Head and Neck Surgery Hospital, Guangzhou Medical University, Guangzhou, China
| | - Yuelong Jiao
- Department of Otolaryngology-Head and Neck Surgery, Guangzhou Otorhinolaryngology Head and Neck Surgery Hospital, Guangzhou Medical University, Guangzhou, China
| | - Feng Zhou
- Department of Otolaryngology-Head and Neck Surgery, Guangzhou Otorhinolaryngology Head and Neck Surgery Hospital, Guangzhou Medical University, Guangzhou, China
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Talbi S, Bonnet C, Boudjenah F, Mansouri MT, Petit C, Ammar Khodja F. The spectrum of GJB2 gene mutations in Algerian families with nonsyndromic hearing loss from Sahara and Kabylie regions. Int J Pediatr Otorhinolaryngol 2019; 124:157-160. [PMID: 31200317 DOI: 10.1016/j.ijporl.2019.05.036] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/25/2019] [Revised: 05/23/2019] [Accepted: 05/23/2019] [Indexed: 01/14/2023]
Abstract
INTRODUCTION DFNB1, caused by mutations of GJB2 or GJB6, is the most prevalent genetic form of nonsyndromic (i.e., isolated) congenital deafness in countries located around the Mediterranean Sea. Because some mutations are restricted to specific ethnic-geographic groups, we studied the prevalence and spectrum of GJB2/GJB6 mutations in deaf patients originating from two different Algerian regions, Kabylie and Sahara. PATIENTS AND METHODS Among 91 reportedly unrelated Algerian patients affected by prelingual deafness, 80 patients (41 from Kabylie and 39 from Sahara) were diagnosed with isolated deafness. All had profound deafness, except one patient with mild deafness. They were screened for the presence of GJB2 mutations by direct sequencing of the single coding exon of GJB2. Patients without mutations were then screened for the presence of the most frequent two deletions of GJB6: del(GJB6-D13S1854) and del(GJB6-D13S1830). RESULTS Causative mutations were found in 13 and 8 patients from Kabylie and Sahara, respectively, accounting for more than a quarter of the cohort. The c.35delG, p.Gly12Valfs*2 mutation remains the most important mutation both in Kabylie (10 patients) and Sahara (7 patients). All detected patients were homozygous for this mutation. In addition, two other mutations (c.139G > T, p.Glu47* and c.167delT, p.Leu56Argfs*26) were found homozygous in one family each, and two patients were compound heterozygotes for (c.35delG p.Gly12Valfs*2/c.139G > T, p.Glu47*). No deletion of GJB6 was detected. CONCLUSION We confirm that mutations in GJB2, mainly c.35delG, are one of the most prevalent causes of nonsyndromic congenital deafness in Algeria, whereas the del (GJB6-D13S1854) and del (GJB6-D13S1830) deletions of GJB6 contribute little, if any. Further investigation is needed to identify the cause of deafness in other patients without diagnostic.
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Affiliation(s)
- Sonia Talbi
- Equipe de Génétique, Laboratoire de Biologie Cellulaire et Moléculaire, Faculté des Sciences Biologiques, Université des Sciences et de la Technologie Houari Boumediene (USTHB), POB32 ElAlia, 16111, Bab Ezzouar, Alger, Algeria.
| | - Crystel Bonnet
- Inserm UMRS 1120, Institut de la Vision, Sorbonne Université, Paris, France
| | - Farid Boudjenah
- Service d'Otorhinolaryngologie (ORL), Hôpital de Frantz fanon, Bejaia, Algeria; Service d'Otorhinolaryngologie (ORL), Hôpital Sidi Belloua, Tizi-Ouzou, Algeria
| | | | - Christine Petit
- Inserm UMRS 1120, Institut de la Vision, Sorbonne Université, Paris, France; Institut Pasteur, Collège de France, Paris, France
| | - Fatima Ammar Khodja
- Equipe de Génétique, Laboratoire de Biologie Cellulaire et Moléculaire, Faculté des Sciences Biologiques, Université des Sciences et de la Technologie Houari Boumediene (USTHB), POB32 ElAlia, 16111, Bab Ezzouar, Alger, Algeria
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Figueroa-Ildefonso E, Bademci G, Rajabli F, Cornejo-Olivas M, Villanueva RDC, Badillo-Carrillo R, Inca-Martinez M, Neyra KM, Sineni C, Tekin M. Identification of Main Genetic Causes Responsible for Non-Syndromic Hearing Loss in a Peruvian Population. Genes (Basel) 2019; 10:E581. [PMID: 31370293 PMCID: PMC6723399 DOI: 10.3390/genes10080581] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/20/2019] [Revised: 07/23/2019] [Accepted: 07/30/2019] [Indexed: 12/30/2022] Open
Abstract
: Hearing loss (HL) is a common sensory disorder affecting over 5% of the global population. The etiology underlying HL includes congenital and acquired causes; genetic factors are the main cause in over 50% of congenital cases. Pathogenic variants in the GJB2 gene are a major cause of congenital non-syndromic hearing loss (NSHL), while their distribution is highly heterogeneous in different populations. To the best of our knowledge, there is no data regarding the genetic etiologies of HL in Peru. In this study, we screened 133 Peruvian families with NSHL living in Lima. We sequenced both exons of the GJB2 gene for all probands. Seven probands with familial NSHL that remained negative for GJB2 variants underwent whole genome sequencing (WGS). We identified biallelic pathogenic variants in GJB2 in 43 probands; seven were heterozygous for only one allele. The c.427C>T variant was the most common pathogenic variant followed by the c.35delG variant. WGS revealed three novel variants in MYO15A in two probands, one of them was predicted to affect splicing and the others produce a premature stop codon. The Peruvian population showed a complex profile for genetic variants in the GJB2 gene, this particular profile might be a consequence of the admixture history in Peru.
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Affiliation(s)
- Erick Figueroa-Ildefonso
- Neurogenetics Research Center, Instituto Nacional de Ciencias Neurológicas, Lima 15003, Peru
- John P. Hussman Institute for Human Genomics, University of Miami Miller School of Medicine, Miami, FL 33136, USA
| | - Guney Bademci
- John P. Hussman Institute for Human Genomics, University of Miami Miller School of Medicine, Miami, FL 33136, USA
- Dr. John T. Macdonald Foundation Department of Human Genetics, University of Miami Miller School of Medicine, Miami, FL 33136, USA
| | - Farid Rajabli
- John P. Hussman Institute for Human Genomics, University of Miami Miller School of Medicine, Miami, FL 33136, USA
| | - Mario Cornejo-Olivas
- Neurogenetics Research Center, Instituto Nacional de Ciencias Neurológicas, Lima 15003, Peru
- Center for Global Health, Universidad Peruana Cayetano Heredia, Lima 15102, Peru
| | - Ruy Diego Chacón Villanueva
- Neurogenetics Research Center, Instituto Nacional de Ciencias Neurológicas, Lima 15003, Peru
- Inter-units Program in Biotechnology, Institute of Biomedical Sciences, University of São Paulo, São Paulo 05508-270, Brazil
| | - Rodolfo Badillo-Carrillo
- Centro de Investigaciones Básicas en el Área Otoneurológica, Instituto Nacional de Ciencias Neurológicas, Lima 15003, Peru
| | - Miguel Inca-Martinez
- Neurogenetics Research Center, Instituto Nacional de Ciencias Neurológicas, Lima 15003, Peru
- Lerner Research Institute, Genomic Medicine, Cleveland Clinic Foundation, Cleveland, OH 44195, USA
| | - Karina Milla Neyra
- Neurogenetics Research Center, Instituto Nacional de Ciencias Neurológicas, Lima 15003, Peru
| | - Claire Sineni
- John P. Hussman Institute for Human Genomics, University of Miami Miller School of Medicine, Miami, FL 33136, USA
| | - Mustafa Tekin
- John P. Hussman Institute for Human Genomics, University of Miami Miller School of Medicine, Miami, FL 33136, USA.
- Dr. John T. Macdonald Foundation Department of Human Genetics, University of Miami Miller School of Medicine, Miami, FL 33136, USA.
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Carranza C, Menendez I, Herrera M, Castellanos P, Amado C, Maldonado F, Rosales L, Escobar N, Guerra M, Alvarez D, Foster J, Guo S, Blanton SH, Bademci G, Tekin M. A Mayan founder mutation is a common cause of deafness in Guatemala. Clin Genet 2015; 89:461-465. [PMID: 26346709 DOI: 10.1111/cge.12676] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/24/2015] [Revised: 08/14/2015] [Accepted: 09/04/2015] [Indexed: 11/29/2022]
Abstract
Over 5% of the world's population has varying degrees of hearing loss. Mutations in GJB2 are the most common cause of autosomal recessive non-syndromic hearing loss (ARNHL) in many populations. The frequency and type of mutations are influenced by ethnicity. Guatemala is a multi-ethnic country with four major populations: Maya, Ladino, Xinca, and Garifuna. To determine the mutation profile of GJB2 in a ARNHL population from Guatemala, we sequenced both exons of GJB2 in 133 unrelated families. A total of six pathogenic variants were detected. The most frequent pathogenic variant is c.131G>A (p.Trp44*) detected in 21 of 266 alleles. We show that c.131G>A is associated with a conserved haplotype in Guatemala suggesting a single founder. The majority of Mayan population lives in the west region of the country from where all c.131G>A carriers originated. Further analysis of genome-wide variation of individuals carrying the c.131G>A mutation compared with those of Native American, European, and African populations shows a close match with the Mayan population.
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Affiliation(s)
- C Carranza
- Institute for Research on Genetic and Metabolic Diseases, INVEGEM, Guatemala City, Guatemala
| | - I Menendez
- Dr. John T. Macdonald Foundation Department of Human Genetics and John P. Hussman Institute for Human Genomics, University of Miami Miller School of Medicine, Miami, FL, USA
| | - M Herrera
- Institute for Research on Genetic and Metabolic Diseases, INVEGEM, Guatemala City, Guatemala
| | - P Castellanos
- Center for Hearing and Phonetic Training, CEDAF, Guatemala City, Guatemala
| | - C Amado
- Institute for Research on Genetic and Metabolic Diseases, INVEGEM, Guatemala City, Guatemala
| | - F Maldonado
- Therapeutic Center for Hearing and Language, CEAL, Guatemala City, Guatemala
| | - L Rosales
- Institute for Research on Genetic and Metabolic Diseases, INVEGEM, Guatemala City, Guatemala
| | - N Escobar
- Institute for Research on Genetic and Metabolic Diseases, INVEGEM, Guatemala City, Guatemala
| | - M Guerra
- Institute for Research on Genetic and Metabolic Diseases, INVEGEM, Guatemala City, Guatemala
| | - D Alvarez
- Institute for Research on Genetic and Metabolic Diseases, INVEGEM, Guatemala City, Guatemala
| | - J Foster
- Dr. John T. Macdonald Foundation Department of Human Genetics and John P. Hussman Institute for Human Genomics, University of Miami Miller School of Medicine, Miami, FL, USA
| | - S Guo
- Dr. John T. Macdonald Foundation Department of Human Genetics and John P. Hussman Institute for Human Genomics, University of Miami Miller School of Medicine, Miami, FL, USA
| | - S H Blanton
- Dr. John T. Macdonald Foundation Department of Human Genetics and John P. Hussman Institute for Human Genomics, University of Miami Miller School of Medicine, Miami, FL, USA
| | - G Bademci
- Dr. John T. Macdonald Foundation Department of Human Genetics and John P. Hussman Institute for Human Genomics, University of Miami Miller School of Medicine, Miami, FL, USA
| | - M Tekin
- Dr. John T. Macdonald Foundation Department of Human Genetics and John P. Hussman Institute for Human Genomics, University of Miami Miller School of Medicine, Miami, FL, USA
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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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Hernández-Juárez AA, Lugo-Trampe JDJ, Campos-Acevedo LD, Lugo-Trampe A, Treviño-González JL, de-la-Cruz-Ávila I, Martínez-de-Villarreal LE. GJB2 and GJB6 mutations are an infrequent cause of autosomal-recessive nonsyndromic hearing loss in residents of Mexico. Int J Pediatr Otorhinolaryngol 2014; 78:2107-12. [PMID: 25288386 DOI: 10.1016/j.ijporl.2014.09.016] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/16/2014] [Revised: 09/12/2014] [Accepted: 09/16/2014] [Indexed: 12/11/2022]
Abstract
OBJECTIVES Mutations in the DFNB1 locus are the most common cause of autosomal-recessive nonsyndromic hearing loss (ARNSHL) worldwide. The aim of this study was to identify the most frequent mutations in patients with ARNSHL who reside in Northeastern Mexico. METHODS We determined the nucleotide sequence the coding region of GJB2 of 78 patients with ARNSHL. Polymerase chain reaction assays were used to detect the GJB2 IVS1+1G>A mutation and deletions within GJB6. RESULTS GJB2 mutations were detected in 9.6% of the alleles, and c.35delG was the most frequent. Six other less-frequent mutations were detected, including an extremely rare variant (c.645_648delTAGA), a novel mutation (c.35G>A), and one of possible Mexican origin (c.34G>T). GJB6 deletions and GJB2 IVS1+1G>A were not detected. CONCLUSIONS These data suggest that mutations in the DFNB1 locus are a rare cause of ARNSHL among the population of Northeastern Mexico. This confirms the genetic heterogeneity of this condition and indicates that further research is required to determine the other mechanisms of pathogenesis of ARNSHL in Mexicans.
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Affiliation(s)
- Aideé Alejandra Hernández-Juárez
- Departamento de Genética, Facultad de Medicina y Hospital Universitario "José E. González", Universidad Autónoma de Nuevo León (UANL), Av. Gonzalitos s/n cruce con Av. Madero, Col. Mitras Centro CP 64460, Monterrey, N.L., México
| | - José de Jesús Lugo-Trampe
- Departamento de Genética, Facultad de Medicina y Hospital Universitario "José E. González", Universidad Autónoma de Nuevo León (UANL), Av. Gonzalitos s/n cruce con Av. Madero, Col. Mitras Centro CP 64460, Monterrey, N.L., México
| | - Luis Daniel Campos-Acevedo
- Departamento de Genética, Facultad de Medicina y Hospital Universitario "José E. González", Universidad Autónoma de Nuevo León (UANL), Av. Gonzalitos s/n cruce con Av. Madero, Col. Mitras Centro CP 64460, Monterrey, N.L., México
| | - Angel Lugo-Trampe
- Centro Mesoamericano de Estudios en Salud Pública y Desastres, Universidad Autónoma de Chiapas (UNACH), Carretera Antiguo Aeropuerto; Pista Principal cruce con Pista Secundaria S/N, Col. Solidaridad 2000, CP 30798, Tapachula, Chis, México
| | - José Luis Treviño-González
- Departamento de Otorrinolaringología, Facultad de Medicina y Hospital Universitario "José E. González", Universidad Autónoma de Nuevo León (UANL), Av. Gonzalitos s/n cruce con Av. Madero, Col. Mitras Centro CP 64460, Monterrey, N.L., México
| | - Israel de-la-Cruz-Ávila
- Servicio de Audiología Pediátrica, Hospital Materno-Infantil, Aldama 460, Col. San Rafael, CP. 67190, Guadalupe, N.L., México
| | - Laura Elia Martínez-de-Villarreal
- Departamento de Genética, Facultad de Medicina y Hospital Universitario "José E. González", Universidad Autónoma de Nuevo León (UANL), Av. Gonzalitos s/n cruce con Av. Madero, Col. Mitras Centro CP 64460, Monterrey, N.L., México.
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Frequency of GJB2 and del(GJB6-D13S1830) mutations among an Ecuadorian mestizo population. Int J Pediatr Otorhinolaryngol 2014; 78:1648-54. [PMID: 25085072 DOI: 10.1016/j.ijporl.2014.07.014] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/10/2014] [Revised: 07/08/2014] [Accepted: 07/12/2014] [Indexed: 12/11/2022]
Abstract
OBJECTIVE The frequency of GJB2 mutations and of the del(GJB6-D13S1830) mutation has not been established among the Ecuadorian mestizo population diagnosed with autosomal recessive non-syndromic hearing loss. A genetic analysis was therefore designed in order to do so. METHODS The sample population included 111 subjects of which 26 were autosomal recessive non-syndromic hearing loss probands. Posterior to PCR amplification, sequencing analysis of exon 2 was used for mutational detection of the GJB2 gene; a multiplex PCR method was used for detection of the del(GJB6-D13S1830) mutation. The ratio of subjects with a certain state of the mutation (heterozygous/homozygous) is expressed as a percentage and significant differences between probands and controls were calculated using Fisher's exact test; P<0.05 was considered significant. RESULTS A total of 104 mutations belonging to 8 allelic variations were identified. The most common being the V27I (58.9%); however, as this variation is a non-pathogenic polymorphism, Q7X, with a total of 19 mutated alleles, was the most frequent mutation (18.3%). The V27I polymorphism was the only variation distributed homogenously among probands and controls (P=0.351). Based on physical analyses of multiple patients we confirm that Q7X causes a non-syndromic form of hearing loss and propose that it is a possible predominant mutation in the Ecuadorian population. CONCLUSIONS This is the first study of its kind among the Ecuadorian population and a preliminary step in establishing GJB2 and del(GJB6-D13S1830) mutational frequencies in this population; it is also the first to report of such a high frequency of the Q7X mutation. The data presented here brings Ecuador a step closer to providing more efficient treatment for a broader number of patients; additionally, it contributes to a better understanding of the relationship between autosomal recessive non-syndromic hearing loss and mutations on the GJB2 gene.
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JIANG HUA, CHEN JIA, SHAN XINJI, LI YING, HE JIANGUO, YANG BEIBEI. Prevalence and range of GJB2 and SLC26A4 mutations in patients with autosomal recessive non-syndromic hearing loss. Mol Med Rep 2014; 10:379-86. [DOI: 10.3892/mmr.2014.2148] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/11/2013] [Accepted: 03/13/2014] [Indexed: 11/05/2022] Open
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Chan DK, Chang KW. GJB2-associated hearing loss: Systematic review of worldwide prevalence, genotype, and auditory phenotype. Laryngoscope 2013; 124:E34-53. [DOI: 10.1002/lary.24332] [Citation(s) in RCA: 183] [Impact Index Per Article: 16.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 07/10/2013] [Indexed: 12/17/2022]
Affiliation(s)
- Dylan K. Chan
- Department of Otolaryngology-Head and Neck Surgery; University of California; San Francisco U.S.A
| | - Kay W. Chang
- Department of Otolaryngology-Head and Neck Surgery; Stanford University School of Medicine; Stanford California U.S.A
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Yoshida H, Takahashi H, Kanda Y, Usami SI. Long term speech perception after cochlear implant in pediatric patients with GJB2 mutations. Auris Nasus Larynx 2013; 40:435-9. [PMID: 23477838 DOI: 10.1016/j.anl.2013.01.006] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/04/2012] [Revised: 01/18/2013] [Accepted: 01/24/2013] [Indexed: 10/27/2022]
Abstract
OBJECTIVES To determine the long term effect of cochlear implant (CI) in children with GJB2-related deafness in Japan. METHODS Genetic testing was performed on 29 children with CI. The speech perception in 9 children with GJB2 gene-related deafness fitted with CI was compared with those in matched 10 children who were diagnosed as having no genetic loci. The average follow-up period after CI was 55.9 months and 54.6 months, respectively. RESULTS A definitive inherited hearing impairment could be confirmed in 12 (41.4%) of the 29 CI children, including 10 with GJB2-related hearing impairment and 2 with SLC26A4-related hearing impairment. The results of IT-MAIS, word or speech perception testing under the noise, and development of speech perception and production testing using the Enjoji scale were slightly better for the GJB2 group after CI than for the control group without statistical significant difference. CONCLUSION The long-term results of this study show that CI is also effective in the development of speech performance after CI in Japanese children with GJB2-related hearing impairments as HL due to other etiologies.
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Affiliation(s)
- Haruo Yoshida
- Department of Otolaryngology-Head and Neck Surgery, National Hospital Organization Ureshino Medical Center, Saga, Japan.
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Faundes V, Pardo RA, Castillo Taucher S. Genética de la sordera congénita. Med Clin (Barc) 2012; 139:446-51. [DOI: 10.1016/j.medcli.2012.02.014] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/03/2012] [Revised: 02/14/2012] [Accepted: 02/23/2012] [Indexed: 10/28/2022]
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