Spectrum and frequency of connexin 26 & connexin 30 gene mutations in patients with congenital hearing loss from Ladakh India

Meta Gene ◽  
2021 ◽  
pp. 100960
Author(s):  
Mohd Murtaza ◽  
Mahrukh Hameed Zargar ◽  
Oliyat Ali ◽  
Ishfaq Shafi Khan ◽  
Md Niamat Ali
Keyword(s):  
Hearing Loss ◽  
Gene Mutations ◽  
Connexin 26 ◽  
Congenital Hearing Loss ◽  
Connexin 30

scholarly journals Connexin 26 Gene Mutations in Non-Syndromic Hearing Loss Among Kuwaiti Patients

2014 ◽  
Vol 23 (1) ◽  
pp. 74-79 ◽  
Author(s):  
Khalid Al-Sebeih ◽  
Marium Al-Kandari ◽  
Sadika A. Al-Awadi ◽  
Fatma F. Hegazy ◽  
Ghada A. Al-Khamees ◽  
...  
Keyword(s):  
Hearing Loss ◽  
Gene Mutations ◽  
Connexin 26 ◽  
Syndromic Hearing Loss

scholarly journals Spectrum and Frequency of the GJB2 Gene Mutations Among Latvian Patients with Prelingual Nonsyndromic Hearing Loss

2009 ◽  
Vol 63 (4-5) ◽  
pp. 198-203
Author(s):  
Olga Šterna ◽  
Natālija Proņina ◽  
Ieva Grīnfelde ◽  
Sandra Kušķe ◽  
Astrīda Krūmiņa ◽  
...  
Keyword(s):  
Hearing Loss ◽  
Gene Mutations ◽  
Gjb2 Gene ◽  
Connexin 26 ◽  
Compound Heterozygous ◽  
Nonsyndromic Hearing Loss ◽  
Profound Hearing Loss ◽  
Common Cause ◽  
Gjb2 Mutation ◽  
35Delg Mutation

Spectrum and Frequency of the GJB2 Gene Mutations Among Latvian Patients with Prelingual Nonsyndromic Hearing Loss Mutations in the GJB2 gene (connexin 26) are the most common cause of congenital nonsyndromic severe-to-profound hearing loss. Sixty-five hearing impaired probands from Latvia were tested for mutations in the GJB2 gene to determine the percentage of hearing loss attributed to connexin 26 and the types of mutations in this population. A total of 62% of patients tested had GJB2 mutations. Four different mutations in the GJB2 gene were identified in Latvian patients with nonsyndromic sensorineural hearing loss: 35delG, 311-324del14, 235delC and M34T. The most prevalent mutation is 35delG (47% of all probands were homozygous and 8% compound heterozygous). Our findings support the conclusion that the 35delG mutation is the most prevalent GJB2 mutation and that it is the common cause of hereditary nonsyndromic hearing loss in populations of European descent.

Connexin 26 and 30 mutations in paediatric patients with congenital, non-syndromic hearing loss treated with cochlear implantation in Mediterranean Turkey

2012 ◽  
Vol 127 (1) ◽  
pp. 33-37 ◽  
Author(s):  
Ö Tarkan ◽  
P Sari ◽  
O Demirhan ◽  
M Kiroğlu ◽  
Ü Tuncer ◽  
...  
Keyword(s):  
Hearing Loss ◽  
Cochlear Implantation ◽  
Autosomal Recessive ◽  
Connexin 26 ◽  
Enzyme Linked Immunosorbent Assay ◽  
Paediatric Patients ◽  
Study Population ◽  
Connexin 30 ◽  
Syndromic Hearing Loss ◽  
35Delg Mutation

AbstractObjective:Mutations in the genes for connexin 26 (GJB2) and connexin 30 (GJB6) play an important role in autosomal recessive, non-syndromic hearing loss. This study aimed to detect the 35delG and 167delT mutations of theGJB2gene and the del(GJB6-D13S1830) mutation of theGJB6gene in paediatric patients diagnosed with congenital, non-syndromic hearing loss and treated with cochlear implantation in Mediterranean Turkey.Materials and method:We included 94 children diagnosed with congenital, non-syndromic hearing loss and treated with cochlear implantation. Blood samples were collected, DNA extracted and an enzyme-linked immunosorbent assay performed to enable molecular diagnosis of mutations.Results:Of the 94 children analysed, the 35delG mutation was detected in 12 (12.7 per cent): 10 (83.3 per cent) were homozygous and 2 (16.7 per cent) heterozygous mutant. The 167delT and del(GJB6-D13S1830) mutations were not detected.Conclusion:The GJB2-35delG mutation is a major cause of congenital, non-syndromic hearing loss in this study population.

scholarly journals Connexin 26 (GJB2) Gene Mutations Linked With Autosomal Recessive Nonsyndromic Sensorineural Hearing Loss in Iraqi Population

2021 ◽  
Author(s):  
Anwar Madlool Al-janabi ◽  
Habeeb Shuhaib Ahmmed ◽  
Salih Mahdi Al-Khafaji
Keyword(s):  
Hearing Loss ◽  
Autosomal Recessive ◽  
Gene Mutations ◽  
Sensorineural Deafness ◽  
Healthy Control Group ◽  
Gjb2 Gene ◽  
Connexin 26 ◽  
Control Group ◽  
Current Case ◽  
Healthy Control

Abstract Background:Deafness is a total or partial hearing loss that may appear at any ages with different degrees of severity. Approximately 50% of hearing loss have a genetic origin, among them, the nonsyndromic sensorineural deafness represents about 70% of the cases. From them 80% corresponding to autosomal recessive inheritance deafness. Objective: Autosomal recessive deafness was not been studied enough at molecular level in Iraq, so this study aimed to detect the prevalence of the three most common mutations of Connexin 26 (GJB2) gene in nonsyndromic sensorineural deafness for Iraqi population.Method: The current case-control study was conducted from January 2018 to January 2020 at molecular laboratory in Anatomy and Histology Department/ faculty of Medicine/ Kufa University/Najaf/ Iraq. The study was included 95 deaf patients (55 males and 40 females) their age range between 11-40 years old and 21.5 ± 6.3 year (mean ± SD) and 110 healthy control group, their ages range between 10-40 years old and 20.1 ± 5.9 year (mean ± SD), these two groups were matched in age and gender. In order to detect c.35delG, 235delC and 167delT mutations in GJB2 gene, we were employed the polymerase chain reaction - restriction fragment length polymorphism (PCR-RFLP) technique.Results: From 95 deaf patients with ARNSHL who were participated in this study, the c.35delG was the main frequent mutation encountered with GJB2 gene, among them 35(36.8%) were homozygous, 40(42.1%) were heterozygous and 20 (21.1%) were wild genotypes. The second degree mutation in GJB2 gene was c.235delC mutation, which from the 95 deaf patients, there were 21 (22.1%) carried out homozygous, 33 (34.7%) heterozygous and 42(44.2%) wild genotypes. None of the 95 deaf patients were showed the c.167delT mutation, on the other hand these variants were not detected in healthy control group which was studied parallel with patients group.Conclusion: Our data conclude that the GJB2 c.35delG and c.235delC gene mutations were the main cause of ARNSHL in Iraqi deaf population.

Hearing loss associated with 35delG mutation in Connexin-26 (GJB2) gene: audiogram analysis

2004 ◽  
Vol 118 (1) ◽  
pp. 8-11 ◽  
Author(s):  
Fabrizio Salvinelli ◽  
Manuele Casale ◽  
Luca D’Ascanio ◽  
Luca Firrisi ◽  
Fabio Greco ◽  
...  
Keyword(s):  
Hearing Loss ◽  
Autosomal Recessive ◽  
Pure Tone Audiometry ◽  
Gjb2 Gene ◽  
Connexin 26 ◽  
Common Mutation ◽  
Congenital Hearing Loss ◽  
35Delg Mutation ◽  
The Relationship

35delG is the most common mutation in the Connexin-26 gene, representing a major cause of autosomal recessive hearing loss. The aim of this study was to evaluate the relationship between the audiological phenotype and the 35delG mutation in 64 Sicilians with non-syndromic deafness. Pure-tone audiometry and a screening for 35delG mutation were performed. Audiograms were evaluated according to the classification of Liu and Xu. Thirteen homozygotes and nine heterozygotes for the investigated mutation were found. Symmetrical hearing loss was significantly (p=0.008) more common in homozygous subjects than in those without the Connexin-26 mutation. Profound-severe hypoacusia was found in 92.3 per cent of 35delG homozygous, 22.3 per cent of heterozygous and 58.7 per cent of 35delG absent patients. Residual shape audiograms were more frequent in homozygotes. A molecular analysis for the 35delG mutation should be performed in cases of symmetric, severe-profound congenital hearing loss, as a genetic cause is probable in such cases.

Connexin 26 and Connexin 30 Mutations in Children with Nonsyndromic Hearing Loss

2004 ◽  
Vol 114 (4) ◽  
pp. 607-611 ◽  
Author(s):  
Christy B. Erbe ◽  
Kevin C. Harris ◽  
Christina L. Runge-Samuelson ◽  
Valerie A. Flanary ◽  
Phillip Ashley Wackym
Keyword(s):  
Hearing Loss ◽  
Connexin 26 ◽  
Nonsyndromic Hearing Loss ◽  
Connexin 30

scholarly journals Relevance of Connexin 26 (GJB2) Gene Mutations With Congenital Nonsyndromic Sensorineural Hearing Loss in Lraqi Deafness Patients.

2021 ◽  
Author(s):  
Anwar Madlool Al-janabi ◽  
Habeeb Shuhaib Ahmmed ◽  
Salih Mahdi Alkhafaji
Keyword(s):  
Hearing Loss ◽  
Gene Mutations ◽  
Sensorineural Deafness ◽  
Healthy Control Group ◽  
Gjb2 Gene ◽  
Connexin 26 ◽  
Control Group ◽  
Current Case ◽  
Healthy Control ◽  
And Gender

Abstract Objective: This study aimed to detect the frequency of the three most common mutations of GJB2 in nonsyndromic sensorineural deafness for Iraqi population.Method: The current case-control study was conducted from January 2018 to November 2019 at ENT Departments from middle Euphrates region of Iraq. The study was included 95 deaf patients group (55 males and 40 females) their age range between 11-40 years old and 21.5 ± 6.3 year (mean ± SD). and 110 healthy control group, their ages range between 10-40 years old and 20.1 ± 5.9 year (mean ± SD), these two groups were matched in age and gender. In order to detect c.35delG, 235delC and 167delT mutations in GJB2 gene, we were employed the polymerase chain reaction – restriction fragment length polymorphism (PCR-RFLP) technique.Results: From 95 deaf patients with non syndromic hearing loss (NSHL), were participated in this study. The c.35delG was the main frequent mutation encountered with GJB2 gene, of the 95 patients, 38(40%) were heterozygous and the others 57(60%) were homozygous genotypes. The second degree mutation in GJB2 gene was c.235delC mutation. Which from the 95 deaf patients, 35 (36.8%) were carried out homozygous, 5 (5.3%) were carried out heterozygous and 55(57.9) of the study individuals were appeared wild genotypes. None of the 95 deaf patients were showed the c.167delT mutation, while Connexin 26 studied mutations were not detected in healthy control group.Conclusion: Our data conclude that the GJB2 c.35delG and c.235delC gene mutations were the main cause of congenital hearing loss in Iraqi deaf population.

Connexin 26 Immunohistochemistry in Temporal Bones With Cochlear Otosclerosis

2018 ◽  
Vol 127 (8) ◽  
pp. 536-542 ◽  
Author(s):  
Mia E. Miller ◽  
Ivan A. Lopez ◽  
Fred H. Linthicum ◽  
Akira Ishiyama
Keyword(s):  
Hearing Loss ◽  
Stria Vascularis ◽  
Organ Of Corti ◽  
Connexin 26 ◽  
Spiral Ligament ◽  
Mixed Hearing Loss ◽  
Cell Counts ◽  
Normal Hair ◽  
Connexin 30 ◽  
Temporal Bones

Hypothesis: Connexin-26 (Cx26) expression is diminished in the spiral ligament of subjects with hearing loss and cochlear otosclerosis (CO). Background: Human temporal bone (HTB) studies have demonstrated that CO is associated with hyalinization of the spiral ligament. We hypothesize that hyalinization is associated with a loss of fibrocytes with a consequent decline in Cx26 expression. Cx26 and Connexin-30 (Cx30) encode gap junction proteins expressed in supporting cells of the organ of Corti, the spiral limbus, stria vascularis, and in fibrocytes of the spiral ligament. These gap junctions are critical for potassium recycling and maintenance of the endocochlear potential. Diminished expression of these proteins would likely be associated with hearing dysfunction. Methods: Histopathology and clinical characteristics of 45 HTB specimens with CO and spiral ligament hyalinization were reviewed. Those with sensorineural or mixed hearing loss but normal or near-normal hair cell counts were analyzed with light microscopy, and Cx26-immunoreactive (IR) signal was qualitatively assessed. Results: H&E staining demonstrated hyalinization in the spiral ligament and loss of type II and type III fibrocytes. Cx26-IR was diminished throughout the cochlea affected with CO compared with normal controls. Conclusions: Cx26-IR reduction in the spiral ligament of subjects with CO likely plays a role in hearing loss.

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