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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.

Deafness is a total or partial hearing loss that may appear at any age and with different degrees of severity. Approximately 50% of hearing loss have a genetic origin, and among them, non-syndromic sensorineural deafness represents about 70% of the cases. From them, 80% correspond to autosomal recessive inheritance deafness. Autosomal recessive deafness was not studied enough at the molecular level in Iraq. This study aimed to verify the frequency of three GJB2 mutations in non-syndromic sensorineural deafness in the Iraqi population. The current case-control study was conducted from January 2018 to January 2020. The study included 95 deafness patients (55 males and 40 females) and 110 healthy control group. Age and sex were matched between the two groups. In order to detect c.35delG, 235delC, and 167delT mutations in the GJB2 gene, we employed the PCR-RFLP technique. The c.35delG was the main frequent mutation encountered with the GJB2 gene among patients with autosomal recessive non-syndromic sensorineural hearing loss. Among them, 35 (36.8%) were homozygous, 40 (42.1%) were heterozygous, and 20 (21.1%) were wild genotypes. The second-degree mutation in the GJB2 gene was c.235delC mutation, which from the 95 deaf patients, there were 20 (21.1%) with homozygous, 33 (34.7%) heterozygous, and 42 (44.2%) wild genotypes. None of the 95 deaf patients showed the c.167delT mutation, and no mutations appeared in the control group. Our data concluded that the GJB2 c.35delG and c.235delC gene mutations were the main cause of autosomal recessive non-syndromic sensorineural hearing loss in the Iraqi deaf population.

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.

Objectives: The ARNSHL wasn’t been studied enough in Iraq, this study aimed to detect the prevalence of the three most common mutations of Connexin 26 gene in Iraqi population. This study was conducted in order to detect c.35delG, c.235delC and c.167delT mutations in GJB2 gene, we were employed PCR-RFLP assays.Results: The current case-control study was conducted from January 2018 to January 2020, The study was included 95 deaf patients (55 males and 40 females) their age range between 11-40 years and 21.5 ± 6.3 year (mean ± SD) and 110 healthy control group, their ages range between 10-40 years and 20.1 ± 5.9 year (mean ± SD), these two groups were matched in age and gender. From 95 deaf patients with ARNSHL who were participated in this study, c.35delG was the main frequent mutation encountered with GJB2 gene, The second frequent mutation was c.235delC, None of 95 deaf patients were showed the c.167delT mutation, these variants were not detected in healthy control group which was studied parallel with patients group. Our data conclude that GJB2 c.35delG and c.235delC gene mutations were the main cause of ARNSHL in Iraqi deaf population.