Frequency of c.35delG Mutation in GJB2 Gene (Connexin 26) in Syrian Patients with Nonsyndromic Hearing Impairment

BACKGROUND: Hearing impairments (HI) are the most common birth defect worldwide. Very large numbers of genes have been identified but the most profound is GJB2. The clinical interest regarding this gene is very pronounced due to its high carrier frequency (0.5–5.4%) across different ethnic groups. This study aimed to determine the prevalence of common GJB2 mutations in Syrian patients with profound sensorineural HI. METHODS: We carried out PCR, restriction enzyme based screening, and sequencing of 132 Syrian patients diagnosed clinically with hereditary deafness for different GJB2 mutations. RESULTS: The result revealed that, in GJB2 gene, c.35delG is the most prevalent among affected studied subjects (13.64%), followed by c.457G>A (2.4%). CONCLUSION: The benefit of this study on the one hand is its first report of prelingual deafness causative gene mutations identified by sequencing technology in the Syrian families. It is obvious from the results that the deployment in biomedical research is highly effective and has a great impact on the ability to uncover the cause of genetic variation in different genetic diseases.