An update of spectrum and frequency of GJB2 mutations causing hearing loss in the south of Iran: A literature review

Objective: Mutations in the GJB2 gene are a major cause of autosomal recessive non-syndromic HL (ARNSHL) in many populations. Previous studies have estimated the average frequency of GJB2 mutations to be between 16 and 18% in Iran, but would vary among different ethnic groups. Here, we have taken together and reviewed results from our three previous publications and data from search other published mutation reports to provide a comprehensive collection of data for GJB2 mutations and HL in the south of Iran. Methods: In all, 447 unrelated families were included and analyzed for the prevalence and type of the GJB2 gene mutations. Results: Totally, the frequency of GJB2 mutations was found to be 11.5% in the southern provinces studied which is significantly lower than that identified in Northern populations of Iran, and also a southwest to southeast Iranian gradient in the frequency of GJB2 mutations is suggested. Conclusions: This study highlights the importance of establishing prevalence, based on the local population for screening and diagnostic programs of live births in Iran.