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

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. In all, 447 unrelated families were included and analyzed for the prevalence and type of the GJB2 gene mutations. 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. This study highlights the importance of establishing prevalence, based on the local population for screening and diagnostic programs of live births in Iran.