Deafness is one of the common sensory impairments in humans, affecting approximately 1 to 3 individuals in every 1000 live human births. Genetic mutations in the gap junction proteins, Cx26 and Cx30 are the major contributors to sensorineural, non-syndromic and prelingual hearing loss in humans. The GJB6 gene encoding connexin (Cx30) protein is expressed in mesenchymal and epithelial structures of the inner ears. Mutation in GJB6 gene results in loss of function mutation that causes hearing loss in humans. The current study was thus designed to explore genetic mutations in GJB6 gene in deaf individuals from District Mansehra, Pakistan. The DNA of non-syndromic deaf-individuals and normal controls were isolated from their saliva. The whole coding area of GJB6 gene was amplified by using PCR specific primers and subsequently sequenced by Sanger method. After sequence data analysis we identified 3 mutations in the coding area of GJB6 gene. It was observed that at position 242, Guanine (G) is substituted by Thymine (T), at position 338 Thymine (T) is substituted by Cytosine (C), and at position 381 Adenine (A) is substituted by Guanine (G). The identification of these novel mutations in coding region of GJB6 gene has enabled us to establish the genetic bases for hearing loss in deaf individuals. The occurrence of higher frequency of genetic mutations in GJB6 gene in some populations suggests the use of molecular markers as tools for diagnosis, carrier detection, and prenatal diagnosis of deafness.

Index Terms- Deafness, Mutations, GJB6 gene, Pakistan