Review Studies of GJB2 Gene in Patients with Hearing Impairment in Pakistan

Deafness is inherited as one of the most frequent type of neurosensory disorder. The specific physiologic mechanisms of the different types of hearing loss are still unknown. Recent studies have listed numerous causative agents for hearing loss. Genetic factors contribute to a greater extent in hearing disability. GJB2 gene is one of the most promising candidates. 35delG is the most common mutation which accounts for about 50% of all GJB2 gene mutation. After collection of data and isolation of blood, extraction of DNA was performed for each sample. Direct sequencing of GJB2 gene was performed. Primary sequencing data of the representative sample concluded that GJB2 gene is not mutated in the studied family. There are other candidates for hearing disability; further investigations are needed for assessment of other members of the selected family or other genes that are responsible for hearing loss. Human GJB2 protein was compared with that of mouse and rabbit. The data from multiple alignment shows that there is only alteration at nine different points of rabbit compared to human GJB2 protein while this variation is sixteen times when we compared human GJB2 protein sequence with that of mouse.