AbstractObjective(s)Despite the enormous heterogeneity of genetic hearing loss, most non-syndromic hearing losses are caused by mutations in the GJB2 gene. We aimed to characterize the mutation profiles of 100 Iranian deaf patients that were under 10 years old.Materials and MethodsPatients were tested with direct sequencing of entire coding region of the GJB2 gene.ResultsEight known mutations plus one novel (358delGAG) were found in 25% of study group. The 35delG mutation (64%) constituted the majority of GJB2 mutations. ConclusionRole of GJB2 mutation in Iranian young deaf population is more prominent than previous study that can be a result of higher consanguine marriage in population. But our result shows that there is only 25% non-syndromic hearing loss due to high frequency of consanguine marriage in Iranian population. Identification of other genes involved in genetic deafness will help us understand the fundamental mechanisms of normal hearing, both in early diagnosis and therapy.