Mojgan Babanejad - Genetic Research Cen ter, University of Social Welfare and Rehabilitation Sciences, Tehran, Iran
Mohammad Reza Akbari - Women’s College Research Institute, Women's College Hospital, University of Toronto, Toronto, Canada.
Hossein Najmabadi - Genetic Research Cen ter, University of Social Welfare and Rehabilitation Sciences, Tehran, Iran
Kimia Kahrizi - Genetic Research Cen ter, University of Social Welfare and Rehabilitation Sciences, Tehran, Iran

With prevalence figures close to 0.2% at birth, hearing loss (HL) is the most frequent sensory impairment in childhood. In developed countries, genetic causes account for more than 60% of congenital HL, most often resulting in non-syndromicdeafness, which is usually autosomal recessive.Hereditary nonsyndromic hearing loss (NSHL) in Iran is highly heterogeneous, and more than 50% of patients with a presumed genetic etiology lack a specific molecular diagnosis with STR analysis. Whole-exome sequencing (WES) has recently opened a new page in Mendelian disease gene discovery – enabling to study autosomal recessive HL in a new way.The aim of this study is to find more causative genes and their mutations for NSARHL in Iranian families by WES. Afterruling out any association to prevalent genes for NSARHL in Iran, ten families will be subjected to WES.Until now, WES has been performed with genomic DNA from affected individuals of two consanguineous families with profound deafness. Analysis of these data revealed a novel homozygous mutation in MYO7A gene in one family but cosegregation study failed to confirm this variant as the only cause of HL in this family. Additional clinical investigation revealed that an intra-familial phenotypic variation and existence of both syndromic and non-syndromic HL in this family ispossible. Further studies to find the other variants which may be associated with HL in this family, the data analysis of the second family and also WES of remaining families are underway

Non-syndromic autosomal recessive hearing loss, whole-exome sequencing, Iran