Congenital deafness is the most common sensory defect in human, with an incidence of about 1:1000 births. Approximately, 50% of congenital deafness has a genetic origin. Most cases of deafness are not accompanied by additional obvious abnormalities and are, therefore, considered to be non-syndromic. It is estimated that approximately 80% of inherited non-syndromic deafness is caused by autosomal recessive defects.