In the majority of hereditary deafness, hearing impairment is the only clinical feature (Non-syndromal) but it can also be associated with other clinical features (syndromal). Non-syndromal autosomal recessive deafness (NSRD) accounts for <85% of nonsyndromic sensorineural deafness. It has a very high degree of genetic heterogeneity, which is expected due to the structural and functional complexity of the inner ear. At least 35 different loci may be involved in NSRD even though it is a clinically homogenous disorder because in most cases, the hearing loss has a prelingual onset, involves all the frequencies, is severe or profound, and nonprogressive.