Low incidence of variants among the prelingual hearing impaired from southern India.

The broad spectrum of causal variants in the newly discovered gene is well reflected in worldwide studies. Except for one missense variant, none of the reported variants had reoccurred, thus reflecting the intragenic heterogeneity. We screened all the six coding exons of gene in a large cohort of 177 unrelated prelingual hearing impaired after excluding the common , nuclear and A1555G mitochondrial variants.

Role of DFNB1 mutations in hereditary hearing loss among assortative mating hearing impaired families from South India.

Background: DFNB1, the first locus to have been associated with deafness, has two major genes GJB2 & GJB6, whose mutations have played vital role in hearing impairment across many ethnicities in the world. In our present study we have focused on the role of these mutations in assortative mating hearing impaired families from south India.

Methods: One hundred and six assortatively mating hearing impaired (HI) families of south Indian origin comprising of two subsets: 60 deaf marrying deaf (DXD) families and 46 deaf marrying normal hearing (DXN) families were recruited for this study.

Recurrence of reported CDH23 mutations causing DFNB12 in a special cohort of South Indian hearing impaired assortative mating families - an evaluation.

Mutations in CDH23 are known to cause autosomal-recessive nonsyndromic hearing loss (DFNB12). Until now, there was only one study describing its frequency in Indian population. We screened for CDH23 mutations to identify prevalent and recurring mutations among South Indian assortative mating hearing-impaired individuals who were identified as non-DFNB1 (GJB2 and GJB6).