Genetics of deafness in India.

Linkage analysis in families with hereditary hearing loss have revealed a plethora of chromosomal locations linked to deafness reflecting the extreme heterogeneity of the disorder. 40 of the genes contained within these loci have been mapped lending an insight into the diverse molecules operating in the inner ear and the remarkable complexity of the cellular and molecular processes involved in the transucdation of sound in the auditory system. Among this diversity, Connexin 26 has been found to be the most common cause of deafness the world around. The authors review here the prevalence of this gene in the Indian population as found in their study, together with other deafness genes segregating non-syndromic deafness, accounting for approximately 40% of all cases. This indicates there are several more to be identified yet. Knowledge of the genetic cause of deafness in our families is important for accurate genetic counseling and early diagnosis for timely intervention and treatment options.

Cystic Fibrosis In India : Report Of 30 Cases And Frequency Of Delta F508 Mutation.

Cystic fibrosis (CF) is the most common potentially lethal disorder of Caucassians. Its frequency in India is not known. We diagnosed 30 cases of CF based on sweat chloride testing. The clinical profile and frequency of delta F508 mutation was studied. The frequency of F508 mutation was 27% (16 chromosomes) which is much lower as compared to that patients in the Western world. Eight patients carried other mutations, three of them were new mutations.