Absence of KCNQ4 mutation in Bengali families with ADNSHL originated from West Bengal, India.

OBJECTIVE: Autosomal Dominant Non-Syndromic Hearing Loss (ADNSHL) is extremely heterogeneous in nature. More than 60 loci with 30 different genes have been identified linked to ADNSHL. Mutation in KCNQ4 is considered as one of the most common causative factor responsible for ADNSHL. No study focused on the genetic alteration of KCNQ4 gene among hearing loss patients in India. The present study for the first time was carried out to determine the mutation spectrum of KCNQ4 gene in ADNSHL patients of West Bengal state, India.

METHOD: Twenty nine individuals from 10 independent ADNSHL family (with two or more generation affected) were studied both clinically and genetically. Most of the patients showed moderate progressive sensorineural hearing loss. Mutation analysis was conducted for KCNQ4 gene using polymerase chain reaction followed by direct sequencing.

RESULTS: Neither any reported nor a novel pathogenic mutation in KCNQ4was detected in our studied group, in contrast to the findings among East Asians.

CONCLUSION: The result of the present study suggests that mutations in KCNQ4 gene are unlikely to be a major causative factor of ADNSHL in our studied patients from West Bengal, India, pointing to other genes might be responsible for ADNSHL in our studied patients.