Mutations in the connexin 29 gene are not a major cause of nonsyndromic hearing impairment in India.

Mutations in the GJC3 gene are known to cause nonsyndromic hearing impairment (NSHI). In this study, we screened for mutations in the connexin 29 (Cx29) gene in peripheral blood collected from patients with NSHI. DNA was extracted from peripheral blood cells of 123 NSHI patients and 127 normal-hearing control subjects. Coding regions of Cx29 were amplified by polymerase chain reaction using primer pairs flanking both exons. Sequences were analyzed and compared with the published Cx29 sequence. On comparison with control subjects, only one patient and her normal-hearing mother showed a novel heterozygous variant in exon 1 c.569T>A (p. Ile190Asn), which most likely represents a rare polymorphism. From the study, we conclude that mutations in the Cx29 gene do not play a role in the causation of NSHI in Indian population.