A novel compound heterozygous mutation in the GJB2 gene is associated with non-syndromic hearing loss in a Chinese family

Abstract

Autosomal recessive (AR) non-syndromic hearing loss (NSHL) is the most common form of hereditary deafness. Mutations in the gap junction protein beta 2 (GJB2) gene encoding connexin 26 (Cx26) account for about 50% of cases of ARNSHL. In the current study, a combination of exome sequencing and Sanger sequencing in a Chinese Dong family with ARNSHL allowed identification of a novel compound heterozygous mutation c.240G>C(p. Q80H)/C.109G>A(p.V37I) in exon 2 of the GJB2 gene, which co-segregated with the disease phenotype in this family and was not evident in 100 healthy controls. Bioinformatic analysis revealed that the two mutations in the GJB2 gene were probably pathogenic. Results indicated that the compound heterozygous variants, p.Q80H and p.V37I, in the GJB2 gene are associated with ARNSHL. The Q80H variant was initially identified in patients of Dong Chinese origin with NSHL. The current results broaden the spectrum of GJB2 mutations responsible for NSHL and have important implications for molecular diagnosis, treatment, and genetic counseling for this family.