GJB2 and hearing loss disorder: Our study is mainly concerned with exploring the genetic etiology of congenital hearing loss through Sanger sequencing of the coding exon in GJB2, the most common causative gene worldwide, in 17 patients from 13 unrelated families followed by whole exome sequencing for cases showing biallelic wildtype GJB2. Eleven patients from eight families showed homozygous and compound heterozygous variants in the GJB2 gene.