Nevertheless, our study showed that in a substantial number of these patients, the cause of hearing loss can be clarified by pathogenic variants in genes other than the GJB2. We recommend commencing the Sanger sequencing of the GJB2 gene before WES since it is possible to cover the 5 ́UTR of exon 2 and non-coding exon 1 with Sanger; these regions are covered poorly by WES. Here, GJB2 is linked to hearing loss disorder.