GJB2 and Waardenburg syndrome: GJB2, also known as connexin 26 (Cx26), forms gap junction channels, and its mutation has been found to be digenic with other genes mutation in Waardenburg syndrome, which is characterized by varying degrees of deafness and pigmentation (coloring) abnormalities in the eyes, hair, and/or skin (Yan et al., 2011; Kim et al., 2016; Wang P. et al., 2020).