PAX3 and Waardenburg syndrome: The known genes associated with Waardenburg syndrome are mainly localized on chromosomes 2, 3, 8, 12, 13, 20 and 22; their associated genes are PAX3, MITF, SNAI2, KITLG, EDNRB, EDN3, and SOX10. WS1 and WS3 are predominantly caused by PAX3 variants, typical clinical features are ectopic endophthalmos, asymmetric hearing loss, skin depigmentation and gray hair on the forehead [4].