For example, four subtypes of Waardenburg syndrome have been described and are known to be caused by mutations in PAX3 (chromosome 2q35), [53–56], MITF (chromosome 3p14-p13) [57–58], SOX10 (chromosome 22q13.1) [59–61], SNAI2 (chromosome 8q11.21) [62], EDNRB (13q22) [63], and EDN3 (chromosome 20q13.32) [64–65]. This evidence concerns the gene EDNRB and Waardenburg syndrome.