Waardenburg-Shah syndrome (WS type IV, WS-IV), which is caused by mutations in the transcription factor Sox10 [28], cytokine endothelin (ET)-3 [29] and its receptor endothelin receptor B (Ednrb) [30], is characterized by hypopigmentation, megacolon disease and hearing loss. The gene discussed is EDNRB; the disease is hearing loss disorder.