Endothelins are endothelium-derived vasoconstrictor peptides. Defects in EDN3 are the cause of Hirschsprung disease type 4 (HSCR4); also known as aganglionic megacolon (MGC). A genetic disorder of neural crest development characterized by the absence of intramural ganglion cells in the hindgut; often resulting in intestinal obstruction. Defects in EDN3 are a cause of congenital central hypoventilation syndrome (CCHS); also known as congenital failure of autonomic control or Ondine curse. CCHS is a rare disorder characterized by abnormal control of respiration in the absence of neuromuscular or lung disease, or an identifiable brain stem lesion. A deficiency in autonomic control of respiration results in inadequate or negligible ventilatory and arousal responses to hypercapnia and hypoxemia. Defects in EDN3 are a cause of Waardenburg syndrome type 4 (WS4B); also known as Waardenburg-Shah syndrome. WS4B is characterized by the association of Waardenburg features (depigmentation and deafness) and the absence of enteric ganglia in the distal part of the intestine (Hirschsprung disease). Belongs to the endothelin/sarafotoxin family. 3 isoforms of the human protein are produced by alternative splicing. Note: This description may include information from UniProtKB.