question: Are EDNRB mutations involved in the development of Hirschsprung disease?
answer: Although mutations in eight different genes (EDNRB, EDN3, ECE1, SOX10, RET, GDNF, NTN, SIP1) have been identified in affected individuals, it is now clear that RET and EDNRB are the primary genes implicated in the etiology of HSCR. Mutations in genes of the RET receptor tyrosine kinase and endothelin receptor B (EDNRB) signaling pathways have been shown to be associated in HSCR patients.  Molecular genetic analyses have revealed that interactions between mutations in the genes encoding the RET receptor tyrosine kinase and the endothelin receptor type B (EDNRB) are central to the genesis of HSCR.