Albeit the important role of Grb10 in organismal development, and in contrast to the RET tyrosine kinase, which is one of its upstream signaling receptors, mutations in GRB10 were not linked to Hirschsprung disease, a congenital condition characterized by the absence of intrinsic enteric ganglion cells in some sectors of the gastrointestinal track, including the colon, which results in a distended atonic megacolon [69]. Here, GRB10 is linked to Hirschsprung disease.