RET and Hirschsprung disease: Previous study have identified some susceptibility genes implicated in HSCR, such as RET, which is the major gene in HSCR with mutations found in most of the cases and was identified to be crucial for the development of neural crest cells thus involved in the pathogenesis of HSCR (Heanue et al., 2016; Porokuokka et al., 2018).