Moreover, RET, ARHGEF3 and CTNNAL1 might functionally contribute to the regulation of cell projection organization, small GTPase-mediated signal transduction and positive regulation of neuron projection development, and thus they might be involved in HSCR etiology, as HSCR is due to a deficit in the development of the enteric nervous system. Here, CTNNAL1 is linked to Hirschsprung disease.