It was elucidated in research more than 20 years ago that heterozygous mutation of ZEB2 was one of the etiologic causes of Mowat-Wilson syndrome (MWS)[33,34,65], a neurocristopathy characterized by facial gestalt, intellectual disability, microcephaly, congenital heart defects, and Hirschsprung’s disease[66,67]. The gene discussed is ZEB2; the disease is Hirschsprung disease.