ZEB2 and Hirschsprung disease: Mowat-Wilson syndrome (MWS; MIM# 235730) is a genetic disease caused by heterozygous mutations or deletions of the ZEB2 gene, and characterized by typical face, moderate-to-severe mental retardation, epilepsy and variable congenital malformations, including Hirschsprung disease (HSCR), genital anomalies (particularly hypospadias in males), congenital heart disease (CHD), agenesis of the corpus callosum (ACC) and eye defects.