Mondo Description Holoprosencephaly (HPE) is a complex brain malformation resulting from incomplete cleavage of the prosencephalon, occurring between the 18th and 28th day of gestation, and affecting both the forebrain and face, which results in neurological manifestations and facial anomalies of variable severity.

Disease Ontology Description A congenital nervous system abnormality characterized by failed or incomplete separation of the forebrain early in gestation; it is accompanied by a spectrum of characteristic craniofacial anomalies.