Schizencephaly is another migrational disorder that refers to a gray matter lined cleft in the cerebral hemisphere that typically extends from the lateral ventricle to the surface of the brain. In most cases, there is associated agenesis of the corpus callosum. The presence of gray matter lining the entire cleft is the diagnostic feature that differentiates it from other causes of clefts such as porencephaly, which is lined by both gray and white matter.