CEP55 and hydranencephaly: It is conceivable that the apoptosis seen in brain sections could progress to a major loss of cerebral hemisphere parenchyma, resulting in marked cavitation, leaving only a small amount of residual cortical tissue, and compensatory expansion of the lateral ventricles (termed hydranencephaly: seen in human with CEP55 mutation), or porencephaly, if the cystic change and parenchymal loss was less severe.