Idiopathic neonatal hepatitis: discordance in monozygotic twins.

Idiopathic neonatal hepatitis is the uncommon syndrome of prolonged obstructive jaundice associated with giant cell transformation in the liver and patent bile ducts. Either hepatitis virus or an inherited abnormality has been suggested as a likely pathogenic agent for the syndrome.Recent observation of discordance for idiopathic neonatal hepatitis in monozygotic twins is felt to be inconsistent with either an infectious or a simple genetic etiology. Immaturity of the hepatic parenchymal cell bilirubin excretory pathway is postulated as a cause of jaundice in some of these babies.