In the neonate it may cause prolonged jaundice (which resolves), neonatal hepatitis, fat-soluble vitamin deficiency (especially vitamin K), or inspissated bile syndrome. In older children it presents with hepatomegaly and abnormal transaminases and may remain subclinical until advanced.

Portal hypertension with hypersplenism and variceal bleeding occurs with the development of cirrhosis. Liver function may be maintained for years prior to decompensation.