Biliary atresia-the underdevelopment, inflammation, or obstruction of the bile ducts that carry bile from the liver to the gall bladder and small intestine-causes bile to build up in the liver and forces the bilirubin into the blood.
Pfeiffer syndrome-This condition includes craniosynostosis, shallow eye sockets, underdevelopment of the midface, short thumbs and big toes, and possible webbing of hands and feet.
Often there is an accompanying underdevelopment of the foreskin in which the penis has a hooded appearance.
Type IV malformation consists of an underdevelopment of the cerebrum and involves no herniation of brain tissue into the spinal area.
As with Type III malformation, many neurologists do not consider this a Chiari malformation but rather cerebellar hypoplasia (underdevelopment).