Disturbances of bilirubin metabolism.

The inherited disorders of bilirubin metabolism are syndromes where the cause of hyperbilirubinemia is related to a genetic disorder of bilirubin transport and metabolism. They may be classified as unconjugated and conjugated hyperbilirubinemias: the first are Gilbert syndrome and Crigler–Najjar syndrome types I and II, and the second Dubin–Johnson and Rotor syndromes. Gilbert syndrome is the most common familial hyperbilirubinemia, while the others are rare. The most severe is Crigler–Najjar syndrome type I because of the possibility of neurological damage. All the other syndromes have an excellent prognosis.