Hereditary hyperbilirubinemias.

Inherited disorders of bilirubin metabolism involve four autosomal recessive syndromes: Gilbert, CriglerNajjar, Dubin-Johnson and Rotor, among which the first two are characterized by unconjugated and the second two by conjugated hyperbilirubinemia. Gilbert syndrome occurs in 2%-10% of general population, while others are rare. Except for Crigler-Najjar syndrome, hereditary hyperbilirubinemias belong to benign disorders and thus no treatment is required.