Hereditary or inborn metabolic disorders may cause unconjugated or conjugated hyperbilirubinemia.
Primary Shunt Hyperbilirubinemia
This rare, familial, benign condition is characterized by overproduction of early-labeled bilirubin (bilirubin derived from ineffective erythropoiesis and nonhemoglobin heme rather than from normal RBC turnover).
Dubin-Johnson Syndrome and Rotor Syndrome
Dubin-Johnson syndrome and Rotor syndrome cause conjugated hyperbilirubinemia, but without cholestasis, causing no symptoms or sequelae other than jaundice. In contrast to unconjugated hyperbilirubinemia in Gilbert syndrome (which also causes no other symptoms), bilirubin may appear in the urine. Aminotransferase and alkaline phosphatase levels are usually normal. Treatment is unnecessary.
This rare autosomal recessive disorder involves impaired excretion of bilirubin glucuronides. It is usually diagnosed by liver biopsy; the liver is deeply pigmented as a result of an intracellular melanin-like substance but is otherwise histologically normal.
Rotor syndrome :
This rare disorder is clinically similar to Dubin-Johnson syndrome, but the liver is not pigmented, and other subtle metabolic differences are present.
Last full review/revision July 2014 by Steven K. Herrine, MD
Content last modified July 2014