Congenital disorders in bilirubin metabolism

1. Gilbert’s Syndrome

† Partial block in bilirubin conjugation

† Benign elevation in total and unconjugated bilirubin

2. Criglar-Najjar Syndrome, Type I

† Absence of bilirubin conjugation enzyme

†Marked unconjugated hyperbilirubinemia & jaundice

†May cause death in infancy

3. Criglar-Najjar Syndrome, Type II (Arias Syndrome)

†Defect uncertain

†Moderate hyperbilirubinemia

†Bilirubin decreasese with phenobarbital treatment, which increases the amount and activity (“induces”) the conjugating enzymes in hepatocytes

4. Dubin-Johnson Syndrome

† Defect in transport of bilirubin into bile

†Mild conjugated and unconjugated hyperbilirubinemia; conjugated predominates

†Jaundice may be precipitated by other illnesses

†Urinary coproporphyrin I is elevated

5. Rotor Syndrome

† Defect in transport of bilirubin into bile

† Mild conjugated hyperbilirubinemia

† Jaundice may be precipitated by other illnesses

† Serum bile acid levels are increased