Hereditary Hyperbilirubinemias

Question 1

Gilbert’s syndrome

Answer 1

Mildly decreased UDP-glucruonyl transferase or decreased bilirubin uptake. Asymptomatic. Elevated unconjugated bilirubin without overthermolysis. Bilirubin increases with fasting and stress.

No clinical consequences.

Question 2

Crigler-Najjar syndrome, type I

Answer 2

Absent UDP-glucruonyl transferase. Presents early in life; patients die within a few years.
Findings: jaundice, kernicterus (bilirubin deposition in brain), increased unconjugated bilirubin.
Treatment: plasmapheresis and phototherapy.

Type II is less severe and responds to phenobarbital, which increases liver enzyme synthesis.

Question 3

Dubin-Johnson syndrome

Answer 3

Conjugated hyperbilirubinemia due to defective liver excretion. Grossly black liver. Benign.

Rotor’s syndrome is similar but even milder and does not cause black liver.