Gilbert's syndrome is an autosomal recessive* condition of defective bilirubin conjugation due to a deficiency of UDP glucuronosyltransferase. The prevalence is approximately 1-2% in the general population.


  • Incidence: 500.00 cases per 100,000 person-years
  • Peak incidence: 20-30 years
  • Sex ratio: 1:1
<1 1-5 6+ 16+ 30+ 40+ 50+ 60+ 70+ 80+

Clinical features

  • unconjugated hyperbilirubinaemia (i.e. not in urine)
  • jaundice may only be seen during an intercurrent illness, exercise or fasting


No investigation is generally required - it is typically diagnosed on the basis of an isolated rise in bilirubin, which is typically more pronounced on prolonged fasting.

Provocative testing with IV nicotinic acid may sometimes be used to investigate certain cases.


No management is required.