- Most common inherited disorder of bilirubin metabolism. Autosomal dominant gene mutations in the promoter for UDP-glucuronyl transferase enzyme (decreasing expression)
- Results in decreased conjugation of bilirubin and accumulation of unconjugated bilirubin in the blood
- There is no evidence of haemolysis, normal liver function and no evidence of liver disease
- Usually presents with non-pruritic jaundice, usually in the setting of physical stress/illness or fasting.
- Usually diagnosed in early adolescence
- There may also be features such as dark stools/urine
- LFTs- raised bilirubin (although usually <100μmol/l or <6mg/dl); split bilirubin may identify unconjugated hyperbilirubinaemia
- Other tests are usually normal
- No management is usually required.
- Important not to misdiagnose as a more serious cause of liver disease
- Avoidance of certain drugs may be required (although the list is limited)