Genetic syndrome of mild unconjugated hyperbilirubinemia, by definition <6 mg/dL (rarely exceeding 4 mg/dL). The liver function is otherwise normal.
Common syndrome affecting 8% of the general population.
Decreased uridine-diphosphoglucuronate glucuronosyltransferase (UDPGT) activity leads to decreased conjugation of unconjugated bilirubin. In general, the bilirubin clearance is reduced by 60%.
Presentation usually asymptomatic, with mild icterus (jaundice) seen during times of fasting or physiologic stress.
No treatment is needed since there is no liver injury or progression to end stage liver disease.
Although prognosis continues to be excellent, there is evidence that some patients with Gilbert syndrome may have abnormalities in the metabolism of selective protease inhibitor drugs and monoclonal antibodies used in the treatment of rheumatologic and autoimmune diseases.
Patient on right is jaundiced, similar to jaundice caused by severe Gilbert syndrome
From the personal collection of Dr John L. Gollan
- postpubertal age
- positive FHx of Gilbert syndrome
- icterus (jaundice)
- absence of hepatosplenomegaly
- no stigmata of chronic liver disease
1st Tests To Order
- unconjugated bilirubin
- liver aminotransferases
- gamma-glutamyl transpeptidase
- lactate dehydrogenase
- peripheral blood smear
- direct Coombs test
Other Tests to Consider
- liver biopsy
- plasma unconjugated bilirubin response to fasting
- plasma unconjugated bilirubin response to nicotinic acid
- UDPGT-1A1 genotyping
- UDPGT enzyme activity
- patient education + avoidance or reversal of inciting agents