Which is the hallmark of Gilbert's syndrome?

• A. Benign unconjugated hyperbilirubinemia
• B. Conjugated hyperbilirubinemia
• C. Elevated ALT
• D. Hemolysis

Answer: (A)

Gilbert's syndrome is marked by a mild, intermittent rise in unconjugated bilirubin caused by reduced activity of the hepatic enzyme that conjugates bilirubin. Because the conjugation pathway is only mildly impaired, liver enzymes stay normal and there is no true hemolysis or liver injury. The jaundice who’s present tends to be mild and can be triggered or worsened by fasting, illness, or stress. This pattern—benign, unconjugated hyperbilirubinemia with normal liver tests and no signs of hemolysis—is the hallmark. Conjugated hyperbilirubinemia would suggest cholestasis or hepatocellular disease; elevated ALT points to liver injury; and hemolysis would show signs of red blood cell breakdown and often anemia, which are not features of Gilbert's despite possible transient unconjugated bilirubin elevations.