Gene UGT1A1

Also known as

GNT1, UGT1, BILIQTL1, UDP glucuronosyltransferase 1A1

Overview

UGT1A1 (UDP Glucuronosyltransferase Family 1 Member A1) encodes the enzyme responsible for conjugating bilirubin with glucuronic acid, making it water-soluble for excretion in bile. This is the primary mechanism for bilirubin elimination from the body. UGT1A1 also metabolizes many drugs, dietary compounds, and hormones.

The UGT1A1*28 allele, characterized by an additional TA repeat in the promoter, reduces enzyme expression and causes Gilbert syndrome, a benign condition affecting approximately 5-10% of the population. Individuals with Gilbert syndrome have mildly elevated unconjugated bilirubin but typically require no treatment. The same variant affects metabolism of the chemotherapy drug irinotecan, increasing toxicity risk.

Understanding your UGT1A1 status is important for pharmacogenetics, particularly for irinotecan-based cancer therapy where dose reductions may be needed. The mild hyperbilirubinemia of Gilbert syndrome may actually be protective, as bilirubin has antioxidant properties.

NutraHacker Raw DNA Analysis Products that include this gene

• Complete Mutation Nutrition Report
• WGS True Pharmacogenetics Panel

Upload raw DNA data to get your very own analysis of gene UGT1A1 through your personalized DNA reports.