UGT1A1

UGT1A1 is an enzyme that in humans is encoded by the UGT1A1 gene. It is a member of the UDP-glucuronosyltransferase (UGT) family, which plays a significant role in the glucuronidation process.

Function

The UGT1A1 enzyme is primarily found in the liver and the gastrointestinal tract. It is responsible for the glucuronidation of bilirubin, a waste product of red blood cell breakdown. This process makes bilirubin water-soluble, allowing it to be excreted in the bile and urine.

Clinical significance

Mutations in the UGT1A1 gene can lead to several diseases. The most common of these is Gilbert's syndrome, a mild and usually asymptomatic condition characterized by intermittent jaundice. More severe mutations can cause Crigler-Najjar syndrome, a rare and potentially lethal disease that results in severe jaundice and can lead to brain damage.

UGT1A1 is also involved in the metabolism of certain drugs, including irinotecan, a chemotherapy medication. Variations in the UGT1A1 gene can affect how individuals respond to this drug, with certain variants associated with a higher risk of toxicity.

Genetic testing

Genetic testing can identify mutations in the UGT1A1 gene. This can be useful for diagnosing Gilbert's syndrome and Crigler-Najjar syndrome, as well as for predicting an individual's response to drugs metabolized by UGT1A1.

See also

• UDP-glucuronosyltransferase
• Glucuronidation
• Gilbert's syndrome
• Crigler-Najjar syndrome
• Irinotecan