UDP-glucuronosyltransferase 1A6 (UGT1A6)

UDP-glucuronosyltransferase 1A6 is an enzyme encoded by the *UGT1A6* gene that plays a key role in phase II metabolism through glucuronidation—a process that attaches glucuronic acid to small lipophilic molecules such as drugs (notably acetaminophen), steroids, bilirubin, hormones, and various xenobiotics. This modification increases their water solubility for easier excretion from the body. The enzyme is expressed predominantly in liver but also found in extrahepatic tissues including brain. It is particularly active on phenolic and planar compounds. The *UGT* superfamily includes multiple isoforms with overlapping substrate specificities; genetic polymorphisms within *UGT* genes—including *UGT1A6*—can result in substantial variability among individuals regarding how efficiently they metabolize certain medications or endogenous substances. Loss-of-function mutations have clinical relevance for susceptibility to adverse effects from common analgesics. Drug-drug interactions involving inhibition or induction of this enzyme are clinically important considerations during therapy management because they can alter plasma concentrations of co-administered medications metabolized via this pathway.

Other names

UGT1A6GNT1HLUGPHLUGP1UDPGTUDPGT 1-6UGT1FUDP glucuronosyltransferase family 1 member A6UGT1.5hUG-BR1UGT1.3UGT-1CUGT1AUGT1EUGT-1AUGT2B7

Drugs are metabolized by conjugation with glucuronic acid via the enzyme’s catalytic activity; this generally increases water solubility and facilitates excretion. Inhibitors may block this process, leading to increased drug levels or toxicity; inducers may increase clearance.