CPT® Code 81350

UGT1A1 (UDP glucuronosyltransferase 1 family, polypeptide A1) (eg, drug metabolism, hereditary unconjugated hyperbilirubinemia [Gilbert syndrome]) gene analysis, common variants (eg, *28, *36, *37)

The CPT® Code 81350 pertains to the molecular genetic testing of the UGT1A1 gene, which encodes for enzymes involved in the glucuronidation pathway. This pathway is crucial for the metabolism of various substances, including steroids, bilirubin, hormones, drugs, and environmental toxins, converting them into water-soluble metabolites that can be efficiently filtered by the kidneys and excreted in urine. The analysis specifically targets common variants of the UGT1A1 gene, such as *28, *36, and *37, which are associated with hereditary unconjugated hyperbilirubinemia, commonly known as Gilbert syndrome. Gilbert syndrome is an autosomal recessive condition characterized by elevated bilirubin levels in the blood, resulting from the impaired function of the UGT1A1 enzyme. Individuals who inherit mutations from both parents are at risk of developing this syndrome, while those who inherit a mutation from only one parent are considered carriers and may experience reduced enzyme activity. The *28 variant is particularly notable for its prevalence among Caucasian and African populations, while the *36 and *37 variants are predominantly found in individuals of African descent. Understanding these genetic variations is essential, especially for patients undergoing chemotherapy with irinotecan, as those with specific UGT1A1 mutations may require dosage adjustments to mitigate the risk of toxicity.