CPT® Code 81226

CYP2D6 (cytochrome P450, family 2, subfamily D, polypeptide 6) (eg, drug metabolism), gene analysis, common variants (eg, *2, *3, *4, *5, *6, *9, *10, *17, *19, *29, *35, *41, *1XN, *2XN, *4XN)

The CPT® Code 81226 pertains to the molecular genetic testing of the CYP2D6 gene, which is located on chromosome 22. This gene encodes for the cytochrome P450, family 2, subfamily D, polypeptide 6, a crucial enzyme involved in the metabolism of various xenobiotics, including drugs and toxins. The CYP2D6 enzyme plays a significant role in the mixed function oxidase system, which is responsible for the bioactivation and synthesis of essential substances such as cholesterol, steroids, and other lipids. Due to genetic polymorphism, there is considerable variability in how individuals metabolize drugs, which can lead to different therapeutic outcomes. The common variants of the CYP2D6 gene are classified into several categories based on their functionality: normal-fully functional variants (*1, *2, with exceptions for *1xN and *2xN), partial functioning-decreased variants (*9, *10, *17, *29, *41), partial functioning-increased variants (*1xN, *2xN), and non-functioning variants (*3, *4, *5, *6, *19, *4xN). This genetic testing is particularly relevant for patients undergoing specific drug therapies, such as Tamoxifen for breast cancer, as it helps identify mutations that may affect drug metabolism, potentially leading to adverse drug responses or effects.