CPT® Code 81225

CYP2C19 (cytochrome P450, family 2, subfamily C, polypeptide 19) (eg, drug metabolism), gene analysis, common variants (eg, *2, *3, *4, *8, *17)

The CPT® Code 81225 pertains to the molecular genetic testing of the CYP2C19 gene, which is located on chromosome 10. This gene encodes for the cytochrome P450, family 2, subfamily C, polypeptide 19, a crucial enzyme involved in the metabolism of various xenobiotics, including drugs and toxins. The enzyme plays a significant role in the bioactivation and synthesis of essential substances such as cholesterol, steroids, and other lipids. Due to genetic polymorphisms, there is considerable variability in how individuals metabolize drugs, which can lead to different responses to medications. The common variants of the CYP2C19 gene are classified based on their functional capacity: the normal variant (*1) is fully functional, while variants such as *2 and *3 are associated with decreased or non-functioning enzyme activity. Other variants, including *4, *5, *6, *7, and *8, indicate decreased or partial enzyme function, whereas variant *17 is linked to increased partial function. This genetic testing is particularly relevant for patients undergoing specific drug therapies, such as those involving antiepileptics, proton pump inhibitors, and antidepressants, as it helps identify mutations that may affect drug metabolism and lead to adverse drug reactions or effects.