CPT® Code 81232

DPYD (dihydropyrimidine dehydrogenase) (eg, 5-fluorouracil/5-FU and capecitabine drug metabolism), gene analysis, common variant(s) (eg, *2A, *4, *5, *6)

The CPT® Code 81232 pertains to the gene analysis of the dihydropyrimidine dehydrogenase (DPYD) gene, which plays a crucial role in the metabolism of certain chemotherapeutic agents, specifically 5-fluorouracil (5-FU) and capecitabine. This analysis focuses on identifying common genetic variants, such as *2A, *4, *5, and *6, that can influence how patients metabolize these drugs. The DPYD gene is located on the short (p) arm of chromosome 1 at position 21.3, and it encodes an enzyme that is essential for the breakdown of pyrimidine nucleotides, which include uracil and thymine, as well as drugs that share similar structures. Understanding the genetic variants present in a patient can help predict their risk of experiencing dose-related toxicity when undergoing treatment with 5-FU or capecitabine. Notably, the *2A allele is linked to a significantly increased risk of drug toxicity, making it the most frequently identified variant in this context. In contrast, the *4, *5, and *6 alleles are associated with normal gene function, indicating that individuals with these variants may metabolize the drugs without heightened risk. The testing process involves obtaining a blood sample, which is then analyzed using polymerase chain reaction (PCR) techniques with fluorescence monitoring to detect the presence of these genetic variants.