DYPD Genotyping (5FU Assay)

5-Fluorouracil (5-FU) is a chemotherapy agent belonging to the drug class of fluropyrimidines. 5-FU is used in the palliative management of carcinoma of many solid tumors including (but not limited to) colon, rectum, breast, esophagus, cholangiocarcinoma (bile duct cancers), stomach, and pancreas. 5-FU also has severe side effects and can be toxic if not metabolized in the body. The DPYD gene encodes dihydropyrimidine dehydrogenase (DPD), an enzyme that catalyzes the rate-limiting step in fluorouracil metabolism. Genetic variations in the DPYD gene can lead to enzymes with reduced or absent activity. Consequently, individuals with these genetic variants are at risk of potentially life-threatening fluorouracil toxicity, such as bone marrow suppression, diarrhea, and neurotoxicity.

DYPD genotyping is an important pharmacogenomic assay to determine whether a patient will be able to metabolise 5-FU before administering it to them as a form of treatment.