5-fluorouracil

Chemotherapeutic treatment using 5-fluorouracil may pose increased risk of toxicity to patients with variations in certain genes, including the DPYD and TYMS genes.

For example, carriers of a rs3918290(A) allele are at increased risk for toxicity when treated with 5-fluorouracil.[1]

PGx Table for 5-Fluorouracil (5-FU)

Genotype/Genoset	Diplotype	Gene	Drug Use/Category/Class	Medical Field	Summary	Descriptive Sentence
gs313	Normal metabolizer	DPYD	Chemotherapeutic	Oncology	Normal Response Expected	You do not appear to carry any DPYD mutations linked to adverse side effects from 5-fluorouracil use.
gs312	Intermediate Metabolizer	DPYD	Chemotherapeutic	Oncology	Consider Half-Dose and/or Pharmacokinetic Studies	You carry a nonfunctional DPYD allele that increases your risk for a toxicity upon 5-FU administration; consider starting at half-dose and/or doing pharmacokinetic studies.
gs306	Poor Metabolizer	DPYD	Chemotherapeutic	Oncology	Avoid 5-FU; use an alternative drug	You may be at very high risk for severe toxicity from 5-FU administration; all major drug regulatory agencies recommend you select a non-fluoropyrimidine alternative chemotherapeutic.