Pharmacogenetic testing for 5-Fluorouracil

  • Fluorouracil (5-FU) is a commonly used anticancer drug. It functions by irreversibly inhibiting thymidylate synthase.
  • 5-FU is widely used in a number of cancers worldwide and is in the WHO list of Essential Medicines.
  • Detoxification of 5-FU is mediated by the dihydropyrimidine dehydrogenase (DPD) gene. 
  • Apart from 5-FU, the gene also is involved in detoxification of Capecitabine, and Tegafur.
  • Genetic variations in the gene can cause a partial or complete deficiency of function, which may lead to drug toxicity, which are severe.
Pharmacogenetic testing is recommended on the FDA Drug label
The USFDA-approved drug label for fluorouracil states that the drug is contraindicated in patients with known DPD deficiency.

CPIC Dosing Guidelines for fluoropyrimidines recommends an alternative drug for patients who are homozygous for DPYD non-functional variants as these patients are typically DPD deficient and a 50% reduction for heterozygous patients.

Information Brochure
Referring your patient for Pharmacogenetic testing of DPD gene
Pharmacogenetic testing in research mode for 5FU is available through GOMED for variants rs67376798 , rs3918290, rs5586062 and rs2297595 in DPD gene.

The test can be availed FREE of cost if appropriately referred by a clinician.

How to request a test ?
Ordering a test is simple. You could register and key in your details to refer a patient/family for genomic analysis online. Once you have referred the patient/family, we would shortly get back to you with a sample code and detailed instructions on collecting and posting out the samples.

What samples are required ?
We would require approx 5ml of blood in vacutainers (EDTA/ACD). In some cases, saliva/body fluids/tissues may also be considered, but please confirm before sending the samples.
Documentation required for referring

1) Genomic test request
Please write a referral on your letterhead regarding the referral and the test you would be requesting. Pack the documents with the box you would be sending across

2) Consent forms (one each for each patient)
The consent forms for genomic analysis needs to be signed individually by each member (or parent/guardian in case the person is a minor). Each consent needs to be counter-signed by the investigator.
Since you would be posting out blood samples, you would require to attach a declaration which should be signed/stamped and given to the courier/postage department for processing your courier.

Consignments need to be addressed to

Dr. Mohammed Faruq
CSIR Institute of Genomics and Integrative Biology (CSIR-IGIB)
Mall Road, Delhi 110007, India