Dihydropyrimidine Dehydrogenase (DPYD)

Casandra

Casandra Test Code AR48433Version 1 (DRAFT)

Performing Lab

Lab ARUP LaboratoriesLab Test ID 2012166CPT Code 81232

Dihydropyrimidine Dehydrogenase (DPYD)

Also known as: DPYD

Clinical Use

Order Test

Use

This test predicts the risk of dose-related toxicity to 5-fluorouracil (5-FU) therapy. 5-FU is a commonly used chemotherapeutic drug, particularly for colorectal adenocarcinoma. Variants in the DPYD gene can lead to reduced catabolism of 5-FU, resulting in increased drug concentrations and risk of severe toxicity, potentially causing hematologic, gastrointestinal, and dermatologic complications. A decrease in dihydropyrimidine dehydrogenase enzymatic activity may lead to increased risk for grade III-IV toxicity, affecting approximately 16% of patients. The test helps in identifying reduced 5-FU catabolism and related toxicity complications due to genetic variations.

Special Instructions

Informed consent for genetic testing is required for patients in New York. Specimens must be transported refrigerated. Unacceptable specimens include plasma or serum, heparinized specimens, and frozen specimens in glass collection tubes. Counseling and informed consent are recommended for genetic testing. Consent forms are available online.

Limitations

This test detects only the targeted DPYD variants. Diagnostic errors may occur due to rare sequence variations. 5-FU drug metabolism, efficacy, and toxicity risks may be influenced by factors not evaluated by this test. Genotyping does not replace the need for therapeutic drug monitoring or clinical observation. The test does not provide medication recommendations; any dosage adjustments should be made in consultation with a medical provider.

Test Details

New York Approved