Dihydropyrimidine Dehydrogenase Genotype

DPD, 5FU toxicity, Xeloda, DPYD

Test Codes

EPIC: LAB1232468, Beaker: DYPD Geno, Quest: 18573

Department

Send Outs

Specimen Collection Criteria

Collect (preferred specimen):  One Pink or Lavender-top EDTA tube.

Physician Office/Draw Specimen Preparation

Do not centrifuge. Room Temperature (20-26°C or 68-78.8°F) specimens in original collection tube after collection.

Preparation for Courier Transport

Transport: 5.0 mL whole blood, at room temperature (20-26°C or 68-78.8°F). (Minimum: 2.0 mL)

Rejection Criteria

• Frozen specimens.
• Specimens not collected and processed as indicated.

In-Lab Processing

Do not centrifuge. Room temperature (20-26°C or 68-78.8°F) specimens in original collection tube after collection.

Transport: 5.0 mL whole blood, at room temperature (20-26°C or 68-78.8°F). (Minimum: 2.0 mL)

Storage

Specimen Stability for Testing:

Room Temperature (20-26°C or 68-78.8°F): 30 days
Refrigerated (2-8°C or 36-46°F): 8 days
Frozen (-20°C/-4°F or below): Unacceptable

Specimen Storage in Department Prior to Disposal:

Specimen retention time is determined by the policy of the reference laboratory. Contact the Send Outs Laboratory with any questions.

Laboratory

Sent to Quest Diagnostics, Wood Dale, IL.

Performed

Monday, Tuesday, Thursday, Saturday.
Results available in 8-24 days.

Reference Range

By report.

Test Methodology

Microarray, Real-Time Polymerase Chain Reaction

Interpretation

By report.

Clinical Utility

Dihydropyrimidine Dehydrogenase (DPYD) Genotype – Dihydropyrimidine dehydrogenase, an enzyme encoded by the DPYD gene, is responsible for metabolizing fluoropyrimidines (5-fluorouracil (5-FU) and capecitabine) which are chemotherapeutic drugs frequently used to treat many types of cancer, including colorectal, breast, and cancers of the aerodigestive tract. Germline variants in DPYD affect enzyme production, which may result in an increased risk of significant, potentially fatal toxicity.

CPT Codes

81232

Contacts

Last Updated

10/27/2026