DPYD Genotyping
Also known as: Dihydropyrimidine Dehydrogenase
Use
The dihydropyrimidine dehydrogenase gene (DPYD) produces a drug-metabolizing enzyme, dihydropyrimidine dehydrogenase (DPD), which is involved in the metabolism of several clinically important drugs including the fluoropyrimidines 5-fluorouracil and capecitabine, which are frequently used as chemotherapeutic drugs. Individuals with some variant DPYD alleles are at increased risk for side effects from drugs that are metabolized by DPD. DPYD genotype information can be utilized to predict DPD metabolic activity, which can be used as an aid in determining a therapeutic strategy for drugs that are metabolized by DPD. For example, DPD eliminates over 80% of the drug 5-fluoracil. An intermediate or poor metabolizer may be subjected to a buildup of 5-fluoracil, which can be associated with severe toxicity. Substantial evidence supports the use of DPYD genotyping for guiding fluoropyrimidine dosage/use.
Special Instructions
Not provided.
Limitations
The effect of a particular DPYD genotype on drug metabolism can vary. Drug metabolism is influenced by genotype as well as environmental, dietary, and medication factors. Results do not exclude other DPYD variant alleles not detected by this test or alleles in other drug metabolism pathways. Molecular testing, while highly accurate, is not infallible. Patients should discuss results with healthcare providers.
Methodology
PCR-based (RT-PCR)
Biomarkers
DPYD
Gene
LOINC Codes
- 93199-8 - DPYD gene Mut Anl Bld/T
- 93199-8 - DPYD gene Mut Anl Bld/T
- 79719-1 - DPYD gene prod met act imp Bld/T-Imp
- 69426-5 - Medical director review
- 56850-1 - Imp & review of lab results
- 55752-0 - Clinical info
- 8262-8 - Service Cmnt 02-Imp
Result Turnaround Time
7-10 days
Related Documents
For more information, please review the documents below
Specimen
Whole Blood
Volume
2 mL
Minimum Volume
1 mL
Container
Lavender-top (EDTA) tube or yellow-top (ACD) tube
Collection Instructions
Collect specimen in a lavender-top (EDTA) or yellow-top (ACD) tube. Ship whole blood specimen at room temperature or frozen.
Storage Instructions
Maintain whole blood specimen at room temperature or refrigerated for 28 days or frozen for 2 years.
Causes for Rejection
Quantity not sufficient for analysis; improper container; frozen glass tube
Stability Requirements
| Temperature | Period |
|---|---|
| Room Temperature | 28 days |
| Refrigerated | 28 days |
| Frozen | 2 years |
Other tests from different labs that may be relevant