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HelpTest Code LAB3442 Dihydropyrimidine Dehydrogenase, DPYD Full Gene Sequencing, Varies
Ordering Guidance
This test and DPYDQ / Dihydropyrimidine Dehydrogenase Genotype, Varies are both used to test for genetic variants in the DPYD gene that are associated with fluoropyrimidine toxicity. This test can detect rare variants in addition to common variants and is the appropriate test for diagnosis of dihydropyrimidine dehydrogenase deficiency. Additionally, this test is expected to have an overall higher detection rate than DPYDQ, particularly for individuals of non-European ancestry.
Shipping Instructions
Specimen preferred to arrive within 96 hours of collection.
Specimen Required
Submit only 1 of the following specimens:
Specimen Type: Whole blood
Container/Tube: Lavender top (EDTA)
Specimen Volume: 3 mL
Collection Instructions:
1. Invert several times to mix blood.
2. Send whole blood specimen in original tube. Do not aliquot.
Specimen Stability Information: Ambient (preferred) 9 days/Refrigerated 30 days
Additional Information: To ensure minimum volume and concentration of DNA is met, the preferred volume of blood must be submitted. Testing may be canceled if DNA requirements are inadequate.
Specimen Type: Saliva
Patient Preparation: Patient should not eat, drink, smoke, or chew gum 30 minutes prior to collection.
Supplies: Saliva Swab Collection Kit (T786)
Specimen Volume: 1 Swab
Collection Instructions: Collect and send specimen per kit instructions.
Specimen Stability Information: Ambient 30 days
Additional Information: Due to lower quantity/quality of DNA yielded from saliva, some aspects of the test may not perform as well as DNA extracted from a whole blood sample. When applicable, specific gene regions that were unable to be interrogated will be noted in the report. Alternatively, additional specimen may be required to complete testing.
Forms
1. New York Clients-Informed consent is required. Document on the request form or electronic order that a copy is on file. The following documents are available in Special Instructions:
-Informed Consent for Genetic Testing (T576)
-Informed Consent for Genetic Testing (Spanish) (T826)
2. If not ordering electronically, complete, print, and send a Therapeutics Test Request (T831) with the specimen.
Secondary ID
610051Useful For
Identifying individuals at increased risk of toxicity when considering 5-fluorouracil and capecitabine chemotherapy treatment
Identifying common and rare variants associated with decreased or absent dihydropyrimidine dehydrogenase (DPD) enzyme activity in individuals with suspected DPD deficiency
Special Instructions
Method Name
Polymerase Chain Reaction (PCR) followed by DNA Sequence Analysis
Reporting Name
DPYD Full Gene Sequencing, VSpecimen Type
VariesSpecimen Minimum Volume
Blood: 0.45 mL; Saliva: See Specimen Required
Specimen Stability Information
| Specimen Type | Temperature | Time |
|---|---|---|
| Varies | Varies | |
Reject Due To
All specimens will be evaluated at Mayo Clinic Laboratories for test suitability.Reference Values
DPYD Total Activity Score: 2
DPYD Phenotype: Normal metabolizer
An interpretive report will be provided.
Cautions
Samples may contain donor DNA if obtained from patients who received non-leukocyte reduced blood transfusions or allogeneic hematopoietic stem cell transplantation. Results from samples obtained under these circumstances may not accurately reflect the recipient's genotype. For individuals who have received blood transfusions, the genotype usually reverts to that of the recipient within 6 weeks. For individuals who have received allogeneic hematopoietic stem cell transplantation, a pretransplant DNA specimen is recommended for testing.
DPYD genetic test results in patients who have undergone liver transplantation may not accurately reflect the patient's dihydropyrimidine dehydrogenase (DPD) status.
Rare genetic variants in the primer binding regions can affect the testing, and ultimately, the genotype assessment made, including false-negative or false-positive results.
Test results should be interpreted in the context of clinical findings, family history, and other laboratory data. Large deletions or rearrangements are not detected by this assay, and these may affect DPD protein expression and fluoropyrimidine-related adverse effects or tumor response.
Sometimes a genetic alteration of unknown significance may be identified. In this case, testing of appropriate family members may be useful to determine pathogenicity of the alteration.
This test is not designed to provide specific dosing or drug selection recommendations and is to be used as an aid to clinical decision making only. Drug-label guidance should be used when dosing patients with medications regardless of the predicted phenotype.
Day(s) Performed
Monday through Friday
Report Available
5 to 10 daysPerforming Laboratory
Mayo Clinic Laboratories in Rochester
Test Classification
This test was developed and its performance characteristics determined by Mayo Clinic in a manner consistent with CLIA requirements. It has not been cleared or approved by the US Food and Drug Administration.CPT Code Information
81232
LOINC Code Information
| Test ID | Test Order Name | Order LOINC Value |
|---|---|---|
| DPYDZ | DPYD Full Gene Sequencing, V | 94198-9 |
| Result ID | Test Result Name | Result LOINC Value |
|---|---|---|
| 618600 | DPYD Total Activity Score | 104665-5 |
| 618601 | DPYD Phenotype | 79719-1 |
| 618602 | Result Details | 82939-0 |
| 618603 | Interpretation | 69047-9 |
| 618604 | Method | 85069-3 |
| 618605 | Disclaimer | 62364-5 |
| 618606 | Additional Information | 48767-8 |
| 618607 | Reviewed by | 18771-6 |