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Test ID WARSV Warfarin Response Genotype


Advisory Information


If patient is using medications other than warfarin, the preferred test is 2C9GV / Cytochrome P450 2C9 Genotype, which tests for only the CYP2C9 gene.

 

Testing is available as the single gene assay (this test) or as a part of a focused pharmacogenomics panel, which includes testing for the following genes: CYPs 1A2, 2C9, 2C19, 2D6, 3A4, 3A5, 4F2, SLCO1B1, and VKORC1. Order PGXFP / Focused Pharmacogenomics Panel if multiple pharmacogenomic genotype testing is desired.



Specimen Required


Multiple genotype tests can be performed on a single specimen after a single extraction. See Multiple Genotype Test List in Special Instructions for a list of tests that can be ordered together.

 

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 specimen in original tube.

Specimen Stability Information: Ambient (preferred)/Refrigerated

 

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

 

Specimen Type: DNA

Container/Tube: 2 mL screw top tube

Specimen Volume: 100 mcL (microliters)

Collection Instructions:

1. The preferred volume is 100 mcL at a concentration of 50 ng/mcL.

2. Include concentration and volume on tube.

Specimen Stability Information: Frozen (preferred)/Ambient/Refrigerated


Forms

1. New York Clients-Informed consent is required. Please document on the request form or electronic order that a copy is on file. An Informed Consent for Genetic Testing (T576) is available in Special Instructions.

2. If not ordering electronically, complete, print, and send 1 of the following forms with the specimen:

-Pharmacogenomics Test Request (T797)

-Cardiovascular Test Request (T724)

-Neurology Specialty Testing Client Test Request (T732)

Useful For

Identifying patients who may require warfarin dosing adjustments(3,4) including:

-Patients being started on a first prescription for warfarin

-Patients who have previously been prescribed warfarin and have required multiple dosing adjustments to maintain the international normalized ratio in the target range

-Patients with a history of thrombosis or bleeding when taking warfarin

Genetics Test Information

This test is used for assessing CYP2C9, VKORC1, CYP4F2, and rs12777823 for variants affecting the metabolism of warfarin (Coumadin). This assay should be ordered on patients who are receiving warfarin for the first time or who are experiencing difficulties in maintaining the international normalized ratio (INR) in the therapeutic range.

Method Name

Real-Time Polymerase Chain Reaction (PCR) with Allelic Discrimination Analysis

Reporting Name

Warfarin Response Genotype

Specimen Type

Varies

Specimen Minimum Volume

Blood: 0.4 mL
Saliva: 1 swab

Specimen Stability Information

Specimen Type Temperature Time
Varies Varies

Reference Values

An interpretive report will be provided.

Day(s) and Time(s) Performed

Monday through Friday; 8 a.m.

Performing 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. This test has not been cleared or approved by the U.S. Food and Drug Administration.

CPT Code Information

0030U

LOINC Code Information

Test ID Test Order Name Order LOINC Value
WARSV Warfarin Response Genotype In Process

 

Result ID Test Result Name Result LOINC Value
BA0251 CYP2C9 Genotype In Process
BA0248 VKORC1 Genotype In Process
BA0232 Additional VKORC1 Variants 82939-0
BA0254 CYP4F2 *3 Genotype In Process
BA0257 rs12777823 Genotype In Process
BA0234 Interpretation 69047-9
BA0260 Additional Information 48767-8
BA0236 Method 49549-9
BA0237 Disclaimer 62364-5
BA0238 Reviewed by 18771-6