Warfarin Sensitivity (CYP2C9, CYP2C cluster, CYP4F2, VKORC1) Genotyping
Test Mnemonic
WRFSEN
CPT Codes
- 81227 - QTY (1)
- 81355 - QTY (1)
- 81479 - QTY (1)
Aliases
- CYP4F2 genotyping
- Cytochrome P450 2C9 Genotyping
- VKORC1 genotyping
- CYP2C Cluster genotyping
Includes
- CYP2C9 Phenotype
- EER Warfarin Sensitivity Genotyping
- CYP2C Cluster Genotype
- CYP2C Cluster Phenotype
- CYP4F2 Phenotype
- VKORC1 Phenotype
- Interpretation
- CYP2C9 Genotype
- CYP4F2 Genotype
- VKORC1 Genotype
Performing Laboratory
ARUP
Specimen Requirements
| Volume | Type | Container | Collect Temperature | Transport Temperature | Special Instructions |
|---|---|---|---|---|---|
| 3 mL | Whole blood | EDTA (Lavender) | Refrigerated |
Alternate Specimen Requirements
| Volume | Type | Container | Collect Temperature | Transport Temperature | Special Instructions |
|---|---|---|---|---|---|
| 3 mL | Whole blood | ACD A or B (Yellow) | Refrigerated |
Minimum Specimen Requirements
| Volume | Type | Container | Collect Temperature | Transport Temperature | Special Instructions |
|---|---|---|---|---|---|
| 1 mL | Whole blood |
Stability
| Environmental Condition | Description |
|---|---|
| Refrigerated | Whole blood: 1 week; Saliva: Unacceptable |
| Frozen | Whole blood: 1 month; Saliva: Unacceptable |
| Ambient | Whole blood: 72 hours; Saliva: 2 weeks |
Days Performed
Varies
Turnaround Time
6 - 11 days
Methodology
| Name | Description |
|---|---|
| Fluorescence Monitoring | |
| Polymerase Chain Reaction (PCR) |
Special Info
Plasma, serum and frozen specimens in glass collection tubes will be rejected. Whole blood is the preferred specimen. This test is New York DOH approved.
Clinical Info
Only the targeted CYP2C9, CYP2C cluster, CYP4F2, and VKORC1 variants will be detected by this panel, and assumptions about phase and content are made to assign alleles. Publicly available sources such as the www.pharmvar.org or www.pharmgkb.org provide guidance on phenotype predictions and allele frequencies. Diagnostic errors can occur due to rare sequence variations. Risk of therapeutic failure or adverse reactions with CYP2C9 substrates may be affected by genetic and nongenetic factors that are not detected by this test. This result does not replace the need for therapeutic drug or clinical monitoring.