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 mLWhole bloodEDTA (Lavender) Refrigerated 

Alternate Specimen Requirements

Volume Type Container Collect Temperature Transport Temperature Special Instructions
3 mLWhole bloodACD 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
RefrigeratedWhole blood: 1 week; Saliva: Unacceptable
FrozenWhole blood: 1 month; Saliva: Unacceptable
AmbientWhole 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.