Factor V Leiden Mutation

CPT Code(s):


Specimen Requirements:

4 mL of blood in a lavender (purple-top) tube (EDTA)

Stability (collection to initiation of testing):
  • Ambient: 3 days
  • Refrigerated: 7 days
Unacceptable Conditions: Frozen specimens


This test is used to detect factor V Leiden mutation, which is a risk factor for thrombosis.


Polymerase chain reaction with sequence specific primers (PCR-SSP), combined with agarose gel electrophoresis


Within 10 days

Reference Values:

Negative for the Factor V Leiden R506Q mutation

Interpretation Data:

The “mutation” is actually a common polymorphism in the Factor V gene that replaces a critical arginine with a glutamine at position 506 of the protein (FV R506Q). This removes a cleavage site for activated protein C. Approximately 5% of Caucasians is heterozygous for the R506Q polymorphism. Heterozygous FV R506Q carriers have a 4-fold risk increase for venous thromboembolism. Homozygotes have an 80-fold increased risk.