Test Details


Contributes to the risk assessment for venous thromboembolism (VTE) to better inform decisions regarding treatment and clinical management decisions of patients with relevant personal history of VTE and potential preventative care for patients with significant family history of VTE.


Variant analyzed: c.1601G>A (p.Arg534Gln), referred to as Factor V Leiden; NM_000130.5. Results must be combined with clinical information for the most accurate interpretation. Molecular-based testing is highly accurate, but as in any laboratory test, diagnostic errors may occur. False positive or false negative results may occur for reasons that include genetic variants, blood transfusions, bone marrow transplantation, somatic or tissue-specific mosaicism, mislabeled samples, or erroneous representation of family relationships.

This test was developed and its performance characteristics determined by Labcorp. It has not been cleared or approved by the Food and Drug Administration.


Allele-specific polymerase chain reaction (PCR)

Related Documents

For more information, please view the literature below.

Procedures for Hemostasis and Thrombosis: A Clinical Test Compendium


Kujovich JL. Factor V Leiden Thrombophilia. 1999 May 14 [Updated 2018 Jan 4]. In: Adam MP, Ardinger HH, Pagon RA, et al., editors. GeneReviews® [Internet]. Seattle (WA): University of Washington, Seattle; 1993-2021. Accessed at https://www.ncbi.nlm.nih.gov/books/NBK1368/.
Zhang S, Taylor AK, Huang X, et al. Venous thromboembolism laboratory testing (factor V Leiden and factor II c.*97G>A), 2018 update: a technical standard of the American College of Medical Genetics and Genomics (ACMG). Genet Med. 2018 Dec;20(12):1489-1498. Epub 2018 Oct 5.30297698

Additional Information

Venous thromboembolism is a multifactorial disease influenced by genetic, environmental, and circumstantial risk factors. The c.1601G>A (p. Arg534Gln) variant in the F5 gene, commonly referred to as Factor V Leiden, is a genetic risk factor for venous thromboembolism. Heterozygous carriers of this variant have a 6- to 8-fold increased risk for venous thromboembolism. Individuals homozygous for this variant (ie, they have a copy of the variant on each chromosome) have an approximately 80-fold increased risk for venous thromboembolism. Individuals who carry both a *97G>A variant in the F2 gene and Factor V Leiden have an approximately 20-fold increased risk for venous thromboembolism. Risks are likely to be even higher in more complex genotype combinations involving the F2 c.*97G>A variant and Factor V Leiden.1 Additional risk factors include but are not limited to: deficiency of protein C, protein S, or antithrombin III, age, male sex, personal or family history of deep vein thromboembolism, smoking, surgery, prolonged immobilization, malignant neoplasm, tamoxifen treatment, raloxifene treatment, oral contraceptive use, hormone replacement therapy, and pregnancy. Management of thrombotic risk and thrombotic events should follow established guidelines and fit the clinical circumstance. This result cannot predict the occurrence or recurrence of a thrombotic event.

Genetic coordinators are available for health care providers to discuss results and for information on how to order additional testing, if desired, at 1-800-345-GENE.

Specimen Requirements

Information on collection, storage, and volume


Whole blood or Labcorp buccal swab kit (buccal swab collection kit contains instructions for use of a buccal swab)


7 mL whole blood or Labcorp buccal swab kit

Minimum Volume

3 mL whole blood or two buccal swabs


Lavender-top (EDTA) tube, yellow-top (ACD) tube, or Labcorp buccal swab kit

Storage Instructions

Maintain specimen at room temperature.

Causes for Rejection

Frozen specimen; hemolysis; quantity not sufficient for analysis; improper container; one buccal swab; wet buccal swab