Factor V Leiden Mutation

Specimen Collection, Storage, and Shipping

Test Information:

This sequencing assay is designed to detect the Factor V Leiden (FVL) mutation (1691G>A) in the F5 gene leading to an amino acid change (Arg506Gln) in factor V protein and activated protein C resistance (aPC). Individuals with FVL have an increased risk for venous thromboembolism (VTE), and testing may be considered for individuals with unprovoked VTE, recurrent VTE, venous thrombosis at unusual locations (e.g., cerebral vein), or pregnancy-associated VTE. Heterozygous adults have a 5- to 7-fold and homozygous adults have a 50- to 80-fold increased risk over background for thrombosis.

The assay detects a single G to A substitution at nucleotide position 1691 (1691G>A) in the F5 gene that leads to an amino acid substitution (Arg506Gln or R506Q). The mutation renders activated-F5 resistant to degradation by aPC. Genotyping is accomplished by PCR amplification followed by pyrosequencing.  Rarely, genetic variants other than FVL (1689G>A, 1690C>T, 1692A>C, 1696A>G) may be detected by this assay, but only FVL is linked to aPC resistance. Other sequence variants within the F5 gene or within other genes may increase susceptibility to thrombosis but will not be detected by this method. The presence of polymorphisms underlying primers used in the assay may lead to aberrant genotyping but are rare.

Requisition Code:

Factor V Leiden mutation

CPT Codes:

81241; G0452-26

Turn-Around Time:

7-10 days

Specimen Requirements:

Collect:            Peripheral blood: 2-5 mL in EDTA (purple top) tube

Storage:          Room temperature

Remarks:       

Transport:        See Standard Shipping Procedures

References:
  1. Kujovich JL. Factor V Leiden Thrombophilia. 1999 May 14 [Updated 2010 Mar 9]. In: Pagon RA, Adam MP, Ardinger HH, et al., editors. GeneReviews® [Internet]. Seattle (WA): University of Washington, Seattle; 1993-2016. Available from: https://www.ncbi.nlm.nih.gov/books/NBK1368/
  2. Evaluation of Genomic Applications in Practice and Prevention (EGAPP) Working Group. Recommendations from the EGAPP Working Group: Routine testing for Factor V Leiden (R506Q) and prothrombin (20210G>A) mutations in adults with a history of idiopathic venous thromboembolism and their adult family members. Genetics in Medicine. 2011 Jan;13(1):67-76.
  3. Kujovich, JL. Factor V Leiden Thrombophilia. Genetics in Medicine. 2011 Jan;13(1):1-16.