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Factor V Leiden (F5) R506Q Mutation
0097720
Ordering Recommendation

Order to detect factor V Leiden variant.

Mnemonic
FACV
Methodology
Polymerase Chain Reaction/Fluorescence Monitoring
Performed
Sun-Sat
Reported
2-5 days
New York DOH Approval Status
This test is New York DOH approved.
Submit With Order
Specimen Required
Patient Preparation
 
Collect
Lavender (EDTA), Pink (K2EDTA), or Yellow (ACD Solution A or B). 
Specimen Preparation
Transport 3 mL whole blood. (Min: 1 mL) 
Storage/Transport Temperature
Refrigerated. 
Unacceptable Conditions
Plasma or serum; collection of specimen in sodium heparin tubes. 
Remarks
 
Stability
Ambient: 72 hours; Refrigerated: 1 week; Frozen: 1 month 
Reference Interval
Negative: This sample is negative for factor V Leiden, R506Q mutation.
Interpretive Data
Background Information for Factor V Leiden (F5) R506Q Mutation
Characteristics:
Venous thromboembolism (VTE) is a multifactorial condition caused by a combination of genetic and environmental factors. The Factor V Leiden (FVL) variant is the most common cause of inherited VTEs, accounting for over 90 percent of activated protein C (APC) resistance. Because the FVL variant eliminates the APC cleavage site, factor V is inactivated slower, thus persisting longer in blood circulation, leading to more thrombin production. Other genetic risk factors for VTE include, male sex and variants in antithrombin, protein C, protein S, or factor XIII. Non-genetic risk factors include, age, smoking, prolonged immobilization, malignant neoplasms, surgery, pregnancy, oral contraceptives, estrogen replacement therapy, tamoxifen and raloxifene therapy.
Incidence of Factor V Leiden Variant:
Approximately 5 percent of Caucasians, 2 percent of Hispanics, 1 percent of African Americans and 0.5 percent of Asians are heterozygous; homozygosity occurs in 1 in 1500 Caucasians.
Inheritance:
Semi-dominant; both heterozygotes and homozygotes are at increased risk for VTE.
Penetrance:
Lifetime risk of VTE is 10 percent for heterozygotes and 80 percent for homozygotes.
Cause:
The pathogenic gain of function in the F5 gene variant c.1601G>A (p.Arg534Gln). Legacy nomenclature: R506Q (1691G>A).
Clinical Sensitivity: 20-50 percent of individuals with an isolated VTE have the FVL variant.
Methodology:
Polymerase chain reaction and fluorescence monitoring.
Analytical Sensitivity and Specificity:
99 percent.
Limitations:
Diagnostic errors can occur due to rare sequence variations. F5 gene mutations, other than p.Arg534Gln, will not be detected.

Compliance Statement C: For human genetic inheritable conditions and mutations. This test was developed and its performance characteristics determined by ARUP Laboratories. The U. S. Food and Drug Administration has not approved or cleared this test; however, FDA clearance or approval is not currently required for clinical use. The results are not intended to be used as the sole means for clinical diagnosis or patient management decisions.

Counseling and informed consent are recommended for genetic testing. Consent forms are available online.

Note
This test is not recommended for nonsymptomatic patients under 18 years of age.
Hotline History
View Hotline History
Components
Component Test Code*Component Chart NameLOINC
0097720Factor V Leiden (F5) R506Q Mutation21668-9
2001387FACV Specimen31208-2
* Component test codes cannot be used to order tests. The information provided here is not sufficient for interface builds; for a complete test mix, please click the sidebar link to access the Interface Map.
Aliases
  • Activated protein C resistance mutation
  • APC Resistance Mutation Detection
  • FVL R506Q mutation testing