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Factor 5 Leiden ([LAB001987])
Test Mnemonic:


Specimen Requirements:

Whole Blood


EDTA (lavender), K2EDTA (pink), Sodium Citrate (blue), or Acid Citrate Dextrose (yellow) anticoagulant tube.

Minimum Volume:

3 mL of whole blood


Refrigerate (2-8C) up to 15 days.

Specimen Preparation:

Do NOT centrifuge.


Refrigerate (2-8C) up to 15 days.

Causes for Rejection:

Specimens that have been centrifuged. Insufficient quantity, gross hemolysis, lipemia. Specimen container unlabeled or labeled incorrectly. No date or time of collection or collector information on order.

Reference Range:


Turnaround Time:

3 days


Reverse transcription polymerase chain reaction


Clinical Microbiology


Thrombophilia risk, Leiden mutation, R506Q (1691G>A) Mutation, F5, coagulation factor V, F5 R506Q mutation, factor V leiden, FVL, activated protein C resistance mutation, APC resistance mutation

CPT 4 Code:



Factor 5 Comment:

Phenotype Characteristics: Thrombophilia due to mutation of coagulation factor 5 (F5) leading to activated protein C resistance.

Incidence: Between 3 and 8 percent of people with European ancestry are heterozygous and about 1 in 5000 individuals are homozygous with two copies of the mutation. The mutation is less common in other population.

Inheritance: Autosomal dominant.

Penetrance: Lifetime risk of thrombosis is 10 percent for heterozygotes and 80 percent for homozygotes.

Mutation tested: Missence F5 gene mutation R506Q (1691G>A). Note: Standardized nomenclature for the Factor 5 Leiden mutation is c.1601G>A(p.Arg534Gln).

Methodology: Polymerase chain reaction and fluorescence monitoring

Limitations: Rare Factor V mutations (A1696G, G1689A, and A1692C) and any additional SNPs in the probe binding region may interfere with the target detection and yield an INVALID result. The performance of this assay has not been evaluated with samples from pediatric patients. 

Counseling and informed consent are recommended for genetic testing.

References: OMIN:612309


When ordering tests for which Medicare or Medicaid reimbursement will be sought, physicians should only order tests that are medically necessary for the diagnosis or treatment of the patient. Components of the organ or disease panels may be ordered individually. The diagnostic information must substantiate all tests ordered and must be in the form of an ICD-10 code or its verbal equivalent.
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