Factor V Leiden Analysis

Factor V Leiden (F5) R506Q mutation is the most common cause of inherited thrombophilia and accounts for over 90 percent of activated protein C (APC) resistance. Individuals heterozygous for this mutation have an increased risk for venous thrombosis (approximately five- to tenfold). Individuals homozygous for this mutation have an even higher risk for venous thrombosis (approximately fifty- to one hundredfold). Specific acquired or environmental factors may dramatically increase this baseline risk.

Analysis for the factor V Leiden R506Q mutation is offered as a specific DNA test, or as part of the thrombosis panel which also includes the Prothrombin (Factor II) G20210A mutation analysis. Individuals with multiple thrombophilic mutations develop venous thromboembolism at a younger age and are at higher risk for recurrent thrombosis than those with a single defect.

Indications for Testing

  • Deep vein thrombosis
  • Pulmonary embolism
  • Superficial venous thrombosis, phlebitis or thrombophlebitis
  • Personal history of two or more blood-clotting incidents
  • Family history of blood clots or factor V Leiden
  • Unexplained fetal loss after 10 weeks gestation
  • Unexplained severe preeclampsia, placental abruption, or a fetus with intrauterine growth retardation

Sample Requirements

3 – 4 mL whole blood in purple top EDTA tube

Sample Handling

Blood samples stored overnight should be refrigerated or kept cold. Blood samples should never be frozen. Specimens being sent from outside facilities should be packaged with a cold pack according to standard medical safety practices. The specimen should be shipped by overnight priority [scheduled to arrive by Friday morning at the latest].

Shipping Address

Center for Human Genetics Laboratory
10524 Euclid Avenue, Sixth Floor
Cleveland, OH 44106

For local samples, please call Client Service (216-844-5227) to arrange for sample pick-up.

Turnaround Time

3 – 9 days

CPT Codes

  • Factor V Leiden Analysis – 81241

Please submit a completed Molecular Requisition for each sample.