Factor II (Prothrombin) 20210 G>A
Test Code
Factor II (Prothrombin), FII
CPT Codes
83891-3G x1; 83892-3G x2; 83900-3G x1; 83914-3G x1; 83909-3G x1; 83912-3G x1; 83912-25 x1
Specimen
Whole blood or buccal swabs
Volume
5 mL of whole blood or four buccal swabs
Minimum Volume
3 mL of whole blood or four buccal swabs
Container
Lavender-stopper (EDTA) tube or paper envelope for dried buccal swabs
Storage Instructions
Maintain at room temperature or refrigerate
Cause for Rejection
Hemolyzed specimen; quantity not sufficient
Use
The Factor II (prothrombin) polymorphism is the result of a single point mutation (20210 G>A) in the 3’ untranslated region of the gene. The 20210 G>A gives rise to increased circulating prothrombin levels, thus creating the potential of a hypercoagulable state. This polymorphism is found in approximately 2% of individuals in the U.S. and it raises the risk of thrombosis significantly for both males and females in all age groups. People with this polymorphism are at 2-3 fold increased risk of deep venous thrombosis (DVT), without other confounding non-genetic factors such as smoking, hormone therapy, and immobility.
.Limitations
Other genetic variants of the Factor II gene that are not detected in the assay may influence Factor II enzymatic activity. Other genetic and non-genetic factors may also influence the balance of proper coagulation.
Methodology
Multiplex polymerase chain reaction and allele specific primer extension (Tag-It [TM]).
Turnaround Time
Five business days after receipt of specimen. STAT turnaround time of 3 business days is available for an additional charge.
References
Ho WK et al. Risk of recurrent venous thromboembolism in patients with common thrombophilia. Arch Intern Med 2006;166:729-736.
Tripodi A. Issues concerning the laboratory investigation of inherited thrombophilia. Mol Diag 2005;9(4):181-186.
Bauer KA. Role of thrombophilia in deciding on the duration of anticoagulation. Semin Thromb Hem 2004;30(6):633-637.
Kim RJ and Becker RC. Association between factor V Leiden, prothrombin G20210A, and methylenetetrahydrofolate reductase C677T mutations and events of the arterial circulatory system: a meta-analysis of published studies. Am Heart J 2003;146:948-957.