Factor II

Factor II (Prothrombin 20210 G>A)

Test Code
Factor II (Prothrombin), FII

CPT Code
81240

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

General Purpose and 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.

Alleles Detected
20210 G>A

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
Real-time polymerase chain reaction with fluorescence detection.

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