Consider this test in patients who present with previous or family history of thrombosis, as a pre-emptive screening for those undergoing surgery or for frequent travellers. The test should also be considered in women who are considering falling pregnant and those who have previously suffered pregnancy loss (alongside GrowBaby), as well as those women considering hormonal contraceptive use or hormone replacement therapy (HRT).
Factor V functions as a cofactor to allow Factor Xa to activate the enzyme thrombin, and in turn cleaves fibrinogen to form fibrin. This polymerizes to form the dense meshwork that makes up the majority of a clot. Activated protein C (aPC) is a natural anticoagulant that acts to limit the extent of clotting by cleaving and degrading factor V.
The Factor II gene encodes the coagulation factor II, or prothrombin, which is a vitamin K–dependent proenzyme that functions in the area of blood coagulation. Factor II is a precursor to thrombin, which converts fibrinogen into fibrin, which in turn strengthens a protective clot.