Prothrombin (Factor II) 20210 Gene Mutation
(See also Overview of Thrombotic Disorders.)
A genetic mutation causes increased serum levels of prothrombin (factor II), predisposing to venous thrombosis.
Prothrombin (factor II) is a vitamin K-dependent precursor of thrombin, the end-product of the coagulation cascade. A mutation of the prothrombin 20210 gene results in increased plasma prothrombin levels (with potentially increased thrombin generation) and increases the risk of venous thromboembolism.
The prevalence of the mutation ranges from < 1% to 6.5%, depending on the population studied.
The diagnosis is made by genetic analysis of the prothrombin 20210 gene using blood samples.
Anticoagulation with heparin or low molecular weight heparin, followed by warfarin, is used for venous thrombosis, or for prophylaxis in patients at increased thrombotic risk (eg, by immobilization, severe injury, or surgery).
It is not known if the newer oral anticoagulants that inhibit either thrombin (dabigatran) or factor Xa (eg, rivaroxaban, apixaban) can be used in place of other anticoagulants for this disorder.