A 40-year-old female presented with acute painful swelling of left leg. USG of left leg showed deep venous thrombosis. Which of the following abnormality is least likely to be involved in this condition?

Factor V Leiden mutation results in an abnormal form of factor V that is resistant to protein C. It is associated with increased risk for recurrent thromboembolism. The most common thromobphilic genotypes - point mutations in the factor V gene (Factor V Leiden) and prothrombin gene (G20210A variant). Rare inherited causes of primary hypercoagulability include deficiencies of anticoagulants such as antithrombin III, protein C, or protein S. Inherited or acquired causes of elevated homocysteine levels (hyperhomocysteinemia) can be prothrombotic. Prothrombotic effects of homocysteine may be due to ester linkages formed between homocysteine metabolites and a variety of proteins, including fibrinogen.