The most prevalent hereditary thrombophilias [11] are related to pathological mutations located at prothrombin (Factor II) gene mutation, in the G20210A position, the factor V Leiden (FVL) gene mutation in the G1691A position [11], the methylenetetrahydrofolate reductase (MTHFR) gene mutation in the C677T and A1298C positions, and the Plasminogen Activator Inhibitor-1 (PAI-1) gene mutation; these pathological mutations can all increase the risk of developing thrombosis. The gene discussed is MTHFR; the disease is Venous thrombosis.