F5 and Rare hereditary thrombophilia: Among the inherited factors of thrombophilia, the four most common genetic markers are Factor V Leiden (FVL, G1691A), methylenetetrahydrofolate reductase polymorphisms (MTHFR C677T and A1298C), prothrombin gene (FII, G20210A), and plasminogen activator inhibitor-1 (PAI-1) variants—and their relation to various vascular diseases is known [13].