Thrombophilia, polymorphisms, and vascular disease

Thrombophilia traditionally refers to rare inherited defects leading to enh anced coagulation, especially of the venous system. In recent years, a broa der search for genetic polymorphisms of prothrombotic genes has been carrie d out to determine the relative impact on venous and arterial thrombosis. T he bulk of evidence is drawn from numerous, often small, heterogeneous, cas e control association studies, with a variety of end points (deep venous th rombosis, myocardial infarction, or stroke). The data are often conflicting and inconclusive with only factor V Leiden and prothrombin polymorphisms h aving clear associations with venous thrombosis. Many of the polymorphisms interact with established cardiovascular risk factors, in particular smokin g, to increase greatly the risk of a thrombotic episode. Future studies wil l need to consider the confounding factors of sample size, race, and clinic al end points as well gene environment interactions.