[Genetics of venous thromboembolism]

Venous thrombo-embolic disease is a multifactorial disease which arises in situations of thrombosis risk with poorly understood genetic and/or acquired risk factors. Constitutional anomalies concerning five coagulation proteins (antithrombin, protein C, protein S, factor V and prothrombin) are established risk factors for which the harmful role has been demonstrated in thrombophilic families and/or in case-control studies. New studies (twin studies, GAIT study) which use joint subjects and appropriate statistical methods are aimed at a better understanding of the genetic component and the environmental component of thrombotic risk. They have allowed demonstration of the importance of the contribution of heredity to the variability of the coagulation parameter concentration and the variability of susceptibility to thrombosis, and have implied the influence of genes with pleiotrophic effect. The identification of these new loci will allow a better evaluation of the components of thrombotic risk and perhaps lead to individualised preventive therapeutic management.