Regulation of blood coagulation and thrombosis

The syndrome of the hereditary tendency to venous thrombosis or thrombophilia has been recognized only after the discovery of regulatory mechanisms of the haemostatic system. At present, several distinct defects are known as causes of this syndrome: antithrombin III deficiency, protein C deficiency, protein S deficiency, dysfibrinogenaemia and dysplasminogenaemia. It is likely that several additional defects will be found in the near future. Consequently, it is important that a family history be taken in all cases of 'spontaneous' venous thrombosis and that laboratory studies be done to identify any underlying defect in the regulation of the blood coagulation system. We present preliminary data, which suggest that the incidence of the thrombophilia syndrome is higher than that of the haemophilias.