[Thrombophlebitis and pulmonary embolism in congenital factor XII deficiency]

The case of a young man hospitalised for bilateral lower limb deep vein thrombosis is reported. None of the usual causes were found after systematic wide-ranging investigation. The only abnormality on admission was a spontaneous increase in the cephalin-kaolin time to 65 seconds compared to a control time of 40 seconds. Measurements of the clotting factors showed a moderate and isolated deficiency in factor XII (30 p. 100), also present in a brother (50 p. 100) and a sister (42.5 p. 100). Fibrinolytic therapy was administered : an initial course of Streptokinase was followed by extension of a left femoral vein thrombosis and pulmonary embolism. Two courses of Urokinase were given with an eight day interval without significantly improving the venous circulation. This case is an example of thrombogenic disease due to a deficiency of a clotting factor resulting in non-activation of physiological fibrinolysis.