Thromboembolism in Hageman trait.

The case of a patient with severe deficiency of Hageman factor (factor XII) in whom a thrombus embolized to arteries in a lower extremity is described. In addition to its action in intiating blood clotting through the intrinsic pathway, Hageman factor can influence kinin generation, fibrinolysis, and activation of complement. While individuals with Hageman factor deficiency have no hemorrhagic disorder, this case emphasizes the role factor XII may normally assume in clot dissolution.