Arterial and venous thrombosis and normal response to streptokinase treatment in a young patient with severe Hageman factor deficiency.

The case history of a patient with severe factor XII deficiency (factor XII activity and concentration below 1%) is described. The case reported gives further evidence that factor XII deficiency leads to a prolonged euglobulin lysis time. This might be a risk factor indicating a proneness to thromboembolic events. The young man suffered from arterial and venous thrombosis, and underwent lower extremity amputation without bleeding complications, as well as thrombolytic therapy to save the other leg. There was a normal response to streptokinase, heparin, and phenprocoumon treatment.