Homocysteine associated hypercoagulability and disseminated thrombosis--a case report

The authors report the occurrence of vascular occlusion due to hyperhomocysteinemia without significant underlying atherosclerotic disease. This unique observation supports the potential of hyperhomocysteinemia to induce thrombosis and the independence of the thrombosis from hyperhomocysteinemia's associated atherosclerosis. The case demonstrates the clinical relevance of the effects of hyperhomocysteinemia on the coagulation cascade. A 42-year-old woman who lacked signs of classic homocystinuria developed disseminated thrombosis with a 24-hour urine homocysteine concentration of 384 mg, twelve times the upper limit of normal. Thrombosis was present in the aortic arch and its major branches and in the mesenteric arteries and veins. A fatal stroke resulted from the thrombosis. Autopsy revealed minimal atherosclerotic disease and no complicated plaques. This case demonstrates an expanded role of hyperhomocysteinemia in clinically significant vascular occlusion. Serum homocysteine concentration determination may be a factor in the evaluation of a hypercoagulable state. Hyperhomocysteinemia should be considered when evaluating arterial or venous thrombosis in a young person regardless of whether atherosclerosis or other signs of abnormal homocysteine metabolism are present.