A patient with spontaneous venous thrombotic events, myocardial infarction and a positive family history of thrombosis was investigated for underlying disorders of haemostasis. Abnormally high levels of histidine-rich glycoprotein were found. No other abnormality known or suspected of increasing the risk for thrombosis was present. Elevated levels of histidine-rich glycoprotein appeared to be present in four other members of the family over two generations suggesting a hereditary disorder. Further study on the relation of elevated histidine-rich glycoprotein levels and thrombosis is indicated.
