VWF and blood coagulation disease: Other coagulopathies found were hypofibrinogenemia (15.2%), low VWF activity (11.1%; 2 patients with blood type O positive and 2 patients with A positive), factor XIII deficiency (6.7%), prolonged aPTT (10.5%), prolonged PFA-ADP (8.5%) and prolonged PFA-EPI (10.2%).