[Hereditary dysprothrombinemia with a mild bleeding tendency (prothrombin Magdeburg)].

Seven members of one family over three generations were found to have a characteristic reduction to about 0.5 of the ratio between factor II clotting activity and factor II concentration, which was not seen when measuring prothrombin after activation with staphylocoagulase. In addition to the "normal" prothrombin, two abnormal prothrombins, with higher molecular weights and lower isoelectric points, were found by SDS-polyacrylamide gel electrophoresis. This is an autosomal hereditary dysprothrombinemia, the affected persons being heterozygotes. Five of the seven persons had a slightly increased bleeding tendency which manifested itself especially in more marked or prolonged posttraumatic and postoperative bleedings.