Decreased blood coagulation activities in carbohydrate-deficient glycoprotein syndrome

The carbohydrate-deficient glycoprotein (CDG) syndromes are a newly recognized group of inherited metabolic diseases. We report a Japanese brother and sister with a CDG syndrome. Both patients showed decreased activities of blood coagulation Factor XI and of the coagulation inhibitor protein C. In one of them there was also a somewhat decreased activity of Factor IX and of antithrombin III. Isoelectric focusing of antithrombin III revealed a decrease of negatively charged fractions and an increase of more cathodal bands. Furthermore, there was a discrepancy between activity and antigen level of Factor VIII and protein C. The patients had an incidental deficiency of factor XII. This is the first detailed report on blood coagulation systems in the CDG syndromes. These blood coagulation abnormalities may explain at least in part the thrombotic or haemorrhagic complications of the CDG syndromes.