Additionally, they may be classified into two categories: in the first one, inhibitors of coagulation are decreased—deficiency of coagulation inhibitor factor such as antithrombin III (AT III), protein C and protein S deficiency; in the second category, coagulation factors are elevated—activated Protein C resistance (APC), Factor V Leiden, prothrombin gene mutation, increased levels of VIII, IX, XI factors, and dysfibrinogenemias. This evidence concerns the gene SERPINC1 and familial hypodysfibrinogenemia.