hematology and oncology
Uncommon Hereditary Coagulation Disorders
Introduction
Most hereditary coagulation disorders other than Hemophilia are rare autosomal recessive conditions that cause In patients with a deficiency of factor XI, there is no clear association between factor XI plasma levels and the severity of bleeding, indicating that the molecular action of factor XI in normal hemostasis is not precisely understood. In the other rare coagulation disorders (excluding hemophilia A and B), normal hemostasis usually requires a plasma level of the deficient factor in excess of about 20% of normal (see table). 