Sections View Full Chapter Figures Tables Videos Full Chapter Figures Tables Videos Supplementary Content ++ INTRODUCTION ++ Inherited deficiencies of coagulation factors other than factor VIII (hemophilia A) and factor IX (hemophilia B) are rare bleeding disorders that occur in most populations. Patients are usually homozygotes or compound heterozygotes. Factor XI and factor VII deficiency occur relatively frequently, and other deficiencies are relatively rare (Table 81–1). The severity of the bleeding disorder usually relates to the severity of the factor deficiency. All may be caused by decreased synthesis of a specific coagulation factor, by synthesis of a dysfunctional form of the coagulation factor, or both. Inherited deficiency of a coagulation factor does not protect patients from thrombosis. ++Table Graphic Jump LocationTABLE 81–1RELATIVE PREVALENCE OF RARE BLEEDING DISORDERS*View Table|Favorite Table|Download (.pdf) TABLE 81–1 RELATIVE PREVALENCE OF RARE BLEEDING DISORDERS* Deficiency WFH Survey (2002)† Six National Registries (2007)† UK Data (Oct. 2008)‡ Survey of 64 Centers (Aug. 2008)† N % N % N % N % Factor XI 2446 35.3 1947 39.4 1762 59.5 770 23.5 Factor VII 1689 24.4 1050 21.3 580 19.6 927 28.3 Afibrinogenemia 644 9.3 496 10.0 203 6.9 241 7.4 Factor X 597 8.6 446 9.0 190 6.4 339 10.4 Factor V 769 11.1 415 8.4 129 4.4 233 7.1 Factor XIII 434 6.3 282 5.7 60 2.0 211 6.5 Factor V/Factor VIII 188 2.7 203 4.1 25 0.8 495 15.1 Factor II 167 2.4 101 2.0 13 0.4 55 1.7 Total 6934 100 4940 100 2962 100 3271 100 *Patients with partial deficiency were included. †Data courtesy of Professor Flora Peyvandi, Milan, Italy. ‡Data courtesy of Professor Paula Bolton-Maggs, Manchester, UK. Source: Williams Hematology, 8th ed, Chap. 125, Table 125–1. ++ PROTHROMBIN (FACTOR II) DEFICIENCY ++ Pathogenesis ++ Hypoprothrombinemia or dysprothrombinemia may be involved. Both are inherited as autosomal recessive disorders. Both interfere with hemostasis by impairing thrombin generation. ++ Clinical Features ++ The disorders are characterized by mucocutaneous and soft-tissue bleeding, usually in proportion to the severity of the functional prothrombin deficiency. Bleeding may be spontaneous if prothrombin levels are less than 1%. Hemarthroses may occur. Individuals with higher prothrombin levels have a variable bleeding tendency, and some may be asymptomatic. ++ Laboratory Features ++ The activated partial thromboplastin time (aPTT) and prothrombin time (PT) are prolonged. The thrombin time (TT) is normal. Diagnosis is established by demonstrating reduced levels of functional prothrombin. Both functional and antigen assays are required to identify dysprothrombinemia. Immunoelectrophoretic studies may demonstrate some forms of dysprothrombinemia. ++ Differential Diagnosis ++ Differential diagnosis includes inherited factor V or factor X deficiency, acquired deficiency of the vitamin K–dependent factors, or lupus anticoagulant. ++ Treatment ++ Prothrombin deficiency may be corrected with intravenous prothrombin complex concentrates, but with risk of transmission of viruses not ... GET ACCESS TO THIS RESOURCE Sign In Username Error: Please enter User Name Password Error: Please enter Password Forgot Username? Forgot Password? Sign in via OpenAthens Sign in via Shibboleth Get Free Access Through Your Institution Contact your institution's library to ask if they subscribe to McGraw-Hill Medical Products. What is MyAccess? Create a FREE MyAccess profile to: Use this site remotely Bookmark your favorite content Track your self-assessment progress and more!