Sections View Full Chapter Figures Tables Videos Annotate 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 are rare but occur relatively frequently compared to other factor deficiencies (apart from hemophilia A and B), whereas the other deficiencies are very rare (Table 82–1). 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. Rare bleeding disorders are often caused by mutations unique for each kindred and scattered throughout the genes. The molecular diagnosis is based on the mutation search in the genes encoding the corresponding coagulation factor (Table 82–2). ++ Table Graphic Jump Location|Download (.pdf)|Print TABLE 82–1 WORLDWIDE DISTRIBUTION OF RARE BLEEDING DISORDERS DERIVED FROM THE WORLD FEDERATION OF HEMOPHILIA AND THE EUROPEAN NETWORK OF RARE BLEEDING DISORDERS SURVEYS Deficiency WFH Survey (%) EN-RBD Database (%) Fibrinogen 9 8 Factor II 1 1 Factor V 8 10 Factor V + factor VIII 2 3 Factor VII 38 39 Factor X 7 8 Factor XI 30 24 Factor XIII 5 7 EN-RBD, European Network of the Rare Bleeding Disorders (www.rbdd.eu); WFH, World Federation of Hemophilia (www.wfh.org), report of 2017. ++ Table Graphic Jump Location|Download (.pdf)|Print TABLE 82–2 GENERAL GENETIC FEATURES OF COAGULATION FACTORS Deficiency Gene Chromosome Factor II F2 11p11–q12 Factor V F5 1q21–25 Factors V + VIII LMAN1 18q21.3–q22 MCFD2 2p21–p16.3 Factor VII F7 13q34 Factor X F10 13q34–qter Factor XI F11 4q34–35 Factor XIII F13A 6p24–p25 F13B 1q31–q32.1 +++ 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 ... Your Access profile is currently affiliated with '[InstitutionA]' and is in the process of switching affiliations to '[InstitutionB]'. Please click ‘Continue’ to continue the affiliation switch, otherwise click ‘Cancel’ to cancel signing in. Get Free Access Through Your Institution Learn how to see if your library subscribes to McGraw Hill Medical products. Subscribe: Institutional or Individual Sign In Username Error: Please enter User Name Password Error: Please enter Password Forgot Password? Forgot Username? Sign in via OpenAthens Sign in via Shibboleth