The patient most likely has von Willebrand disease (vWD). vWD is an autosomal codominant disorder. Von Willebrand factor (vWF) protects factor VIII from degradation, and factor VIII levels can be low enough in vWD to cause slight prolongation of the activated partial thromboplastin time (aPTT), although typically the prothrombin time (PT) and aPTT are normal. Hemorrhagic manifestations of vWD are characterized by mucocutaneous bleeding, not hemarthroses as in hemophilia. Many women with vWD have significant menorrhagia, endometriosis, and postpartum hemorrhage. Mild vWD may not be detected by the Platelet Function Analyzer-100 (PFA-100®) assay, necessitating measurement of vWF antigen and activity levels for diagnosis. Additionally, levels of vWF fluctuate in response to estrogens, stress, exercise, inflammation, and bleeding, and repeated assays may be required to make the diagnosis.
Factor VII deficiency may be inherited or acquired as a result of vitamin K deficiency or warfarin therapy. Patients with factor VII deficiency will have an abnormal prolongation of the PT but a normal aPTT, which is incompatible with this patient's findings.
Factor XI deficiency is an autosomal recessive bleeding disorder and may be associated with a prolonged aPTT and significant bleeding with surgery or trauma. Severe factor XI deficiency is much more frequent in persons of European Jewish descent. Severe factor XI deficiency will prolong the aPTT and is not associated with spontaneous bleeding or with the classic bleeding manifestations of hemophilia, such as hemarthrosis or soft-tissue bleeding, making this diagnosis unlikely.
Factor XII deficiency also produces a normal PT and markedly prolonged aPTT but is not associated with bleeding manifestations and, therefore, is not a likely diagnosis for this patient.
Factor VIII deficiency is responsible for hemophilia A, an X-linked recessive disorder. Severe hemophilia A is characterized by recurrent hemarthroses resulting in chronic, crippling degenerative joint disease unless treated prophylactically with factor replacement. Mild hemophilia may present in adulthood, characterized by posttraumatic or surgical bleeding and a prolonged aPTT. This patient's clinical presentation of mucocutaneous bleeding, normal aPTT, and apparent inheritance pattern of bleeding are not compatible with hemophilia.