.Snapshot A 25-year-old woman presents to the emergency room with prolonged bleeding after a dental procedure early that day. She has gone through several gauze packing with no success. Her past medical history includes heavy and prolonged menses. As a child, she had several episodes of unexplained nosebleeds. Labs show normal PT, PTT, and platelet count. Introduction Inherited mixed platelet and coagulation disorder from deficiency in von Willebrand factor (vWF) Genetics autosomal dominant Epidemiology most common inherited bleeding disorder more likely in Caucasians Pathogenesis affects coagulation - vWF carries and protects factor VIII produced by endothelial cells and megakaryocytes intrinsic pathway coagulation defect affects platelets – vWF is important in platelet adherence to endothelial lining platelet aggregation is normal (mediated by fibrinogen) Presentation Symptoms mucocutaneous bleeding epistaxis gingival bleeding petechiae easy bruising menorrhagia increased bleeding after aspirin use Evaluation Normal or ↑ PTT (like hemophilia) Normal PT ↑ bleeding time (unlike hemophilia) CBC normal platelet count and appearance may have anemia Diagnosis by ristocetin cofactor assay tests ability of platelets to bind to ristocetin (artificial endothelial surface) ↓ platelet agglutination Differential Diagnosis Bernard-Soulier syndrome Glanzmann thrombasthenia Hemophilia Treatment DDAVP (desmopressin acetate) releases vWF stored in endothelial cells Factor VIII replacement if refractory to DDAVP contains vWF Prognosis, Prevention, and Complications Prognosis most are mild or moderate in severity Prevention avoid aspirin Complications excessive bleeding