This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: None, Subject name: Pediatrics
[{'content': 'Von willebrands disease all are true except – a) Factor VIII C deficiencyb) B.T. Prolongedc) Normal Ristocetin testd) Defective aggregation \nSelect and explain. \nA. a, B. bc, C. ac, D. b', 'role': 'user'}, {'content': 'Answer: C \nExplanation: Von Willebrand disease is characterized by the deficiency of vWF, while the synthesis of factor VIIIc is normal.\nVWF has two major functions -\n\n\nHelps in platelet adhesion\nStabilizes factor VIIIc\n\n\nSo, deficiency of vWF results in manifestation of both -\n\n1) Platelet adhesion defect\n\nBleeding from small venules and capillaries of skin and mucous membrane e.g. epistaxis. a Menorrhagia and GI bleeding\nProlonged bleeding time\n\n2)\xa0\xa0 Coagulation defect (due to factor VIII dysfunction)\n\nBleeding into weight bearing joints\nLarge post traumatic ecchymoses or hematoma\nProlonged bleeding after any form of surgical procedure or a laceration.\nProlonged PTT\nVWF can be assayed by ristocetin agglutination test which measures the ability of ristocetin to promote the interaction between VWF and platelet membrane glycoprotein Ib-IX.', 'role': 'assistant'}]