<prompt> A patient is having deficiency of Von Willebrand factor. Which of the following abnormalities are seen in this patient?Increased PTT, increased PTDecreased PT, Increased PTTNormal PT , Normal PTTNormal PT Increased PTT  <response>: Von Willebrand disease is caused by is deficiency of Von Willebrand factor vWF, an adhesive protein that connects subendothelial collagen to activated platelets and also binds to circulating factor VIII. There will be prolonged bleeding time in the presence of normal platelet count, prothrombin time PT and paial thromboplastin time PTT. Ref: Essentials of Pathophysiology: Concepts of Altered Health States by Carol Mattson Poh, 2010, Page 274 ; Handbook of Pediatric Hematology and Oncology: Childrens Hospital and ... By Caroline A. Hastings, Joseph C. Torkildson, Anurag K. Agrawal, 2012, Page 66 