The coagulation profile in a 13 year old girl with Menorrhagia having von Willebrands disease is:: (A) Isolated prolonged aPTT with a normal PT, (B) Isolated prolonged PT with a normal aPTT, (C) Prolongation of both PT and aPTT, (D) Prolongation of thrombin time
Answer is A. - Von Willebrand factor acts as a plasma carrier of factor VIII and circulates in blood as factor VIII-VWF complex. - Thus, VWF deficiency impairs intrinsic pathway of coagulation & prolongs aPTT - Extrinsic pathway of coagulation remains unimpaired, PT is not altered.