Von Wiliebrand disease is associated with -

Ans. is 'd' i.e., |PTT; Normal PT; |BT; |CT LABORATORY DIAGNOSIS OF VON WILLEBRAND'S DISEASE.Screening testsVon Vilebrand disease||Deficiency ofVonvilebrand factordefect in factor VIIIc(VWf carries VIIIc)||Leads to plateletdysfunctionLeads to defect inintrinsic coagulation pathway||o Increased bleeding timeQo Increased PTTQo Normal PTQo Increased clotting timeQ Laboratory findings in Von wilebrand diseaseo Tourniquet test (Hess test)- Is positive because of defective platelet adhesionso Bleeding time- Prolonged because of platelet function defecto APTT- Prolonged because of secondarily reduced VIIIc activityo VWF assay- | levelso Ristocetin induced aggregation is defective- It Is diagnostic of vWD. This is insensitive to mild deficiency of vWF. However in platelet type vWD - Ristocetin induced platelet aggregation is increasedo vWF immunoassay- Levels of VWF antigen (VWF: Ag) axe assayed by EUSAor automated assays and are reduced in type vWD while in type 2 vWD, the vWF: Ag levels may be normal indicating that just measuring VWF: Ag is not enough for diagnosing vWDo Muitimeric analysis of vWF o Genetic studies of specific CDNA regions