von Willebrand's disease (comparison with the features of Haemophilia A and Haemophilia B)
Last reviewed 01/2018
Comparison between the clinical and laboratory features found in Haemophilia A, Haemophilia B and Von Willebrand's disease
| Haemophilia A | Haemophilia B | Von Willebrand's disease | |
| Mode of inheritance | X-linked | X-linked | Autosomal Dominant (incomplete) |
| Main sites of Bleeding | muscle, joints, following trauma or post operation | muscle, joints, following trauma or post operation | skin cuts, mucous membranes, following trauma and post operation |
| platelets | normal platelet count | normal platelet count | normal platelet count |
| bleeding time | normal | normal | prolongation of bleeding time |
| prothrombin time | normal | normal | normal |
| Activated partial thromboplastin time (APTT) | prolonged | prolonged | prolonged |
| von Willebrand's Factor | normal | normal | reduced levels |
| factor VIII | low levels | normal | low levels - vWF is the carrier molecule for factor VIII thus preventing it from premature destruction - this property explains the reduced factor VIII levels found in von Willebrands disease |
| factor IX | normal | low levels | low levels |
| ristocetin-induced platelet aggregation | normal | normal | ristocetin fails to induce platelet aggregation in von Willebrand's patients because of lack of vWF:R - a cofactor for ristocetin |
von Willebrand's disease (congenital deficiency of von Willebrand's factor )