This is an autosomal recessive disorder in which there is an absence of platelet membrane receptor GPIb/IX thus resulting in an inability of the platelets to bind von Willebrand factor.  This inability to bind von Willebrand factor results in a lack of platelet adherence to subendothelial connective tissues.  Clinically, this disorder manifests as epistaxis, mucocutaneous bleeding and purpura which begins during childhood and tends to improve with age.  Laboratory abnormalities include a bleeding time in excess of 20 minutes and a normal to slightly reduced platelet count with platelet morphology revealing large platelets without Dohle bodies and ristocetin testing revealing an abnormal aggregation response.  However, unlike von Willebrand disease, the abnormal ristocetin aggregation does not correct with the addition of von Willebrand factor.