Abstract: Von Willebrand-s disease is the most common
inherited bleeding disorder in humans, it
caused by qualitative abnormalities of the von Willebrand factor
(vWF). Our objective is to determine the prevalence of this disease at
part of the Algerian population in the East and the South by a
biological diagnosis based on specific biological tests (automated
platelet count, the bleeding time (TS), the time of cephalin + activator
(TCA), measure of the prothrombin rate (TP), vWF rate and factor
VIII rate, Molecular electrophoresis of vWF multimers in agarose gel
in the presence of SDS). Four patients of type III or severe
Willebrand-s disease were found on 200 suspect cases. All cases are
showed a deficit in vWF rate (< 5%), and factor VIII (P