Type 2A vWD is characterized by defective plateletbinding due to the absence of high molecular weight vWF (HMW-vWF) multimers in both plasma and platelets.Type 2A vWD patients have a low vWF:RCo to vWF:Agratio (<0.6) [37]. This evidence concerns the gene VWF and von Willebrand disease (hereditary or acquired).