ABO blood group system (and Factor VIII) than do non-O individuals. In addition, vWF is degraded more rapidly due to the higher prevalence of blood group O with the Cys1584 variant of vWF (an amino acid polymorphism in VWF): the gene for ADAMTS13 (vWF-cleaving protease) maps to the ninth chromosome (9q34), the same locus as ABO blood type. Higher levels of vWF are more common amongst people who have had ischemic stroke (from blood clotting) for the first time. The results of this study found that the occurrence was not affected by ADAMTS13 polymorphism, and the only significant genetic factor was the person's blood
Jehovah's Witnesses and blood transfusions was released, outlining Jehovah's Witnesses' general doctrine on blood. In 2000, the Watch Tower Society's stand on blood fractions was clearly stated. Members were instructed to personally decide if accepting a fraction would violate the doctrine on blood. In a later article, members were reminded that Jehovah's Witnesses do not donate blood or store their own blood prior to surgery. In May 2001, the Watch Tower Society revised its medical directives and identity cards addressing its doctrinal position on blood; the revised materials were distributed from May 3, 2001. These revised documents specified that "allogeneic blood transfusions" were unacceptable whereas