VWF and von Willebrand disease (hereditary or acquired): Plasma from a type 2B VWD patient who carried a mutant VWF (p.V1316M) gene was mixed 9:1 (v/v) with citrated PRP from healthy donors to a platelet count of 20 k μl−1 before undergoing uniform shear of 13 and 18 dyn cm−2.