Effect of D1472H polymorphism on VWF:RCo and VWF:IbCo ELISA assays. VWF:RCo/VWF:Ag and VWF:IbCo ELISA/VWF:Ag are shown for wild-type A1 domain subjects (●) compared with subjects with the D1472H polymorphism (○). The line indicates the mean for each assay.