The molecular defect in type IIB von Willebrand disease. Identification of four potential missense mutations within the putative GPIb binding domain - Cooney, K A; Nichols, W C; Bruck, M E; Bahou, W F; Shapiro, A D; Bowie, E JW; Gralnick, H R; Ginsburg, D (J Clin Invest, 1991)