Pseudohemophilia of Erik von Willebrand caused by homozygous one nucleotide deletion in exon 18 of the VW-factor gene

Figure 1 Pedigree of the original family S described by von Willebrand updated by Blombäck and Nilsson in the 1990s.

Figure 2 Results of molecular investigations in the original family S in the 1990s reveal a heterozygous nonsense mutation in seven affected members with mild bleeding diathesis[4].

Figure 3 State of the Art characterization of a family with autosomal recessive von Willebrand disease type 1 by Casonato and co-workers using a complete set of laboratory assays related to von Willebrand disease diagnosis, von Willebrand factor multimeric analysis in plasma and platelets and the response of FVIII, VWF: Ag and VWF: RCo to desmopressin acetate before and at several time points after desmopressin acetate according to standardized recommendations anno 2006. RIPA: Ristocetin induced platelet aggregation; VWF: von Willebrand factor; VWD: von Willebrand disease; DDAVP: Desmopressin acetate.

Figure 4 Good response of FVIII: C and restricted response of von Willebrand factor: RCo to desmopressin acetate (0. 3 ug/kg) in a carrier of a null allele (Q2470X/normal). VWF: von Willebrand factor; DDAVP: Desmopressin acetate.