Variant p.Tyr1584Cys: a frequent von Willebrand factor variant in search of von Willebrand disease

Figures

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  Figure 1. Underlying mechanisms of the variant p.Tyr1584Cys. Patients with p.Tyr1584Cys showed a higher median of factor (F)VIII procoagulant activity/von Willebrand factor (VWF) antigen (FVIII:C/VWF:Ag) ratio (A) and a lower median of VWF propeptide (pp) antigen (VWFpp) (B) in comparison with controls, suggesting defective VWF synthesis/secretion. In addition, the median VWFpp/VWF:Ag ratio was higher in patients than in controls, indicating an enhanced clearance of VWF (C).

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  Figure 2. The multimer pattern (densitometric analysis) for patients with the variant p.Tyr1584Cys. Densitometric representation of peaks from left to right, with peaks 1 to 3 being low molecular weight multimers (LMWM), peaks 4 to 7 being intermediate molecular weight multimers (IMWM), and all other peaks representing high molecular weight multimers (HMWM). Overall, cases with p.Tyr1584Cys showed a lower ratio of HMWM/LMWM compared with that of pooled plasma (2.17 vs 3.93), suggesting a slight quantitative reduction of HMWM. The last multimer densitometry is for a patient with type 2A von Willebrand disease phenotype who carries p.Tyr1584Cys/p.Arg1597Gln. Gray, pool of normal samples; pink, tested samples.