Significant linkage and non-linkage of type 1 von Willebrand disease to the von Willebrand factor gene

SummaryType I von Willebrand disease (vWD) Vicenza is a rare variant with autosomal dominant transmission, characterized by the presence of supranormal von Willebrand factor (vWF) multimers in plasma, similar to those normally found in endothelial cells and megakaryocytes. The patients have very low levels of plasma vWF contrasting with a mild bleeding tendency. The pathophysiology of this subtype is still unknown. The presence of supranormal multimers in the patients’ plasma could be due to a mutation in the vWF molecule which affects post-translational processing, or to a defect in the cells’ processing machinery, independent of the vWF molecule. In order to determne if type I vWD Vicenza is linked to the vWF gene, we studied six polymorphic systems identified within the vWF gene in two apparently unrelated families with type I vWD Vicenza. The results of this study indicate a linkage between vWF gene and the type I vWD Vicenza trait. This strongly suggests that type I vWD Vicenza is due to a mutation in one of the vWF alleles, which results in an abnormal vWF molecule that is processed to a lesser extent than normal vWF.

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Characterization of Partial Gene Deletions in Type III von Willebrand Disease with Alloantibody Inhibitors

Thrombosis and Haemostasis ◽

10.1055/s-0038-1648835 ◽

1994 ◽

Vol 72 (02) ◽

pp. 180-185 ◽

Cited By ~ 22

Author(s):

David J Mancuso ◽

Elodee A Tuley ◽

Ricardo Castillo ◽

Norma de Bosch ◽

Pler M Mannucci ◽

...

Keyword(s):

Von Willebrand Factor ◽

Von Willebrand Disease ◽

Pcr Analysis ◽

Gene Deletions ◽

Factor Gene ◽

Type Iii ◽

Large Deletions ◽

Von Willebrand ◽

Willebrand Factor

Summaryvon Willebrand factor gene deletions were characterized in four patients with severe type III von Willebrand disease and alloantibodies to von Willebrand factor. A PCR-based strategy was used to characterize the boundaries of the deletions. Identical 30 kb von Willebrand factor gene deletions which include exons 33 through 38 were identified in two siblings of one family by this method. A small 5 base pair insertion (CCTGG) was sequenced at the deletion breakpoint. PCR analysis was used to detect the deletion in three generations of the family, including two family members who are heterozygous for the deletion. In a second family, two type III vWD patients, who are distant cousins, share an -56 kb deletion of exons 22 through 43. The identification and characterization of large vWF gene deletions in these type III vWD patients provides further support for the association between large deletions in both von Willebrand factor alleles and the development of inhibitory alloantibodies.

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Toward Personalized Treatment for Patients with Low von Willebrand Factor and Quantitative von Willebrand Disease

Seminars in Thrombosis and Hemostasis ◽

10.1055/s-0041-1722864 ◽

2021 ◽

Vol 47 (02) ◽

pp. 192-200

Author(s):

James S. O'Donnell

Keyword(s):

Von Willebrand Factor ◽

Bleeding Risk ◽

Von Willebrand Disease ◽

Personalized Treatment ◽

Treatment Plans ◽

Type 3 ◽

Von Willebrand ◽

Willebrand Factor

AbstractThe biological mechanisms involved in the pathogenesis of type 2 and type 3 von Willebrand disease (VWD) have been studied extensively. In contrast, although accounting for the majority of VWD cases, the pathobiology underlying partial quantitative VWD has remained somewhat elusive. However, important insights have been attained following several recent cohort studies that have investigated mechanisms in patients with type 1 VWD and low von Willebrand factor (VWF), respectively. These studies have demonstrated that reduced plasma VWF levels may result from either (1) decreased VWF biosynthesis and/or secretion in endothelial cells and (2) pathological increased VWF clearance. In addition, it has become clear that some patients with only mild to moderate reductions in plasma VWF levels in the 30 to 50 IU/dL range may have significant bleeding phenotypes. Importantly in these low VWF patients, bleeding risk fails to correlate with plasma VWF levels and inheritance is typically independent of the VWF gene. Although plasma VWF levels may increase to > 50 IU/dL with progressive aging or pregnancy in these subjects, emerging data suggest that this apparent normalization in VWF levels does not necessarily equate to a complete correction in bleeding phenotype in patients with partial quantitative VWD. In this review, these recent advances in our understanding of quantitative VWD pathogenesis are discussed. Furthermore, the translational implications of these emerging findings are considered, particularly with respect to designing personalized treatment plans for VWD patients undergoing elective procedures.

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