Identification of a missense mutation (p.Leu1733Pro) in the A3 domain of von Willebrand factor in a family with type 2M von Willebrand disease

2019 ◽  
Vol 111 (3) ◽  
pp. 467-470
Author(s):  
Toshio Shigekiyo ◽  
Hikaru Yagi ◽  
Etsuko Sekimoto ◽  
Hironobu Shibata ◽  
Shuji Ozaki ◽  
...  
Keyword(s):  
Missense Mutation ◽  
Von Willebrand Factor ◽  
Von Willebrand Disease ◽  
Von Willebrand ◽  
Willebrand Factor

Identification of a New Type 2M von Willebrand Disease Mutation also at Position 1324 of von Willebrand Factor

2002 ◽  
Vol 87 (04) ◽  
pp. 635-640 ◽  
Author(s):  
E. Fressinaud ◽  
A. S. Ribba ◽  
D. Meyer ◽  
C. Mazurier ◽  
L. Hilbert ◽  
...  
Keyword(s):  
Missense Mutation ◽  
Von Willebrand Factor ◽  
Stop Codon ◽  
Von Willebrand Disease ◽  
Platelet Glycoprotein ◽  
Patient Reported ◽  
French Family ◽  
New Type ◽  
Von Willebrand ◽  
Willebrand Factor

SummaryType 2M von Willebrand disease (VWD) refers to variants with decreased platelet-dependent function that is not associated with the loss of high molecular weight (HMW) von Willebrand factor (VWF) multimers. This category includes the so-called “phenotype B” responsible for inexistent ristocetin-induced but normal botrocetin-induced binding of VWF to platelet glycoprotein Ib. The missense mutation G1324S was identified in the first patient reported to display “phenotype B”.We report here on the identification in four members of a French family of a missense mutation also affecting this glycine residue but changing it into an alanine residue. These individuals are heterozygous for this mutation and two of them display an additional quantitative VWF deficiency resulting from a stop codon at position 2470. After transient transfection in Cos-7 cells, the mutated recombinant protein harbouring the G1324A substitution was shown to exhibit normal multimers and inexistent ristocetin-induced but normal botrocetininduced binding to GPIb, confirming the classification of this new mutation as a type 2M VWD mutation.

scholarly journals Type 2M von Willebrand Disease: F606I and I662F Mutations in the Glycoprotein Ib Binding Domain Selectively Impair Ristocetin- but not Botrocetin-Mediated Binding of von Willebrand Factor to Platelets

Blood ◽  
1998 ◽  
Vol 91 (5) ◽  
pp. 1572-1581 ◽  
Author(s):  
Cheryl A. Hillery ◽  
David J. Mancuso ◽  
J. Evan Sadler ◽  
Jay W. Ponder ◽  
Mary A. Jozwiak ◽  
...  
Keyword(s):  
Amino Acid ◽  
Missense Mutation ◽  
Von Willebrand Factor ◽  
Amino Acid Substitution ◽  
Von Willebrand Disease ◽  
Glycoprotein Ib ◽  
Collagen Binding ◽  
Platelet Binding ◽  
Von Willebrand ◽  
Willebrand Factor

Abstractvon Willebrand disease (vWD) is a common, autosomally inherited, bleeding disorder caused by quantitative and/or qualitative deficiency of von Willebrand factor (vWF). We describe two families with a variant form of vWD where affected members of both families have borderline or low vWF antigen levels, normal vWF multimer patterns, disproportionately low ristocetin cofactor activity, and significant bleeding symptoms. Whereas ristocetin-induced binding of plasma vWF from affected members of both families to fixed platelets was reduced, botrocetin-induced platelet binding was normal. The sequencing of genomic DNA identified unique missense mutations in each family in the vWF exon 28. In Family A, a missense mutation at nucleotide 4105T → A resulted in a Phe606Ile amino acid substitution (F606I) and in Family B, a missense mutation at nucleotide 4273A → T resulted in an Ile662Phe amino acid substitution (I662F). Both mutations are within the large disulfide loop between Cys509 and Cys695 in the A1 domain that mediates vWF interaction with platelet glycoprotein Ib. Expression of recombinant vWF containing either F606I or I662F mutations resulted in mutant recombinant vWF with decreased ristocetin-induced platelet binding, but normal multimer structure, botrocetin-induced platelet binding, collagen binding, and binding to the conformation-sensitive monoclonal antibody, AvW-3. Both mutations are phenotypically distinct from the previously reported variant type 2MMilwaukee-1 because of the presence of normal botrocetin-induced platelet binding, collagen binding, and AvW-3 binding, as well as the greater frequency and intensity of clinical bleeding. When the reported type 2M mutations are mapped on the predicted three-dimensional structure of the A1 loop of vWF, the mutations cluster in one region that is distinct from the region in which the type 2B mutations cluster.

scholarly journals Type 2M von Willebrand Disease: F606I and I662F Mutations in the Glycoprotein Ib Binding Domain Selectively Impair Ristocetin- but not Botrocetin-Mediated Binding of von Willebrand Factor to Platelets

Blood ◽  
1998 ◽  
Vol 91 (5) ◽  
pp. 1572-1581 ◽  
Author(s):  
Cheryl A. Hillery ◽  
David J. Mancuso ◽  
J. Evan Sadler ◽  
Jay W. Ponder ◽  
Mary A. Jozwiak ◽  
...  
Keyword(s):  
Amino Acid ◽  
Missense Mutation ◽  
Von Willebrand Factor ◽  
Amino Acid Substitution ◽  
Von Willebrand Disease ◽  
Glycoprotein Ib ◽  
Collagen Binding ◽  
Platelet Binding ◽  
Von Willebrand ◽  
Willebrand Factor

von Willebrand disease (vWD) is a common, autosomally inherited, bleeding disorder caused by quantitative and/or qualitative deficiency of von Willebrand factor (vWF). We describe two families with a variant form of vWD where affected members of both families have borderline or low vWF antigen levels, normal vWF multimer patterns, disproportionately low ristocetin cofactor activity, and significant bleeding symptoms. Whereas ristocetin-induced binding of plasma vWF from affected members of both families to fixed platelets was reduced, botrocetin-induced platelet binding was normal. The sequencing of genomic DNA identified unique missense mutations in each family in the vWF exon 28. In Family A, a missense mutation at nucleotide 4105T → A resulted in a Phe606Ile amino acid substitution (F606I) and in Family B, a missense mutation at nucleotide 4273A → T resulted in an Ile662Phe amino acid substitution (I662F). Both mutations are within the large disulfide loop between Cys509 and Cys695 in the A1 domain that mediates vWF interaction with platelet glycoprotein Ib. Expression of recombinant vWF containing either F606I or I662F mutations resulted in mutant recombinant vWF with decreased ristocetin-induced platelet binding, but normal multimer structure, botrocetin-induced platelet binding, collagen binding, and binding to the conformation-sensitive monoclonal antibody, AvW-3. Both mutations are phenotypically distinct from the previously reported variant type 2MMilwaukee-1 because of the presence of normal botrocetin-induced platelet binding, collagen binding, and AvW-3 binding, as well as the greater frequency and intensity of clinical bleeding. When the reported type 2M mutations are mapped on the predicted three-dimensional structure of the A1 loop of vWF, the mutations cluster in one region that is distinct from the region in which the type 2B mutations cluster.

Identifying Carriers of Type 2N von Willebrand Disease

2007 ◽  
Vol 13 (2) ◽  
pp. 194-200 ◽  
Author(s):  
A. Casonato ◽  
E. Pontara ◽  
F. Sartorello ◽  
M.G. Cattini ◽  
P. Perutelli ◽  
...  
Keyword(s):  
Missense Mutation ◽  
Von Willebrand Factor ◽  
Hemophilia A ◽  
Von Willebrand Disease ◽  
Retrospective Evaluation ◽  
Laboratory Parameters ◽  
Diagnostic Capacity ◽  
Von Willebrand ◽  
Willebrand Factor

The defective FVIII carrier function of von Willebrand factor (VWF) identifies type 2N von Willebrand disease (VWD), a variant with a pattern resembling hemophilia A. Type 2N characterization is based on the evaluation of the capacity of VWF to bind exogenous FVIII (VWF:FVIIIB). Here we report on a retrospective evaluation of hemostatic laboratory parameters most useful in detecting type 2N carriers. The diagnostic capacity of aPTT, FVIII, VWF:Ag, FVIII/VWF:Ag ratio, VWF:FVIIIB and VWF:FVIIIB/VWF:Ag ratio was evaluated in 21 type 2N VWD carriers. Twenty subjects were heterozygous for the R854Q mutation, one was heterozygous for the R760C missense mutation, which interferes with cleavage of the VWF propeptide. We found that prolongation of aPTT and decrease in FVIII and FVIII/VWF:Ag ratio were not frequent findings in type 2N carriers. The same was true for VWF:FVIIIB which was not always abnormal. On the contrary, VWF:FVIIIB/VWF:Ag ratio was always defective and its values were not related with FVIII and FVIII/VWF:Ag ratio or influenced by plasma VWF concentration. Given these results, we attribute the greatest significance to VWF:FVIIIB/VWF:Ag ratio in the diagnosis of type 2N defects, and only search for type 2N mutations, to validate the diagnosis, if the ratio proves abnormal.

The Interaction of Botrocetin with Normal or Variant von Willebrand Factor (Types IIA and IIB) and Its Inhibition by Monoclonal Antibodies that Block Receptor Binding

1992 ◽  
Vol 68 (04) ◽  
pp. 464-469 ◽  
Author(s):  
Y Fujimura ◽  
S Miyata ◽  
S Nishida ◽  
S Miura ◽  
M Kaneda ◽  
...  
Keyword(s):  
Monoclonal Antibodies ◽  
Von Willebrand Factor ◽  
Binding Activity ◽  
Von Willebrand Disease ◽  
Platelet Glycoprotein ◽  
Normal Individuals ◽  
Rag 1 ◽  
The One ◽  
Von Willebrand ◽  
Willebrand Factor

SummaryWe have recently shown the existence of two distinct forms of botrocetin (one-chain and two-chain), and demonstrated that the two-chain species is approximately 30 times more active than the one-chain in promoting von Willebrand factor (vWF) binding to platelet glycoprotein (GP) Ib. The N-terminal sequence of two-chain botrocetin is highly homologous to sea-urchin Echinoidin and other Ca2+-dependent lectins (Fujimura et al., Biochemistry 1991; 30: 1957–64).Present data indicate that purified two-chain botrocetin binds to vWF from plasmas of patients with type IIA or IIB von Willebrand disease and its interaction is indistinguishable from that with vWF from normal individuals. However, an “activated complex” formed between botrocetin and IIB vWF expresses an enhanced biological activity for binding to GP Ib whereas the complex with IIA vWF has a decreased binding activity. Among several anti-vWF monoclonal antibodies (MoAbs) which inhibit ristocetin-induced platelet aggregation and/or vWF binding to GPIb, only two MoAbs (NMC-4 and RFF-VIII RAG:1) abolished direct binding between purified botrocetin and vWF. This suggests that they recognize an epitope(s) on the vWF molecule in close proximity to the botrocetin binding site.

The Genetic Defect of Type I von Willebrand Disease “Vicenza” Is Linked to the von Willebrand Factor Gene

1993 ◽  
Vol 69 (02) ◽  
pp. 173-176 ◽  
Author(s):  
Anna M Randi ◽  
Elisabetta Sacchi ◽  
Gian Carlo Castaman ◽  
Francesco Rodeghiero ◽  
Pier Mannuccio Mannucci
Keyword(s):  
Von Willebrand Factor ◽  
Autosomal Dominant ◽  
Genetic Defect ◽  
Von Willebrand Disease ◽  
Type I ◽  
Bleeding Tendency ◽  
Factor Gene ◽  
Low Levels ◽  
Von Willebrand ◽  
Willebrand Factor

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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