Characterisation of Type 2N von Willebrand Disease Using Phenotypic and Molecular Techniques

1996 ◽  
Vol 75 (06) ◽  
pp. 959-964 ◽  
Author(s):  
I M Nesbitt ◽  
A C Goodeve ◽  
A M Guilliatt ◽  
M Makris ◽  
F E Preston ◽  
...  
Keyword(s):  
Direct Sequencing ◽  
Von Willebrand Disease ◽  
Molecular Techniques ◽  
Haemophilia A ◽  
Binding Region ◽  
Gene Encoding ◽  
Covalently Linked ◽  
Von Willebrand ◽  
Willebrand Factor

Summaryvon Willebrand factor (vWF) is a multimeric glycoprotein found in plasma non covalently linked to factor VIII (FVIII). Type 2N von Willebrand disease (vWD) is caused by a mutation in the vWF gene that results in vWF with a normal multimeric pattern, but with reduced binding to FVIII.We have utilised methods for the phenotypic and genotypic detection of type 2N vWD. The binding of FVIII to vWF in 69 patients, 36 with type 1 vWD, 32 with mild haemophilia A and one possible haemophilia A carrier with low FVIII levels was studied. Of these, six were found to have reduced binding (five type 1 vWD, one possible haemophilia A carrier), DNA was extracted from these patients and exons 18-23 of the vWF gene encoding the FVIII binding region of vWF were analysed. After direct sequencing and chemical cleavage mismatch detection, a Thr28Met mutation was detected in two unrelated individuals, one of whom appears to be a compound heterozygote for the mutation and a null allele. No mutations were found in the region of the vWF gene encoding the FVIII binding region of vWF in the other four patients

Increased Von Willebrand Factor Antigen Clearance in Type 1 Von Willebrand Disease: Investigation of Relationship with ABO Blood Group and Tyr1584Cys Polymorphism.

Blood ◽  
2004 ◽  
Vol 104 (11) ◽  
pp. 256-256 ◽  
Author(s):  
Carolyn M. Millar ◽  
Anne F. Riddell ◽  
Peter V. Jenkins ◽  
Christine A. Lee ◽  
Simon A. Brown
Keyword(s):  
Blood Group ◽  
Von Willebrand Factor ◽  
Von Willebrand Disease ◽  
Abo Blood Group ◽  
Haemophilia A ◽  
Significant Difference ◽  
Von Willebrand ◽  
Willebrand Factor ◽  
Increased Susceptibility

Abstract Type 1 von Willebrand disease (VWD) is a heterogeneous bleeding disorder in which genetic modifying factors, including ABO blood group, contribute towards the variability in von Willebrand factor (VWF) levels. Recent findings have reported an increased incidence of the Tyr1584Cys polymorphism in the VWF-A2 domain of patients with type 1 VWD. Presence of Cys1584 has been shown to cause increased intracellular retention of VWF, as well as lead to increased susceptibility of VWF to proteolysis by the metalloprotease ADAMTS13. An increased susceptibility to proteolysis by ADAMTS13 has also been demonstrated in the VWF of blood group O individuals. We have investigated the relationship between increased VWF antigen (VWF:Ag) clearance, ABO blood group and the presence of the Tyr1584Cys polymorphism in a group of patients with type 1 VWD. The VWF:Ag half-life (VWF:Ag t1/2) was prospectively evaluated in 45 patients with type 1 VWD, which included three families of two or more first-degree relatives. Median VWF:Ag level was 36.0iu/dl (range 4–50iu/dl); median VWF ristocetin cofactor activity (VWF:RCo) level was 35.0iu/dl (range 3–52iu/dl) and VWF:RCo/VWF:Ag ratio 0.97 (range 0.70–1.37). A normal multimeric pattern was demonstrated in all patients. 25 (55.5%) and 20 (44.5%) of the patients were of blood groups O and A respectively. The control group comprised eight patients with haemophilia A. VWF:Ag levels were measured over a 6 hour period following the administration of intravenous DDAVP. VWF:Ag t1/2 was calculated using the formula: C(t)=C0e−k.t, where C(t)=plasma [VWF:Ag] as a function of time; C0=[VWF:Ag] at time zero; e=base for natural logarithms; k=first order rate constant for the elimination phase (ß phase); t=time. The median value of the VWF:Ag t1/2 in the VWD group was 4.1 hours (95% C.I. 3.2–4.9h) and in the haemophilia A group 9.5 hours (95% C.I. 5.3–19h). This represents a significant difference in VWF:Ag t1/2 between the two groups (p<0.05). However, within the VWD patient group, there was no significant difference between the median VWF:Ag t1/2 values of patients of blood group O and those of blood group A (p>0.05). Within the three families, two affected family members of the same ABO blood group were studied and a concordant reduction in the VWF:Ag t1/2s was found in these subjects. To date, 24 of the VWD patients have been genotyped for the A/G polymorphism at nucleotide 24/1282 in the VWF gene, encoding a Tyr1584Cys polymorphism. The heterozygous presence of the G allele encoding Cys 1282 was demonstrated in one patient. The frequency of this polymorphism in normal and type 1 VWD individuals has been reported to be ~1% and 14% respectively. The median VWF:Ag t1/2 value of the 23 homozygous Tyr1584 patients was 3.4 hours (95% C.I. 3.2–4.8h), representative of the whole VWD group. The VWF:Ag t1/2 in the heterozygous patient was 4.8 hours. The finding of increased plasma VWF:Ag clearance as reflected by a reduction in VWF:Ag half-life in a significant number of patients with type 1 VWD, suggests that increased VWF:Ag clearance may be a contributory factor in the aetiology of type 1 VWD. However, this study suggests there is no relationship between increased VWF:Ag clearance and ABO blood group. Furthermore, the Tyr1584Cys polymorphism is not a major determinant of VWF:Ag clearance within this group of type 1 VWD patients.

scholarly journals Dominant type 1 von Willebrand disease caused by mutated cysteine residues in the D3 domain of von Willebrand factor

Blood ◽  
1996 ◽  
Vol 88 (7) ◽  
pp. 2433-2441 ◽  
Author(s):  
JC Eikenboom ◽  
T Matsushita ◽  
PH Reitsma ◽  
EA Tuley ◽  
G Castaman ◽  
...  
Keyword(s):  
Von Willebrand Factor ◽  
Direct Sequencing ◽  
Von Willebrand Disease ◽  
Cysteine Residues ◽  
Dominant Type ◽  
Dominant Phenotype ◽  
Candidate Mutation ◽  
Von Willebrand ◽  
Willebrand Factor

No defects have been reported in moderately severe type 1 von Willebrand disease (vWD) with a clear autosomal dominant inheritance pattern, and the mechanism underlying this form of vWD remains obscure. We have studied a type 1 vWD family with such a dominant phenotype. The entire coding sequence of the von Willebrand factor (vWF) gene was analyzed by direct sequencing of DNA fragments amplified by polymerase chain reaction. Only one candidate mutation T(3445)--&gt;C in exon 26 was detected that predicts a replacement of cysteine (C) at position 386 of the mature vWF subunit by arginine (R). Both mutant and normal vWF alleles were expressed as shown by analysis of platelet mRNA. This substitution segregates with vWD in the family and was not found in 100 unrelated individuals. The recombinant mutant vWF(C386R) was characterized by expression in 293T cells. The secretion of vWF(C386R) was greatly impaired due to retention in the endoplasmic reticulum. In cotransfections of normal and mutant vWF constructs, the vWF(C386R) subunits caused a dose-dependent decrease in the secretion of vWF. The multimer pattern remained nearly normal and consistent with a dominant vWD type 1 phenotype. The importance of the cysteine residues in the D3 domain of vWF in the pathogenesis of dominant type 1 vWD was further shown by the detection of another cysteine mutation, Cys367--&gt;Phe, in two additional unrelated patients with a similar dominant type 1 vWD phenotype. We conclude that the loss of cysteine pairing in the D3 domain, leaving one free cysteine, can induce a purely quantitative deficiency of vWF by dominantly suppressing the secretion of normal vWF.

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

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.

Type 2N von Willebrand Disease: Rapid Genetic Diagnosis of G2811A (R854Q), C2696T (R816W), T2701A (H817Q) and G2823T (C858F) – Detection of a Novel Candidate Type 2N Mutation: C2810T (R854W)

1998 ◽  
Vol 80 (07) ◽  
pp. 32-36 ◽  
Author(s):  
G. R. Standen ◽  
C. Mazurier ◽  
C. Gaucher ◽  
A. Cumming ◽  
S. Keeney ◽  
...  
Keyword(s):  
Genetic Diagnosis ◽  
Von Willebrand Disease ◽  
Rapid Screening ◽  
Gene Encoding ◽  
Single Polymerase Chain Reaction ◽  
The Common ◽  
Polymerase Chain ◽  
Von Willebrand ◽  
Willebrand Factor ◽  
Heteroduplex Formation

SummaryThe majority of patients with type 2N von Willebrand disease (VWD type 2N) have mutations in the region of the von Willebrand factor (VWF) gene encoding the factor VIII binding domain of VWF. Two mutations predominate among VWD type 2N patients: G2811A and C2696T, which respectively bring about the amino acid substitutions R854Q and R816W in VWF. Several other mutations have been found in VWD type 2N, including T2701A (H817Q) and G2823T (C858F). We have developed a genetic test which permits rapid screening for these four mutations in a single polymerase chain reaction (PCR). The test employs induced heteroduplex formation using two universal heteroduplex generators, one of which detects G2811A (R854Q) and G2823T (C858F), the other detects C2696T (R816W) and T2701A (H817Q). The allele frequency of the common G2811A (R854Q) mutation was investigated in the local (S. Wales) population by examination of 216 VWF genes (108 individuals) and was found to be 0.01. The heteroduplex-based test additionally detected a novel candidate type 2N mutation, C2810T (R854W) and a previously described polymorphism, G2805A (R852Q). The polymorphism showed allele frequencies of 0.92 (G nucleotide) and 0.08 (A nucleotide) in the population study.

scholarly journals An apparently silent nucleotide substitution (c.7056C>T) in the von Willebrand factor gene is responsible for type 1 von Willebrand disease

Haematologica ◽  
2011 ◽  
Vol 96 (6) ◽  
pp. 881-887 ◽  
Author(s):  
V. Daidone ◽  
L. Gallinaro ◽  
M. Grazia Cattini ◽  
E. Pontara ◽  
A. Bertomoro ◽  
...  
Keyword(s):  
Von Willebrand Factor ◽  
Nucleotide Substitution ◽  
Von Willebrand Disease ◽  
Factor Gene ◽  
Von Willebrand ◽  
Willebrand Factor

scholarly journals Low VWF: insights into pathogenesis, diagnosis, and clinical management

2020 ◽  
Vol 4 (13) ◽  
pp. 3191-3199 ◽  
Author(s):  
James S. O’Donnell
Keyword(s):  
Clinical Management ◽  
Molecular Mechanisms ◽  
Optimal Choice ◽  
Von Willebrand Disease ◽  
Limited Information ◽  
Von Willebrand ◽  
The Relationship ◽  
Willebrand Factor ◽  
Choice Of Therapy

Abstract von Willebrand disease (VWD) constitutes the most common inherited human bleeding disorder. Partial quantitative von Willebrand factor (VWF) deficiency is responsible for the majority of VWD cases. International guidelines recommend that patients with mild to moderate reductions in plasma VWF antigen (VWF:Ag) levels (typically in the range of 30-50 IU/dL) should be diagnosed with low VWF. Over the past decade, a series of large cohort studies have provided significant insights into the biological mechanisms involved in type 1 VWD (plasma VWF:Ag levels &lt;30 IU/dL). In striking contrast, however, the pathogenesis underpinning low VWF has remained poorly understood. Consequently, low VWF patients continue to present significant clinical challenges with respect to genetic counseling, diagnosis, and management. For example, there is limited information regarding the relationship between plasma VWF:Ag levels and bleeding phenotype in subjects with low VWF. In addition, it is not clear whether patients with low VWF need treatment. For those patients with low VWF in whom treatment is deemed necessary, the optimal choice of therapy remains unknown. However, a number of recent studies have provided important novel insights into these clinical conundrums and the molecular mechanisms responsible for the reduced levels observed in low VWF patients. These emerging clinical and scientific findings are considered in this review, with particular focus on pathogenesis, diagnosis, and clinical management of low VWF.

Critical independent regions in the VWF propeptide and mature VWF that enable normal VWF storage

Blood ◽  
2003 ◽  
Vol 101 (4) ◽  
pp. 1384-1391 ◽  
Author(s):  
Sandra L. Haberichter ◽  
Paula Jacobi ◽  
Robert R. Montgomery
Keyword(s):  
Endothelial Cells ◽  
Species Differences ◽  
Intracellular Localization ◽  
Von Willebrand Disease ◽  
Healthy Individuals ◽  
Furin Cleavage ◽  
Storage Granules ◽  
Von Willebrand ◽  
Willebrand Factor

Von Willebrand factor (VWF) is synthesized in endothelial cells, where it is stored in Weibel-Palade bodies. Administration of 1-desamino-8-D-arginine-vasopressin (DDAVP) to patients with type 1 von Willebrand disease and to healthy individuals causes a rapid increase in plasma VWF levels. This increase is the result of stimulated release of VWF from Weibel-Palade bodies in certain beds of endothelial cells. The VWF propeptide (VWFpp) targets VWF to storage granules through a noncovalent association. The nature of the VWFpp/VWF interaction was investigated by using cross-species differences in VWF storage. While canine VWFpp traffics to storage granules and facilitates the multimerization of human VWF, it does not direct human VWF to storage granules. Since storage takes place after furin cleavage, this defect appears to be due to the defective interaction of canine VWFpp and human VWF. To determine the regions within VWFpp and VWF important for this VWFpp/VWF association and costorage, a series of human-canine chimeric VWFpp and propeptide-deleted VWF (Δpro) constructs were produced and expressed in AtT-20 cells. The intracellular localization of coexpressed proteins was examined by confocal microscopy. Two amino acids, 416 in VWFpp and 869 in the mature VWF molecule, were identified as being critical for the association and granular storage of VWF.

Genetic Background of von Willebrand Disease: History, Current State, and Future Perspectives

2019 ◽  
Vol 46 (04) ◽  
pp. 484-500 ◽  
Author(s):  
Jana Zolkova ◽  
Juraj Sokol ◽  
Tomas Simurda ◽  
Lubica Vadelova ◽  
Zuzana Snahnicanova ◽  
...  
Keyword(s):  
Genetic Background ◽  
Molecular Mechanisms ◽  
Diagnostic Algorithm ◽  
Coagulation Factors ◽  
Von Willebrand Disease ◽  
Molecular Testing ◽  
Gene Encoding ◽  
Gene Panels ◽  
Von Willebrand

AbstractSequencing of the gene encoding for von Willebrand factor (VWF) has brought new insight into the physiology of VWF as well as its pathophysiology in the context of von Willebrand disease (VWD). Molecular testing in VWD patients has shown high variability in the overall genetic background of this condition. Almost 600 mutations and many disease-causing mechanisms have been described in the 35 years since the VWF gene was identified. Genetic testing in VWD patients is now available in many centers as a part of the VWD diagnostic algorithm. Molecular mechanisms leading to types 2 and 3 VWD are well characterized; thus, information from genetic analysis in these VWD types may be beneficial for their correct classification. However, the molecular basis of type 1 VWD is still not fully elucidated and most likely represents a multifactorial disorder reflecting a combined impact of environmental and genetic factors within and outside of VWF. Regarding sequencing methods, the previous gold-standard Sanger sequencing is gradually being replaced with next-generation sequencing methods that are more cost- and time-effective. Instead of gene-by-gene approaches, gene panels of genes for coagulation factors and related proteins have recently become a center of attention in patients with inherited bleeding disorders, especially because a high proportion of VWD patients, mainly those with low VWF plasma levels (type 1), appear to be free of mutations in VWF. Whole-exome sequencing (WES) and whole-genome sequencing (WGS) are accessible in a very limited number of laboratories. Results from these studies have presented several genes other than VWF or ABO possibly affecting VWF levels, and such findings will need further validation studies.

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