Phenotypic and molecular characterisation of type 3 von Willebrand disease in a cohort of Indian patients

2013 ◽  
Vol 109 (04) ◽  
pp. 652-660 ◽  
Author(s):  
Ulrich Budde ◽  
Rifat Jan ◽  
Florian Oyen ◽  
Meganathan Kannan ◽  
Reinhard Schneppenheim ◽  
...  

SummarySevere type 3 VWD (VWD3) is characterised by complete absence or presence of trace amounts of non-functional von Willebrand factor (VWF). The study was designed to evaluate the VWF mutations in VWD3 patients and characterise the breakpoints of two identified homozygous novel large deletions. Patients were diagnosed by conventional tests and VWF multimer analysis. Mutation screening was performed in 19 VWD3 patients by direct sequencing of VWF including flanking intronic sequence and multiplex ligation-dependent probe amplification (MLPA) analysis. Breakpoint characterisation of two identified novel large deletions was done using walking primers and long spanning PCR. A total of 21 different mutations including 15 (71.4%) novel ones were identified in 17 (89.5%) patients. Of these mutations, five (23.8%) were nonsense (p.R1659*, p.R1779*, p.R1853*, p.Q2470*, p.Q2520*), one was a putative splice site (p.M814I) and seven (33.3%) were deletions (p.L254fs*48, p.C849fs*60, p.L1871fs*6, p.E2720fs*24) including three novel large deletions of exon 14–15, 80,830bp (−41510_657+7928A*del) and 2,231bp [1534–2072T_c.1692G*del(p.512fs*terminus)] respectively. A patient carried gene conversion comprising of pseudogene harbouring mutations. The missense mutations (p.G19R, p.K355R, p.D437Y, p.C633R, p.M771V, p.G2044D, p.C2491R) appear to play a major role and were identified in seven (36.8%) patients. In conclusion, a high frequency of novel mutations suggests the high propensity of VWF for new mutations. Missense and deletion mutations found to be a common cause of VWD3 in cohort of Indian VWD3 patients. Breakpoints characterisation of two large deletions reveals the double strand break and non-homologous recombination as deletions mechanism.

2012 ◽  
Vol 108 (10) ◽  
pp. 662-671 ◽  
Author(s):  
Hamideh Yadegari ◽  
Julia Driesen ◽  
Anna Pavlova ◽  
Arijit Biswas ◽  
Hans-Jörg Hertfelder ◽  
...  

SummaryVon Willebrand disease (VWD) is the most common inherited bleeding disorder caused by quantitative or qualitative defects of the von Willebrand factor (VWF). VWD is classified into three types – type 1 (partial quantitative deficiencies), type 2 (qualitative defects) and type 3 (complete deficiency of VWF). In this study we explored genotype and phenotype characteristics of patients with VWD with the aim of dissecting the distribution of mutations in different types of VWD. One hundred fourteen patients belonging to 78 families diagnosed to have VWD were studied. Mutation analysis was performed by direct sequencing of the VWF. Large deletions were investigated by multiplex ligation-dependent probe amplification (MLPA) analysis. The impact of novel candidate missense mutations and potential splice site mutations was predicted by in silico assessments. We identified mutations in 66 index patients (IPs) (84.6%). Mutation detection rate was 68%, 94% and 94% for VWD type 1, 2 and 3, respectively. In total, 68 different putative mutations were detected comprising 37 missense mutations (54.4%), 10 small deletions (14.7%), two small insertions (2.9%), seven nonsense mutations (10.3%), five splice-site mutations (7.4%), six large deletions (8.8%) and one silent mutation (1.5%). Twenty-six of these mutations were novel. Furthermore, in type 1 and type 2 VWD, the majority of identified mutations (74% vs. 88.1%) were missense substitutions while mutations in type 3 VWD mostly caused null alleles (82%). Genotyping in VWD is a helpful tool to further elucidate the pathogenesis of VWD and to establish the relationship between genotype and phenotype.


Blood ◽  
2009 ◽  
Vol 114 (22) ◽  
pp. 3498-3498
Author(s):  
Maria Solimando ◽  
Augusto B. Federici ◽  
Luciano Baronciani ◽  
Alberto Mussetti ◽  
Margherita Punzo ◽  
...  

Abstract Abstract 3498 Poster Board III-435 Introduction Type 3 von Willebrand disease (VWD3) is a severe autosomal recessive inherited bleeding disorder caused by a virtually complete absence of von Willebrand Factor (VWF). Classically, patients are homozygous or compound heterozygous for null alleles due to nonsense mutations, small insertions/deletions, splice site defects or, more rarely, large gene deletions spread throughout the VWF gene. Nevertheless, several missense mutations have also been reported. Aims of the study, patients and methods The aim of this study was to investigate the molecular basis of VWD3 in 10 Italian patients using DNA direct sequencing, High Resolution Melting (HRM) analysis and duplex PCR. HRM is a simple, low-cost, and rapid PCR-based method for detecting sequence variation by measuring changes in the melting temperature of double stranded DNA. Duplex PCR was used to screen for the presence of some known large deletions causing VWD3: the 61-kb deletion encompassing exons 6-16 (Xie et al. Blood Cells Mol Dis. 2006; 36: 385), the 253-kb deletion involving the whole VWF gene (Schneppenheim et al. J Thromb Haemost. 2007; 5: 722), the exons 1-3 deletion (Mohl et al. J Thromb Haemost. 2008; 6: 1729), and the exons 4-5 deletion (Sutherland et al. Blood. 2009; 114: 1091). Results and discussion Twenty-four exons were analyzed by direct sequencing, 21 exons by HRM and, so far, 6 exons using both methods. The following mutations were identified in 8 of the 10 patients investigated: 2157delA/7729+7C>T; C2184S*/undetermined; Q1526X*/C2325S*; del ex1-3/3940delG*; 8155+1G>T*/8155+1G>T*; E1549X*/undetermined; 658-2A>G*/658-2A>G*; del ex 1-3/undetermined. Direct sequencing revealed 7 mutations, HRM analysis could detect 2 defects (2157delA, C2325S) and duplex PCR identified one large deletion. Seven of these 11 mutations were novel (indicated with *). Two patients were found to carry mutations in the homozygous state. To confirm these findings, their parents will have to be investigated in order to exclude the presence of a large gene deletion in one of the alleles. Interestingly, the large deletion involving exons 1-3, which was previously reported in the Hungarian population, was also found in 2 unrelated patients. Two missense mutations were identified, both involving a cysteine residue, further suggesting the importance of these residues in the correct folding/processing/secretion of the neo-synthesized VWF. In those patients who still remain uncharacterized further analysis should be performed to search for intronic mutations or heterozygous large deletions responsible for aberrant splicing/post-transcriptional events. Conclusion Based on these preliminary data, HRM analysis, to our knowledge used for the first time in the molecular diagnosis of VWD3, in our hands seems to be an accurate and rapid method for mutational screening of VWF gene. However, so far, the presence of many polymorphic sites in the VWF coding region has strongly limited the use of this technique to 21 exons of the gene. Disclosures: Baronciani: Bayer Awards: Research Funding.


2000 ◽  
Vol 84 (10) ◽  
pp. 536-540 ◽  
Author(s):  
Giovanna Cozzi ◽  
Maria Canciani ◽  
Flora Peyvandi ◽  
Alok Srivastava ◽  
Augusto Federici ◽  
...  

SummaryType 3 von Willebrand disease is a rare autosomal disorder characterized by unmeasurable levels of von Willebrand factor and severe hemorrhagic symptoms. We studied a multiethnic group of 37 patients, from Italy (n = 14), Iran (n = 10) and India (n = 13) to identify the molecular defects and to evaluate genetic heterogeneity among these populations. Twenty-one patients (6 Italians, 9 Iranians and 6 Indians) were fully characterized at the molecular level. Twenty-four different gene alterations were identified, 20 of which have not been described previously. The majority of the mutations caused null alleles, 11 being nonsense mutations (Q218*, W222*, R365*, R373*, E644*, Q706*, S1338*, Q1346*, Y1542*, R1659*, E2129*), 4 small deletions (437delG, 2680delC, 6431delT, del 8491-8499), 3 possible splice site mutations [IVS9(-1)g→a, IVS29(+10)c→t, IVS40(-1)g → c], 3 candidate missense mutations (C275S, C2174G, C2804Y), 2 small insertions (7375insC, 7921insC) and 1 large gene deletion. The latter mutation was associated with the development of alloantibodies to VWF, but this complication was also found in a patient homozygous for a nonsense mutation (Q1346*). Due to the ethnic origin of the patients most of them were the offspring of consanguineous marriages and so were homozygous for the mutations found (18/21). Our results indicate that molecular defects responsible for type 3 VWD are scattered throughout the entire VWF gene (from exon 3 to 52), and that there is no prevalent and common gene defect in the three populations studied by us.


1998 ◽  
Vol 79 (01) ◽  
pp. 211-216 ◽  
Author(s):  
Lysiane Hilbert ◽  
Claudine Mazurier ◽  
Christophe de Romeuf

SummaryType 2B of von Willebrand disease (vWD) refers to qualitative variants with increased affinity of von Willebrand factor (vWF) for platelet glycoprotein Ib (GPIb). All the mutations responsible for type 2B vWD have been located in the A1 domain of vWF. In this study, various recombinant von Willebrand factors (rvWF) reproducing four type 2B vWD missense mutations were compared to wild-type rvWF (WT-rvWF) for their spontaneous binding to platelets and their capacity to induce platelet activation and aggregation. Our data show that the multimeric pattern of each mutated rvWF is similar to that of WT-rvWF but the extent of spontaneous binding and the capacity to induce platelet activation and aggregation are more important for the R543Q and V553M mutations than for the L697V and A698V mutations. Both the binding of mutated rvWFs to platelets and platelet aggregation induced by type 2B rvWFs are inhibited by monoclonal anti-GPIb and anti-vWF antibodies, inhibitors of vWF binding to platelets in the presence of ristocetin, as well as by aurin tricarboxylic acid. On the other hand, EDTA and a monoclonal antibody directed against GPIIb/IIIa only inhibit platelet aggregation. Furthermore, the incubation of type 2B rvWFs with platelets, under stirring conditions, results in the decrease in high molecular weight vWF multimers in solution, the extent of which appears correlated with that of plasma vWF from type 2B vWD patients harboring the corresponding missense mutation. This study supports that the binding of different mutated type 2B vWFs onto platelet GPIb induces various degrees of platelet activation and aggregation and thus suggests that the phenotypic heterogeneity of type 2B vWD may be related to the nature and/or location of the causative point mutation.


1996 ◽  
Vol 76 (02) ◽  
pp. 253-257 ◽  
Author(s):  
Takeshi Hagiwara ◽  
Hiroshi Inaba ◽  
Shinichi Yoshida ◽  
Keiko Nagaizumi ◽  
Morio Arai ◽  
...  

SummaryGenetic materials from 16 unrelated Japanese patients with von Willebrand disease (vWD) were analyzed for mutations. Exon 28 of the von Willebrand factor (vWF) gene, where point mutations have been found most frequent, was screened by various restriction-enzyme analyses. Six patients were observed to have abnormal restriction patterns. By sequence analyses of the polymerase chain-reaction products, we identified a homozygous R1308C missense mutation in a patient with type 2B vWD; R1597W, R1597Q, G1609R and G1672R missense mutations in five patients with type 2A; and a G1659ter nonsense mutation in a patient with type 3 vWD. The G1672R was a novel missense mutation of the carboxyl-terminal end of the A2 domain. In addition, we detected an A/C polymorphism at nucleotide 4915 with HaeIII. There was no particular linkage disequilibrium of the A/C polymorphism, either with the G/A polymorphism at nucleotide 4391 detected with Hphl or with the C/T at 4891 detected with BstEll.


1994 ◽  
Vol 72 (02) ◽  
pp. 180-185 ◽  
Author(s):  
David J Mancuso ◽  
Elodee A Tuley ◽  
Ricardo Castillo ◽  
Norma de Bosch ◽  
Pler M Mannucci ◽  
...  

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.


1996 ◽  
Vol 75 (06) ◽  
pp. 959-964 ◽  
Author(s):  
I M Nesbitt ◽  
A C Goodeve ◽  
A M Guilliatt ◽  
M Makris ◽  
F E Preston ◽  
...  

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


2021 ◽  
Vol 47 (02) ◽  
pp. 192-200
Author(s):  
James S. O'Donnell

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.


2021 ◽  
Author(s):  
Andrew Yee ◽  
Manhong Dai ◽  
Stacy E. Croteau ◽  
Jordan A. Shavit ◽  
Steven W. Pipe ◽  
...  

SummaryBackgroundCorrection of von Willebrand factor (VWF) deficiency with replacement products containing VWF can lead to the development of anti-VWF alloantibodies (i.e., VWF inhibitors) in patients with severe von Willebrand disease (VWD).ObjectiveLocate inhibitor-reactive regions within VWF using phage display.MethodsWe screened a phage library displaying random, overlapping fragments covering the full length VWF protein sequence for binding to a commercial anti-VWF antibody or to immunoglobulins from three type 3 VWD patients who developed VWF inhibitors in response to treatment with plasma-derived VWF. Immunoreactive phage clones were identified and quantified by next generation DNA sequencing (NGS).ResultsNGS markedly increased the number of phage analyzed for locating immunoreactive regions within VWF following a single round of selection and identified regions not recognized in previous reports using standard phage display methods. Extending this approach to characterize VWF inhibitors from three type 3 VWD patients (including two siblings homozygous for the same VWF gene deletion) revealed patterns of immunoreactivity distinct from the commercial antibody and between unrelated patients, though with notable areas of overlap. Alloantibody reactivity against the VWF propeptide is consistent with incomplete removal of the propeptide from plasma-derived VWF replacement products.ConclusionThese results demonstrate the utility of phage display and NGS to characterize diverse anti-VWF antibody reactivities.


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