The Use of High Resolution Melting (HRM) Analysis for Molecular Gene Defects of Type 3 Von Willebrand Disease: Studies of An Italian Cohort of 10 Patients.

Blood ◽  
2009 ◽  
Vol 114 (22) ◽  
pp. 3498-3498
Author(s):  
Maria Solimando ◽  
Augusto B. Federici ◽  
Luciano Baronciani ◽  
Alberto Mussetti ◽  
Margherita Punzo ◽  
...  
Keyword(s):  
Direct Sequencing ◽  
Large Deletion ◽  
Von Willebrand Disease ◽  
Missense Mutations ◽  
Duplex Pcr ◽  
Hrm Analysis ◽  
Large Deletions ◽  
Large Gene ◽  
Type 3 ◽  
Von Willebrand

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.

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 ◽  
...  
Keyword(s):  
Direct Sequencing ◽  
Mutation Screening ◽  
Strand Break ◽  
Von Willebrand Disease ◽  
Missense Mutations ◽  
Large Deletions ◽  
High Propensity ◽  
Type 3 ◽  
Von Willebrand ◽  
Willebrand Factor

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.

Novel Large Deletion Is the Most Frequent Cause of Type 3 von Willebrand Disease in Hungary.

Blood ◽  
2006 ◽  
Vol 108 (11) ◽  
pp. 1013-1013
Author(s):  
Adrien Mohl ◽  
Tamás Masszi ◽  
Eszter Nagy ◽  
Tobias Obser ◽  
Florian Oyen ◽  
...  
Keyword(s):  
Direct Sequencing ◽  
Large Deletion ◽  
Severe Form ◽  
Von Willebrand Disease ◽  
Rational Approach ◽  
Molecular Testing ◽  
Spontaneous Bleeding ◽  
Virtual Absence ◽  
Type 3 ◽  
Von Willebrand

Abstract Background: Type 3 is the most severe form of von Willebrand disease (VWD) caused by the virtual absence of von Willebrand factor (VWF) in affected patients. The prevalence of type 3 VWD in Hungary is 2.6 per million. Capitalizing on a nationwide National Bleeding Disorder Registry, we designed a study to characterize the genetic background of the entire Hungarian type 3 VWD population. The current report focuses on the molecular characterization of a novel large deletion. Methods: 24 patients from 23 unrelated families were studied by direct sequencing of the 52 exons of the VWF gene. The breakpoints of a large deletion were characterized by standard gene mapping. Breakpoint-specific PCR was used to confirm the presence of the deletion, and to screen for identical deletions in other populations from Germany, Russia, and Poland. Results: A large partial deletion (delExon1-3) of the 5′-region of the VWF gene was detected in 10 alleles (19 percent of all type 3 mutations). Five patients from 4 unrelated families were homozygous, and 2 patients were heterozygous for the deletion. Consanguinity was known in one of the families. In comparison, 2435 delC in exon 18, a common cause of type 3 VWD in some European populations, was found on 6 alleles (12 percent; one patient homozygous). The large deletion resulted in the loss of a 35 kb fragment, incorporating exons 1, 2 and 3. The 5′ breakpoint is located in the 5′ untranslated region, while the 3′ breakpoint is in intron 3 of VWF. No other known gene is lost with the deletion. Clinically, all homozygous patients had serious bleeding episodes from infancy requiring frequent VWF substitutions. However, bleeding became much milder in all patients with no significant spontaneous bleeding after the age of 3-5 years. No inhibitor to VWF was detected. delExon1-3 was not detected in any of the other screened populations. Conclusion: We report a large novel deletion including exons 1, 2 and 3 of VWF commonly causing type 3 VWD in the Hungarian population. This mutation, which is most probably due to a founder effect, seems to be unique to Hungarian patients with a high allele frequency. Together, delExon1-3 and 2435delC make up 31 % of genetic defects in Hungarian patients with VWD type 3. This offers a rational approach to molecular testing of respective families in Hungary.

Mutation distribution in the von Willebrand factor gene related to the different von Willebrand disease (VWD) types in a cohort of VWD patients

2012 ◽  
Vol 108 (10) ◽  
pp. 662-671 ◽  
Author(s):  
Hamideh Yadegari ◽  
Julia Driesen ◽  
Anna Pavlova ◽  
Arijit Biswas ◽  
Hans-Jörg Hertfelder ◽  
...  
Keyword(s):  
Von Willebrand Factor ◽  
Splice Site ◽  
Von Willebrand Disease ◽  
Missense Mutations ◽  
Large Deletions ◽  
Type 3 ◽  
Von Willebrand ◽  
Willebrand Factor

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.

Molecular Characterization of a Multiethnic Group of 21 Patients with Type 3 von Willebrand Disease

2000 ◽  
Vol 84 (10) ◽  
pp. 536-540 ◽  
Author(s):  
Giovanna Cozzi ◽  
Maria Canciani ◽  
Flora Peyvandi ◽  
Alok Srivastava ◽  
Augusto Federici ◽  
...  
Keyword(s):  
Ethnic Origin ◽  
Von Willebrand Disease ◽  
Null Alleles ◽  
Missense Mutations ◽  
Nonsense Mutations ◽  
Molecular Defects ◽  
Large Gene ◽  
Type 3 ◽  
Von Willebrand ◽  
Willebrand Factor

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.

A Novel Mutation Glyl672→Arg in Type 2A and a Homozygous Mutation in Type 2B von Willebrand Disease

1996 ◽  
Vol 76 (02) ◽  
pp. 253-257 ◽  
Author(s):  
Takeshi Hagiwara ◽  
Hiroshi Inaba ◽  
Shinichi Yoshida ◽  
Keiko Nagaizumi ◽  
Morio Arai ◽  
...  
Keyword(s):  
Missense Mutation ◽  
Novel Mutation ◽  
Point Mutations ◽  
Japanese Patients ◽  
Von Willebrand Disease ◽  
Homozygous Mutation ◽  
Missense Mutations ◽  
Reaction Products ◽  
Type 3 ◽  
Von Willebrand

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.

An Alu-mediated novel large deletion is the most frequent cause of type 3 von Willebrand disease in Hungary

2008 ◽  
Vol 6 (10) ◽  
pp. 1729-1735 ◽  
Author(s):  
A. MOHL ◽  
R. MARSCHALEK ◽  
T. MASSZI ◽  
E. NAGY ◽  
T. OBSER ◽  
...  
Keyword(s):  
Large Deletion ◽  
Von Willebrand Disease ◽  
Type 3 ◽  
Von Willebrand

P061 Type 3 von Willebrand disease in Hungary: A partial large deletion is the most common genetic defect

Blood Reviews ◽  
2007 ◽  
Vol 21 ◽  
pp. S105
Author(s):  
A. Mohl ◽  
Z. Boda ◽  
R. Jager ◽  
H. Losonczy ◽  
A. Marosi ◽  
...  
Keyword(s):  
Genetic Defect ◽  
Large Deletion ◽  
Von Willebrand Disease ◽  
Type 3 ◽  
Von Willebrand

Characterization of the Genetic Defects in Recessive Type 1 and Type 3 von Willebrand Disease Patients of Italian Origin

1998 ◽  
Vol 79 (04) ◽  
pp. 709-717 ◽  
Author(s):  
Giancarlo Castaman ◽  
Hans Vos ◽  
Rogier Bertina ◽  
Francesco Rodeghiero ◽  
Jeroen Eikenboom
Keyword(s):  
Stop Codon ◽  
Von Willebrand Disease ◽  
Genetic Defects ◽  
Missense Mutations ◽  
Molecular Defects ◽  
Recessive Type ◽  
Italian Origin ◽  
Type 3 ◽  
Von Willebrand

SummaryThe genetic defects causing recessive type 1 and type 3 von Wille-brand disease (VWD) in eight families from the northern part of Italy have been investigated. Mutations were identified in 14 of the 16 disease-associated von Willebrand factor (VWF) genes. Only one mutation, a stop codon in exon 45, was previously reported. Several new mutations were identified: one cytosine insertion in exon 42, one guanine deletion in exon 28, one probably complete VWF gene deletion, one substitution in the 3’ splice site of intron 13, one possible gene conversion, and three candidate missense mutations. One missense mutation, the substitution of a cysteine in exon 42, was identified in all type 3 VWD patients that were previously characterized as a subgroup with significant increase of factor VIII procoagulant activity after desmopressin infusion. This paper demonstrates again that the molecular defects of quantitative VWD are diverse and located throughout the entire VWF gene.

A novel deletion mutation is recurrent in von Willebrand disease types 1 and 3

Blood ◽  
2009 ◽  
Vol 114 (5) ◽  
pp. 1091-1098 ◽  
Author(s):  
Megan S. Sutherland ◽  
Anthony M. Cumming ◽  
Mackenzie Bowman ◽  
Paula H. B. Bolton-Maggs ◽  
Derrick J. Bowen ◽  
...  
Keyword(s):  
Genomic Dna ◽  
Direct Sequencing ◽  
Von Willebrand Disease ◽  
Compound Heterozygous ◽  
Asian Origin ◽  
Expression Studies ◽  
Autosomal Dominant Fashion ◽  
Type 3 ◽  
Von Willebrand

Direct sequencing of VWF genomic DNA in 21 patients with type 3 von Willebrand disease (VWD) failed to reveal a causative homozygous or compound heterozygous VWF genotype in 5 cases. Subsequent analysis of VWF mRNA led to the discovery of a deletion (c.221-977_532 + 7059del [p.Asp75_Gly178del]) of VWF in 7 of 12 white type 3 VWD patients from 6 unrelated families. This deletion of VWF exons 4 and 5 was absent in 9 patients of Asian origin. We developed a genomic DNA-based assay for the deletion, which also revealed its presence in 2 of 34 type 1 VWD families, segregating with VWD in an autosomal dominant fashion. The deletion was associated with a specific VWF haplotype, indicating a possible founder origin. Expression studies indicated markedly decreased secretion and defective multimerization of the mutant VWF protein. Further studies have found the mutation in additional type 1 VWD patients and in a family expressing both type 3 and type 1 VWD. The c.221-977_532 + 7059del mutation represents a previously unreported cause of both types 1 and 3 VWD. Screening for this mutation in other type 1 and type 3 VWD patient populations is required to elucidate further its overall contribution to VWD arising from quantitative deficiencies of VWF.

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