Use of a new enzyme-linked immunosorbent assay for the detection of type 2N von Willebrand disease and its prevalence in an Indian population

Ghosh, Kanjaksha; Trasi, Sucheta; Shetty, Shrimati; Mohanty, Dipika

doi:10.1097/01.mbc.0000198048.42634.5a

Cited by 11 publications

(10 citation statements)

References 10 publications

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“…from these workers in a later more focused study, in which nine of 97 VWD patients (10%) were found to be type 2N VWD [26]. A prevalence of around 10% for type 2N VWD within a small VWD cohort has also recently been reported in a Mexican study [27], and a type 2N VWD prevalence of around 12% of tested samples was also identified in an international (but 2N VWD focused) cross laboratory investigation [28].…”

Section: Discussionmentioning

confidence: 72%

Identification and prevalence of von Willebrand disease type 2N (Normandy) in Australia

Favaloro

Mohammed

Koutts

2009

Blood Coagulation &Amp; Fibrinolysis

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We report an investigation of type 2N von Willebrand disease (VWD), covering the past 7 years and evaluating 1031 plasma samples from over 500 patients. Samples included specific requests for investigation of possible type 2N VWD (including family studies) and samples from 'hemophilia' or nonspecified VWD investigations that could unknowingly be type 2N VWD. In total, 13 new patients with type 2N VWD were identified, four of whom initially presented with normal levels of factor VIII and only three of whom (i.e. 23%) derived from specific clinical requests for investigation of type 2N VWD. Furthermore, type 2N VWD was excluded in 91% of specific clinical requests for type 2N VWD investigations. Poststudy evaluation indicates that type 2N VWD in this geographic region has an incidence rate similar to that in other westernized regions, accounting for around 1-2% of all identified VWD cases and about 13% of all type 2 VWD cases. In conclusion, this study highlights that clinicians requesting laboratory investigations related to a bleeding tendency often fail to appropriately recognize the possibility of type 2N VWD, that a normal plasma factor VIII will not exclude type 2N VWD, and although a relatively uncommon form of VWD overall, type 2N VWD represents a significant qualitative disorder.

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Section: Discussionmentioning

confidence: 72%

Identification and prevalence of von Willebrand disease type 2N (Normandy) in Australia

Favaloro

Mohammed

Koutts

2009

Blood Coagulation &Amp; Fibrinolysis

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“…In our cohort of VWD patients, the prevalence of type 2N disease amounts to 2.5%-higher than previously reported in Italy (0.5%-1.2%), 28,29 but similar to findings in Australia reported by Favaloro et al 30 An even higher prevalence of type 2N VWD has been reported in other countries, such as India (3.6%), and especially Mexico (10%). 31,32 Such marked differences may be due to different geographical areas having homogeneous genetic patterns, especially in more remote regions where the type 2N defect is present (due to inbreeding).…”

Section: Discussionmentioning

confidence: 99%

“…30 An even higher prevalence of type 2N VWD has been reported in other countries, such as India (3.6%), and especially Mexico (10%). 31,32 Such marked differences may be due to different geographical areas having homogeneous genetic patterns, especially in more remote regions where the type 2N defect is present (due to inbreeding).…”

Section: Prevalence Of Type 2n Von Willebrand Disease (Vwd) In Our mentioning

confidence: 99%

Type 2N von Willebrand disease: Characterization and diagnostic difficulties

et al. 2017

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Introduction An abnormal factor VIII (FVIII) binding capacity of von Willebrand factor (VWF) identifies type 2N von Willebrand disease (VWD). Type 2N VWD patients are identified by means of the VWF FVIII binding (VWF:FVIIIB) assay, and especially their VWF:FVIIIB/VWF:Ag ratio (VWF:FVIIIB ratio). Aim We report on our 15‐year experience of diagnosing type 2N VWD. Methods We have performed 2178 VWF:FVIIIB assays in bleeders and normal subjects. Results von Willebrand factor (VWF):FVIIIB was reduced in 682, but only 60 had low VWF:FVIIIB ratios (<0.74). Among nine patients who had a VWF:FVIIIB ratio below 0.3, four had normal VWF levels and were homozygotes for the p.R854Q mutation; the other five had low VWF levels due to a quantitative VWF mutation combined with p.R854Q. The VWF:FVIIIB ratio ranged between 0.3 and 0.73 in 51 subjects; 34 of them were heterozygotes for the p.R854Q mutation, while one carried the p.R760C. The heterozygotes for type 2N included subjects with or without bleeding symptoms, the former with significantly lower mean VWF levels than the latter. Among the 116 normal subjects tested, six were heterozygotes for the p.R854Q mutation (all asymptomatic). Conclusions The prevalence of type 2N in our VWD cohort was 2.5%, and 5.2% of the general population in Northeast Italy was found heterozygous for the p.R854Q mutation. It might be difficult to reveal a type 2N defect using routine tests alone, especially when it is combined with a quantitative VWF mutation. Accordingly, we always recommend VWF:FVIIIB assay in the diagnostic workup of VWD.

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“…Several phenotypic assays were developed to detect this defect and approximately 5% of von Willebrand disease patients in the West were found to have this kind of von Willebrand disease, known as the Normandy-type VWD or 2N-type VWD. [44]…”

Section: Dominant Hemophilia Now Classified By Molecular Biologymentioning

confidence: 99%

“…[44] The assay needs some more modification to make it sufficiently sensitive. In our series, we found that approximately 10% of our severe VWD patients have 2N-type VWD.…”

Section: Dominant Hemophilia Now Classified By Molecular Biologymentioning

confidence: 99%

Coagulation disorders seen through the window of molecular biology

Ghosh

2007

Indian J Hum Genet

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Coagulation disorders have been traditionally worked up by their clinical phenotypes and coagulation factor assays which are dependent on APTT- and PT-based techniques. Development of chromogenic substrates in the late seventies and early eighties allowed coagulation factors to be measured like enzymes. There was still a major lacuna in the understanding of the biology of different coagulation disorders. Modern molecular biology - which developed as an unique synthesis of biochemistry, immunology, cell biology, and genetics - allowed us to have a more comprehensive understanding of the pathobiology of many of these coagulation disorders. This overview presents several examples which show how we have enriched our understanding about the varied clinical phenotypes of different coagulation disorders.

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Use of a new enzyme-linked immunosorbent assay for the detection of type 2N von Willebrand disease and its prevalence in an Indian population

Cited by 11 publications

References 10 publications

Identification and prevalence of von Willebrand disease type 2N (Normandy) in Australia

Identification and prevalence of von Willebrand disease type 2N (Normandy) in Australia

Type 2N von Willebrand disease: Characterization and diagnostic difficulties

Coagulation disorders seen through the window of molecular biology

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