Also, in patients with vWD type 1 and borderline to normal ristocetin-cofactor (vWF:RCo) activity values, collagen receptor density correlates inversely with closure time in a high shear stress system (platelet function analyzer [PFA-100]).
We screened the vWF multimerization domains (regions D1-D3 of the vWF gene) of 12 unrelated patients with dominant vWD type 1 to investigate the hypothesis that multimerization of vWF sub-units may be inhibited or reduced by a "dominant negative" mechanism.
Also, in patients with vWD type 1 and borderline to normal ristocetin-cofactor (vWF:RCo) activity values, collagen receptor density correlates inversely with closure time in a high shear stress system (platelet function analyzer [PFA-100]).
Type 1 von Willebrand disease is characterized by a decreased plasma concentration of functionally normal von Willebrand factor (vWF) whereas type 2M is characterised by an abnormal vWF displaying decreased affinity for platelets.
In order to investigate the possibility that qualitative type 2 defects in von Willebrand factor (VWF) occurred in patients previously diagnosed with quantitative type 1 von Willebrand disease (VWD), the phenotypes and genotypes were reanalysed in 30 patients who exhibited discrepant VWF activity/VWF:Ag ratios of less than 0.7.
Autosomal dominant type 1 von willebrand disease due to G3639T mutation (C1130F) in exon 26 of von Willebrand factor gene: description of five Italian families and evidence for a founder effect.
On reclassification, only 144/246 (59%) patients had low VWF levels adjusted for blood group, 88/246 (36%) patients met all the criteria for 'definite' type 1 VWD and 51/246 (21%) patients were 'possible' type 1 VWD.
A novel von Willebrand disease-causing mutation (Arg273Trp) in the von Willebrand factor propeptide that results in defective multimerization and secretion.
Among the major subtypes, type I von Willebrand disease represents by far the more prevalent category (about 70%) and includes cases with a partial deficiency of plasma von Willebrand factor and no evidence of qualitative defects.
In the present study, we prospectively evaluated the contribution of the von Willebrand factor collagen-binding activity (vWF:CBA) assay, vWF multimeric analysis, and the response to intravenous desmopressin (DDAVP) to correctly diagnose and classify congenital von Willebrand disease (CvWD) in 24 probands with mild to moderate type 1 vWD, 6 probands with severe CvWD type 1, and 12 probands with type 2 CvWD.
Most cases appear to have a partial quantitative deficiency of VWF (type 1 VWD) with variable bleeding tendency, whereas qualitative variants (type 2 VWD), due to a dysfunctional VWF, are clinically more homogeneous.
Considering the recent suggestion that platelet membrane glycoprotein polymorphisms (PltGPs) may play a role as modulators of thromboembolic or haemorrhagic diseases, we investigated the role of different PltGPs and GPVI content in the clinical expression of patients with VWD type 1.The diagnosis of VWD (n = 76) was based on laboratory findings (VWF:Ag, VWF:RCo, VWF:CB, FVIII:C, and multimer analysis), family and personal history of bleeding.
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.
Considering the recent suggestion that platelet membrane glycoprotein polymorphisms (PltGPs) may play a role as modulators of thromboembolic or haemorrhagic diseases, we investigated the role of different PltGPs and GPVI content in the clinical expression of patients with VWD type 1.The diagnosis of VWD (n = 76) was based on laboratory findings (VWF:Ag, VWF:RCo, VWF:CB, FVIII:C, and multimer analysis), family and personal history of bleeding.
Considering the recent suggestion that platelet membrane glycoprotein polymorphisms (PltGPs) may play a role as modulators of thromboembolic or haemorrhagic diseases, we investigated the role of different PltGPs and GPVI content in the clinical expression of patients with VWD type 1.The diagnosis of VWD (n = 76) was based on laboratory findings (VWF:Ag, VWF:RCo, VWF:CB, FVIII:C, and multimer analysis), family and personal history of bleeding.
Mutations in the VWF gene were previously known or newly identified in most patients with types 2A (n = 15 of 15), 2M (n = 15 of 21), and 2N (n = 4 of 4), but in none of those with type 1 VWD.
von Willebrand disease (VWD) type 1 is difficult to diagnose because of bleeding variability and low heritability of von Willebrand factor (VWF) levels.