Laboratory Diagnosis of von Willebrand Disease Type 1/2E (2A Subtype IIE), Type 1 Vicenza and Mild Type 1 Caused by Mutations in the D3, D4, B1-B3 and C1-C2 Domains of the von Willebrand Factor Gene. Role of von Willebrand Factor Multimers and the von Willebrand Factor Propeptide/Antigen Ratio. Acta haematologica [Acta Haematol] Journal article | | Title | Laboratory Diagnosis of von Willebrand Disease Type 1/2E (2A Subtype IIE), Type 1 Vicenza and Mild Type 1 Caused by Mutations in the D3, D4, B1-B3 and C1-C2 Domains of the von Willebrand Factor Gene. Role of von Willebrand Factor Multimers and the von Willebrand Factor Propeptide/Antigen Ratio. | | Author(s) | Gadisseur A, Berneman Z, Schroyens W, Michiels JJ | | Institution | Hemostasis and Thrombosis Research Center, Antwerp University Hospital, Edegem, Belgium. | | Source | Acta Haematol 2009; 121(2-3):128-138. | | Abstract | Autosomal dominant von Willebrand disease (VWD) type 1/2E is a quantitative/qualitative defect in the von Willebrand factor (VWF) caused by heterozygous cysteine and non-cysteine mutations in the D3 domain of the VWF gene and results in a secretion-multimerization-clearance defect in mutant VWF with the loss of large VWF multimers not due to proteolysis. The multimers of patients with dominant VWD type 1/2E due to mutations in the D3 domain show an aberrant triplet structure with lack of outer bands but with pronounced inner bands of the triplet structure combined with a relative decrease in large multimers reflecting heterozygosity for multimerization defects. There is a good response to desmopressin (DDAVP) followed by rapid clearance of VWF:antigen (Ag), factor VIII coagulant activity (FVIII:C) and VWF:ristocetin cofactor activity (RCo) as the main cause of VWD type 1 or 2 with typical 2E multimeric pattern (VWD type 1/2E). Cysteine mutations in the D3 domains (C1130, C1149 and C1190) show pronounced features of VWD 1/2E with the relative loss of large and relative increase in small VWF multimers with abnormal triplet structure in heterozygotes. Such abnormalities are less pronounced in patients with a milder form of VWD type 1 due to non-cysteine mutations W1144G, T1156M and W1120S in the D3 domain. VWD type 1 Vicenza is caused by the R1205H mutation in the D3 domain and characterized by equally low levels of FVIII:C, VWF:Ag and VWF:RCo. The response to DDAVP in VWD Vicenza is good for FVIII:C, VWF:Ag and VWF:RCo, which is followed by a rapid clearance in less than a few hours of FVIII:C and VWF parameters. The ratios for FVIII:C/VWF:Ag, VWF:RCo/Ag and VWF:CB/Ag remain normal before and after DDAVP indicating that VWD Vicenza clearly differs from VWD type 1, 1/2E and 2M. A new set of missense mutations in D4, B1-B3 and C1-C2 domains has been discovered as the cause of a mild VWD type 1 secretion defect with normal VWF multimers or smeary VWF multimeric pattern. Cysteine mutations in exons 38, 40, 42 and 43 (D4, B1-B3 and C1 domain), show smeary patterns (either smf or sm), with the presence of large VWF multimers and a laboratory phenotype of mild VWD type 1 with variable penetrance of bleeding manifestations. Recent studies showed that the ratio of VWF propeptide (pp) to VWF:Ag can be used to predict a shorter than normal half-life for VWF:Ag. There is a strong inverse correlation between rapid clearance of VWF:Ag after DDAVP and increased VWFpp/Ag ratios >10 in VWD type 1 Vicenza, and >2 in VWD type 1/2E but normal or slightly increased (1-<2) VWFpp/Ag ratios in mild-type VWD due to nonsense or missense mutations in the D1, D2, D4, B and C domains. | | Language | ENG | | Pub Type(s) | JOURNAL ARTICLE
| | PubMed ID | 19506359 |
|
|
| |
Advertise on this site.
| | |
|
