A cluster of mutations in the D3 domain of von Willebrand factor correlates with a distinct subgroup of von Willebrand disease: type 2A/IIE

Blood. 2010 Jun 10;115(23):4894-901. doi: 10.1182/blood-2009-07-226324. Epub 2010 Mar 29.

Abstract

Among the different phenotypes of von Willebrand disease (VWD) type 2A, we identified a particular subgroup with a high frequency of 29%, characterized by a relative decrease of large von Willebrand factor (VWF) multimers and decreased A Disintegrin And Metalloproteinase with ThromboSpondin type 1 motifs, member 13 (ADAMTS13)-mediated proteolysis previously described in a single family as VWD type IIE (VWD2A/IIE). Phenotype and genotype of 57 patients from 38 unrelated families displaying a particular multimer pattern resembling the original VWD2A/IIE were studied. Pathogenicity of candidate mutations was confirmed by expression studies and phenotypic characterization of recombinant mutants. Specific mutations were identified in all patients. Twenty-two different mutations, most of them affecting cysteine residues, 17 of them being novel, are clustering mainly in the VWF D3 domain and correlate with the VWD2A/IIE phenotype. An intracellular retention of most mutants and/or a defect of multimerization seem to be the main pathogenic molecular mechanisms. ADAMTS13 proteolysis of mutant VWF was not different from wild-type VWF in a static assay, suggesting that reduced in vivo proteolysis is not an intrinsic property of mutant VWF. Our study identified a distinct VWD subtype with a common molecular background which contributes significantly to the heterogeneous spectrum of VWD.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • ADAM Proteins / genetics
  • ADAM Proteins / metabolism
  • ADAMTS13 Protein
  • Amino Acid Motifs
  • Case-Control Studies
  • Disintegrins / genetics
  • Disintegrins / metabolism
  • Family
  • Female
  • Gene Expression
  • Genotype
  • Humans
  • Male
  • Mutation, Missense*
  • Phenotype
  • Protein Multimerization / genetics*
  • Protein Structure, Tertiary
  • Recombinant Proteins / genetics
  • Recombinant Proteins / metabolism
  • von Willebrand Disease, Type 2 / genetics*
  • von Willebrand Disease, Type 2 / metabolism*
  • von Willebrand Factor / genetics*
  • von Willebrand Factor / metabolism*

Substances

  • Disintegrins
  • Recombinant Proteins
  • von Willebrand Factor
  • ADAM Proteins
  • ADAMTS13 Protein
  • ADAMTS13 protein, human