Canadian Project


Project is Now Complete!

ISTH Final Report:


In March 2007, we initiated a project with an overall aim to track PT-VWD patients in Canada and internationally if possible. We had two major questions to be addressed:

  • Is PT-VWD rare or under-diagnosed?
  • How many cases are being misdiagnosed as type 2B VWD cases?

The project was initially planned for 2 years where around 100 cases of type 2B VWD to be collected. Genetic analysis of the VWF gene; region related to platelet binding (A1 domain) to be performed and in mutation- negative cases to analyse the platelet GPIBA gene with the purpose of discrimination between type 2B VWD and PTPVWD. Project plan is outlined below.

In July 2007, during the 53rd Scientific and Standardization Committee (SSC) meeting organized by the International Society of Thrombosis and Haemostasis and held in Geneva, the subject of the discrimination between type 2B VWD and the PT-VWD together with the value of genetic analysis approach caught attention of the SSC working group on “von Willebrand factor” (VWF) and discussion resulted in an approval for initiating an international online database and registry for PT-VWD. Updates about the project and registry will be reported at this site and also to the SSC.

Inclusion Criteria:

  • All patients with an initial diagnosis of type 2B VWD whether genetic analysis has been performed or not.
  • All patients with an enhanced ristocetin induced platelet aggregation.
  • All patients where VWD is suspected and no sub typing performed due to lack of laboratory facilities for VWF testing including VWF mutlimers.

Project Team:

  • Principal Investigator
    • Dr. Maha Othman
  • Co-Investigator
    • Dr. David Lillicrap
  • Research assistants:
    • Colleen Notley
    • Jayne Lego

Pathology and Molecular medicine
Queen’s University
Kingston, Ontario

Project Plan

Project was completed 2010- Project data are published in Thromb Haemost. 2011 Mar;105(3):501-8

Project funded by: