Thromb Haemost 2010; 104(05): 903-910
DOI: 10.1160/TH10-01-0079
Theme Issue Article
Schattauer GmbH

2B or not to be – The 45-year saga of the Montreal Platelet Syndrome

Man-Chiu Poon
1  Division of Hematology and Hematologic Malignancies, Department of Medicine, University of Calgary, Calgary, Alberta, Canada
Margaret L. Rand
2  Division of Hematology/Oncology, The Hospital for Sick Children, and Department of Laboratory Medicine and Pathobiology, University of Toronto, Toronto, Ontario, Canada
Shannon C. Jackson
3  Division of Hematology, Department of Medicine, St. Paul’s Hospital, University of British Columbia, Vancouver, British Columbia, Canada
› Author Affiliations
Further Information

Publication History

Received: 31 January 2010

Accepted after minor revision: 06 April 2010

Publication Date:
24 November 2017 (online)


Over 45 years ago, Montreal Platelet Syndrome was first described as a rare inherited platelet disorder characterised by macrothrombocytopenia with spontaneous platelet clumping, abnormal platelet shape change upon stimulation and a defect in platelet calpain. This syndrome has now been reclassified as type 2B von Willebrand disease with the V1316M VWF mutation in the only kindred ever reported. We herein revisit the historical platelet characteristics originally described in Montreal Platelet Syndrome in light of the new diagnosis. This paper will review the 45-year saga of Montreal Platelet Syndrome, a story that highlights the value of revisiting a rare diagnosis to look for a more common explanation.