1. From the Michael G. DeGroote School of Medicine, McMaster University, Hamilton, Ontario, Canada; Department of Pathology, University of Melbourne, and Department of Haematology, Royal Children's Hospital, Melbourne, Victoria, Australia; Division of Pediatric Hematology/Oncology, Department of Pediatrics, McMaster University, Hamilton, Ontario, Canada, and the Department of Pediatric Laboratory Medicine, The Hospital for Sick Children, Toronto, Ontario, Canada