1. Department of Pediatrics, Dalhousie University and Isaak Walton Killam Health Centre, Halifax, NS;
2. Department of Pediatrics, University of British Columbia, BC Children's Hospital, Vancouver, BC;
3. Division of Hematology/Oncology, Dalhousie University and Izaak Walton Killam Health Centre, Halifax, NS; and
4. Division of Hematology/Oncology, University of British Columbia, BC Children's Hospital, Vancouver, BC