1. From the Department of Laboratory Medicine, Children's Hospital, Columbus, Ohio (Dr Qualman and Mr Bowen); Department of Pathology, Emory University Hospital, Atlanta, Ga (Dr Amin); Department of Laboratory Medicine, Credit Valley Hospital, Mississauga, Ontario (Dr Srigley); Department of Oncology, Cross Cancer Institute, Edmonton, Alberta (Dr Grundy); and Department of Pathology, Children's Memo