1. From the Department of Laboratory Medicine, Children's Hospital, Columbus, Ohio (Drs Qualman and Bowen); Department of Pediatric Pathology, Arkansas Children's Hospital, Little Rock (Dr Parham); Department of Pathology, Inova Fairfax Hospital, Falls Church, Va (Dr Branton); and Section of Pediatric Hematology/Oncology, University of Oklahoma Health Sciences Center, Oklahoma City (Dr Meyer)