1. Department of Pediatrics, Duke University Medical Center, Durham, NC;
2. Department of Pediatrics, Emory University School of Medicine, Atlanta, GA;
3. Clinical Trials and Surveys Corp, Baltimore, MD;
4. Department of Pediatrics, State University of New York Downstate Medical Center/Kings County Hospital Center, Brooklyn, NY;
5. Department of Pediatrics, The Children's Mercy Hospitals and Clinics, Kansas City, MO;
6. Department of Pediatrics, University of Mississippi Medical Center, Jackson, MS;
7. Department of Pediatrics, Johns Hopkins University School of Medicine, Baltimore, MD;
8. Department of Pediatrics, University of Alabama, Birmingham, AL;
9. Department of Pediatrics, University of Miami, Miami, FL;
10. Department of Pediatrics, Baylor College of Medicine, Houston, TX; and
11. Department of Hematology, St Jude Children's Research Hospital, Memphis, TN