1. Department of Pediatrics, Children's National Medical Center, Washington, DC
2. Department of Pediatrics, University of Utah, Salt Lake City, Utah
3. Department of Pediatrics, Children's Hospital of Michigan, Detroit, Michigan
4. Department of Pediatrics, Seattle Children's Hospital, Seattle, Washington
5. Department of Pediatrics, Arkansas Children's Hospital, Little Rock, Arkansas
6. Department of Pediatrics, Children's Hospital of Pittsburgh, Pittsburgh, Pennsylvania
7. Department of Pediatrics, Childrens Hospital Los Angeles, Los Angeles, California
8. Department of Pediatrics, University of California, Los Angeles, California
9. Department of Pediatrics, University of Virginia Children's Hospital, Charlottesville, Virginia
10. Department of Pediatrics, Eunice Kennedy Shriver National Institute of Child Health and Human Development, Bethesda, Maryland