1. Division of Medical Genetics; A.I. duPont Hospital for Children; Wilmington, Delaware, and Sidney Kimmel Medical School at T. Jefferson University; Philadelphia Pennsylvania
2. Department of Biomedical Research; A.I. duPont Hospital for Children; Wilmington Delaware
3. Department of Biological Sciences; University of Delaware; Newark Delaware
4. Johns Hopkins University School of Medicine; Institute of Genetic Medicine; Baltimore Maryland
5. Center for Inherited Disease Research; Institute of Genetic Medicine; Johns Hopkins University School of Medicine; Baltimore Maryland
6. University of California San Diego and Rady Children's Hospital; San Diego California
7. Department of Clinical Genetics; Helsinki University Central Hospital; Helsinki Finland
8. Children's Hospital; Helsinki University Central Hospital and University of Helsinki, and Folkhälsan Institute of Genetics; Helsinki Finland
9. Neurogenetics Unit; Department of Medical Genetics; Centro Hospitalar de São João; Porto Portugal
10. Madigan Army Medical Center; Tacoma Washington
11. Division of Human Genetics and Molecular Biology; Children's Hospital of Philadelphia; Philadelphia Pennsylvania