1. From the Institute of Metabolic Disease, Baylor University Medical Center and Baylor Research Institute, and Department of Neurology, University of Texas Southwestern Medical Center, Dallas; Division of Pediatric Neurology, Pennsylvania State University College of Medicine, Milton S. Hershey Medical Center, Hershey;
2. Division of Clinical Genetics, Department of Pediatrics, University of Copenhagen, Copenhagen, Denmark; Department of Pediatric Neurology, Armand Trousseau Hospital, Paris, France;
3. Division of Clinical Chemistry and Pediatrics Department, Free University Hospital, Amsterdam, the Netherlands; Medical Biochemistry Laboratory, Necker Hospital for Sick Children, Paris, France;
4. Basler Children's Hospital, University of Basel, Basel, Switzerland; Section of Pediatric Neurology, Department of Neurology, Bowman Gray School of Medicine, Wake Forest University, Winston-Salem, NC; and
5. Division of Clinical Genetics and Child Neurology, Department of Pediatrics, University Hospital, Nijmegen, the Netherlands; Division of Pediatric Neurology, Booth Hall Children's Hospital, University of Manchester School of Medicine, Manchester, United Kingdom;
6. Cnopf'sche Children's Hospital, Evangelical-Lutheran-Diakoniewerk Neuendettelsau, Nuremburg, Germany; Division of Child Neurology, Department of Neurology and Pediatrics, University of California Medical Center, San Francisco;
7. Division of Pediatric Genetics, Department of Pediatrics, Stanford University School of Medicine, Palo Alto, CA;
8. Department of Pediatrics, Kuwait University Faculty of Medicine, Safat;
9. Children's Hospital, Department of Neuropediatrics, Eberhard-Karls-Universitat, Tubingen, Germany;
10. Institute of Anthropology and Human Genetics, Department of Clinical Genetics, University of Tubingen, Tubingen, Germany;
11. Division of Pediatric Genetics and Metabolic and Neonatal-Perinatal Medicine, Department of Pediatrics, Duke University Medical Center, Durham, NC; Children's Hospital Oakland, Child Development Center, Oakland, CA.
12. Children's Hospital, Albert-Ludwigs University, Freiburg, Germany;
13. Division of Child Neurology, Department of Neurology, University Hospital Leiden, the Netherlands;
14. Center for Medical Genetics, Johns Hopkins Hospital, Baltimore, MD;
15. Department of Neuropediatrics, Vestische Children's Hospital, University of Witten/Herdecke, Datteln, Germany;
16. Children's Hospital, Lüdenscheid, Germany;