1. Kennedy Krieger Institute MD Baltimore USA
2. Department of Psychiatry and Behavioral Sciences Johns Hopkins University School of Medicine Baltimore MD USA
3. Department of Genetic Medicine Johns Hopkins University School of Medicine Baltimore MD USA
4. Department of Pediatrics Johns Hopkins University School of Medicine Baltimore MD USA
5. Faculty of Medicine University of Iceland Reykjavik Iceland
6. Department of Genetics and Molecular Medicine Landspitali University Hospital Reykjavik Iceland
7. Department of Neurology Johns Hopkins University School of Medicine Baltimore MD USA