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