1. Department of Neurology, University Medical Center Groningen; University of Groningen; Groningen The Netherlands
2. Department of Metabolic medicine; Great Ormond Street Hospital for Children, UCL Institute of Child Health; London UK
3. Charles Dent Metabolic Unit; The National Hospital for Neurology and Neurosurgery; London UK
4. Department of Clinical Neuropsychology; University of Groningen, University Medical Center Groningen; Groningen The Netherlands
5. Department of Pediatrics; Maastricht University Medical Center; Maastricht The Netherlands
6. Department of Pediatrics; University of Amsterdam, Academic Medical Center; Amsterdam The Netherlands
7. Department of Pediatrics, Center of Lysosomal and Metabolic Diseases; Erasmus University Medical Center; Rotterdam The Netherlands
8. Department of Pediatrics; University of Groningen, University Medical Center Groningen; Groningen The Netherlands
9. Department of Internal Medicine; Maastricht University Medical Center; Maastricht The Netherlands
10. Department of Pediatrics; Radboud University Medical Center; Nijmegen The Netherlands