1University Children's Hospital Oldenburg, Department of Neuropaediatric and Metabolic Diseases, Oldenburg, Germany
2Department of Neurology, Medical University Innsbruck, Innsbruck, Austria
3Department of Paediatrics I (Inherited Metabolic Disorders), Medical University of Innsbruck, Innsbruck, Austria
4University Institute of Clinical Chemistry, Bern University Hospital, Bern, Switzerland
5Pediatric Endocrinology, Diabetology and Metabolism, University Children's Hospital Bern, Switzerland
6Institute of Medical Genetics and Applied Genomics, University of Tübingen, Tübingen, Germany
7Department of Neuropediatrics, Developmental Neurology and Social Pediatrics, University of Tübingen, 72076, Tübingen, Germany
8Department of Pediatrics, University Hospital Salzburg, Paracelsus Medical University, Salzburg, Austria
9Department of Pediatrics, Klinikum Reutlingen, Reutlingen, Germany
10Institute for Diagnostic and Interventional Radiology, Klinikum Oldenburg, Oldenburg, Germany
11Division of Child Neurology and Metabolic Medicine, Centre for Child and Adolescent Medicine, University Hospital Heidelberg, Germany
12Institute of Human Genetics, Helmholtz Zentrum München, Neuherberg, Germany
13Institute of Human Genetics, Technische Universität München, Munich, Germany
14Centre for Rare Diseases, University of Tuebingen, Tübingen, Germany