1. Department of Pediatrics; Division of Pediatric Neurology and Metabolism; Ghent University Hospital; Ghent; Belgium
2. Department of Critical Care Medicine; Antwerp University Hospital, Antwerp University; Edegem; Belgium
3. Department of Pathology; Antwerp University; Wilrijk; Belgium
4. Department of Pediatric Ophthalmology; Hôpital Universitaire des Enfants Reine Fabiola; Brussels; Belgium
5. Department of Medical Genetics; Antwerp University Hospital, Antwerp University; Edegem; Belgium
6. Center for Medical Genetics; UZ Brussel and Reproduction and Genetics (REGE); Vrije Universiteit Brussel; Brussels; Belgium
7. Department of General Pediatrics; Division of Inborn Metabolic Diseases; University Children's Hospital; Heidelberg; Germany