1. Department of Medical Genetics, Oslo University Hospital, 0450 Oslo, Norway
2. Faculty of Medicine, University of Oslo, 0450 Oslo, Norway
3. Department of Medical Genetics, Medical University of Warsaw, Żwirki i Wigury 61, 02-091 Warszawa, Poland
4. Genetic Services of Western Australia, King Edward Memorial Hospital, 374 Bagot Rd, Subiaco, WA 6008, Australia
5. Department of Radiology and Nuclear Medicine, Section of Neuroradiology, Oslo University Hospital, 0450 Oslo, Norway
6. Division of Pediatric and Adolescent Medicine, Oslo University Hospital, 0450 Oslo, Norway