1. Department of Neuropathology; University of Bonn Medical Centre; Bonn Germany
2. Department of Pathology; University of Bonn Medical Centre; Bonn Germany
3. Institute of Neurology; Medical University of Vienna; Vienna Austria
4. Department of Pediatric Hematology and Oncology; University Medical Center Hamburg-Eppendorf; Hamburg Germany
5. Department of Pediatric Oncology, Hematology and Immunology; Heidelberg University Hospital; Heidelberg Germany