1. Department of Neuroanatomy, Medical Faculty, Institute of Anatomy II; University of Duisburg-Essen; Essen Germany
2. Medical Faculty; Institute of Human Genetics, Heinrich-Heine University; Düsseldorf Germany
3. Division of Haematology and Oncology; Children's Hospital, University of Duisburg-Essen; Essen Germany
4. Medical Faculty; Institute of Pathology, University of Duisburg-Essen; Essen Germany