Université Paris Saclay - Department of Children and Adolescents Oncology, University of Toronto - The Hospital for Sick Children - SickKids, University of Toronto - The Hospital for Sick Children - SickKids, Medical University Vienna - St. Anna Children's Hospital, Arthur and Sonia Labatt Brain Tumor Research Centre, NHS Foundation Trust - Department of Paediatric Haematology and Oncology, University Hospital Münster, Paris Dauphine University - PSL Research University, Université Libre de Bruxelles (ULB) - Hemato-Oncology department, Arthur and Sonia Labatt Brain Tumor Research Centre, Tel Aviv University - Department of Pediatric Hematology-Oncology, University Hospital Münster, Tel Aviv University - Rabin Medical Center, Medical University of Innsbruck, Poznan University of Medical Sciences, Motol University Hospital, Hannover Medical School, Princess Maxima Center for Pediatric Oncology, Hospital Universitario Doce de Octubre - Pediatric Oncology Unit, Hospital Duran i Reynals (ICO) - Catalan Institute of Oncology, Department of Pediatric and Adolescent Oncology, Institut Gustave Roussy, Hospital Universitario Doce de Octubre - Hereditary Cancer Genetic Diagnostic Laboratory, Centro de Investigación Biomédica en Red de Enfermedades Raras (CIBERER) - Grupo de Medicina Xenómica, Children’s Health Ireland, KU Leuven - Department of Oncology, Medical University of Innsbruck, University Paris-Saclay - Biostatistic and Epidemiology Unit, Gustave Roussy, The Hospital for Sick Children - Division of Haematology / Oncology and Gustave Roussy