1. Department of Pediatrics; Aarhus University Hospital; Aarhus Denmark
2. Cancer Cytogenetics Laboratory; Department of Hematology, Aarhus University Hospital; Aarhus Denmark
3. Institution for Clinical Sciences; Department of Pediatrics, Queen Silvia Children's Hospital; Gothenburg Sweden
4. Department of Pediatrics; Queen Mary Hospital and Hong Kong Pediatric Hematology & Oncology Study Group (HKPHOSG); Hong Kong China
5. Department of Pediatrics; University Hospital; Lund Sweden
6. Children's Hospital, Helsinki University Central Hospital, University of Helsinki; Helsinki Finland
7. Department of Pediatrics; Landspitalinn Reykjavik Iceland
8. Department of Pediatrics and Adolescent Medicine; Rigshospitalet, University of Copenhagen; Copenhagen Denmark
9. Department of Woman's and Children's Health; Uppsala University; Uppsala Sweden
10. Department of Pediatric Medicine; Oslo University Hospital; Oslo Norway
11. Department of Medical Biosciences; Clinical Genetics, Umeå University Hospital; Umeå Sweden