1. Department of Paediatrics and Adolescent Medicine; Aarhus University Hospital; Aarhus Denmark
2. Institution for Clinical Sciences; Department of Paediatrics; Queen Silvia Children's Hospital; Gothenburg Sweden
3. Department of Cytogenetics; Erasmus MC-Sophia Children's Hospital; Rotterdam The Netherlands
4. Department of Paediatrics; University Medical Centre Groningen; Groningen the Netherlands
5. Hong Kong Paediatric Haematology & Oncology Study Group; Department of Paediatrics; Queen Mary Hospital; Hong Kong China
6. Children's Hospital; University of Helsinki and Helsinki University Hospital; Helsinki Finland
7. Department of Paediatrics; Landspitalinn; Reykjavik Iceland
8. Paediatric Oncology/Haematology; VU University Medical Centre, Amsterdam; Academy of Princess Maxima Centre for Paediatric Oncology; Utrecht The Netherlands
9. Department of Paediatrics; Children's Clinical University Hospital; Riga Latvia
10. Department of Paediatrics and Adolescent Medicine, Rigshospitalet; University of Copenhagen; Copenhagen Denmark
11. Department of Paediatrics; Ghent University Hospital; Ghent Belgium
12. Department of Medical Biosciences, Genetics; Umeå University Hospital; Umeå Sweden
13. Department of Woman's and Children's Health; Uppsala University; Uppsala Sweden
14. Department of Paediatrics; SA Tallinna Lastehaigla; Tallinn Estonia
15. Division of Paediatric and Adolescent Medicine; Oslo University Hospital; Oslo Norway
16. Department of Cytogenetics; Aarhus University Hospital; Aarhus Denmark