1. Erasmus MC University Medical Centre Rotterdam, Department of Public Health Rotterdam The Netherlands
2. Erasmus MC – Sophia Children's Hospital University Medical Centre Rotterdam, Department of Paediatric Haematology Rotterdam The Netherlands
3. Erasmus MC Erasmus University Medical Centre Rotterdam, Department of Haematology Rotterdam The Netherlands
4. Emma Children's Hospital Amsterdam UMC University of Amsterdam, Department of Paediatric Haematology Amsterdam The Netherlands
5. Van Creveldkliniek University Medical Centre Utrecht, Utrecht University Utrecht The Netherlands
6. Radboud University Medical Centre, Department of Haematology Nijmegen The Netherlands