1. Central Diagnostic Laboratory‐Research University Medical Centre Utrecht Utrecht University Utrecht The Netherlands
2. Department of Paediatric Haematology University Medical Centre Utrecht Utrecht University Utrecht The Netherlands
3. Centre for Benign Haematology Thrombosis and Haemostasis Van Creveldkliniek University Medical Centre Utrecht Utrecht University Utrecht The Netherlands
4. Department of Paediatric Haematology Erasmus Medical Centre Rotterdam The Netherlands
5. Department of Paediatric Haematology Leiden University Medical Centre Leiden Leiden The Netherlands
6. Department of Paediatric Haematology Maastricht University Medical Centre Maastricht The Netherlands
7. Department of Paediatric Haematology Amalia Children's Hospital RadboudUMC Nijmegen The Netherlands