1. Department of Haematology Oslo University Hospital Oslo Norway
2. Research Institute of Internal Medicine Oslo University Hospital Oslo Norway
3. Department of Haematology Akershus University Hospital Lørenskog Norway
4. Division of Paediatric and Adolescent Medicine Centre for Rare Disorders Oslo University Hospital Oslo Norway
5. Division of Paediatric and Adolescent Medicine Department of Paediatric Research Oslo University Hospital Oslo Norway
6. Institute of Clinical Medicine University of Oslo Oslo Norway