1. Department of Pediatrics and Adolescent MedicineAarhus University Hospital Aarhus Denmark
2. Department of HematologyAarhus University Hospital Aarhus Denmark
3. Hematology‐Pathology Research LaboratoryDepartment of HematologyOdense University Hospital Odense Denmark
4. Department of PathologyThe Norwegian Radium Hospital Oslo Norway
5. Division of Pediatric and Adolescent MedicineOslo University Hospital Oslo Norway
6. Department of Pediatrics and Adolescent MedicineRigshospitalet, University of Copenhagen Copenhagen Denmark