1. Medical Faculty and University Hospital Center of Prevention and Rehabilitation UniReha University of Cologne Cologne Germany
2. Medical Faculty and University Hospital Department of Pediatrics University of Cologne Cologne Germany
3. Department of International Health School CAPHRI, Care and Public Health Research Institute Maastricht University Maastricht the Netherlands
4. Medical Faculty and University Hospital Center for Rare Skeletal Diseases in Childhood University of Cologne Cologne Germany