Abstract Context X-linked hypophosphatemia (XLH) is a rare, genetic, progressive, lifelong disorder manifest by impaired growth and disproportionate short stature. Burosumab, a monoclonal antibody against fibroblast growth factor 23, is approved for treating patients with XLH. Objective To understand the impact of burosumab treatment on growth in a real-world setting. Design Interim data from three ongoing, real-world observational studies (NCT03651505, NCT03193476, NCT03745521), were unified in