Treatment Patterns, Biochemical Profiles and Clinical Outcomes in Adults With X-Linked Hypophosphatemia

Inclusion Criteria: * Informed consent obtained before any trial-related activities, i.e., any procedure related to recording of data according to the protocol. * Male or female and aged 18-64 years (both inclusive) at the time of signing informed consent. * Diagnosis of congenital XLH, confirmed genetically or clinically as determined by the investigator, supported by documentation. * Participants have been treated with burosumab for at least 90 days prior to the screening/baseline visit and treatment is still ongoing. * Participant confirms ability and willingness to attend visits according to routine clinical care and mandatory assessments at the site. Exclusion Criteria: * Previous rescreening for this trial. * Current participation in any interventional clinical trial. Participation in another non-interventional trial, such as a patient registry trial, is permitted. * Any condition not associated with XLH, which in the investigator's opinion might jeopardise participant's safety or compliance with the protocol.