Registry for Patients With X-Linked Hypophosphatemia

A patient must meet the following criteria at the enrolment visit (baseline) to be eligible for inclusion into this XLH Registry Inclusion Criteria: 1. Patients aged from ≥0 years of age at baseline 2. In the opinion of the treating physician the patient has a clinical presentation, radiological, biochemical or genetic investigation results that support diagnosis of XLH 3. Patient is not currently participating in an interventional clinical trial A patient who meets any of the following criteria at the enrolment visit (baseline) will be excluded from this XLH Registry Exclusion Criteria: 1. Patient or their legally designated representative does not have the cognitive capacity to provide informed consent. 2. Patient is currently participating in an interventional clinical trial. Patients will be approached for inclusion into the registry once their involvement in the trial ends (including the completion of all trial follow up assessments). 3. Participation in a Compassionate Use Program, Pre-commercial Program (i.e. Named Patient Sales, Nominative ATU) or Investigator Initiated Study does not preclude a patient from participation in this XLH Registry