Prevalence of enthesopathies in adults with X-linked hypophosphatemia : analysis of risk factors.

Context Enthesopathies are the determinant of a poor quality of life in adults with X-linked hypophosphatemia (XLH). Objective To describe the prevalence of patients with enthesopathies and to identify the risk factors of having enthesopathies. Design and setting Retrospective study in the French Reference Center for Rare Diseases of the Calcium and Phosphate Metabolism between June 2011 and December 2020. Patients Adults XLH patients with full body x-rays performed using the EOS® low-dose radiation system and clinical data collected from medical records. Interventions None. Main outcome measures Demographic, PHEX mutation, conventional treatment and dental disease with the presence of enthesopathies. Results Of the 114 patients included (68% women, mean age 42.2±14.3 years), PHEX mutation was found in 105 patients (94,6%), 86 (78%) had been treated during childhood. Enthesopathies (spine and/or pelvis) were present in 67% of the patients (N=76). Patients with enthesopathies were significantly older (p = 0,001) and more frequently reported dental disease collected from medical records (p = 0,03). There was no correlation between the PHEX mutations and the presence of enthesopathies. Sixty -two patients had a radiographic dental examination in a reference center. Severe dental disease (number of missing teeth, number of teeth endodontically treated, alveolar bone loss and proportion of patients with five abscesses or more) was significantly higher in patients with enthesopathies. Conclusion Adults XLH patients have a high prevalence of enthesopathies in symptomatic adults patients with XLH seen in a reference center. Age and severe dental disease were significantly associated with the presence of enthesopathies.