PRO132 DISEASE BURDEN OF X-LINKED HYPOPHOSPHATEMIA

X-linked hypophosphatemia (XLH) is a rare genetic disease, serious, debilitating and deforming condition, characterized by renal phosphate wasting. XLH is caused by loss of function of the PHEX gene resulting in enhanced secretion of the phosphaturic hormone FGF23 and leading defective bone mineralization, leading to rickets and impaired physical function.This disease, which affects 1:20.000 people, results in impaired quality of life (QoL) of patients, since, despite the treatments, suffer progressive and debilitating complications. The main objective of the study was to determine QoL of patients, children and adults suffering XLH, as well as their caregivers. A multicentre, observational and cross-sectional study has been carried out by a scientific committee consisted of 17 health professionals experts in XLH. QoL was assessed with the following EuroQol-5 Dimensions (EQ-5D) questionnaires: the EQ-5D-3L proxy (completed by caregivers or parents of children under 12 years), the EQ-5D-3L (completed by patients aged between 12 and 18 years), and the EQ-5D-5L (completed by adult patients and caregivers). The total number of participants for this project was 50 patients, 21 children and 29 adults, and their corresponding caregivers. Children had mobility problems due to difficulties walking, moderate pain or discomfort, problems doing their daily activities and felt anxious or depressed. In addition, children showed problems washing or dressing themselves. Similarly, a high percentage of adults were unable to walk, suffered extreme pain, showed difficulties to carry out their daily activities, and reported anxiety and depression. Moreover, the results of QoL for caregivers and parents were slightly lower than the general Spanish population. In conclusion, both children and adults, showed an important deterioration in QoL that were worse than the general Spanish population. These findings suggest the need for new treatments, as in many cases, the conventional treatment does not prevent disease complications and the impairment of QoL.