Abstract
This systematic review collated evidence on the burden of XLH in adults. Data captured highlight the substantial ongoing burden of XLH in adulthood and identified unmet needs. Greater awareness and understanding of the impact of XLH in adulthood are needed to improve care and outcomes in adults with XLH. INTRODUCTION: X-linked hypophosphataemia (XLH) is a rare metabolic bone disease characterized by renal phosphate wasting and musculoskeletal manifestations. Whilst the disease's impact in children is well documented, information on the effects of this progressive, debilitating condition on adults is lacking. This systematic review aimed to collate existing evidence on the burden of XLH in adulthood to identify unmet needs. METHODS: MEDLINE, Embase and Cochrane Library databases and recent congress reports were searched on 19 February 2019 for English-language publications describing the medical, humanistic and socio-economic impact of XLH in adults (≥ 18 years old). In addition, a structured Internet search was conducted. RESULTS: Of the 2351 articles identified, 91 met the selection criteria along with 44 congress abstracts. Data show that adults with XLH experience a range of clinical manifestations, particularly skeletal deformities and (pseudo)fractures, along with pain, dental abnormalities and impaired physical function and mobility. XLH in adulthood impacts on quality of life and places limitations on daily activities. The level of healthcare resource utilization among adults with XLH is indicative of substantial socio-economic burden; further research is needed to quantitate the economic impact on the healthcare system, society and patients. Adults with XLH may not receive appropriate care and treatment; a possible explanation for this is a lack of awareness among healthcare professionals. CONCLUSION: XLH in adults is associated with considerable disease burden and unmet needs. Forthcoming studies and increased awareness of the impact of XLH in adulthood should help to improve management of XLH in adulthood and patient outcomes.