X-linked hypophosphatemic rickets: case report with perspectives and challenges.

Abstract

X-linked dominant hypophosphatemic rickets (XLH) is a rare genetic disorder caused by mutations in the PHEX gene and characterized by chronic hypophosphatemia due to dysregulation of fibroblast growth factor 23 (FGF23). This condition leads to bone deformities, growth impairment, and chronic pain. Conventional treatment with oral phosphate and calcitriol often has limited efficacy and is associated with adverse effects such as hyperparathyroidism and nephrocalcinosis. This case report describes the therapeutic outcomes of three pediatric patients with XLH treated with burosumab, a monoclonal antibody targeting FGF23. Burosumab acts directly on the underlying pathophysiology of the disease, improving phosphate homeostasis and bone metabolism. The patients showed improvements in clinical symptoms and biochemical parameters, with fewer adverse effects and greater treatment adherence compared with traditional therapy. These findings highlight burosumab as a promising and potentially more effective alternative for managing XLH in pediatric patients.