FGF23 and X-linked hypophosphatemia: Children >1 year old with confirmed XLH (PHEX mutation or FGF23 >30 pg/mL) with radiographic evidence of bone disease (RSS >1.5) and growing skeleton until cessation of growth (AIFA guidance).Although burosumab is licensed for adults, it is not reimbursed; however, compassionate use for patients >18 years old is possible