An impaired HRQoL was also found in patients with XLH (a genetic form of a FGF23‐related hypophosphatemic disease).(23, 24, 25) XLH patients showed mean values of SF‐36 score similar to patients with chronic musculoskeletal diseases such as rheumatoid arthritis or juvenile idiopathic arthritis.(25) Indeed, in our population, the physical summary measurements were significantly lower even in comparison with a population with chronic conditions in Argentina. This evidence concerns the gene FGF23 and juvenile idiopathic arthritis.