X-linked hypophosphatemic rickets: from diagnosis to management.

X-linked hypophosphatemia (XLH) is the most common cause of hypophosphatemic rickets, affecting one in 20,000 people. Although conventional therapy for XLH has been introduced for approximately four decades, temporary replacement of oral phosphate salts and activated vitamin D cannot completely control chronic hypophosphatemia, leaving patients with incomplete healing of rickets, residual skeletal deformity, risk of endocrine abnormalities, and adverse drug reactions. However, understanding the pathophysiology has led to the development of a targeted therapy, burosumab, a fibroblast growth factor-23 inhibitor, which was recently approved for the treatment of XLH in Korea. In this review, we provide insight into the diagnosis, evaluation, treatment, and recommended follow-up for a typical case of XLH and review the pathophysiology of this condition.