FGF23 and X-linked dominant hypophosphatemic rickets: XLH is a rare, progressive, and lifelong hereditary phosphate‐wasting disorder characterized by loss of function of the phosphate‐regulating endopeptidase homologue, X‐linked gene, which is associated with premature fusion of cranial sutures due to abnormal phosphate metabolism (hypophosphatemia) and altered bone mineralization or elevated levels of fibroblast growth factor 23.