[6][7] For both XLH and hypophosphatasia, inhibitor-enzyme pair relationships function to regulate mineralization in the extracellular matrix through a double-negative (inhibiting the inhibitors) activation effect in a manner described as the Stenciling Principle.

[8][9] Both these underlying mechanisms (renal phosphate wasting systemically, and mineralization inhibitor accumulation locally) contribute to the pathophysiology of XLH that leads to soft bones and teeth (hypomineralization, osteomalacia/odontomalacia).

[14] Clinical management of hypophosphatemic rickets may differ depending on the specific mutations associated with an individual case, but treatments are aimed at raising phosphate levels to promote normal bone formation.

[citation needed] The clinical laboratory evaluation of rickets begins with assessment of serum calcium, phosphate, and alkaline phosphatase levels.

[36] Carefully evaluate serum phosphate levels in the first year of life, because the concentration reference range for infants (5.0–7.5 mg/dL) is high compared with that for adults (2.7–4.5 mg/dL).

The TRP is calculated with the following formula:[citation needed] Conventional therapy consisted of medications including human growth hormone, calcitriol, and oral phosphate,[37][38] and calcitriol;[37][38] Unwanted effects of this therapy have included secondary hyperparathyroidism, nephrocalcinosis, kidney stones, and cardiovascular abnormalities.

[citation needed] In February 2018 the European Medicines Agency first licensed a monoclonal antibody directed against FGF23, the first drug targeting the underlying cause for this condition,[39] called burosumab.

[40] It was then licensed by the US Food and Drug Administration in June 2018[41] Burosumab is shown to target the major symptoms of XLH by decreasing elevated alkaline phosphatase and normalizing severe hypophosphatemia, leading to substantial improvement of rickets in child and adolescent patients.