Its classic effects are inhibition of the expression of type 2a and 2c sodium‐phosphorus cotransporters on proximal renal tubules, which results in reduced phosphorus reabsorption and hypophosphatemia, and inhibition of the production of 1,25‐dihydroxyvitamin D and parathyroid hormone (PTH).3 Most clinical symptoms of TIO are the consequences of chronic hypophosphatemia. The gene discussed is SGCG; the disease is hypophosphatemia.