FGF23 and idiopathic hypercalciuria: The non-FGF23-mediated disorders displaying hypophosphatemia, including hereditary hypophosphatemic rickets with hypercalciuria, idiopathic hypercalciuria and Fanconi syndrome display similar phenotypes yet, in contrast to the FGF23-mediated syndromes, result in normal FGF23 levels and normal or appropriately elevated 1,25(OH)2D concentrations [34,35,36].