FGF23,besides inhibiting thereabsorption of renal phosphate, also stops the synthesis of calcitriol, active formof vitamin D.12,13,14 In this type of rickets, there is phosphaturia, 1.25 (OH)2,normal or reduced serum vitamin D3, and skeletal changes that are typical of thispathology, such as fractures, rachitic rosary and/or osteomalacia.8 The gene discussed is FGF23; the disease is rickets.