Lack of PV confirmation does not exclude the use of burosumab, as burosumab inhibits FGF23 directly targeting the pathophysiologic disease process and prevents the downstream pathologies of reduced 1,25(OH)2D3, increased urinary phosphate wasting, reduced phosphate absorption, hypophosphatemia and therefore osteomalacia.3 The gene discussed is FGF23; the disease is osteomalacia.