Elevated FGF23 in a patient with hypophosphatemic osteomalacia associated with neurofibromatosis type 1

The mechanism behind hypophosphatemia in the setting of neurofibromatosis type 1 (NF1) is not known. We describe a possible role of fibroblast growth factor-23 (FGF23) in the pathophysiology of hypophosphatemia in a patient with NF1. A 34-year woman with NF1 presented with severe hypophosphatemia, osteomalacia, and elevated plasma FGF23. The patient had considerable improvement on replacement of oral phosphate. Two Ga68 DOTANOC PET-CT scans over...