Endocrine Abstracts

Introduction: Fibroblast growth factor 23 (FGF23) excess is the cause of chronic hypophosphatemia in rare conditions such as X-linked hypophosphataemic rickets (XLHR) and tumour-induced osteomalacia (TIO), but animal studies indicate that the effect of FGF23 on serum phosphorus is dependent on the presence of parathyroid hormone (PTH). In this case series of rare disorders with abnormalities in renal phosphorus handling, we sought to explore the relative roles of PTH and FGF23...