Endocrine Abstracts

Case History: X-linked hypophosphataemia (XLH) manifests as rickets in infancy or childhood, and is caused by mutations of the phosphate-regulating neutral endopeptidase (PHEX) gene, which leads to excess production of the fibroblast growth factor-23 (FGF-23) hormone. We present a case illustrating that mutation of PHEX can also cause hypophosphataemia presenting in adulthood. The proband is a 56-year-old male, who was referred with persistent hypophosphataem...

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...