Read more...

X-linked hypophosphatemia (XLH) is a heritable form of rickets that results from mutations in the gene encoding the phosphate regulating endopeptidase (PHEX). Unlike diet-associated forms of rickets, XLH cannot be ameliorated by vitamin D ingestion. XLH patients have increased serum levels of FGF23, which decreases both inorganic phosphate (Pi) and the activated form of vitamin D.