A clinician's guide to X-linked hypophosphatemia

Abstract

X-linked hypophosphatemia (XLH) is the prototypic disorder of renal phosphate wasting, and the most common form of heritable rickets. Physicians, patients, and support groups have all expressed concerns about the dearth of information about this disease and the lack of treatment guidelines, which frequently lead to missed diagnoses or mismanagement. This perspective addresses the recommendation by conferees for the dissemination of concise and accessible treatment guidelines for clinicians arising from the Advances in Rare Bone Diseases Scientific Conference held at the NIH in October 2008. We briefly review the clinical and pathophysiologic features of the disorder and offer this guide in response to the conference recommendation, based on our collective accumulated experience in the management of this complex disorder.

Figure 1

Lower extremities of a 3-year-old with newly diagnosed XLH. Note the frayed and widened metaphyses of the distal femurs and proximal tibias.

Figure 2

An insufficiency fracture is noted in the medial aspect of the right upper tibia (arrow) in this adult patient with XLH who has not received medical therapy (calcitriol or phosphate) for a number of years.