Endocrine Abstracts

JOINT2611

Summary: X-linked hypophosphataemia (XLH) is a rare metabolic bone disorder where mutations in the PHEX gene lead to increase circulation of hormone fibroblast growth factor 23 (FGFR23), causing a series of clinical manifestations including rickets, lower-limb deformity, short stature, craniosynostosis, Chiari 1 malformations, spinal stenosis, pseudo fractures and osteoarthritis, among others, with significant impact to the patient’s quality of life. Imaging plays an important role in XLH from diagnosis to treatment response, early detection and management of complications. We present a comprehensive pictorial review of different imaging modalities used in our cohort of patients including x-rays, ultrasound, CT, MRI, bone scan and SPECT. We illustrate the most common findings seen at different stages of the disease and explain the advantages vs disadvantages of each imaging modality dependent on the clinical question posed for children and adults.

Methods: We searched the imaging database in our institution and found 42 patients with ages ranging from 3 to 78-years (20 under 16y) reviewed their imaging and selected the ones which best illustrate the findings seen at different stages of the disease including at diagnosis, during treatment response, and evidence of compilations. For some of the abnormalities we provide companion images depicting both normal appearances and the range of specific manifestations seen in non-XLH patients (e.g. grades of nephrocalcinosis) to facilitate a better understanding of the imaging findings.

Objectives: Know the available imaging toolbox and how to use it in XLH, from diagnosis to treatment response, including identification of complications, both in children and adults.