Clinical practice recommendations for the diagnosis and management of X-linked hypophosphataemia.

X-linked hypophosphataemia (XLH) is a rare metabolic bone disorder caused by pathogenic variants in the PHEX gene, which is predominantly expressed in osteoblasts, osteocytes and odontoblasts. XLH is characterized by increased synthesis of the bone-derived phosphaturic hormone fibroblast growth factor 23 (FGF23), which results in renal phosphate wasting with consecutive hypophosphataemia, rickets, osteomalacia, disproportionate short stature, oral manifestations, pseudofractures, craniosynostosis, enthesopathies and osteoarthritis. Patients with XLH should be provided with multidisciplinary care organized by a metabolic bone expert.

X-linked hypophosphataemia.

X-linked hypophosphataemia is a genetic disease caused by defects in the phosphate regulating endopeptidase homolog X-linked (PHEX) gene and is characterised by X-linked dominant inheritance. The main consequence of PHEX deficiency is increased production of the phosphaturic hormone fibroblast growth factor 23 (FGF23) in osteoblasts and osteocytes. Chronic exposure to circulating FGF23 is responsible for renal phosphate wasting and decreased synthesis of calcitriol, which decreases intestinal phosphate absorption.

Metabolically healthy obesity in adults with X-linked hypophosphatemia.

Objectives: X-linked hypophosphatemia (XLH) is characterized by increased concentrations of circulating fibroblast growth factor 23 (FGF-23) resulting in phosphate wasting, hypophosphatemia, atypical growth plate and bone matrix mineralization. Epidemiologic studies suggest a relationship between FGF-23, obesity, and metabolic dysfunction. The prevalence of overweight and obesity is high in children with XLH.

Improved Oral Health in Adults with X-Linked Hypophosphatemia Treated with Burosumab.

Context: X-linked hypophosphatemia (XLH) is a rare genetic bone disease affecting both children and adults, with oral manifestations such as spontaneous dental infections. The main treatments for XLH are conventional treatment (CT) with oral phosphate salts and active vitamin D supplementation, and burosumab, an antibody targeting Fibroblast Growth Factor 23 (FGF23). While the beneficial effect of CT on oral manifestations is established, the effect of burosumab on oral health is unknown, especially in adults.