Abstract

SummaryX‑linked hypophosphatemic rickets (XLH, OMIM #307800) is a rare genetic metabolic disorder caused by dysregulation of fibroblast-like growth factor 23 (FGF23) leading to profound reduction in renal phosphate reabsorption. Impaired growth, severe rickets and complex skeletal deformities are direct consequences of hypophosphatemia representing major symptoms of XLH during childhood. In adults, secondary complications including early development of osteoarthritis substantially impair quality of life and cause significant clinical burden. With the global approval of the monoclonal FGF23 antibody burosumab, a targeted treatment with promising results in phase III studies is available for children with XLH. Nevertheless, complete phenotypic rescue is rarely achieved and remaining multisystemic symptoms demand multidisciplinary specialist care. Coordination of patient management within the major medical disciplines is a mainstay to optimize treatment and reduce disease burden. This review aims to depict different perspectives in XLH patient care in the setting of a multidisciplinary centre of expertise for rare bone diseases.

Highlights

  • PathophysiologyX-linked hypophosphatemic rickets (XLH) is caused by loss-of-function of PHEX and represents the most common form of hereditary hypophosphatemic rickets with a prevalence of 1/20000 newborns [1]

  • This review aims to depict different perspectives in XLH patient care in the setting of a multidisciplinary centre of expertise for rare bone diseases

  • XLH is characterized by profound hypophosphatemia due to increased levels of a key a regulator of phosphate handling, fibroblast-like growth factor 23 (FGF23)

Read more

Summary

Background

X-linked hypophosphatemic rickets (XLH) is caused by loss-of-function of PHEX (phosphate-regulating gene with homology to endopeptidases on the X chromosome) and represents the most common form of hereditary hypophosphatemic rickets with a prevalence of 1/20000 newborns [1]. XLH is characterized by profound hypophosphatemia due to increased levels of a key a regulator of phosphate handling, fibroblast-like growth factor 23 (FGF23). FGF23 and its coactivator alphaKlotho bind to fibroblast-like growth factor receptors (FGFRs) such as FGFR1 and regulate phosphate handling by two independent mechanisms [2]. Endocrine FGF23 represents the major link between phosphate storage in calcified tissues and nutritional phosphate handling and allows the body to react to high phosphate intake as well as to higher phosphate needs during growth periods. While bone represents the main source of endocrine FGF23, expression can be detected in multiple tissues with a so far mostly unclear role in health and disease [5, 6]

Clinical manifestation
Patient management
Diagnosis of XLH in children
Medical treatment
Diagnosis of XLH in adults
If hypertensive
Management of adult XLH patients
Differential diagnosis of low phosphate levels in adults
Orthopaedic management
Surgical treatment options
Findings
Conclusion
Full Text
Published version (Free)

Talk to us

Join us for a 30 min session where you can share your feedback and ask us any queries you have

Schedule a call