X-linked hypophosphatemia is rare genetic disorder causing hypophosphatemic rickets. Typical clinical symptoms in children are: abnormal "duck" gait, deformities of the bones of lower extremities and progressive growth failure.
Conventional therapy involves lifelong administration of phosphate solution and active vitamin D. However, this treatment is not effective for important part of patients and can cause significant side effects.
An alternative to this treatment is anti-FGF-23 monoclonal antibody with the generic name burosumab which was approved for use in XLH in 2018 - this case report illustrates our experience with this novel therapy.