X-Linked Hypophosphatemia, case report

Background: rickets is characterized by an alteration in the normal mineralization of bone tissue and can be classified in acquired or hereditary forms. X-linked hypophosphatemic rickets (XLH) is the most common cause of hereditary forms. It is characterized by an abnormal phosphorus metabolism due to an alteration in the PHEX gene (phosphate regulating endopeptidase analog, X-linked) located on the X chromosome. This abnormal gene affects the codification of a metalloprotease that has the function of decrease the serum levels of the fibroblast growth factor - 23 (FGF-23), generating an abnormal loss of phosphorus through urine. Patients presents with bone deformities in the lower limbs, bone pain, short stature, and dental alterations. The diagnosis is made by the clinical presentation, associated with hypophosphatemia, phosphaturia and radiological findings suggestive of rickets and it is confirmed by molecular testing with the identification of the mutation in the PHEX gene. Case presentation: we describe the case of a 5-year-old patient who was diagnosed with XLH. The early diagnosis allowed to have an early treatment implementation and this improved the clinical outcomes. Conclusion:As a rare hereditary disease that has onset in childhood and has a big impact on longitudinal growth, bone health and can potentially affects the quality of life of children, we aim to provide a basic clinical tools for a comprehensive diagnosis approach of XLH.