Familial X-chromosome linked hypophosphatemic rickets: Report of a case

• Autores: Leon-Rabanal, Cristian, Ponce Gambini, Jenny
• Formato: artículo
• Fecha de Publicación: 2023
• Institución: Colegio Médico del Perú
• Repositorio: Acta Médica Peruana
• Lenguaje: español
• OAI Identifier: oai:ojs.pkp.sfu.ca:article/2431
• Enlace del recurso: https://amp.cmp.org.pe/index.php/AMP/article/view/2431
• Nivel de acceso: acceso abierto
• Materia: Rickets; Hypophosphatemia; X Chromosome

Phosphorus is regulated by the kidney and bone system orchestrated mainly by the action of parathormone (PTH) and a molecule recently described as fibroblast growth factor 23 (FGF-23). We present the cases of two mother-son patients with X-linked hypophosphatemic rickets. Hypophosphatemic rickets is part of a group of tubulopathies characterized by hyperphosphaturia. A genetic study was performed, identifying a mutation in the PHEX gene (pathogenic splicing-type variant in hemizygosis), mutation previously described as HGMD CS126536. Loss-of-function mutation of the PHEX gene leads to increased FGF-23. PHEX degrades FGF-23 into inactive fragments, preventing excessive phosphate excretion and the development of hypophosphatemia. In a patient with hypophosphatemia not dependent on the hormone PTH or vitamin D and of familial presentation, the diagnosis of X-linked hypophosphatemic rickets should be considered.