Hypophosphatemic rickets: diagnosis and treatment

Hypophosphatemicrickets (HR) represents a heterogeneous group of disorders characterized by renal phosphate wasting, impaired bone mineralization, and skeletal deformities. This narrative review provides an overview of phosphate homeostasis and the molecular mechanisms underlying HR, focusing on the role of Fibroblast Growth Factor 23 (FGF23) in regulating renal phosphate use and vitamin D metabolism. The clinical, biochemical, and genetic features of both FGF23-dependent and -independent forms of HR are discussed, including X-linked hypophosphatemia (XLH), autosomal dominant hypophosphatemic rickets (ADHR), autosomal recessive hypophosphatemic rickets (ARHR), tumor-induced osteomalacia (TIO), hereditary hypophosphatemic rickets with hypercalciuria (HHRH), and Fanconi syndrome. Advances in understanding these mechanisms have led to the development of targeted therapies, such as burosumab, which are redefining the clinical management of affected individuals.