X-linked hypophosphatemia (XLH) is a hereditary disorder characterized by increased renal phosphate wasting, which leads to clinical manifestations of rickets, bone deformities and growth retardation. XLN is transmitted as an X-linked dominant trait, affects both sexes equally and accounts for 80% of familial hypophosphatemic disorders. The disease is frequently manifested during the first two years of life. However, because of extremely variable severity and presentation, the diagnosis may be made late in adolescence and adulthood. Early diagnosis and adequate treatment of XLH is of paramount importance for achieving better disease management outcomes, such as fewer bone deformities, improved growth and better dental health. The study of XLH epidemiology is difficult because of low number of studies in this direction. In the recent years new molecular genetic tests have made possible the precise diagnosis and are now included in some of the studies with XLH patients. This publication aims to analyze the available epidemiological data on X-linked hypophosphatemia, as well as to provide an insight into XLH prevalence in Bulgaria. For more information click here.