The most common types of phosphopenic rickets are the Fibroblast Growth Factor 23 (FGF23) mediated disorders, including XLH rickets, autosomal dominant and autosomal recessive forms of hypophosphatemic rickets (less common) and tumor induced osteomalacia, which may be also present in childhood (17). This evidence concerns the gene FGF23 and hypophosphatemic rickets.