FGF23-related hypophosphatemic diseases include various genetic conditions, such as X-linked hypophosphatemic rickets (XLH, MIM #307800), autosomal dominant hypophosphatemic rickets (ADHR, MIM #193100), autosomal recessive hypophosphatemic rickets 1 (ARHR1, MIM #241520), ARHR2 (MIM #613312), and Raine syndrome (RNS, MIM #259775) (4). The gene discussed is FGF23; the disease is autosomal dominant hypophosphatemic rickets.