FGF23 was discovered as a novel member of theFGF family in the year 2000, when mutations putatively interfering with cleavage of theprotein were identified as the cause of autosomal dominant hypophosphatemic rickets (ADHRs),an inherited renal phosphate-wasting disease (The ADHR Consortium 2000). The gene discussed is FGF23; the disease is autosomal dominant hypophosphatemic rickets.