FGF23 and primary Fanconi syndrome: Various inherited phosphate wasting disorders have been identified, including X-linked autosomal hypophosphatemia (XLH; due to a mutation in PHEX), autosomal dominant hypophosphatemic rickets (ADHR; due to impaired cleavage of FGF23 caused by a mutation in FGF23), autosomal recessive hypophosphatemic rickets (ARHR; due to a mutation in DMP1) and Fanconi renotubular syndrome-2 (dysfunction of NaPi2a due to homozygous mutations in SLC34A1) [1].