FGF23 and X-linked hypophosphatemia: Increased serumconcentrations of intact FGF23 are a hallmark of renal phosphate-wasting diseases such asADHR, X-linked hypophosphatemia (XLH), tumor-induced osteomalacia, or autosomal recessivehypophosphatemic rickets 1 (Martin,David, and Quarles 2012).