PTH and X-linked dominant hypophosphatemic rickets: The clinical phenotypes of XLHR include rickets, short stature, bone pain, bone deformities, and dental abnormalities.11 Biochemical findings in XLHR patients demonstrate low serum phosphate, low to normal serum 1,25-dihydroxyvitamin D, normal serum calcium, normal serum parathyroid hormone, and elevated alkaline phosphatase activity.11,12 Distinguishing XLHR from other forms of hypophosphatemic rickets in infancy is challenging, based solely on the clinical features and biochemical findings.