In hypophosphatemic rickets, calcium levels may be within or slightly below the reference range; alkaline phosphatase levels will be significantly above the reference range.Carefully evaluate serum phosphate levels in the first year of life, because the concentration reference range for infants (5.0–7.5 mg/dL) is high compared with that for adults (2.7–4.5 mg/dL).Serum parathyroid hormone levels are within the reference range or slightly elevated, while calcitriol levels are low or within the lower reference range. Most importantly, urinary loss of phosphate is above the reference range.The renal tubular reabsorption of phosphate (TRP) in X-linked hypophosphatemia is 60%; normal TRP exceeds 90% at the same reduced plasma phosphate concentration. The TRP is calculated with the following formula:1 - [Phosphate Clearance (CPi) / Creatinine Clearance (Ccr)] X 100

Treatment
Oral phosphate, calcitriol; in the event of severe bowing, an osteotomy may be performed to correct the leg shape. The monoclonal antibody burosumab was first licensed in February 2018 by the European Medicines Agency, then licensed by the Food and Drug Administration in the United States of America in June 2018 as the first drug targeting the underlying cause for this condition.The leg deformity can be treated with Ilizarov frames and CAOS. It is also treated with medications including human growth hormone, calcitriol, and phosphate. Society and culture
International XLH Alliance – an alliance of international patient groups for individuals affected by XLH and related disorders. Jennyfer Marques Parinos is a Paralympic bronze medalist from Brazil who has XLH. She competes under a class 9 disability.
The FDA gave the drug a 1C rating, meaning that it found little difference between felodipine and the drugs already approved for the same use.In 1994 Astra AB and Merck changed their partnership to a joint venture called Astra Merck, and in 1998 Astra (by that time, AstraZeneca)  bought out Mercks rights in the joint venture.The first generics became available in Sweden in 2003 and in the US in 2004.: 155 In April 2016, AstraZeneca announced that they were selling the right to market felodipine in China to China Medical System Holdings for $310 million; AZ would continue to manufacture the drug. Society and culture
As of 2016, felodipine was marketed under many brand names worldwide: Auronal, Cardioplen, Catrazil, Dewei, Dilahex, Enfelo, Erding, Fedil, Fedisyn, Feldil, Felicipin, Felo, Felocard, Felocor, Feloday, Felodil, Felodin, Felodip, Felodipin, Felodipina, Felodipine, Felodipino, Felodistad, Felogard, Felohexal, Felop, Felopine, Felostad, Feloten, Felotens, Felpin, Flodicar, Flodil, Keliping, Keydipin, Lodistad, Modip, Munobal, Nirmadil, Parmid, Penedil, Perfudal, Phelop, Phenodical, Plendil, Plentopine, Polo, Presid, Preslow, Prevex, Renedil, Sistar, Splendil, Stapin, Topidil, Vascalpha, Versant, and XiaoDing.The combination of felodipine and candesartan was marketed as Atacand.The combination of felodipine and ramipril was marketed as Delmuno, Tazko, Triacor, Triapin, Triasyn, Tri-Plen, Unimax, and Unitens.The combination of felodipine and enalapril was marketed as Lexxel.The combination of felodipine and metoprolol was marketed as Logimat, Logimax, and Mobloc. == References ==