title: The role of fibroblast growth factor 23 for hypophosphatemia and abnormal regulation of vitamin D metabolism in patients with McCune-Albright syndrome.
abstract: McCune-Albright syndrome (MAS) is sometimes complicated by hypophosphatemia and abnormally low levels of 1,25(OH)(2)D in the presence of hypophosphatemia. Recently, fibroblast growth factor 23 (FGF-23) was reported as a phosphaturic and a causal factor of abnormal vitamin D metabolism. This abnormal phosphate and vitamin D metabolism is well known to be found in oncogenic and X-linked hypophosphatemia. We furthermore reported increased circulating plasma FGF-23 levels in patients with oncogenic and X-linked hypophosphatemia. To determine whether FGF-23 may be involved in the pathogenesis of MAS, we measured plasma FGF-23 levels in six MAS patients. As a control for hypophosphatemia, we also investigated the plasma FGF-23 levels in two patients with hereditary hypophosphatemic rickets with hypercalciuria (HHRH). We also investigated the correlation of plasma FGF-23 levels with serum phosphate and 1,25(OH)(2)D levels after short-term pamidronate therapy in three MAS patients. Plasma FGF-23 levels were significantly increased in patients with MAS compared to normal controls, whereas they were not increased in HHRH patients. Serum phosphate levels of the MAS patients were significantly lower than those observed in normal controls. Plasma FGF-23 levels showed significant negative correlation with serum phosphate concentrations. In three MAS patients, pamidronate therapy decreased plasma FGF-23 levels, which showed significant negative correlation with serum 1,25(OH)(2)D concentrations. These data suggested that FGF-23 is a possible causal factor for hypophosphatemia and abnormal vitamin D metabolism in MAS.
authors.affiliation: Department of Pediatrics, Minoh City Hospital, 5-7-1 Kayano, Minoh 562-8562, Japan. takehisa_yamamoto@maple.city.minoh.lg.jp
authors.forename: Takehisa
authors.initials: T
authors.lastname: Yamamoto
authors.forename: Yasuo
authors.initials: Y
authors.lastname: Imanishi
authors.forename: Eiichi
authors.initials: E
authors.lastname: Kinoshita
authors.forename: Yoshiko
authors.initials: Y
authors.lastname: Nakagomi
authors.forename: Nobuhiko
authors.initials: N
authors.lastname: Shimizu
authors.forename: Akimitsu
authors.initials: A
authors.lastname: Miyauchi
authors.forename: Kenichi
authors.initials: K
authors.lastname: Satomura
authors.forename: Hiroyuki
authors.initials: H
authors.lastname: Koshiyama
authors.forename: Masaaki
authors.initials: M
authors.lastname: Inaba
authors.forename: Yoshiki
authors.initials: Y
authors.lastname: Nishizawa
authors.forename: Harald
authors.initials: H
authors.lastname: Jüppner
authors.forename: Keiichi
authors.initials: K
authors.lastname: Ozono
mesh_terms: D000293:Adolescent; D000328:Adult; D002118:Calcium / Q000652:urine; D002648:Child; D004164:Diphosphonates / Q000494:pharmacology; D005260:Female; D000089703:Fibroblast Growth Factor-23; D005346:Fibroblast Growth Factors / Q000097:blood / Q000502:physiology* / Q000652:urine; D005359:Fibrous Dysplasia, Polyostotic / Q000378:metabolism*; D006801:Humans; D017674:Hypophosphatemia / Q000378:metabolism*; D007015:Hypophosphatemia, Familial / Q000378:metabolism; D000077268:Pamidronate; D014807:Vitamin D / Q000378:metabolism*
chemical_list: D004164:Diphosphonates; C000717427:FGF23 protein, human; D014807:Vitamin D; D005346:Fibroblast Growth Factors; D000089703:Fibroblast Growth Factor-23; D000077268:Pamidronate; D002118:Calcium