title: Two Case Reports of FGF23-Induced Hypophosphatemia in Childhood Biliary Atresia.
abstract: Cholestatic liver disease has long been associated with childhood rickets, secondary to impaired absorption of fat-soluble vitamin D. Elevated serum levels of fibroblast growth factor 23 (FGF23), secondary to genetic defects or tumor-induced osteomalacia, causes hypophosphatemic rickets in childhood. We present 2 infants with end-stage liver disease due to biliary atresia (BA) who developed hypophosphatemia with renal phosphate wasting. Serum FGF23 levels were elevated more than 8 times the upper limit of normal, and the older infant showed radiographic evidence of rickets. Both infants required large supplements of phosphate in addition to calcitriol. Following liver transplantation, FGF23 normalized in both patients and phosphate and calcitriol supplementation were discontinued. Immunohistochemistry revealed ectopic overexpression of FGF23 by hepatocytes in the BA liver. These observations highlight a unique cause of hypophosphatemic rickets in childhood and suggest the need for further investigation into the relationship between BA and other cholestatic disorders, and bone metabolism.
authors.affiliation: Divisions of Endocrinology, Halley.wasserman@cchmc.org.
authors.forename: Halley
authors.initials: H
authors.lastname: Wasserman
authors.affiliation: Divisions of Endocrinology.
authors.forename: Chijioke
authors.initials: C
authors.lastname: Ikomi
authors.affiliation: Gastroenterology, Hepatology, and Nutrition, and.
authors.forename: Einar T
authors.initials: ET
authors.lastname: Hafberg
authors.affiliation: Gastroenterology, Hepatology, and Nutrition, and.
authors.forename: Alexander G
authors.initials: AG
authors.lastname: Miethke
authors.affiliation: Pathology, Cincinnati Children's Hospital Medical Center, University of Cincinnati, Cincinnati, Ohio.
authors.forename: Kevin E
authors.initials: KE
authors.lastname: Bove
authors.affiliation: Divisions of Endocrinology.
authors.forename: Philippe F
authors.initials: PF
authors.lastname: Backeljauw
mesh_terms: D001656:Biliary Atresia / Q000150:complications*; D053098:Familial Hypophosphatemic Rickets / Q000097:blood* / Q000209:etiology*; D005260:Female; D000089703:Fibroblast Growth Factor-23; D005346:Fibroblast Growth Factors / Q000097:blood*; D006801:Humans; D007223:Infant; D008297:Male
chemical_list: C000717427:FGF23 protein, human; D005346:Fibroblast Growth Factors; D000089703:Fibroblast Growth Factor-23