title: Hypophosphatemic rickets in opsismodysplasia.
abstract: BACKGROUND
  Opsismodysplasia is a rare spondylo(epi)chondrodysplasia characteristized by delayed skeletal maturation and a constellation of dysplastic features. Although metaphyseal irregularities/cupping have been noted, neither renal phosphate wasting nor rickets have previously been reported.
  
  
  OBJECTIVE
  To evaluate hypophosphatemia and rickets in opsismodysplasia.
  
  
  METHODS
  Two girls with opsismodysplasia presenting with hypophoshpatemia by 3 years of age.
  
  
  METHODS
  Routine biochemistries to assess hypophosphatemia and renal phosphate wasting; radiographs (rachitic changes) and DEXA scan (BMD); FGF23 levels, PHEX and FGF23 gene analyses performed (Patient 1).
  
  
  RESULTS
  Both children had hypophosphatemia, decreased TRP, and rickets. Oral phosphorus and calcitriol improved metaphyseal mineralization, yet serum phosphate levels remained relatively low and renal phosphate wasting persisted. PHEX and FGF23 gene analyses were negative, whereas serum FGF23 levels were markedly elevated in Patient 1.
  
  
  CONCLUSIONS
  We now demonstrate an association between opsismodysplasia, hypophosphatemic rickets, and FGF23 elevation. Screening phosphorus levels may thus uncover a potentially treatable component of this disease.
authors.affiliation: Pediatrics, Thomas Jefferson University, Philadelphia, PA, USA.
authors.forename: Martha Dechert
authors.initials: MD
authors.lastname: Zeger
authors.forename: Deanna
authors.initials: D
authors.lastname: Adkins
authors.forename: Lynn A
authors.initials: LA
authors.lastname: Fordham
authors.forename: Kenneth E
authors.initials: KE
authors.lastname: White
authors.forename: Eckhard
authors.initials: E
authors.lastname: Schoenau
authors.forename: Frank
authors.initials: F
authors.lastname: Rauch
authors.forename: Karen J
authors.initials: KJ
authors.lastname: Loechner
mesh_terms: D002675:Child, Preschool; D005260:Female; D000089703:Fibroblast Growth Factor-23; D005346:Fibroblast Growth Factors / Q000097:blood; D006801:Humans; D017674:Hypophosphatemia / Q000150:complications / Q000175:diagnosis*; D010009:Osteochondrodysplasias / Q000150:complications / Q000175:diagnosis* / Q000000981:diagnostic imaging; D011859:Radiography; D012279:Rickets / Q000150:complications / Q000175:diagnosis* / Q000000981:diagnostic imaging
chemical_list: C000717427:FGF23 protein, human; D005346:Fibroblast Growth Factors; D000089703:Fibroblast Growth Factor-23