title: Cross-sectional study shows that impaired bone mineral status and metabolism are found in nonmosaic triple X syndrome.
abstract: OBJECTIVE
  The effect of a supernumerary X chromosome on bones has not been reported, and this study evaluated bone mineral status and metabolism in nonmosaic triple X syndrome.
  
  
  METHODS
  This cross-sectional study comprised 19 girls, with a median age of 10.9 years, with nonmosaic triple X syndrome and a control group matched for age and body size. We studied ionised and total calcium, phosphate, parathyroid hormone (PTH), 25-hydroxyvitamin D (25(OH)D), 1,25-dihydroxyvitamin D, osteocalcin, bone alkaline phosphatase levels and urinary deoxypyridinoline concentrations. We also measured the phalangeal amplitude-dependent speed of sound (AD-SoS) and the bone transmission time (BTT) Z-scores.
  
  
  RESULTS
  Patients with nonmosaic triple X syndrome showed significantly reduced AD-SoS (p < 0.005) and BTT Z-scores (p < 0.0001) compared to the control group, and these results persisted when we divided the sample into prepubertal and pubertal patients (p < 0.05). These patients also had significantly reduced ionised calcium (p < 0.005) and 25(OH)D levels (p < 0.005) and higher phosphate (p < 0.0001) and PTH (p < 0.0001) levels.
  
  
  CONCLUSIONS
  Subjects with nonmosaic triple X syndrome exhibited a significant impairment in bone mineral status and metabolism similar to other X polisomy, such as Klinefelter's syndrome. This suggests the presence of a primary bone deficit and the need for regular and close monitoring of these subjects.
authors.affiliation: Department of Health Sciences, University of Florence, Anna Meyer Children's University Hospital, Florence, Italy.
authors.forename: Stefano
authors.identifier: http://orcid.org/0000-0002-2259-4685
authors.initials: S
authors.lastname: Stagi
authors.affiliation: Department of Health Sciences, University of Florence, Careggi Hospital, Florence, Italy.
authors.forename: Mariarosaria
authors.initials: M
authors.lastname: Di Tommaso
authors.affiliation: Department of Health Sciences, University of Florence, Anna Meyer Children's University Hospital, Florence, Italy.
authors.forename: Perla
authors.initials: P
authors.lastname: Scalini
authors.affiliation: Department of Health Sciences, University of Florence, Anna Meyer Children's University Hospital, Florence, Italy.
authors.forename: Elena
authors.initials: E
authors.lastname: Sandini
authors.affiliation: Paediatric Unit, Empoli Hospital, Empoli, Italy.
authors.forename: Fabrizio
authors.initials: F
authors.lastname: Masoni
authors.affiliation: Department of Paediatrics, University of Chieti, Chieti, Italy.
authors.forename: Francesco
authors.initials: F
authors.lastname: Chiarelli
authors.affiliation: Department of Paediatrics, University of L'Aquila, L'Aquila, Italy.
authors.forename: Alberto
authors.initials: A
authors.lastname: Verrotti
authors.affiliation: Genetics and Molecular Medicine Unit, Anna Meyer Children's University Hospital, Florence, Italy.
authors.forename: Sabrina
authors.initials: S
authors.lastname: Giglio
authors.affiliation: Genetics and Molecular Medicine Unit, Anna Meyer Children's University Hospital, Florence, Italy.
authors.forename: Silvia
authors.initials: S
authors.lastname: Romano
authors.affiliation: Department of Health Sciences, University of Florence, Anna Meyer Children's University Hospital, Florence, Italy.
authors.forename: Maurizio
authors.initials: M
authors.lastname: de Martino
mesh_terms: D000293:Adolescent; D001842:Bone and Bones / Q000378:metabolism*; D002113:Calcification, Physiologic; D002648:Child; D041321:Chromosomes, Human, X / Q000378:metabolism; D003430:Cross-Sectional Studies; D006801:Humans; D012729:Sex Chromosome Aberrations; D058533:Sex Chromosome Disorders of Sex Development / Q000378:metabolism*; D014314:Trisomy
keywords: Bone metabolism; Bone quality; Parathyroid hormone; Quantitative ultrasonometry; Triple X syndrome