title: Scoliosis in Prader-Willi syndrome: prevalence, effects of age, gender, body mass index, lean body mass and genotype.
abstract: BACKGROUND
  The reported prevalence of scoliosis in children with Prader-Willi syndrome varies from 15% to 86%.
  
  
  OBJECTIVE
  To study the prevalence of scoliosis and the effects of age, gender, body mass index (BMI), total lean body mass (LBM), LBM of the trunk (trunkLBM) and genotype.
  
  
  METHODS
  Radiographs were taken, length and weight were measured (BMI standard deviation scores (BMI SDS) and body surface area (BSA)), and dual energy x-ray absorptiometry was performed, measuring LBM and trunkLBM.
  
  
  METHODS
  96 children, median (interquartile range) age 4.8 years (2.1 to 7.5), were included in a multicentre study. None received growth hormone treatment.
  
  
  METHODS
  Two types of scoliosis were identified: (1) long C-curve type scoliosis (LCS) and (2) idiopathic scoliosis (IS). Children were divided into age categories (infants, 0-3 years; juveniles, 3-10 years; adolescents, 10-16 years).
  
  
  RESULTS
  The prevalence of scoliosis was 37.5% and increased with age (infants and juveniles, approximately 30%; adolescents, 80%); 44% of children with scoliosis had a Cobb angle above 20 degrees . Children with scoliosis were significantly older than those without. Children with LCS were younger and more hypotonic than those with IS: median (interquartile range) age 4.4 years (1.7-5.9) vs 11.1 years (6.5-12.1) (p = 0.002) and trunkLBM/BSA ratio 7080 (6745-7571) vs 7830 (6932-8157) (p = 0.043).
  
  
  CONCLUSIONS
  The prevalence of scoliosis in children with Prader-Willi syndrome is high (37.5%). Many children with scoliosis (13%) had undergone brace treatment or surgery. The type of scoliosis is affected by age and trunkLBM/BSA ratio.
authors.affiliation: Dutch Growth Research Foundation, Rotterdam, The Netherlands. r.delindvanwijngaarden@erasmusmc.nl
authors.forename: R F A
authors.initials: RF
authors.lastname: de Lind van Wijngaarden
authors.forename: L W L
authors.initials: LW
authors.lastname: de Klerk
authors.forename: D A M
authors.initials: DA
authors.lastname: Festen
authors.forename: A C S
authors.initials: AC
authors.lastname: Hokken-Koelega
mesh_terms: D015502:Absorptiometry, Photon; D000293:Adolescent; D017677:Age Distribution; D001823:Body Composition; D015992:Body Mass Index; D002648:Child; D002675:Child, Preschool; D005260:Female; D019382:Human Growth Hormone / Q000009:adverse effects / Q000627:therapeutic use; D006801:Humans; D007223:Infant; D008297:Male; D011218:Prader-Willi Syndrome / Q000150:complications*; D015995:Prevalence; D012600:Scoliosis / Q000000981:diagnostic imaging / Q000453:epidemiology* / Q000628:therapy
chemical_list: D019382:Human Growth Hormone