Objective: The reported prevalence of scoliosis in Prader-Willi Syndrome (PWS) children varies from 15% to 86%. We studied 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.
Design: Children visited our hospital where X-rays were taken, length and weight were measured (BMI standard deviation scores (BMISDS) and body surface area (BSA)) and dual energy x-ray absorptiometry (DXA) was performed, measuring LBM and trunkLBM.
Patients: Ninety-six children, median (interquartile range, iqr) age 4.8 years (2.1 to 7.5), were included in a multi-centre study. None of them received growth hormone treatment.
Main Outcome Measures: 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: ~30%, adolescents: 80%), 44% of children with scoliosis had a Cobb angle above 20°. Children with scoliosis were significantly older than those without. Children with LCS were younger and more hypotonic than those with IS: median (iqr) age 4.4 years (1.7-5.9) vs. 11.1 years (6.5-12.1) (p=0.002) and trunkLBM:BSA 7080 (6745-7571) vs. 7830 (6932-8157) (p=0.043).
Conclusions The prevalence of scoliosis in PWS children is high (37.5%) and many children with scoliosis (13%) had undergone brace treatment or surgery. The type of scoliosis is affected by age and trunkLBM:BSA ratio.
- Prader-Willi syndrome
- body mass index
- lean body mass