title: Epigenetics in Legg-Calvé-Perthes disease: A study of global DNA methylation.
abstract: OBJECTIVE
  To examine the global methylation status of DNA in blood cells of children with Legg-Calvé-Perthes disease (LCPD), since the aetiopathogenesis of LCPD remains unclear, and many factors closely associated with DNA methylation may be linked to the occurrence of LCPD.
  
  
  METHODS
  Children with LCPD and age-, sex- and body mass index-matched controls were evaluated. Methylation levels of the long interspersed nuclear element 1 (LINE-1), a biomarker of global DNA methylation, were quantified by methylation-specific polymerase chain reaction.
  
  
  RESULTS
  Of 82 children with LCPD (68 male/14 female) and 120 matched controls (98 male/22 female), methylation of the LINE-1 promoter was significantly lower in patients with LCPD compared with controls. Subgroup analyses showed that methylation of the LINE-1 promoter was significantly lower in male patients with LCPD compared with male controls. No significant between-group differences were observed in female participants.
  
  
  CONCLUSIONS
  Reduced global DNA methylation may be associated with increased risk of LCPD in male children. Further research is required to understand whether detection of global DNA methylation may provide a basis for clinical diagnosis and early intervention of LCPD.
authors.affiliation: Department of Paediatric Orthopaedics, Nanjing Children's Hospital Affiliated to Nanjing Medical University, Nanjing, China.
authors.forename: Pengfei
authors.initials: P
authors.lastname: Zheng
authors.affiliation: Department of Orthopaedics, People's Hospital of Jingjiang, Jingjiang, China.
authors.forename: Tao
authors.initials: T
authors.lastname: Yang
authors.affiliation: Department of Paediatric Orthopaedics, Nanjing Children's Hospital Affiliated to Nanjing Medical University, Nanjing, China.
authors.forename: Li
authors.initials: L
authors.lastname: Ju
authors.affiliation: Department of Paediatric Orthopaedics, Nanjing Children's Hospital Affiliated to Nanjing Medical University, Nanjing, China.
authors.forename: Bo
authors.initials: B
authors.lastname: Jiang
authors.affiliation: Department of Paediatric Orthopaedics, Nanjing Children's Hospital Affiliated to Nanjing Medical University, Nanjing, China yuelounjmu@sina.com.
authors.forename: Yue
authors.initials: Y
authors.lastname: Lou
mesh_terms: D000293:Adolescent; D016022:Case-Control Studies; D002648:Child; D002675:Child, Preschool; D019175:DNA Methylation / Q000235:genetics*; D044127:Epigenesis, Genetic; D005260:Female; D006801:Humans; D007873:Legg-Calve-Perthes Disease / Q000235:genetics*; D020084:Long Interspersed Nucleotide Elements / Q000235:genetics; D008297:Male; D011401:Promoter Regions, Genetic / Q000235:genetics
keywords: LCPD; Legg–Calvé–Perthes disease; epigenetics; global DNA methylation; long interspersed nuclear element 1