title: Genetic and environmental influences on non-specific neck pain in early adolescence: a classical twin study.
abstract: BACKGROUND
  Prevalence of neck pain has increased among adolescents. The origins of adult chronic neck pain may lie in late childhood, but for early prevention, more information is needed about its aetiology. We investigated the relative roles of genetic and environmental factors in early adolescent neck pain with a classic twin study.
  
  
  METHODS
  Frequency of neck pain was assessed with a validated pain questionnaire in a population-based sample of nearly 1800 pairs of 11-12-year-old Finnish twins. Twin pair similarity for neck pain was quantified by polychoric correlations, and variance components were estimated with biometric structural equation modelling.
  
  
  RESULTS
  Prevalence of neck pain reported at least once monthly was 38% and at least once weekly 16%, with no significant differences between gender and zygosity. A greater polychoric correlation in liability to neck pain was found in monozygotic (0.67) than for dizygotic pairs (0.38), suggesting strong genetic influences. Model fitting indicated that 68% (95% confidence interval 62-74) of the variation in liability to neck pain could be attributed to genetic effects, with the remainder attributed to unshared environmental effects. No evidence for sex-specific genetic effects or for sex differences in the magnitude of genetic effects was found.
  
  
  CONCLUSIONS
  Genetic and unique environmental factors seem to play the most important roles in liability to neck pain in early adolescence. Future research should be directed to identifying pathways for genetic influences on neck pain and in exploring effectiveness of interventions that target already identified environmental risk factors.
authors.affiliation: Department of Physical and Rehabilitation Medicine, Hatanpää Hospital, Tampere, Finland. mikrst@utu.fi
authors.forename: M K
authors.initials: MK
authors.lastname: Ståhl
authors.forename: A A
authors.initials: AA
authors.lastname: El-Metwally
authors.forename: M K
authors.initials: MK
authors.lastname: Mikkelsson
authors.forename: J J
authors.initials: JJ
authors.lastname: Salminen
authors.forename: L R
authors.initials: LR
authors.lastname: Pulkkinen
authors.forename: R J
authors.initials: RJ
authors.lastname: Rose
authors.forename: J A
authors.initials: JA
authors.lastname: Kaprio
mesh_terms: D000293:Adolescent; D002648:Child; D004200:Diseases in Twins / Q000453:epidemiology / Q000235:genetics*; D005260:Female; D006801:Humans; D008297:Male; D019547:Neck Pain / Q000175:diagnosis / Q000235:genetics*; D011795:Surveys and Questionnaires; D014429:Twins, Dizygotic / Q000235:genetics; D014430:Twins, Monozygotic / Q000235:genetics