title: Genetic and environmental influences on growth from late childhood to adulthood: a longitudinal study of two Finnish twin cohorts.
abstract: OBJECTIVE
  Human growth is a complex process that remains insufficiently understood. We aimed to analyze genetic and environmental influences on growth from late childhood to early adulthood.
  
  
  METHODS
  Two cohorts of monozygotic and dizygotic (same sex and opposite sex) Finnish twin pairs were studied longitudinally using self-reported height at 11-12, 14, and 17 years and adult age (FinnTwin12) and at 16, 17, and 18 years and adult age (FinnTwin16). Univariate and multivariate variance component models for twin data were used.
  
  
  RESULTS
  From childhood to adulthood, genetic differences explained 72-81% of the variation of height in boys and 65-86% in girls. Environmental factors common to co-twins explained 5-23% of the variation of height, with the residual variation explained by environmental factors unique to each twin individual. Common environmental factors affecting height were highly correlated between the analyzed ages (0.72-0.99 and 0.91-1.00 for boys and girls, respectively). Genetic (0.58-0.99 and 0.70-0.99, respectively) and unique environmental factors (0.32-0.78 and 0.54-0.82, respectively) affecting height at different ages were more weakly, but still substantially, correlated.
  
  
  CONCLUSIONS
  The genetic contribution to height is strong during adolescence. The high genetic correlations detected across the ages encourage further efforts to identify genes affecting growth. Common and unique environmental factors affecting height during adolescence are also important, and further studies are necessary to identify their nature and test whether they interact with genetic factors.
authors.affiliation: Department of Genetics, Physical Anthropology and Animal Physiology, University of the Basque Country, Bilbao, Spain. aline.jelenkovic@ehu.es
authors.forename: Aline
authors.initials: A
authors.lastname: Jelenkovic
authors.forename: Alfredo
authors.initials: A
authors.lastname: Ortega-Alonso
authors.forename: Richard J
authors.initials: RJ
authors.lastname: Rose
authors.forename: Jaakko
authors.initials: J
authors.lastname: Kaprio
authors.forename: Esther
authors.initials: E
authors.lastname: Rebato
authors.forename: Karri
authors.initials: K
authors.lastname: Silventoinen
mesh_terms: D000293:Adolescent; D041923:Adolescent Development; D000328:Adult; D001827:Body Height; D002648:Child; D002657:Child Development; D015331:Cohort Studies; D004777:Environment; D005260:Female; D005387:Finland; D006801:Humans; D008137:Longitudinal Studies; D008297:Male; D015999:Multivariate Analysis; D012737:Sex Factors; D014427:Twins / Q000235:genetics*; D014429:Twins, Dizygotic / Q000235:genetics; D014430:Twins, Monozygotic / Q000235:genetics; D055815:Young Adult