title: Genetics of pre-pubertal growth: a longitudinal study of Japanese twins.
abstract: BACKGROUND
  Genetic factors explain a major part of the variation of adult stature, but little is still known on the genetics of growth, especially in non-Caucasian populations.
  
  
  OBJECTIVE
  To analyse the quantitative genetics of pre-pubertal growth in Japanese children.
  
  
  METHODS
  Data from birth until 11 years of age were collected on 349 complete twin pairs based on previously recorded height measures. The data were analysed using two different multivariate models by the Mx statistical package.
  
  
  RESULTS
  No major sex differences were found and thus boys and girls were analysed together. Since 1 year of age, genetic factors explained from 42-71% and environmental factors shared by co-twins from 14-33% of the variation of height. Genetic continuity of height was high and 75% of the genetic variance was shared since 1 year of age. Environmental factors affecting height showed weaker correlations between early and late childhood than genetic factors.
  
  
  CONCLUSIONS
  Growth from early to late childhood is largely regulated by the same set of genes. However, also environmental factors shared by co-twins are important for growth. Identifying specific environmental factors affecting growth has potentially important public health implications, even in an affluent society such as Japan.
authors.affiliation: Population Research Unit, Department of Social Research, University of Helsinki, Helsinki, Finland. karri.silventoinen@helsinki.fi
authors.forename: Karri
authors.initials: K
authors.lastname: Silventoinen
authors.forename: Jaakko
authors.initials: J
authors.lastname: Kaprio
authors.forename: Yoshie
authors.initials: Y
authors.lastname: Yokoyama
mesh_terms: D044466:Asian People / Q000235:genetics*; D001827:Body Height / Q000235:genetics; D002648:Child; D002675:Child, Preschool; D016001:Confidence Intervals; D004777:Environment; D005260:Female; D048788:Growth and Development / Q000235:genetics*; D006801:Humans; D007223:Infant; D007231:Infant, Newborn; D007564:Japan; D008137:Longitudinal Studies; D008297:Male; D008957:Models, Genetic; D011627:Puberty / Q000235:genetics*; D019655:Quantitative Trait, Heritable; D014427:Twins / Q000235:genetics*