title: Genetic and gender influences on nocturnal bladder control--a study of 2900 3-year-old twin pairs.
abstract: OBJECTIVE
  The present study of over 2900 twin pairs born in England and Wales in 1994 examines the influences of genetics and gender on nocturnal bladder control at 3 years of age.
  
  
  METHODS
  Parent report data was analysed in terms of means and components of variance, using a sex-limitation model to explore genetic and environmental variation within and between the sexes.
  
  
  RESULTS
  Both genetics and gender are seen to influence acquisition: bladder control at 3 years is moderately heritable (24%), and girls show on average slightly increased acquisition compared with boys, even within opposite-sex pairs. The sex-limitation modelling showed an interaction between genetic influence and gender whereby nocturnal bladder control was significantly more heritable in boys (33%) than girls (10%).
  
  
  CONCLUSIONS
  Both genetics and gender are important and interacting factors in the aetiology of nocturnal bladder control.
authors.affiliation: Department of Clinical Psychology, Community & Mental Health Unit, High Royds Hospital, Leeds, UK.
authors.forename: R J
authors.initials: RJ
authors.lastname: Butler
authors.forename: M J
authors.initials: MJ
authors.lastname: Galsworthy
authors.forename: F
authors.initials: F
authors.lastname: Rijsdijk
authors.forename: R
authors.initials: R
authors.lastname: Plomin
mesh_terms: D002675:Child, Preschool; D004775:Enuresis / Q000235:genetics*; D005260:Female; D006801:Humans; D008297:Male; D012737:Sex Factors