title: Effects of Genotype and Sleep on Temperament.
abstract: OBJECTIVE
  Sleep problems are frequent in young children; however, children vary in the degree to which they are affected by poor sleep quality. We investigated whether a polymorphism in the serotonin transporter gene, which is linked to emotional function, is a potential moderator of the influences of sleep duration on infant temperament using longitudinal data.
  
  
  METHODS
  We examined the interactive effects of average sleep duration between 6 and 36 months of age and the 5-HTTLPR genotype on negative emotionality/behavioral dysregulation at 36 months in 209 children recruited into a longitudinal birth cohort study. Triallelic genotyping of 5-HTTLPR was performed by looking at SLC6A4 genotype, focusing on the serotonin transporter-linked polymorphic region (5-HTTLPR) including the SNP polymorphism (rs23351). Child sleep habits were assessed with a maternal self-report questionnaire.
  
  
  RESULTS
  After controlling for demographics and both previous and concurrent maternal depression, multiple linear regression analyses revealed a significant interaction effect of average sleep duration for the first 3 years of life and 5-HTTLPR genotype on child negative emotionality/behavioral dysregulation such that the effects were exclusive to those with low-expressing 5-HTTLPR genotypes.
  
  
  CONCLUSIONS
  The results suggest differential susceptibility to the effect of sleep duration early in life, which reiterates that the short allele of the 5-HTTLPR represents a marker of increased environmental sensitivity regarding emotional development. Differential susceptibility theory posits that certain factors may increase an individual's susceptibility to the environment, in either a positive or negative fashion.
authors.affiliation: Ludmer Center for Neuroinformatics and Mental Health, and Douglas Mental Health University Institute, McGill University, Montreal Canada; Department of Psychology, University of Montreal, Montreal, Canada; andree-anne.bouvette-turcot@umontreal.ca.
authors.forename: Andrée-Anne
authors.initials: AA
authors.lastname: Bouvette-Turcot
authors.affiliation: Queen Mary University of London, London, United Kingdom;
authors.forename: Michael
authors.initials: M
authors.lastname: Pluess
authors.affiliation: Department of Psychology, University of Montreal, Montreal, Canada;
authors.forename: Annie
authors.initials: A
authors.lastname: Bernier
authors.affiliation: Ludmer Center for Neuroinformatics and Mental Health, and Douglas Mental Health University Institute, McGill University, Montreal Canada;
authors.forename: Marie-Hélène
authors.initials: MH
authors.lastname: Pennestri
authors.affiliation: Center for Addiction and Mental Health, and.
authors.forename: Robert
authors.initials: R
authors.lastname: Levitan
authors.affiliation: Department of Ecology and Evolutionary Biology, University of Toronto, Toronto, Canada;
authors.forename: Marla B
authors.initials: MB
authors.lastname: Sokolowski
authors.affiliation: Center for Addiction and Mental Health, and.
authors.forename: James L
authors.initials: JL
authors.lastname: Kennedy
authors.affiliation: Douglas Mental Health University Institute, McGill University, Montreal Canada;
authors.forename: Klaus
authors.initials: K
authors.lastname: Minde
authors.affiliation: Department of Psychiatry and Behavioral Neurosciences, McMaster University, Hamilton, Canada; Women's Health Concerns Clinic, St. Joseph's Healthcare, Hamilton, Canada; and.
authors.forename: Meir
authors.initials: M
authors.lastname: Steiner
authors.affiliation: Ludmer Center for Neuroinformatics and Mental Health, and Douglas Mental Health University Institute, McGill University, Montreal Canada;
authors.forename: Irina
authors.initials: I
authors.lastname: Pokhvisneva
authors.affiliation: Ludmer Center for Neuroinformatics and Mental Health, and Douglas Mental Health University Institute, McGill University, Montreal Canada; Singapore Institute for Clinical Sciences, Singapore.
authors.forename: Michael J
authors.initials: MJ
authors.lastname: Meaney
authors.affiliation: Ludmer Center for Neuroinformatics and Mental Health, and Douglas Mental Health University Institute, McGill University, Montreal Canada;
authors.forename: Hélène
authors.initials: H
authors.lastname: Gaudreau
mesh_terms: D002170:Canada; D002675:Child, Preschool; D015331:Cohort Studies; D005260:Female; D005838:Genotype; D006801:Humans; D007223:Infant; D008137:Longitudinal Studies; D008297:Male; D011110:Polymorphism, Genetic; D012044:Regression Analysis; D050486:Serotonin Plasma Membrane Transport Proteins / Q000235:genetics*; D012890:Sleep / Q000235:genetics* / Q000502:physiology; D013694:Temperament / Q000502:physiology*
chemical_list: C493230:SLC6A4 protein, human; D050486:Serotonin Plasma Membrane Transport Proteins