title: Interaction between 5-HTTLPR and BDNF Val66Met polymorphisms on HPA axis reactivity in preschoolers.
abstract: This study examined whether the interaction between the serotonin transporter promoter region (5-HTTLPR) and brain-derived neurotrophic factor (BDNF) Val66Met polymorphisms was associated with hypothalamic-pituitary-adrenal (HPA) axis reactivity to stress. A community sample of 144 preschool-aged children was genotyped and exposed to stress-inducing laboratory tasks. Salivary cortisol was obtained at four time points during a standardized laboratory assessment before and after stressors involving separation from a parent and frustrating tasks. Children homozygous for the short-5-HTTLPR allele and carrying the Met-BDNF allele evidenced a significantly lower initial level of cortisol, followed by a positive increase in cortisol in response to the laboratory stressors. In contrast, children who were homozygous for the short-5-HTTLPR and the Val-BDNF alleles evidenced a greater decline in cortisol in response to the laboratory stressors. Findings indicated that the BDNF gene moderated the association between 5-HTTLPR and children's biological stress responses, suggesting that epistatic effects play a role in individual differences in stress regulation, and possibly genetic vulnerability to stress-related disorders.
authors.affiliation: Department of Psychology, Stony Brook University, NY, United States. ldougherty@psyc.umd.edu
authors.forename: Lea R
authors.initials: LR
authors.lastname: Dougherty
authors.forename: Daniel N
authors.initials: DN
authors.lastname: Klein
authors.forename: Eliza
authors.initials: E
authors.lastname: Congdon
authors.forename: Turhan
authors.initials: T
authors.lastname: Canli
authors.forename: Elizabeth P
authors.initials: EP
authors.lastname: Hayden
mesh_terms: D000483:Alleles; D019208:Brain-Derived Neurotrophic Factor / Q000235:genetics*; D002675:Child, Preschool; D005260:Female; D006801:Humans; D006854:Hydrocortisone / Q000032:analysis; D007030:Hypothalamo-Hypophyseal System / Q000502:physiology*; D008297:Male; D010913:Pituitary-Adrenal System / Q000502:physiology*; D011110:Polymorphism, Genetic / Q000235:genetics*; D012463:Saliva / Q000737:chemistry; D050486:Serotonin Plasma Membrane Transport Proteins / Q000235:genetics*; D013312:Stress, Physiological / Q000235:genetics*; D011795:Surveys and Questionnaires; D013694:Temperament
chemical_list: D019208:Brain-Derived Neurotrophic Factor; C493230:SLC6A4 protein, human; D050486:Serotonin Plasma Membrane Transport Proteins; D006854:Hydrocortisone