Variation in the oxytocin receptor gene moderates the protective effects of a family-based prevention program on telomere length

• Authors: Erica L. Smearman, Emory University; Tianyi Yu, University of Georgia; Gene Brody, Emory University
• Journal Title: Brain and Behavior
• Volume: Volume 6, Number 2
• Publisher: Wiley Open Access | 2016-02, Pages n/a-n/a
• Type of Work: Article | Final Publisher PDF
• Publisher DOI: http://doi.org/10.1002/brb3.423
• Subjects: Biology, Genetics; Health Sciences, Human Development; Psychology, Behavioral
• Keywords: Gene–environment interaction; intervention; OXTR; oxytocin; parenting; telomere

Abstract

Introduction Parent–child relationships with high conflict and low warmth and support are associated with later adverse behavioral and physiological child outcomes. These outcomes include shorter telomere lengths, the repetitive sequences at the ends of chromosomes that have been utilized as a biomarker for chronic stress. Our research group furthered this by exploring telomere length outcomes following a family-based prevention program and identified reduced telomere shortening 5 years post intervention among those originally exposed to nonsupportive parenting and randomized to the intervention condition. However, not all individuals respond equally, and a growing literature suggests genetic sensitivity to one's environment, with variations in the oxytocin receptor gene (OXTR) potentially influencing this sensitivity. Methods We utilized data from African American youths (mean age 17) randomized to intervention (n = 100) or control condition (n = 91) with baseline assessments of genetic status and nonsupportive parenting, and 5-year follow-up assessments of telomere length. Results We found a significant three-way interaction between nonsupportive parenting, intervention condition, and OXTR rs53576 genotype. OXTR GG individuals, who are suggested to be more sensitive to their social environment, exhibited significantly more variability, evidencing the shortest telomeres when exposed to nonsupportive parenting and randomized to the control condition, and similar telomere lengths to non at-risk groups when randomized to the intervention. In contrast, those with the A allele showed no statistical difference in telomere lengths across parental and intervention conditions. Subsequent analyses suggest that these findings may be mediated through chronic anger, whereby GG individuals exposed to nonsupportive parenting and randomized to the control condition had a greater increase in chronic anger by study follow-up, compared to those in the intervention, and this change associated with greater telomere shortening. Conclusions These findings highlight the importance of individual differences and potential role of genetic status in moderating the relationship between environmental contexts and biological outcomes.