Effects of early caregiving adversity on children's DNA methylation: lessons from Russian orphanage and foster care
Date
2021
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Publisher
University of Delaware
Abstract
Early adversity in the form of institutional care negatively affects the development of regulatory systems, especially for infants. Children who spend the first years of their lives in institutional settings have alterations in numerous physiological and psychological systems that may reflect adaptation to their environment through genetic regulation. Enhancing the caregiving environment can potentially mitigate the adverse effects of institutionalization on infant self- regulation, but despite gene regulation being a potential mechanism linking institutional care to developmental outcomes, little is known about how gene regulation alters following removal from institutional care. The current study examines the impact of improved caregiving environment on DNA methylation of genes associated with the hypothalamic– pituitary–adrenal (HPA) axis among children in orphanage care, children in foster homes who had previously been in orphanage care, and children living with their biological families. DNA methylation was assessed from saliva samples collected from 135 children in the Russian Federation between the ages of 8 - 48 months, including children residing in orphanages (N = 65), previously institutionalized children residing with foster families (N = 36), and never institutionalized children residing with their biological families (N = 34). Methylation was assessed via bisulfide sequencing of CpG sites within FKBP5 and NR3C1. There was a significant effect of care type on FKBP5 methylation, with significantly lower methylation levels for children in institutional care than for children raised in biological families. No significant effect of care type was detected for methylation of NR3C1. Results support a theory of epigenetic reprogramming as adaptation to environmental factors, and suggests that transitioning children from environments of early deprivation and neglect into more supportive environments may attenuate or reverse epigenetic effects of such early adversity.
Description
Keywords
Institutional care, Caregiving, Foster care, Hypothalamic- pituitary-adrenal (HPA) axis, Orphanages