Guest Post:Traumatic experiences during childhood can leave genetic scars, studies find

Although standard theory suggests that genes are not supposed to change as they are passed down generations, recent studies have found that mistreatment as a child can physically affect one’s genetic material. The recent findings could have important implications on orphan and vulnerable children research, especially projects that pertain to the long-term effects of childhood trauma.

A recent Wall Street Journal article discusses the research results of two recent studies that link exposure to traumatic events—such as bullying, beating and domestic violence—and genetic “scarring.” As a part of one study, researchers examined the effect of psychosocial stress on the physical makeup of telomeres, or regions of genetic sequences on the end of chromosomes. Telomeres are partially meant for protection—they safeguard the chromosome from deterioration and from fusing with other chromosomes. These sequences deteriorate over time—a natural process, but one that is more rapid among people who recall psychosocial stress during childhood, researchers found.

Specifically, Stacy Drury, a professor of psychiatry and neurology at Tulane University, and coworkers discovered that the telomeres of children who resided in Bucharest orphanages were shorter than those who lived in foster families. Another cohort of the research team, from Duke University, used blood samples from study participants—which had been collected throughout their lives—to discover that telomeres shrink more rapidly, on average, in participants who experienced violence. The findings are not completely clear, however—the telomeres grew longer among some individuals.

Another study that the Wall Street Journal article highlights discovered that stress during childhood—either through maltreatment or through the loss of a parent—”results in greater ‘methylation’ of some spots near a gene tied to stress response in adulthood.” This finding is explained in further detail below:

[box] “Methylation, the addition of a methyl group of atoms to one DNA ‘letter,’ tends to reduce the activity of nearby genes. The implication of the Butler study is that adults who recall maltreatment as children may have reduced activity of a key gene in the system that responds to the stress hormone cortisol. This may be linked to increased anxiety or depression.

These are early days in the study of epigenetics. Scientists are like people finding coins under lampposts but not knowing how many coins remain in the dark. Although the ‘methylome’—a complete map of where methylation happens in the genome—is being talked of, others caution that we still have almost no idea of both the causes and effects of most such changes, let alone other epigenetic effects like histone modification.”[/box]

Though the implications of these recent studies is not entirely clear, it is important to note that some of these findings contrast with certain studies published on this site. For instance, the discovery that living in a Bucharest orphanage resulted in shorter telomeres than residing in a foster home conflicts with the finding of Positive Outcomes for Orphans, a longitudinal study conducted across the world that discovered that health, emotional and cognitive functioning, and physical growth were no worse for institution-residing than community-residing orphaned and abandoned children. In other words, the study discovered that living environment—institutional care versus community care—explained very little of the variability in child outcomes.

This study and others demonstrate that early life experiences can have long-term effects—regardless of whether such experiences result in physical DNA damage, or merely influence the emotional and physical wellbeing of an orphan. It will be important to see how studies like these impact policy outcomes, especially regarding the closure orphanages.

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