Markers sit on DNA, change throughout a person’s life, and are even passed along from one generation to the next. The “epigenetic” marks can alter the expression of genes without changing their code. They are affected by a person’s environment and experiences. According to
research, stressful life events may alter a person’s epigenetics. But what about on a large scale? What happens to epigenetics in populations that have been exposed to violence or upheaval multiple times? This question was addressed in a new study published on February 27th, 19659002 by the journal Scientific Reports. The first of its kind results were published by an international team of researchers, convened at Hashemite University, Jordan, led by Rana Dajani, a molecular biologist. They found epigenetic markers of trauma that can be transmitted through the generations. Three generations of Syrians who experienced the Hama Massacre in 1982, and the Syrian Uprising in 2011, were studied. Study finds that epigenetic stress is reflected in sperm cells
Collaboration between generations and countries
Dajani studies mainly the genetics and ethnic groups in Jordan, but has always been interested in epigenetic inheritance and stress. Several studies on lab animals suggested that epigenetic modifications can be passed from generation to generation. Receive the most exciting discoveries from around the globe in your email. The question of epigenetic markers of trauma or displacement being passed on to future generations was still unanswered. Dajani, as the daughter of Syrian refugees, realized that she had a unique opportunity to investigate this question. Dajani spoke to Live Science. Dajani presented the idea to Catherine Panter Brick, a Yale University anthropologist with expertise in stress biomarkers, global health and childhood adversity. Connie Mulligan, an epigeneticist from the University of Florida, was also interested. They worked together for a decade on this study. Dajani Hamadmad, co-author and daughter of Syrian refugee, reached out to families around the globe primarily through word of mouth. Researchers sat with families to listen to their story. They also discussed the epigenetics science, the results of the study, and the ways in which these findings could help bring attention to the stories. Dajani stated.
“This could have only happened because … I’m a scientist and I’m Syrian. So it’s somebody from the community center.”
Hama Massacre was a government assault on Hama in the central west of the country, which resulted in the death or disappearance of between 10,000 and 40,000 civilians. In 2011, the Syrian uprising began, which resulted to the death of many civilians who were protesting against the Assad regime. The study took seven years in order to gather sufficient samples and find enough families that had three generations of females willing to take part. Researchers collected blood from women who were pregnant in 1982, their granddaughters and daughters. The researchers also took samples from women who were pregnant at the time of the uprising in 2011, as well as from their daughters and mothers. The research team also found families where the mother was pregnant during the uprising of 2011, and the daughter who was in utero at that time was exposed to the trauma. They also took samples of families who had fled Syria before the incidents to compare.
“You cannot find three generations of humans who have been subjected to the brutality of war in such a discrete way with grandmothers versus mothers versus children being exposed or non-exposed to war. So that’s a very unique design,” Panter-Brick said. Related: Researchers just changed our understanding of Epigenetics.
The epigenetic changes do not alter DNA’s underlying code, they simply modulate the genes that can be activated and in what degree. (Image credit: koto_feja via Getty Images)
The epigenetic effects of trauma
A study of samples found 21 unique epigenetic variations in the genome of those with direct trauma exposure. Additional 14 epigenetic changes appeared to be specific to grandchildren of women who had been exposed to trauma during pregnancy. These changes were observed at 35 different sites on the genome. The data indicated that the epigenetic pattern at most of these sites was the same regardless of whether the exposure occurred directly, during pregnancy or in a previous generation.
One common epigenetic alteration is a change in the DNA methyl groups. So, across all trauma types and sites, the majority of them showed either an addition or subtraction in “same direction,” . The authors note that this finding was not statistically significant due to small samples sizes. The findings should be confirmed in larger samples. Mulligan said to Live Science. This analysis found
that traumatized children in the womb exhibited epigenetically younger “older” compared to their chronological age. The so-called “accelerated epigenetic ageing” has been associated with a variety of health conditions, although it is unclear whether epigenetic changes are the cause or just reflect the problems. Mulligan (19659030) suggested that the accelerated epigenetic aging could be a result of trauma during an active phase of the fetal developmental process, explaining why the effect was seen only in prenatal exposure.
What is the impact on human health? Scientists don’t know yet what these differences in epigenetic signatures could mean for the health of humans. Mulligan proposed that “might have allowed humans to adapt to environmental stressors, particularly psychosocial stress and violence.” This theory will need to be verified in future research. The researchers will continue to investigate what epigenetics changes are biologically and study different groups of people in order to see if they have changed the same locations. Dajani has published previously about the impact of studies such as these on our perceptions regarding traumatic experiences. She said
“We can use this framing to go from victimhood and vulnerability to agency and adaptability,” . It’s a pure pleasure to watch the results at this stage. She added
“And it just means a lot for the population themselves, for our team of women scientists, and for the results of science,” . “But this is [also] an example of how we can work together for the benefit of humanity by understanding more about the challenges that humans repeatedly find themselves in when they face different kinds of violence.”
