[Cairo] A recent study has confirmed the occurrence of ‘epigenetic’ mutations that are inherited through genetic mechanisms from the generation exposed to war-related violence, through the next, and possibly to the third generation. Further studies may reveal their transmission to a fourth generation.
The psychological trauma caused by wars, while not altering the DNA sequence itself, leaves epigenetic effects—akin to ‘genetic scars’—on the genes. These do not disappear with the end of suffering for the generation that experienced the trauma, but instead play a role in transgenerational changes, affecting gene activity and expression.
‘Gene expression’ is the reading of information within a gene that directs the cell to perform its function, as explained by Rana Dajani, Professor of Cell Biology and Genetics at the Hashemite University in Jordan.
She continues, as co-lead author of the study: “We know that exposure to different environmental conditions causes changes in gene expression.”
Rana told SciDev.Net: “But today, we pose an important question that science has yet to answer: Can this effect be passed on to children and grandchildren?”
She adds: “This led us to study the impact of wars on epigenetic markers among Syrian women who have experienced the horrors of war, and the possibility of these altered markers being passed on to their descendants.”
The study—conducted by a multinational, multidisciplinary research team—analyzed DNA samples from 131 individuals belonging to 48 Syrian refugee families in Jordan, representing three generations. It compared different forms of exposure to violence, whether direct, during pregnancy (in utero), or through what is known as germ cells (cells responsible for passing genetic traits from one generation to the next before birth).
Rana explains that participants were divided into three main groups. The first included three categories from families of Syrian women who witnessed the Hama massacre in 1982: grandmothers who were pregnant at the time and directly traumatized, their daughters who were fetuses then and thus exposed via what is known as the “fetal effect,” and granddaughters who inherited the trauma’s effects through “germ cells.”
The second group included Syrian women who experienced war violence in 2011 while pregnant, and their children who were fetuses at the time.
The third—control—group consisted of Syrian women who moved to Jordan before 1982 and were not exposed to any war-related trauma.
Using oral samples taken from the inside of the cheeks, the research team identified 35 locations in the DNA that showed changes among those exposed to violence: 21 sites linked to direct exposure, and 14 linked to exposure via germ cells. No significant changes were observed in those exposed as fetuses in their mothers’ wombs.
Although the sites linked to direct exposure differed completely from those linked to germ cell exposure, 32 of the sites showed similar patterns of change across all exposure types. This indicates a similar epigenetic response to violence, regardless of the timing of exposure.
Thus, the study—published in the journal Scientific Reports on February 27—establishes an epigenetic fingerprint of violence that can be passed down through generations. It opens new horizons for a deeper understanding of the effects of psychological trauma, not only on those who experience it but also on their descendants.
Rana explains: “When examining the genetic material of participants, we observed 14 epigenetic sites passed from women who experienced wars to their daughters and granddaughters, but we did not see these changes in any members of the control group.”
The study also observed an increased rate of cellular aging in the offspring of women who were directly exposed to violence while pregnant, as measured by the epigenetic biological clock, reflecting inherited biological effects related to trauma.
“The study supports previous findings indicating that epigenetic markers are affected by environmental conditions, causing accelerated aging of cells in those who were fetuses at the time of maternal trauma or violence,” commented Adel El-Sherbiny, a postdoctoral researcher in the Department of Epigenetics at Heidelberg University Hospital.
He adds: “The current study points to a link between war-related trauma and changes in epigenetic markers, but these are not associated with a specific effect or the appearance of particular symptoms.”
He stresses the importance of the study and the need to “pay more attention to the children of those who have suffered the horrors of war.”
Rana agrees, saying: “The study is part of a larger puzzle that calls for further research. Its scope did not allow us to reveal the function of each epigenetic change, but it stands out by linking these changes to participants’ exposure to war trauma, through comparison with multi-generational control groups.”
She adds: “Our next step is to investigate the transmission of these epigenetic markers to a fourth generation, and we will expand the research to include the impact of war violence in the Palestinian community.” She notes that the study’s findings are especially significant amid ongoing armed conflicts, particularly in Gaza, as they could contribute to a deeper understanding of inherited genetic effects of trauma and the need to include them in psychological support and scientific research efforts.
Rana points out that these changes do not necessarily mean a negative effect: “They may even be positive, helping children and grandchildren adapt to and face challenges.”
Asmaa Ibrahim, a clinical psychologist with a PhD in philosophy in psychology, comments: “Post-traumatic stress disorder suffered by a father may be passed on to the son due to incorrect coping patterns, and the problem can reach the grandson as well. This issue is influenced by the surrounding environmental conditions, making therapeutic intervention necessary across generations.”
Asmaa notes that psychological theories explain this transmission, including psychoanalytic theory, which posits the transfer of disorders among family members through implicit messages received during upbringing, and attachment theory, which explains the difficulty in emotional communication among children whose parents have experienced trauma.
Sahar Talaat, a biodynamic psychotherapist and professor of anatomical pathology at Kasr Al-Ainy Faculty of Medicine in Egypt, says that trauma survivors develop defensive behaviors as psychological defenses and coping mechanisms, such as dissociation, which makes the parent emotionally unavailable to their children, displacement of suppressed anger onto children, or resorting to addictive behaviors—all of which facilitate the intergenerational transmission of psychological effects.
Sahar emphasizes that some traumas can be collective and transgenerational, affecting entire families or communities, as seen with the descendants of victims of world wars, genocide, or indigenous peoples under settler colonialism.
She concludes: “There are thousands of cases in the Arab world that have yet to be studied, even though the effects of colonialism and wars are still present in new generations, amid a lack of support and research attention.”
This article was produced by the SciDev.Net Regional Office for the Middle East and North Africa.
