In the early 1980s, the Syrian regime carried out a massacre in the city of Hama that left tens of thousands dead. A survivor (left) and her daughter and granddaughter are part of a study that is investigating whether such trauma can be inherited at a biological level. (Image credit: Photo by Amin Alwani)
There are markers found on DNA that change throughout life and can be passed on to future generations. These “epigenetic” markers affect gene expression—without changing their codes—and are subject to change depending on a person’s life experiences and environment.
Research suggests that stressful events can impact human epigenetics — but what happens at a broader level? How does human epigenetics change in populations that have been repeatedly exposed to trauma or violence over generations?
A new study published Feb. 27 in the journal Scientific Reports aims to answer that question.
An international collaboration of scientists, led by Rana Dajani, a molecular biologist at the Hashemite University in Jordan, has produced unique results: they found that epigenetic signatures of trauma can be passed down through generations. The study covered three generations of Syrian families who survived the Hama massacre of 1982 and the Syrian uprising that began in 2011.
“This is a fascinating and important study that highlights the importance of understanding how traumatic experiences can impact multiple generations,” Michael Place, a developmental psychology researcher at the University of Surrey in the U.K. who was not involved in the work, told Live Science in an email.
Multinational and multigenerational cooperation
Dajani primarily studies the genetics of ethnic groups in Jordan, but has always had an interest in stress and epigenetic inheritance. There are several studies in lab animals that suggest that epigenetic changes can be passed from one generation to the next.
However, the question of whether epigenetic traces of trauma and displacement can be passed down through generations remains open.
As the daughter of a Syrian refugee, Dajani realized she was in a unique position to explore this issue.
“It was in my head that I thought, ‘Wait, we can actually answer this question because of the unique characteristics and history that the Syrian community has experienced,’” Dajani told Live Science.
Dajani pitched her idea to Katherine Panter-Brick, a Yale anthropologist who specializes in stress biomarkers and global health, and Connie Mulligan, an epigeneticist at the University of Florida who studies childhood adversity. The three scientists spent the next decade collaborating on the study.
Connect with the community
Dajani and Dima Hamadmad, a co-author of the study and the daughter of Syrian refugees, reached out to families around the world largely through word of mouth. The researchers met with families and listened to their stories; they also explained the science of epigenetics, what to expect from the study’s results, and how the findings could raise awareness of their stories.
“They [the families] were happy because, firstly, they understood the science, and secondly, they felt a sense of ownership – that they were doing something in response to their experiences,” Dajani said.
“This was only possible because… I am a scientist and I am Syrian. So it was someone from the community center.”
The Hama massacre was a government attack on the city of Hama, in which an estimated 10,000 to 40,000 people were killed or went missing. The Syrian uprising that began in 2011 has left hundreds of thousands of civilians dead as they protested
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