Unimaginable trauma left its mark on the DNA of survivors of the 1994 Rwandan genocide. What is even more shocking is that the imprint left by this psychological trauma in the genome is also passed on to the next generation, and this imprint can be found in the DNA of even unborn offspring at the time of the horrific event.
Scientists from the University of South Florida and the University of Rwanda studied the entire genome of pregnant women living in Rwanda during the genocide, as well as their offspring, and compared their DNA with other Tutsi women living elsewhere in the world during the Holocaust and their offspring.
DNA is sometimes seen as a fixed code, but the expression of certain genes can be altered by epigenetic changes, which are influenced by lifestyle, experience, and the environment. In pregnant women who have experienced genocide horrors, researchers have found chemical modifications to DNA that were previously thought to be associated with the risk of mental health conditions such as post-traumatic stress disorder and depression. These same traits were also found in offspring who were still fetuses at the time, suggesting that epigenetic changes had been inherited.
Professor Monica Uddin of the University of South Florida, the study's lead author, said in a statement: "Epigenetics refers to stable but reversible chemical modifications to DNA that help control the function of genes." "These changes occur shorter than it takes to alter the DNA sequence of a potential gene." Our study found that prenatal exposure to genocide is associated with epigenetic patterns of reduced genetic function in offspring. ”
To understand the depth of the trauma, it is important to understand the brutality of the Rwandan genocide. During the Rwandan civil war, an estimated 1 million people were slaughtered in 100 days from April to July 1994. Sexual violence is also widespread, with an estimated 150,000 to 250,000 women being raped during the crisis.
Most of the victims are Tutsi, a minority that has historically dominated the state's power structure, while the perpetrators are mainly Hutus, a minority that seized power in the 1959 and 1962 revolutions. Civil war broke out in 1990 as the exiled Tutsi rebel group, the Rwandan Patriotic Front ,RNI , attempted to regain power. Although a peace treaty was reached in 1993, on the night of April 6, 1994, the plane on which President Juvénal Habyarimana was travelling was shot down by a rocket, plunging the country into chaos again. Hutu nationalists immediately launched an organized campaign of extreme violence against Tutsi and their sympathizers, with local militias and the Hutu government inciting ordinary citizens to commit atrocities against their neighbors.
Speaking about the latest study, researcher Professor Derek Wildman noted: "The Rwandans involved in this study, as well as the community at large, wanted to know what was going on with them because Rwanda has a lot of PTSD and other mental health conditions and people want to know why they have these feelings and problems."
While this is the first time genetic studies have been conducted to understand the impact of genocide on the people of Rwanda, previous studies have come to similar conclusions in other devastating events in world history. In 2018, a study looked at victims of famine that struck the Nazi-occupied Netherlands at the end of World War II. Like the new study in Rwanda, they found that epigenetic changes triggered by the extreme hardship they experienced while they were still in the womb may well explain why people born after the so-called "starvation winter" have a range of health problems.