This is the first evidence that DNA of children can be affected by the effects of severe trauma from their parents.
We have found the first evidence from humans that epigenetic changes resulting from trauma in a parent may be inherited by the child.
An epigenetic change modifies the way genes are expressed by DNA, rather than a genetic change, which takes place in the DNA code itself. Exposure to trauma appears to cause epigenetic changes in humans.
We have observed epigenetic differences in blood samples of children of Holocaust survivors. These changes were in the same location of the gene as changes in the Holocaust survivors themselves.
In our study, blood samples from 32 Holocaust survivors and 22 of their adult children were studied and compared to a control group consisting of 8 parents and 9 children of similar ages from the Jewish community. Parents in the control group were Jewish, and comparable demographically to the Holocaust survivors, but were not in Europe during the Second World War. Blood samples from these participants were obtained and cytosine methylation was measured on a gene called “FK506 binding protein 5” (FKBP5). Epigenetic changes in this area have previously been linked to early trauma exposure, post-traumatic stress disorder (PTSD) and in major depression.
Adult children showed a decrease in methylation in one region of the gene, whereas their Holocaust survivor parents tended to show an increased methylation. Interestingly, changes in the region of the gene that could be attributed to a parent’s exposure to trauma was different from the region associated with trauma experienced by the child him/herself.
Furthermore, epigenetic changes were linked to lower cortisol levels in the adult children of holocaust survivors upon waking up. Cortisol is a hormone associated with anxiety and stress.
This is the first evidence that DNA of children can be affected by the effects of severe trauma from their parents. It is important to learn more about the nature of these effects. At this point, it is not clear whether the changes we have observed in offspring help adaptation and preparation of the next generation to better cope with stress, or do the opposite and increase vulnerability to stress.