La genetics It's not just a matter of DNA code anymore. Scientists are finding that childhood trauma can leave tangible traces in reproductive cells, altering the way genes are read and expressed. New research published in Molecular Psychiatry (I link it to you here) reveals how early stress can imprint its signature on the epigenetic markers of spermatozoa, opening up new scenarios on the biological transmission of traumatic experiences.
What the Study Reveals About Cellular Memory
A team of researchers led by Dr. Jetro Tuulari (congratulations to the parents for the name "rock": I checked the news 10 times because of you) of theUniversity of Turku in Finland analyzed the sperm of 58 men between 30 and 40 years old, focusing on two specific types of epigenetic markers: methylation DNA and Non-coding RNAs. These markers function as molecular switches, capable of modifying the activity of genes without altering the underlying DNA sequence.
The study is part of a larger project FinnBrain Birth Cohort, which involves over 4.000 families to study the influence of environmental and genetic factors on child development.
Measuring Childhood Trauma
To assess the impact of childhood stress, researchers used the Trauma and Distress Scale (TADS), a standardized questionnaire that investigates the presence of physical, emotional, or sexual abuse and neglect during childhood. The scores were then categorized into two groups: low stress (0-10 points) and high stress (over 39 points).
The analysis revealed significant differences in the epigenetic profile of sperm between the two groups, differences that persisted even after controlling for other factors such as smoking or alcohol consumption.
A small molecule with big meaning
Of particular interest was the discovery of a small non-coding RNA, called hsa-mir-34c-5p, whose expression was altered in men with a more traumatic childhood. This molecule had already attracted the attention of the scientific community for its role in early brain development in mice.
Additionally, the researchers observed changes in DNA methylation near two genes, CRTC1 e GBX2, also involved in brain development.
Il Professor Richard Jenner ofUniversity College London, who was not involved in the study, emphasizes that these results "add weight to the evidence" that life experiences can modify the epigenetics of human sperm. However, scientists remain cautiously optimistic. As he himself points out Dr. Tuulari, the transmission of these epigenetic modifications to offspring has so far been demonstrated only in animal models such as worms and mice, but not in humans.
Traumas transmitted through DNA: perspectives and cautions
It is not yet clear whether these epigenetic modifications have positive, negative, or neutral effects on the health of the offspring. The relatively small sample of the study and the presence of variables such as the age and diet of the participants suggest the need for further research. Especially, research with larger groups.
Nonetheless, the discovery opens new perspectives on understanding how traumatic experiences can affect not only those who directly experience them, but potentially also future generations.
Understanding heredity through genes and DNA has been one of the most crucial elements of our understanding of biology. We are now conducting research that challenges whether we have the full picture.
Therapeutic perspectives
While it is too early to draw definitive conclusions, this research may pave the way for new preventive and therapeutic strategies. The ability to identify and potentially intervene on these epigenetic markers may one day help mitigate the transgenerational impact of childhood trauma.
As the conclusion Professor Jenner, “only time will tell” whether this information can be used to improve the health of children of parents exposed to childhood stress.
