People who were abused as children might still have signs of trauma in their DNA, a new study released Tuesday from the University of British Columbia and Harvard suggests, and that trauma could be transferred to their offspring.
Researchers looked at the chemical tags on the DNA of 34 men and found noticeable differences between those who had been abused and those who had not. The chemical tagging is known methylation, a “dimming” of genes that’s believed to be influenced by someone’s environment or life experiences.
The study specifically looked at sperm cells, with the idea that childhood abuse might carry not only into adulthood but onto the next generation, as previous experiments on animals have shown.
The researchers looked at 12 regions of the men’s genomes and were struck by the degree of “dimming” there. Eight DNA regions were more than 10-per-cent different, while one region revealed a difference of 29 per cent.
“When the sperm meets the egg, there is a massive amount of genetic reshuffling, and most of the methylation is at least temporarily erased,” said lead author Andrea Roberts, a research scientist at the Harvard Chan School.
“But finding a molecular signature in sperm brings us at least a step closer to determining whether child abuse might affect the health of the victim’s offspring.”
Researchers said the study’s small sample size made it hard to extrapolate out to the wider population, but hoped that if replicated in a larger study, the results could provide tools for law enforcement.
”Methylation is starting to be viewed as a potentially useful tool in criminal investigations – for example, by providing investigators with an approximate age of a person who left behind a sample of their DNA,” said senior author Michael Kobor, a medical genetics professor at UBC .
“So it’s conceivable that the correlations we found between methylation and child abuse might provide a percentage probability that abuse had occurred.”