DNA mutations discovered in children of Chernobyl workers

A new study is the first to provide evidence of a transgenerational effect of prolonged paternal exposure to low-dose ionizing radiation on the human genome.

Os damage us not dna that were caused by ionizing radiation emitted by the nuclear catastrophe in 1986, are manifest itself in children of people originally exposed, concluded a team of researchers from the University of Bonn, Germany.

This is the first time that a clearly established transgenerational link of this type.

Previous studies had shown results inconclusive regarding the possibility of this genetic damage being transmitted from parents to children. But in this case, investigators were looking for something slightly different.

Instead of identifying new mutations of DNA in the next generation, they looked for what is called mutations again clustered (cDNM): two or more mutations close to each other, found in children but not in parents.

These would be mutations resulting from breaks in parental DNA caused by exposure to radiation.

“We found a significant increase in the number of cDNM in the descendants of irradiated parents, and a potential association between dose estimates and the number of cNDM in the respective descendants”, write the authors of the , which was published in the journal Scientific Reports.

“Despite the uncertainty regarding the precise nature and quantity of the ionizing radiation involved, the present study is the first to provide evidence of the existence of a transgenerational effect of prolonged paternal exposure low-dose ionizing radiation on the human genome.”

The conclusions are based on complete genome sequences of 130 descendants of Chernobyl cleanup workers, 110 descendants of German military radar operators who were likely exposed to stray radiation, and 1,275 descendants of parents not exposed to radiation, used as a control group.

On average, researchers found 2.65 cDNM per child in the Chernobyl group, 1.48 per child in the German radar group, and 0.88 per child in the control group. Researchers say these numbers are likely overestimated due to noise in the databut even after statistical adjustments, the difference continued to be significant.

Furthermore, a higher radiation dose to the parent tended to mean a mgreater number of clusters in the childwhich is in line with the idea that radiation creates molecules known as reactive oxygen speciescapable of breaking DNA chains – breaks that can leave behind the clusters described in this study, if they are repaired imperfectly.

The good news is that the health risk must be relatively small: children of exposed parents did not present any risk plus illness. This is partly due to the fact that many of the cDNM are likely to be located in DNA.”non-coding“, rather than in genes that directly code for proteins, explains .

“Given the low overall increase in cDNM following paternal exposure to ionizing radiation and low proportion of the genome that is coding of proteins, the likelihood of a disease occurring in offspring of exposed parents being triggered by a cNDM is minimal,” the researchers write.

To put this into perspective, we know that older parents are more likely to transmit more DNA mutations to your children. The subsequent risk of disease associated with parental age at conception is greater than the potential risks of radiation exposure examined here, the researchers report.

There are some limitations to be noted. Because the initial exposure to radiation happened decades ago, researchers had to estimate people’s exposures using historical records and devices that are decades old.

A Participation in the study was also voluntarywhich may have introduced some envyas those who suspected they had been exposed to radiation may have been more likely to sign up.

Even with these limitations, we now know that, with prolonged exposure, ionizing radiation can leave subtle traces in DNA generations to come – highlighting the need for safety precautions and careful monitoring for those at risk.

“The potential for transmitting radiation-induced genetic changes to the next generation is particularly worrying for parents who may have been exposed to higher doses of ionizing radiation and potentially for longer periods of time than considered safe,” the researchers conclude.