LONDON (Agence de Presse Medicale for Reuters Health) - Radiation exposure causes a high rate of genetic mutations for at least the next two generations, according to findings from a mouse study presented at the Children with Leukaemia conference in London on Tuesday.
Yuri Dubrova, Professor of Genetics at Leicester University, central England, said: “We have obtained the first experimental evidence that germ-line mutation rates in unexposed offspring of irradiated male mice do not return to normal unexposed mutation rates but are very similar to that of the irradiated males.
“Our results show that radiation-induced instability can be transmitted for at least two generations after initial paternal exposure to either fission neutrons or X-rays.”
The Ukrainian researcher told APM that the mutation rate in the offspring of exposed male mice was three to four times higher than in controls in many different cell types, including bone marrow and sperm.
The high mutation rate persisted not only in the first but also the second generation of mice. “This goes against all predictions of classical radiation biology. My major concern is to analyse why,” he said.
Dr. Dubrova’s group has also monitored radiation-induced mutation in humans and studied germ-line mutations among families from rural areas of Ukraine and Belarus, which were heavily contaminated by fallout from the Chernobyl disaster.
They found a statistically significant 1.6-fold increase in mutation rate in the germ-line of exposed fathers whereas the maternal germ-line mutation rate was not elevated.
Commenting on the results, Dr. Dubrova said: “Experimental evidence for radiation-induced mutation in the human germ-line remains highly controversial. But our studies in Ukraine and Belarus have shown that genomic instability can be induced in the paternal germ-line in humans.
“It remains to be seen whether this instability can be transmitted to further generations, as has shown to be the case in our mouse studies.”
A previous case-control study has suggested that occupational exposure of fathers working at the Sellafield nuclear reprocessing plant in Cumbria, north-west England, could explain a cluster of childhood leukamia cases in the nearby village of Seascale.
However other studies have failed to find any effect of paternal preconceptional irradiation.
MeSH Headings:Congresses: Health Care Economics and Organizations: Organizations: Germ-Line Mutation: Health CareCopyright © 2002 Reuters Limited. All rights reserved. Republication or redistribution of Reuters content, including by framing or similar means, is expressly prohibited without the prior written consent of Reuters. Reuters shall not be liable for any errors or delays in the content, or for any actions taken in reliance thereon. Reuters and the Reuters sphere logo are registered trademarks and trademarks of the Reuters group of companies around the world.
