Trans-generational effect of radiation. Finding a tomorrow guide by the past lessons

This review describes findings concerning the trans-generational effect of radiation in animals and man. In experimental animals, there are findings of the effect in Drosophila irradiated by X-ray in 1927 and in mice by X- and gamma rays in 1982. Thereafter, many studies have been done on genetic stability of hypervariable minisatellite locus Ms6-hm in mice. In man, epidemiological findings are related with the effect. Although many studies are conducted on the epidemiology of people living in the high background radiation areas in China, of leukemia in radiation-exposed father's children, of Japanese A-bomb survivors and their descendants, and of people after Chernobyl accident, a possible trans-generational effect has been seen only in one of reports concerned with Chernobyl accident. Dynamic mutations of regions of hypervariable repeated sequence in man are discussed in relation with its genetic instability associated with hereditary diseases like fragile X syndrome. The author mentions that findings of the effect should provide answers for people's anxiety and questions. (N.I.)