Fibroblasts from Li-Fraumeni patients are resistant to low dose-rate irradiation

A group of adult skin fibroblast cultures from four individuals representing Li-Fraumeni families with different mutations in the p53 gene were found to be resistant to low dose-rate (0.011 Gy per min) 60Co radiation when compared with a control group of four cultures from normal individuals. The Li-Fraumeni fibroblasts, which could not be distinguished from controls after high dose rate (1.07 Gy per min) irradiation, were shown to be heterozygous (+/mut) at the p53 locus at the time of irradiation.