Variations in DNA Repair Among People

摘要: A number of inherited, cancer-prone diseases are associated with severe defects in the abilities cells to repair damaged DNA (Setlow, 1978; Friedberg, 1985; Maher, this volume; Paterson, volume). The largest xeroderma pigmentosum (XP) and ataxia telangiectasia (AT), former showing high levels skin cancer as a result sunlight irradiation latter, lymphoreticular whose etiologic origins unknown. cytotoxic effects ultraviolet radiation (UV) much greater on XP than normal cells, whereas X-rays AT ones. It is known that defective one or more pathways, but molecular nature defect(s) not known. In XP, susceptibility UV their vitro show good correlations ability UV-damaged by process nucleotide excision. range from approximately 20 95 percent. important recognize 100 percent actually average somewhere neighborhood 80 This defect an 104-fold increase prevalence 1980; Kraemer et al., 1984) 12-fold internal cancers at sites exposed (Kraemer 1984).