Apurinic DNA endonuclease activities in repair-deficient human cell lines

Several autosomal recessive diseases are associated with apparent DNA repair defects in cell culture. It seemed likely that a defect in excision repair reported for ataxia telangiectasia cells might reflect a lack of apurinic endonuclease activity. We report here normal levels of apurinic endonuclease activity in extracts of cell lines derived from patients with ataxia telangiectasia, xeroderma pigmentosum (complementation group D), Cockayne dwarfism, Fanconi anemia and Bloom syndrome.