Influence of the OGG1 Ser326Cys polymorphism on oxidatively damaged DNA and repair activity

► OGG1 excising oxidized guanine in DNA harbors the Ser326Cys polymorphism. ► Cys/Cys carriers had elevated level of oxidized DNA bases in mononuclear blood cells. ► There was similar DNA repair activity in cells from subjects with different genotype. ► Expression of enzymes preventing oxidized guanine in DNA did not depend on Ser326Cys.