[DNA lesions: mechanisms of recognition and repair].

Numerous structural lesions or disorders accumulate in DNA either spontaneously or following genotoxic stresses. Living cells have developed various strategies to eliminate most of these lesions so as to preserve a life-compatible genetic information. Several human diseases are associated to some DNA-repair processes. Analysis of cells derived from these patients has allowed the isolation of repair genes and the molecular analysis of lesions proofreading mechanisms. Most of these diseases are extremely severe, pointing out to the biological extent of repair systems, and are associated to genetic instability which frequently lead to high cancer proneness.