Accumulation of mutations or increased levels of DNA damage might contribute to the ageing process leading to loss of cellular function, tissue atrophism, cell death or tumours.

Several studies addressed the relationship between DNA damage, DNA repair and ageing, suggesting an age-dependent accumulation of DNA damage that could be in part responsible for the impairment of cellular functions and increased incidence of diseases, such as cancer, occurring with age. In addition, a positive correlation between life span and DNA repair capacity has been demonstrated. Most of the studies focused on Nucleotide Excision Repair Mechanism, particularly regarding its role on repair of UV-induced damage. The present review will focus on these topics and on the role of the Mismatch Repair System that is recently emerging as a possible additional mechanism contributing to the accumulation of genetic instability during ageing.