WRN and Werner syndrome: It is of note that WRN helicase is mutated in the human autosomal recessive disease Werner syndrome (WS) and that this segmental progeroid syndrome manifests as skin atrophy, wrinkling and hair greying 44, suggesting that unrepaired DNA damage in skin cells by the lack of DNA repair factors including SNEV and WRN contributes to accelerated ageing of the skin.