Germline defects in three of these helicases lead to syndromes with hallmarks of premature ageing and cancer predisposition: Bloom syndrome (caused by mutations in Bloom syndrome helicase [BLM]), Rothmund–Thompson syndrome (caused by mutations in RECQL4) and Werner syndrome (WS), caused by mutations in WRN helicase. The gene discussed is RECQL4; the disease is Werner syndrome.