Mutations in these helicases are associated with Werner syndrome (WRN)79–82, Bloom syndrome (BLM)83–88, Fanconi anemia (FANCJ)89–93, Hoyeraal–Hreidarsson syndrome (RTEL1)94–98, and Rothmund–Thomson syndrome (RECQL4)99–101. Here, RTEL1 is linked to Werner syndrome.