Pathogenic variants in the ERCC4 gene are associated with Fanconi anemia Group Q (MIM 615272), xeroderma pigmentosum group F (MIM 278760), xeroderma pigmentosum type F/Cockayne syndrome (MIM 278760), and progeroid syndrome XF (MIM 610965); FANCD2 and FANCG are associated with Fanconi anemia Group D2 (MIM 227646) and Group C (MIM 614082), respectively; while MUTYH is associated with MUTYH‐associated polyposis (MIM 608456) and RAD50 is associated with Nijmegen breakage syndrome‐like disorder (MIM 613078). Here, MUTYH is linked to Cockayne syndrome.