Carriers were identified in the sporadic OC study group with frequencies of 0.2% (1/435) for EXO1 variant carriers and 0.5% (2/435) for carriers of each NTHL1, ERCC5 or NEIL1 variants, and one NTHL1 carrier among sporadic BC cases (0.2%, 1/563). Here, ERCC5 is linked to breast cancer.