The ATPase reduced, helicase deficient P47A (helicase domain I) was seen in both cohorts. Helicase deficient, dominant negative mutant A349P (Fe-S domain, 276-362aa) was identified in a single ovarian cancer patient. Rare alleles in the C-terminal region of the helicase domain (Q540L, I691L, Q740H and A745T) identified in both cohorts are indicated with black arrowheads. Mutation plot generated using cBioPortal MutationMapper tool. Helicase domain motifs: I (39-57); Ia (245-258); II (385-398); III (610-624); IV (689-710); V (748-775); VI (819-836). BRCA1 binding domain: 888-1063aa.