The cumulative lifetime risk of ovarian cancer in women with LS has been estimated at 4% to 12%,76 although in our centre we found a cumulative risk of 20%.79 Affected women can develop ovarian cancer in their 40s, 15 to 22 years earlier than the general population.76 Women with truncating pathogenic variations have been observed to be older (median 6.3 years) at diagnosis.80 Analysis of contribution of individual MMR genes has found significant cumulative lifetime risks of ovarian cancer for MSH2 and MLH1 pathogenic variant carriers (6%‐24%)81, 82 and MSH6 carriers (1%‐13%).82, 83. This evidence concerns the gene MRC1 and ovarian cancer.