Recently RAD51C mutations were identified in families with breast and ovarian cancer1. This observation prompted us to investigate the role of RAD51D in cancer susceptibility. We identified eight inactivating RAD51D mutations in unrelated individuals from 911 breast-ovarian cancer families compared with one in 1060 controls (P=0.01). The association was principally with ovarian cancer with three mutations identified in the 59 pedigrees with three or more ovarian cancer cases (P=0.0005). The relative risk of ovarian cancer for RAD51D mutation carriers was estimated to be 6.30 (95%CI: 2.86-13.85; P=4.8×10−6). By contrast, the relative risk of breast cancer was estimated to be 1.32 (95%CI: 0.59-2.96; P=0.50). These data indicate that RAD51D mutation testing may have clinical utility in individuals with ovarian cancer and their families. Moreover, we show that cells deficient in RAD51D are sensitive to treatment with a PARP inhibitor, suggesting a possible therapeutic approach for cancers arising in RAD51D mutation carriers.

Overgrowth disorders are a heterogeneous group of conditions characterised by increased growth parameters and variable other clinical features, such as intellectual disability and facial dysmorphism1. To identify novel causes of human overgrowth we performed exome sequencing in 10 proband-parent trios and detected two de novo DNMT3A mutations. We identified 11 additional de novo mutations through DNMT3A sequencing of a further 142 individuals with overgrowth. The mutations were all located in functional DNMT3A domains and protein modelling suggests they interfere with domain-domain interactions and histone binding. No similar mutations were present in 1000 UK population controls (13/152 vs 0/1000; P<0.0001). Mutation carriers had a distinctive facial appearance, intellectual disability and increased height. DNMT3A encodes a key methyltransferase essential for establishing the methylation imprint in embryogenesis and is commonly somatically mutated in acute myeloid leukaemia2-4. Thus DNMT3A joins an emerging group of epigenetic DNA and histone modifying genes associated with both developmental growth disorders and haematological malignancies5.

Background:Technological advances raise the possibility of systematic population-based genetic testing for cancer-predisposing mutations, but it is uncertain whether benefits outweigh disadvantages. We directly compared the psychological/quality-of-life consequences of such an approach to family history (FH)–based testing.Methods:In a randomized controlled trial of BRCA1/2 gene-mutation testing in the Ashkenazi Jewish (AJ) population, we compared testing all participants in the population screening (PS) arm with testing those fulfilling standard FH-based clinical criteria (FH arm). Following a targeted community campaign, AJ participants older than 18 years were recruited by self-referral after pretest genetic counseling. The effects of BRCA1/2 genetic testing on acceptability, psychological impact, and quality-of-life measures were assessed by random effects regression analysis. All statistical tests were two-sided.Results:One thousand, one hundred sixty-eight AJ individuals were counseled, 1042 consented, 1034 were randomly assigned (691 women, 343 men), and 1017 were eligible for analysis. Mean age was 54.3 (SD = 14.66) years. Thirteen BRCA1/2 carriers were identified in the PS arm, nine in the FH arm. Five more carriers were detected among FH-negative FH-arm participants following study completion. There were no statistically significant differences between the FH and PS arms at seven days or three months on measures of anxiety, depression, health anxiety, distress, uncertainty, and quality-of-life. Contrast tests indicated that overall anxiety (P = .0001) and uncertainty (P = .005) associated with genetic testing decreased; positive experience scores increased (P = .0001); quality-of-life and health anxiety did not change with time. Overall, 56% of carriers did not fulfill clinical criteria for genetic testing, and the BRCA1/2 prevalence was 2.45%.Conclusion:Compared with FH-based testing, population-based genetic testing in Ashkenazi Jews doesn’t adversely affect short-term psychological/quality-of-life outcomes and may detect 56% additional BRCA carriers.