BackgroundAssessment of the clinical significance of unclassified variants (UVs) identified in BRCA1 and BRCA2 is very important for genetic counselling. The analysis of co-segregation of the variant with the disease in families is a powerful tool for the classification of these variants. Statistical methods have been described in literature but these methods are not always easy to apply in a diagnostic setting.MethodsWe have developed an easy to use method which calculates the likelihood ratio (LR) of an UV being deleterious, with penetrance as a function of age of onset, thereby avoiding the use of liability classes. The application of this algorithm is publicly available http://www.msbi.nl/cosegregation. It can easily be used in a diagnostic setting since it requires only information on gender, genotype, present age and/or age of onset for breast and/or ovarian cancer.ResultsWe have used the algorithm to calculate the likelihood ratio in favour of causality for 3 UVs in BRCA1 (p.M18T, p.S1655F and p.R1699Q) and 5 in BRCA2 (p.E462G p.Y2660D, p.R2784Q, p.R3052W and p.R3052Q). Likelihood ratios varied from 0.097 (BRCA2, p.E462G) to 230.69 (BRCA2, p.Y2660D). Typing distantly related individuals with extreme phenotypes (i.e. very early onset cancer or old healthy individuals) are most informative and give the strongest likelihood ratios for or against causality.ConclusionAlthough co-segregation analysis on itself is in most cases insufficient to prove pathogenicity of an UV, this method simplifies the use of co-segregation as one of the key features in a multifactorial approach considerably.

Our results confirm that *R1699Q confers an intermediate risk for BC and OC. Breast surveillance for female carriers based on mammogram annually from age 40 is advised. Bilateral salpingo-oophorectomy should be considered based on family history.

The use of pre-implantation genetic diagnosis (PGD) for hereditary cancer is subject to on-going debate, particularly among professionals. This study evaluates the attitude towards PGD and attitude-associated characteristics of those concerned: family members with a hereditary cancer predisposition. Forty-eight Von Hippel-Lindau and 18 Li-Fraumeni Syndrome families were identified via the 9 family cancer clinics in the Netherlands. In total, 216 high risk family members and partners were approached, of whom 179 (83%) completed a self-report questionnaire. Of the high risk family members, 35% expressed a positive attitude towards PGD. Those with a current desire to have children were significantly more likely to have a positive attitude: 48% would consider the use of PGD. No other sociodemographic, medical or psychosocial variables were associated significantly with a positive attitude. The most frequently reported advantage of PGD is the avoidance of a possible pregnancy termination. Uncertainty about late effects was the most frequently reported disadvantage. These results indicate that approximately half of those contemplating a future pregnancy would consider the use of PGD. The actual uptake, however, is expected to be lower. There is no indication that psychosocial factors affect interest in PGD.

A subset of the unclassified variants (UVs) identified during genetic screening of BRCA1/2 genes may affect splicing. We assessed at RNA level the effect of four BRCA1 and ten BRCA2 UVs with a putative splice effect, as predicted in silico. The variants selected for this study were beyond the positions -1, -2 or +1, +2 from the exon, and were not previously described (n = 8) or their effect on splicing was not assessed previously (n = 6). Lymphocytes from UV carriers and healthy controls were cultured and treated with puromycin to prevent nonsense-mediated mRNA decay. The relative contribution of each allele to the various transcripts was assessed using combinations of allele-specific and transcript-specific primers. BRCA2 c.425G>T, c.7976+3_7976+4del and c.8754+3G>C give rise to aberrant transcripts BRCA2Δ4, BRCA2Δ17 and retention of 46nt of intron 21, respectively, and were considered pathogenic. BRCA1 c.4987-3C>G gives rise to BRCA1Δ17 that is likely pathogenic; however, residual expression of the full-length transcript from the variant allele could not be excluded. BRCA1 c.692C>T, c.693G>A and BRCA2 c.6935A>T, besides expressing the full-length transcript, increased expression of BRCA1Δ11 and BRCA2Δ12, respectively. As these are naturally occurring isoforms, also observed in controls, the clinical relevance is unclear. The seven remaining UVs did not affect splicing and three intronic variants were therefore classified as neutral. In conclusion, the RNA analysis results clarified the clinical relevance of 6 of the 14 studied UVs and thereby greatly improve the genetic counselling of high-risk breast/ovarian cancer patients carrying these classified variants.

Lynch syndrome (LS) mutation carriers may reduce their cancer risk by adhering to lifestyle recommendations for cancer prevention. This study tested the effect of providing LS mutation carriers with World Cancer Research Fund-the Netherlands (WCRF-NL) health promotion materials on awareness and knowledge of and adherence to these recommendations. In this randomized controlled trial (n = 226), the intervention group (n = 114) received WCRF-NL health promotion materials. All LS mutation carriers were asked to fill out questionnaires at 2 weeks before (baseline, T0) and at 2 weeks (T1) and 6 months (T2) after the intervention. Linear mixed models were performed on awareness (0-7) and knowledge (0-7) of the recommendations, and on the secondary outcomes, that is adherence, distress, cancer worry, and risk perception. Compared with the control group, the intervention group became significantly more aware (overall mean difference = 1.24; 95%CI = 0.82-1.67) and obtained significantly improved knowledge of the recommendations (overall mean difference = 1.65; 95%CI = 1.27-2.03). Differences were significantly larger for T1 (P interaction = .003 and ≤.001, respectively) but remained significant for T2. No effect on secondary outcomes was found. In conclusion, provision of WCRF-NL health promotion materials increases awareness and knowledge of lifestyle recommendations for cancer prevention among LS mutation carriers without causing additional distress, but does not affect adherence. This may subsequently promote adherence to lifestyle recommendations, leading to potential health benefits. The aim of this randomized controlled study was to test the effect of providing LS mutation carriers with WCRF-NL health promotion materials on awareness and knowledge of the WCRF/AICR cancer prevention recommendations.In addition, we tested the effect of providing these WCRF-NL health promotion materials on adherence to these recommendations and on levels of distress, cancer worry and cancer risk perception. | METHODSThe medical ethical research committees of the Radboud university medical center and Maastricht University Medical Centre granted permission to perform this study. | Participants and study proceduresLS mutation carriers were eligible for participation in this study if mutation status was confirmed by DNA testing and carriers were informed about the LS carriership at Radboud or Maastricht University Medical Center within the last 6 years, and were aged between 18 and 65 years at the time of inclusion in the study between April and September 2015. LS mutations carriers were excluded if they had insufficient command of the Dutch language to fill out Dutch questionnaires or if they were currently participating in the GeoLynch study, a prospective cohort study among LS mutation carriers, 18 to prevent interference between both studies.After informed consent was obtained, eligible participants were randomized into an intervention or control group (Figure 1). To minimize the risk of interference between family members, randomizati...