Sainte-Foy-lès-Lyon, France
Sainte-Foy-lès-Lyon, France

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Walker L.C.,Queensland Institute of Medical Research | Fredericksen Z.S.,Mayo Medical School | Wang X.,Mayo Medical School | Tarrell R.,Mayo Medical School | And 71 more authors.
Breast Cancer Research | Year: 2010

Introduction: Current attempts to identify genetic modifiers of BRCA1 and BRCA2 associated risk have focused on a candidate gene approach, based on knowledge of gene functions, or the development of large genome-wide association studies. In this study, we evaluated 24 SNPs tagged to 14 candidate genes derived through a novel approach that analysed gene expression differences to prioritise candidate modifier genes for association studies.Methods: We successfully genotyped 24 SNPs in a cohort of up to 4,724 BRCA1 and 2,693 BRCA2 female mutation carriers from 15 study groups and assessed whether these variants were associated with risk of breast cancer in BRCA1 and BRCA2 mutation carriers.Results: SNPs in five of the 14 candidate genes showed evidence of association with breast cancer risk for BRCA1 or BRCA2 carriers (P < 0.05). Notably, the minor alleles of two SNPs (rs7166081 and rs3825977) in high linkage disequilibrium (r2= 0.77), located at the SMAD3 locus (15q22), were each associated with increased breast cancer risk for BRCA2 mutation carriers (relative risk = 1.25, 95% confidence interval = 1.07 to 1.45, Ptrend= 0.004; and relative risk = 1.20, 95% confidence interval = 1.03 to 1.40, Ptrend= 0.018).Conclusions: This study provides evidence that the SMAD3 gene, which encodes a key regulatory protein in the transforming growth factor beta signalling pathway and is known to interact directly with BRCA2, may contribute to increased risk of breast cancer in BRCA2 mutation carriers. This finding suggests that genes with expression associated with BRCA1 and BRCA2 mutation status are enriched for the presence of common genetic modifiers of breast cancer risk in these populations. © 2010 Walker et al.; licensee BioMed Central Ltd.


Jakubowska A.,Pomeranian Medical University | Rozkrut D.,University Of Szczecin | Antoniou A.,University of Cambridge | Hamann U.,German Cancer Research Center | And 114 more authors.
British Journal of Cancer | Year: 2012

Background: The variable penetrance of breast cancer in BRCA1/2 mutation carriers suggests that other genetic or environmental factors modify breast cancer risk. Two genes of special interest are prohibitin (PHB) and methylene-tetrahydrofolate reductase (MTHFR), both of which are important either directly or indirectly in maintaining genomic integrity. Methods: To evaluate the potential role of genetic variants within PHB and MTHFR in breast and ovarian cancer risk, 4102 BRCA1 and 2093 BRCA2 mutation carriers, and 6211 BRCA1 and 2902 BRCA2 carriers from the Consortium of Investigators of Modifiers of BRCA1 and BRCA2 (CIMBA) were genotyped for the PHB 1630 C>T (rs6917) polymorphism and the MTHFR 677 C>T (rs1801133) polymorphism, respectively. Results: There was no evidence of association between the PHB 1630 C>T and MTHFR 677 C>T polymorphisms with either disease for BRCA1 or BRCA2 mutation carriers when breast and ovarian cancer associations were evaluated separately. Analysis that evaluated associations for breast and ovarian cancer simultaneously showed some evidence that BRCA1 mutation carriers who had the rare homozygote genotype (TT) of the PHB 1630 C>T polymorphism were at increased risk of both breast and ovarian cancer (HR 1.50, 95%CI 1.10-2.04 and HR 2.16, 95%CI 1.24-3.76, respectively). However, there was no evidence of association under a multiplicative model for the effect of each minor allele. Conclusion: The PHB 1630TT genotype may modify breast and ovarian cancer risks in BRCA1 mutation carriers. This association need to be evaluated in larger series of BRCA1 mutation carriers. © 2012 Cancer Research UK All rights reserved.


PubMed | University of Cologne, St George's, University of London, Vilnius University, Institute of Human Genetics and 119 more.
Type: Journal Article | Journal: Cancer epidemiology, biomarkers & prevention : a publication of the American Association for Cancer Research, cosponsored by the American Society of Preventive Oncology | Year: 2015

BRCA1 and BRCA2 mutation carriers are at substantially increased risk for developing breast and ovarian cancer. The incomplete penetrance coupled with the variable age at diagnosis in carriers of the same mutation suggests the existence of genetic and nongenetic modifying factors. In this study, we evaluated the putative role of variants in many candidate modifier genes.Genotyping data from 15,252 BRCA1 and 8,211 BRCA2 mutation carriers, for known variants (n = 3,248) located within or around 445 candidate genes, were available through the iCOGS custom-designed array. Breast and ovarian cancer association analysis was performed within a retrospective cohort approach.The observed P values of association ranged between 0.005 and 1.000. None of the variants was significantly associated with breast or ovarian cancer risk in either BRCA1 or BRCA2 mutation carriers, after multiple testing adjustments.There is little evidence that any of the evaluated candidate variants act as modifiers of breast and/or ovarian cancer risk in BRCA1 or BRCA2 mutation carriers.Genome-wide association studies have been more successful at identifying genetic modifiers of BRCA1/2 penetrance than candidate gene studies.


PubMed | University of Cologne, University of Turin, Vilnius University, Erasmus Medical Center and 133 more.
Type: Journal Article | Journal: JAMA | Year: 2015

Limited information about the relationship between specific mutations in BRCA1 or BRCA2 (BRCA1/2) and cancer risk exists.To identify mutation-specific cancer risks for carriers of BRCA1/2.Observational study of women who were ascertained between 1937 and 2011 (median, 1999) and found to carry disease-associated BRCA1 or BRCA2 mutations. The international sample comprised 19,581 carriers of BRCA1 mutations and 11,900 carriers of BRCA2 mutations from 55 centers in 33 countries on 6 continents. We estimated hazard ratios for breast and ovarian cancer based on mutation type, function, and nucleotide position. We also estimated RHR, the ratio of breast vs ovarian cancer hazard ratios. A value of RHR greater than 1 indicated elevated breast cancer risk; a value of RHR less than 1 indicated elevated ovarian cancer risk.Mutations of BRCA1 or BRCA2.Breast and ovarian cancer risks.Among BRCA1 mutation carriers, 9052 women (46%) were diagnosed with breast cancer, 2317 (12%) with ovarian cancer, 1041 (5%) with breast and ovarian cancer, and 7171 (37%) without cancer. Among BRCA2 mutation carriers, 6180 women (52%) were diagnosed with breast cancer, 682 (6%) with ovarian cancer, 272 (2%) with breast and ovarian cancer, and 4766 (40%) without cancer. In BRCA1, we identified 3 breast cancer cluster regions (BCCRs) located at c.179 to c.505 (BCCR1; RHR=1.46; 95% CI, 1.22-1.74; P=210(-6)), c.4328 to c.4945 (BCCR2; RHR=1.34; 95% CI, 1.01-1.78; P=.04), and c. 5261 to c.5563 (BCCR2, RHR=1.38; 95% CI, 1.22-1.55; P=610(-9)). We also identified an ovarian cancer cluster region (OCCR) from c.1380 to c.4062 (approximately exon 11) with RHR=0.62 (95% CI, 0.56-0.70; P=910(-17)). In BRCA2, we observed multiple BCCRs spanning c.1 to c.596 (BCCR1; RHR=1.71; 95% CI, 1.06-2.78; P=.03), c.772 to c.1806 (BCCR1; RHR=1.63; 95% CI, 1.10-2.40; P=.01), and c.7394 to c.8904 (BCCR2; RHR=2.31; 95% CI, 1.69-3.16; P=.00002). We also identified 3 OCCRs: the first (OCCR1) spanned c.3249 to c.5681 that was adjacent to c.5946delT (6174delT; RHR=0.51; 95% CI, 0.44-0.60; P=610(-17)). The second OCCR spanned c.6645 to c.7471 (OCCR2; RHR=0.57; 95% CI, 0.41-0.80; P=.001). Mutations conferring nonsense-mediated decay were associated with differential breast or ovarian cancer risks and an earlier age of breast cancer diagnosis for both BRCA1 and BRCA2 mutation carriers.Breast and ovarian cancer risks varied by type and location of BRCA1/2 mutations. With appropriate validation, these data may have implications for risk assessment and cancer prevention decision making for carriers of BRCA1 and BRCA2 mutations.


Damiola F.,University of Lyon | Schultz I.,Center Paul Strauss | Barjhoux L.,University of Lyon | Sornin V.,University of Lyon | And 37 more authors.
Breast Cancer Research and Treatment | Year: 2015

Several population-based and family-based studies have demonstrated that germline mutations of the PALB2 gene (Partner and Localizer of BRCA2) are associated with an increased risk of breast cancer. Distinct mutation frequencies and spectrums have been described depending on the population studied. Here we describe the first complete PALB2 coding sequence screening in the French population. We screened the complete coding sequence and intron–exon boundaries of PALB2, using the EMMA technique, to assess the contribution of pathogenic mutations in a set of 835 familial breast cancer cases and 662 unrelated controls from the French national study GENESIS and the Paul Strauss Cancer Centre, all previously tested negative for BRCA1 and BRCA2 pathogenic mutations. Our analysis revealed the presence of four novel deleterious mutations: c.1186insT, c.1857delT and c.2850delC in three cases, c.3418dupT in one control. In addition, we identified two in-frame insertion/deletion, 19 missense substitutions (two of them predicted as pathogenic), 9 synonymous variants, 28 variants located in introns and 2 in UTRs, as well as frequent variants. Truncating PALB2 mutations were found in 0.36 % of familial breast cancer cases, a frequency lower than the one detected in comparable studies in other populations (0.73–3.40 %). This suggests a small but significant contribution of PALB2 mutations to the breast cancer susceptibility in the French population. © 2015, Springer Science+Business Media New York.


PubMed | Center Francois Baclesse, University Claude Bernard Lyon 1, University of Lyon, Institute Bergonie and 9 more.
Type: Journal Article | Journal: Breast cancer research and treatment | Year: 2015

Several population-based and family-based studies have demonstrated that germline mutations of the PALB2 gene (Partner and Localizer of BRCA2) are associated with an increased risk of breast cancer. Distinct mutation frequencies and spectrums have been described depending on the population studied. Here we describe the first complete PALB2 coding sequence screening in the French population. We screened the complete coding sequence and intron-exon boundaries of PALB2, using the EMMA technique, to assess the contribution of pathogenic mutations in a set of 835 familial breast cancer cases and 662 unrelated controls from the French national study GENESIS and the Paul Strauss Cancer Centre, all previously tested negative for BRCA1 and BRCA2 pathogenic mutations. Our analysis revealed the presence of four novel deleterious mutations: c.1186insT, c.1857delT and c.2850delC in three cases, c.3418dupT in one control. In addition, we identified two in-frame insertion/deletion, 19 missense substitutions (two of them predicted as pathogenic), 9 synonymous variants, 28 variants located in introns and 2 in UTRs, as well as frequent variants. Truncating PALB2 mutations were found in 0.36% of familial breast cancer cases, a frequency lower than the one detected in comparable studies in other populations (0.73-3.40%). This suggests a small but significant contribution of PALB2 mutations to the breast cancer susceptibility in the French population.

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