A case-only study to identify genetic modifiers of breast cancer risk for BRCA1/BRCA2 mutation carriers

Breast cancer (BC) risk for BRCA1 and BRCA2 mutation carriers varies by genetic and familial factors. About 50 common variants have been shown to modify BC risk for mutation carriers. All but three, were identified in general population studies. Other mutation carrier-specific susceptibility variants may exist but studies of mutation carriers have so far been underpowered. We conduct a novel case-only genome-wide association study comparing genotype frequencies between 60,212 general population BC cases and 13,007 cases with BRCA1 or BRCA2 mutations. We identify robust novel associations for 2 variants with BC for BRCA1 and 3 for BRCA2 mutation carriers, P < 10−8, at 5 loci, which are not associated with risk in the general population. They include rs60882887 at 11p11.2 where MADD, SP11 and EIF1, genes previously implicated in BC biology, are predicted as potential targets. These findings will contribute towards customising BC polygenic risk scores for BRCA1 and BRCA2 mutation carriers

Spectrum and frequency of germline FANCM protein-truncating variants in 44,803 European female breast cancer cases

Simple Summary Mutations in the FANCM gene may cause a particular type of breast cancer known as ER-negative. In this study, we describe the geographic distribution of 66 different FANCM mutations identified in 44,803 female breast cancer cases from Europe, USA, Canada and Australia. We found that the FANCM:p.Gln1701* mutation is most common in Northern Europe and has lower frequencies in Southern European countries. In contrast, the FANCM:p.Gly1906Alafs*12 mutation is most common in Southern Europe and rarer in Central and Northern Europe. We found that the FANCM:p.Arg658* mutation is most prevalent in Central Europe and that the FANCM:p.Gln498Thrfs*7 mutation originates from Lithuania. Finally, we showed that many and varied FANCM mutations are present in Southwestern and Central Europeans while a much more limited range of mutations is present in Northeastern Europeans. The knowledge of this geographic distribution of FANCM mutations is important to establish more efficient genetic testing strategies in specific populations. FANCM germline protein truncating variants (PTVs) are moderate-risk factors for ER-negative breast cancer. We previously described the spectrum of FANCM PTVs in 114 European breast cancer cases. In the present, larger cohort, we report the spectrum and frequency of four common and 62 rare FANCM PTVs found in 274 carriers detected among 44,803 breast cancer cases. We confirmed that p.Gln1701* was the most common PTV in Northern Europe with lower frequencies in Southern Europe. In contrast, p.Gly1906Alafs*12 was the most common PTV in Southern Europe with decreasing frequencies in Central and Northern Europe. We verified that p.Arg658* was prevalent in Central Europe and had highest frequencies in Eastern Europe. We also confirmed that the fourth most common PTV, p.Gln498Thrfs*7, might be a founder variant from Lithuania. Based on the frequency distribution of the carriers of rare PTVs, we showed that the FANCM PTVs spectra in Southwestern and Central Europe were much more heterogeneous than those from Northeastern Europe. These findings will inform the development of more efficient FANCM genetic testing strategies for breast cancer cases from specific European populations.Molecular tumour pathology - and tumour geneticsMTG1 - Moleculaire genetica en pathologie van borstkanke

An Attempt to Observe Directly Beauty Particles in Nuclear Emulsions

An attempt at the direct observation of the cascade decay of beauty particles, produced by π- of 350 GeV/c leading to 3 muons or 4 muons in the final state, has been made in an emulsion/counter hybrid experiment at CERN. Under the assumption that the lifetime of beauty particles is of the order of 10-13s the non-observation of any candidates provides an upper limit for beauty production of ∼90 nb at the 90% confidence level.0SCOPUS: ar.jinfo:eu-repo/semantics/publishe