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The common single-nucleotide polymorphism (SNP) rs3802842 at 11q23.1 has recently been reported to be associated with risk of colorectal cancer (CRC). To examine this association in detail we genotyped rs3802842 in eight independent case-control series comprising a total of 10 638 cases and 10 457 healthy individuals. A significant association between the C allele of rs3802842 and CRC risk was found (per allele OR = 1.17; 95% confidence interval [CI]: 1.12-1.22; P = 1.08 x 10(-12)) with the risk allele more frequent in rectal than colonic disease (P = 0.02). In combination with 8q21, 8q24, 10p14, 11q, 15q13.3 and 18q21 variants, the risk of CRC increases with an increasing numbers of variant alleles for the six loci (OR(per allele) = 1.19; 95% CI: 1.15-1.23; P(trend) = 7.4 x 10(-24)). Using the data from our genome-wide association study of CRC, LD mapping and imputation, we were able to refine the location of the causal locus to a 60 kb region and screened for coding changes. The absence of exonic mutations in any of the transcripts (FLJ45803, LOC120376, C11orf53 and POU2AF1) mapping to this region makes the association likely to be a consequence of non-coding effects on gene expression.

To identify colorectal cancer (CRC) susceptibility alleles, we conducted a genome-wide association study. In phase 1, we genotyped 550,163 tagSNPs in 940 familial colorectal tumor cases (627 CRC, 313 high-risk adenoma) and 965 controls. In phase 2, we genotyped 42,708 selected SNPs in 2,873 CRC cases and 2,871 controls. In phase 3, we evaluated 11 SNPs showing association at P < 10(-4) in a joint analysis of phases 1 and 2 in 4,287 CRC cases and 3,743 controls. Two SNPs were taken forward to phase 4 genotyping (10,731 CRC cases and 10,961 controls from eight centers). In addition to the previously reported 8q24, 15q13 and 18q21 CRC risk loci, we identified two previously unreported associations: rs10795668, located at 10p14 (P = 2.5 x 10(-13) overall; P = 6.9 x 10(-12) replication), and rs16892766, at 8q23.3 (P = 3.3 x 10(-18) overall; P = 9.6 x 10(-17) replication), which tags a plausible causative gene, EIF3H. These data provide further evidence for the 'common-disease common-variant' model of CRC predisposition.

We describe an association between TGFBR1 polymorphism rs868 and mismatch repair proficient hereditary colorectal cancers. This polymorphism results in more binding of TGFBR1 to let-7b-5p miRNA, which would result in lower expression of TGFBR1 and thus higher colorectal cancer risk.The purpose of this study was to identify novel colorectal cancer (CRC)-causing alleles in unexplained familial CRC cases. In order to do so, coding regions in five candidate genes (MGMT, AXIN2, CTNNB1, TGFBR1 and TGFBR2) were sequenced in 11 unrelated microsatellite-stable hereditary non-polyposis CRC (MSS HNPCC) cases. Selected genetic variants were genotyped in a discovery set of 27 MSS HNPCC cases and 85 controls. One genetic variant, rs67687202, in TGFBR1 emerged as significant (P = 0.002), and it was genotyped in a replication set of 87 additional MSS HNPCC-like cases and 338 controls where it was also significantly associated with MSS HNPCC cases (P = 0.041). In the combined genotype data, rs67687202 was associated with a moderate increase in CRC risk (OR = 1.68; 95% CI = 1.13-2.50; P = 0.010). We tested a highly correlated SNP rs868 in 723 non-familial CRC cases compared with 629 controls, and it was not significantly associated with CRC risk (P = 0.370). rs868 is contained in a let-7 miRNA binding site in the 3'UTR of TGFBR1, which might provide a functional basis for the association in MSS HNPCC. In luciferase assays, the risk-associated allele for rs868 was associated with half the luciferase expression in the presence of miRNA let-7b-5p compared with protective allele, suggesting more binding of let-7b-5p and less TGFBR1 expression. Thus, rs868 potentially is a CRC risk-causing allele. Our results support the concept that rs868 is associated with lower TGFBR1 expression thereby increasing CRC risk.

BACKGROUND: Most BRCA1 or BRCA2 mutation carriers have inherited a single (heterozygous) mutation. Transheterozygotes (TH) who have inherited deleterious mutations in both BRCA1 and BRCA2 are rare, and the consequences of transheterozygosity are poorly understood. METHODS: From 32,295 female BRCA1/2 mutation carriers, we identified 93 TH (0.3 %). 'Cases' were defined as TH, and 'controls' were single mutations at BRCA1 (SH1) or BRCA2 (SH2). Matched SH1 'controls' carried a BRCA1 mutation found in the TH 'case'. Matched SH2 'controls' carried a BRCA2 mutation found in the TH 'case'. After matching the TH carriers with SH1 or SH2, 91 TH were matched to 9316 SH1, and 89 TH were matched to 3370 SH2. RESULTS: The majority of TH (45.2 %) involved the three common Jewish mutations. TH were more likely than SH1 and SH2 women to have been ever diagnosed with breast cancer (BC; p = 0.002). TH were more likely to be diagnosed with ovarian cancer (OC) than SH2 (p = 0.017), but not SH1. Age at BC diagnosis was the same in TH vs. SH1 (p = 0.231), but was on average 4.5 years younger in TH than in SH2 (p, published_or_final_version

Ovarian Cancer Association Consortium, Breast Cancer Association Consortium, and Consortium of Modifiers of BRCA1 and BRCA2: et al., [Objective]: Clinical genetic testing is commercially available for rs61764370, an inherited variant residing in a KRAS 3' UTR microRNA binding site, based on suggested associations with increased ovarian and breast cancer risk as well as with survival time. However, prior studies, emphasizing particular subgroups, were relatively small. Therefore, we comprehensively evaluated ovarian and breast cancer risks as well as clinical outcome associated with rs61764370. [Methods]: Centralized genotyping and analysis were performed for 140,012 women enrolled in the Ovarian Cancer Association Consortium (15,357 ovarian cancer patients; 30,816 controls), the Breast Cancer Association Consortium (33,530 breast cancer patients; 37,640 controls), and the Consortium of Modifiers of BRCA1 and BRCA2 (14,765 BRCA1 and 7904 BRCA2 mutation carriers). [Results]: We found no association with risk of ovarian cancer (OR = 0.99, 95% CI 0.94-1.04, p = 0.74) or breast cancer (OR = 0.98, 95% CI 0.94-1.01, p = 0.19) and results were consistent among mutation carriers (BRCA1, ovarian cancer HR = 1.09, 95% CI 0.97-1.23, p = 0.14, breast cancer HR = 1.04, 95% CI 0.97-1.12, p = 0.27; BRCA2, ovarian cancer HR = 0.89, 95% CI 0.71-1.13, p = 0.34, breast cancer HR = 1.06, 95% CI 0.94-1.19, p = 0.35). Null results were also obtained for associations with overall survival following ovarian cancer (HR = 0.94, 95% CI 0.83-1.07, p = 0.38), breast cancer (HR = 0.96, 95% CI 0.87-1.06, p = 0.38), and all other previously-reported associations. [Conclusions]: rs61764370 is not associated with risk of ovarian or breast cancer nor with clinical outcome for patients with these cancers. Therefore, genotyping this variant has no clinical utility related to the prediction or management of these cancers., The COGS project is funded through a European Commission's Seventh Framework Programme grant (agreement number 223175 — HEALTH-F2-2009-223175). The scientific development and funding for this project were in part supported by the US National Cancer Institute GAME-ON Post-GWAS Initiative (U19-CA148112). Funding for the project was provided by the Wellcome Trust under award 076113. This work was partially supported by Spanish Association against Cancer (AECC08), RTICC 06/0020/1060, FISPI08/1120, Mutua Madrileña Foundation (FMMA) and SAF2010-20493. Was supported by a grant RD12/00369/0006 and 12/00539 from ISCIII (Spain), partially supported by European Regional Development FEDER funds. Contract grant sponsor: Asociación Española Contra el Cáncer, Spanish Health Research Fund; Carlos III Health Institute; Catalan Health Institute and Autonomous Government of Catalonia. Contract grant numbers: ISCIIIRETIC RD06/0020/1051, RD12/0036/008, PI10/01422, PI10/00748, PI13/00285 and 2009SGR290.

BARD1 Val507Met (1592 A>G) is an interesting marker for association studies on cancer risk. However, studies are scarce in the literature, probably reflecting the methodological problem imposed by the fact that next to the 1592 A>G stands the 1591 C>T single nucleotide polymorphism (SNP). We have designed an allele-specific PCR method capable of molecular haplotyping tandem SNPs. In the tandem SNPs haplotyping assay (tSNPh), four reverse primers are designed to be perfect matches of each potential haplotype. The forward primer is labeled with a fluorochrome. PCR products are analyzed by capillary electrophoresis. Haplotyping is performed by size calling. To ascertain the accuracy and reproducibility of the assay, we measured the level of concordance with sequencing data in 124 samples. In vitro-generated templates have been used for further testing. We developed a novel and reliable assay that permits typing two SNPs directly adjacent to each other, avoiding mutual interferences. The method is amenable to automation and high throughput. We expect that this assay will contribute to clarifying the role of BARD1 in cancer susceptibility. In addition, we suggest that tandem SNPs are potentially interesting polymorphic markers in which molecular haplotyping can be performed easily.

SummaryThromboembolic events are the second cause of death in cancer patients, although the mechanisms underlying this increased thromboembolic risk remain unclear. The aims of this study were to examine whether BRCA2 gene mutations may modify the circulating levels of thrombocoagulation biomarkers and whether breast cancer development may influence changes in such circulating biomarkers. The study was performed in 25 women with mutations in the BRCA2 gene (n=12 breast cancer, n=13 breast cancer-free) and in 13 BRCA2 nonmutant controls. Results revealed that plasma levels of fibrinogen gamma chain isotypes 2 and 3, haptoglobin isotypes 4 and 5, serotransferrin isotypes 3 and 4 and convertase C3/C5 isotypes 4 and 5 were significantly higher in BRCA2 mutation carriers compared to controls. However, plasma levels of vitamin D binding protein isotype 1 and alpha1-antitrypsin isotypes 2, 3 and 4 were significantly decreased in BRCA2 mutation carriers compared to controls. Plasma expression of PF4 and P-selectin was significantly higher in BRCA2 mutations carriers than in controls. BRCA2 truncated mutations conserving a binding region for RAD51 were associated with increased plasma levels of alpha1-antitrypsin isotypes 3 and 4 with respect to women showing BRCA2 mutations that loss the binding RD51 region to BRCA2. Only plasma levels of vitamin D binding protein isotypes 1 and 3 were significantly reduced and alpha 1-antitrypsin isotype 1 was increased in cancer-free BRCA2 mutation carriers compared to BRCA2 mutation carriers with breast cancer. The presence of BRCA2 mutations is associated with increased plasma levels of thrombo-coagulating-related proteins, which are independent to breast cancer development.

Germ-line mutations in BRCA1 and BRCA2 are responsible for about 30-60% of the hereditary breast and ovarian cancer (HBOC). A large number of point mutations have been described in both genes. However, large deletions and duplications that disrupt one or more exons are overlooked by point mutation detection approaches. Over the past years several rearrangements have been identified in BRCA1, while few studies have been designed to screen this type of mutations in BRCA2. Our aim was to estimate the prevalence of large genomic rearrangements in the BRCA2 gene in Spanish breast/ovarian cancer families. The multiplex ligation-dependent probe amplification (MLPA) was employed to search gross deletions or duplications of BRCA2 in 335 Spanish moderate to high-risk breast/ovarian cancer families previously screened negative for point mutations by conventional methods. Four different and novel large genomic alterations were consistently identified by MLPA in five families, respectively: deletions of exon 2, exons 10-12 and exons 15-16 and duplication of exon 20 (in two families). RT-PCR experiments confirmed the deletion of exons 15-16. All patients harbouring a genomic rearrangement were members of high-risk families, with three or more breast/ovarian cancer cases or the presence of breast cancer in males. We provide evidence that the BRCA2 rearrangements seem to account for a relatively small proportion of familial breast cancer cases in Spanish population. The screening for these alterations as part of the comprehensive genetic testing can be recommended, especially in multiple case breast/ovarian families and families with male breast cancer cases.

Six SNPs have been detected in the DNA repair genes RAD51C and RAD51D, not previously characterized. The novel variant E233G in RAD51D is more highly represented in high-risk, site-specific, familial breast cancer cases that are not associated with the BRCA1/2 genes, with a frequency of 5.74% (n = 174) compared to a control population (n = 567) and another subset of breast cancer patients (n = 765) with a prevalence of around 2% only (comparison to controls, OR = 2.6, 95% CI 1.12–6.03; p < 0.021). We found that the immunohistochemical profile detected in available tumors from these patients differs slightly from those described in non-BRCA1/2 tumors. Finally, the structural prediction of the putative functional consequence of this change indicates that it can diminish protein stability and structure. This suggests a role for E233G as a low-penetrance susceptibility gene in the specific subgroup of high-risk familial breast cancer cases that are not related to BRCA1/2. © 2004 Wiley-Liss, Inc.

We screened index cases from 410 Spanish breast/ovarian cancer families and 214 patients (19 of them males) with breast cancer for germ-line mutations in the BRCA1 and BRCA2 genes, using SSCP, PTT, CSGE, DGGE, and direct sequencing. We identified 60 mutations in BRCA1 and 53 in BRCA2. Of the 53 distinct mutations observed, 11 are novel and 12 have been reported only in Spanish families (41.5%). The prevalence of mutations in this set of families was 26.3%, but the percentage was higher in the families with breast and ovarian cancer (52.1%). The lowest proportion of mutations was found in the site-specific female breast cancer families (15.4%). Of the families with male breast cancer cases, 59.1% presented mutations in the BRCA2 gene. We found a higher frequency of ovarian cancer associated with mutations localized in the 5′ end of the BRCA1 gene, but there was no association between the prevalence of this type of cancer and mutations situated in the ovarian cancer cluster region (OCCR) region of exon 11 of the BRCA2 gene. The mutations 187_188delAG, 330A>G, 5236G>A, 5242C>A, and 589_590del (numbered after GenBank U14680) account for 46.6% of BRCA1 detected mutations whereas 3036_3039del, 6857_6858del, 9254_9258del, and 9538_9539del (numbered after GenBank U43746) account for 56.6% of the BRCA2 mutations. The BRCA1 330A>G has a Galician origin (northwest Spain), and BRCA2 6857_6858del and 9254_9258del probably originated in Catalonia (northeast Spain). Knowledge of the spectrum of mutations and their geographical distribution in Spain will allow a more effective detection strategy in countries with large Spanish populations. © 2003 Wiley-Liss, Inc.

Background BRCA1 is a key protein in cell network, involved in DNA repair pathways and cell cycle. Recently, the ENIGMA consortium has reported a high number of alternative splicing (AS) events at this locus in blood-derived samples. However, BRCA1 splicing pattern in breast tissue samples is unknown. Here, we provide an accurate description of BRCA1 splicing events distribution in breast tissue samples. Methods BRCA1 splicing events were scanned in 70 breast tumor samples, 4 breast samples from healthy individuals and in 72 blood-derived samples by capillary electrophoresis (capillary EP). Molecular subtype was identified in all tumor samples. Splicing events were considered predominant if their relative expression level was at least the 10% of the full-length reference signal. Results 54 BRCA1 AS events were identified, 27 of them were annotated as predominant in at least one sample. Δ5q, Δ13, Δ9, Δ5 and ▼1aA were significantly more frequently annotated as predominant in breast tumor samples than in blood-derived samples. Predominant splicing events were, on average, more frequent in tumor samples than in normal breast tissue samples (P = 0.010). Similarly, likely inactivating splicing events (PTC-NMDs, Non-Coding, Δ5 and Δ18) were more frequently annotated as predominant in tumor than in normal breast samples (P = 0.020), whereas there were no significant differences for other splicing events (No-Fs) frequency distribution between tumor and normal breast samples (P = 0.689). Conclusions Our results complement recent findings by the ENIGMA consortium, demonstrating that BRCA1 AS, despite its tremendous complexity, is similar in breast and blood samples, with no evidences for tissue specific AS events. Further on, we conclude that somatic inactivation of BRCA1 through spliciogenic mutations is, at best, a rare mechanism in breast carcinogenesis, albeit our data detects an excess of likely inactivating AS events in breast tumor samples. Electronic supplementary material The online version of this article (doi:10.1186/s12885-015-1145-9) contains supplementary material, which is available to authorized users.

HNPCC is an autosomal dominantly inherited cancer-susceptibility syndrome that confers an increased risk for colorectal cancer and endometrial cancer at a young age. It also entails an increased risk of a variety of other tumors, such as ovarian, gastric, uroepithelial and biliary tract cancers. The underlying pathogenic mutation lies in 1 of the 5 known DNA MMR genes (MSH2, MLH1, PMS1, PMS2 and MSH6). We screened a total of 140 individuals from 56 Spanish families with suspected HNPCC for mutations in the DNA mismatch repair genes MLH1 and MSH2, using DGGE and direct DNA sequencing. Families were selected on the basis of a history of HNPCC-related tumors or the occurrence of other associated tumors in members besides the index case affected with colorectal cancer. We detected 14 definite pathogenic germline mutations, 9 in MLH1 and 5 in MSH2 in 13 unrelated families selected by the Amsterdam criteria and Bethesda guidelines (1 family carries 2 mutations) and 3 missense mutations in 3 unrelated families selected by the Amsterdam criteria. Among the 17 germline mutations noted in the Spanish cohort, 10 are novel, 7 in MLH1 and 3 in MSH2, perhaps demonstrating different mutational spectra in the Spanish population, where no founder mutation has been identified. Based on our results, we suggest that in the Spanish population not only HNPCC families fulfilling the Amsterdam criteria but also those following Bethesda guidelines should undergo genetic testing for MSH2 and MLH1 mutations. © 2002 Wiley-Liss, Inc.

The BRCA1 and BRCA2 genes are responsible for a high proportion of familial breast cancer; germline mutations in these genes confer a lifetime risk of about 70% for developing breast cancer. Most of the described deleterious mutations are small deletions or insertions that originate a truncated protein; however, in many cases, they are amino acid changes whose significance is unknown. In these cases, there are some tests that can analyze the meaning of these variants, but most remain unclassified. The BRCA genes are tumor supressors and it is beleived that complete loss of the wild-type allele is a common mechanism of inactivation in tumors from patients carrying a germline deleterious mutation in these genes; if this is true, loss of heterozygosity (LOH) analysis in the tumor sample could help to distinguish if a rare variant is either a deleterious mutation or a common polymorphism. In the present study, we performed LOH analysis at the BRCA loci in 47 tumors from patients who belonged to high-risk breast cancer families and were carriers of any type of alteration in these genes. Our results suggest that (i) loss of the wild-type allele is the most common mechanism of inactivation in tumors from patients who carry a deleterious mutation in any of the genes, (ii) this loss is not common when we analyze familial tumors not associated with mutations in BRCA and (iii) LOH can be used to clarify variants of unknown significance in the BRCA genes. © 2002 Wiley-Liss, Inc.

Index cases from a clinically relevant cohort of 102 Spanish families with at least 3 cases of breast and/or ovarian cancer (at least 1 case diagnosed before age 50) in the same lineage were screened for germline mutations in the entire coding sequence and intron boundaries of the breast cancer susceptibility genes BRCA1 and BRCA2. Overall, the prevalence of mutations was 43% in female breast/ovarian cancer families, 15% in female breast cancer families and 100% in male breast cancer families. Three recurrent mutations (185delAG, 589delCT and A1708E) explained 63% of BRCA1-related families. Early age at diagnosis of breast cancer, ovarian cancer, bilateral breast cancer, concomitant breast/ovarian cancer in a single patient and prostate cancer but not unilateral breast cancer were associated with BRCA1 and BRCA2 mutations. Male breast cancer was associated with BRCA2 mutations. The presence of male breast cancer was the only cancer phenotype that distinguished BRCA2- from BRCA1-related families. We have developed a logistic regression model for predicting the probability of harbouring a mutation in either BRCA1 or BRCA2 as a function of the cancer phenotype present in the family. The predictive positive and negative values of this model were 77.4% and 79%, respectively (probability cutoff of 30%). The findings of our work may be a useful tool for increasing the cost-effectiveness of genetic testing in familial cancer clinics.

In some tumors, defects in mismatch repair enzymes lead to errors in the replication of simple nucleotide repeat segments RER+ tumors. This condition is commonly known as microsatellite instability (MSI) because of the frequent mutations of microsatellite sequences. Although the MSI phenotype is well recognized in some colon, gastric, pancreatic, and endometrial cancers, reports of MSI in breast cancer are inconsistent. The purpose of this study was to determine the presence of MSI in breast cancer and to correlate its occurrence with clinicopathological parameters, including expression of estrogen and progesterone receptors. We analyzed the status of 10 different microsatellite loci (mono- and dinucleotide repeats). In this study, microsatellite size patterns were compared in 88 paired breast-cancer/peripheral-blood DNA samples. Fluorescent polymerase chain reaction (PCR) for typing microsatellites coupled with DNA fragment analysis in an automated DNA sequencer was applied. MSI in at least two microsatellite markers was observed in 6 out of 88 (7%) of the cases, all belonging to Stage II or III. These MSI data were analyzed using a range of clinicopathological parameters; no correlation between MSI and histopathological characteristics were found. A significant correlation was observed between MSI and negative expression of both estrogen and progesterone receptors (P < 0.02), indicating a possible relationship between specific genetic changes at these microsatellite regions and hormonal deregulation in the progression of breast cancer. Teratogenesis Carcinog. Mutagen. 20:283–291, 2000. © 2000 Wiley-Liss, Inc.

Loss-of-function germline mutations in BRCA1 (MIM #113705) confer markedly increased risk of breast and ovarian cancer. The full-length transcript codifies for a protein involved in DNA repair pathways and cell-cycle checkpoints. Several BRCA1 splicing isoforms have been described in public domain databases, but the physiological role (if any) of BRCA1 alternative splicing remains to be established. An accurate description of 'naturally occurring' alternative splicing at this locus is a prerequisite to understand its biological significance. However, a systematic analysis of alternative splicing at the BRCA1 locus is yet to be conducted. Here, the Evidence-Based Network for the Interpretation of Germ-Line Mutant Alleles consortium combines RT-PCR, exon scanning, cloning, sequencing and relative semi-quantification to describe naturally occurring BRCA1 alternative splicing with unprecedented resolution. The study has been conducted in blood-related RNA sources, commonly used for clinical splicing assays, as well as in one healthy breast tissue. We have characterized a total of 63 BRCA1 alternative splicing events, including 35 novel findings. A minimum of 10 splicing events (Delta 1Aq, Delta 5, Delta 5q, Delta 8p, Delta 9, Delta(9,10), Delta 9_11, Delta 11q, Delta 13p and Delta 14p) represent a substantial fraction of the full-length expression level (ranging from 5 to 100%). Remarkably, our data indicate that BRCA1 alternative splicing is similar in blood and breast, a finding supporting the clinical relevance of blood-based in vitro splicing assays. Overall, our data suggest an alternative splicing model in which most non-mutually exclusive alternative splicing events are randomly combined into individual mRNA molecules to produce hundreds of different BRCA1 isoforms.

et al., Rare sequence variants in >high-risk> disease genes, often referred as unclassified variants (UVs), pose a serious challenge to genetic testing. However, UVs resulting in splicing alterations can be readily assessed by in vitro assays. Unfortunately, analytical and clinical interpretation of these assays is often challenging. Here, we explore this issue by conducting splicing assays in 31 BRCA2 genetic variants. All variants were assessed by RT-PCR followed by capillary electrophoresis and direct sequencing. If assays did not produce clear-cut outputs (Class-2 or Class-5 according to analytical International Agency for Research on Cancer guidelines), we performed qPCR and/or minigene assays. The latter were performed with a new splicing vector (pSAD) developed by authors of the present manuscript (patent #P201231427 CSIC). We have identified three clinically relevant Class-5 variants (c.682-2A>G, c.7617+1G>A, and c.8954-5A>G), and 27 analytical Class-2 variants (not inducing splicing alterations). In addition, we demonstrate that rs9534262 (c.7806-14T>C) is a BRCA2 splicing quantitative trait locus. Splicing analyses are widely used in the clinical setting to address the significance of rare genetic variants. However, interpretation of results is often challenging. Here we show that incorporating capillary electrophoresis (EP) and direct sequencing to the analysis of RT-PCR splicing assays often produces clear-cut analytical outputs. Indeed, we have produced clear-cut outputs in 29 out of 31 BRCA2 variants investigated, including the identified of clinically relevant splicing aberrations, and one splicing quantitative trait locus., Contract grant sponsors: EAV was supported by research grants PI10/2910 (Instituto de Salud Carlos III), CSI004A10-2 (Consejería de Educación, Regional Government of Castilla y León) and BIO39/VA27/10 (Consejería de Sanidad, Regional Government of Castilla y León). Alberto Acedo is supported by the European Social Fund and Regional Government of Castilla y León (P.O. 2007-2013). ZGC is supported by the Genetic Counseling Program (Regional Government of Valencia). SGE is funded by a Miguel Servet contract (CP10/00617, Instituto de Salud Carlos III). HUVH-VHIO research was supported by a Miguel Servet research grant CP10/00617, Instituto de Salud Carlos III). MH was supported by research grants PI 09/00859 and PI 12/00539 (Instituto de Salud Carlos III). Instituto de Salud Carlos III research grants are partially supported by European Regional Development FEDER Funds.

The pituitary-specific transcription factor Pit-1/GHF-1 is a member of the POU domain family of regulatory proteins. It is involved in the commitment and expansion of the somatotropic cell lineage and activates the transcription of a set of anterior pituitary genes. We have cloned the human PIT1/GHF1 gene and characterized the regulatory mechanisms controlling its promoter activation and regulation. A minimal promoter region (-102 to +15) contains the cis-acting elements that confer to the human PIT1/GHF1 gene a high basal transcriptional activity, the tissue-specific expression, and the autoregulation by Pit-1/GHF-1 protein. The upstream promoter region contains a multiplicity of Pit-1/GHF-1 binding sites that do not show any synergistic interaction with the minimal promoter. The transcriptional activity is negatively regulated by Oct-1 and mediated by an octamer-binding site (OTF). In addition, we have also identified a 12-O-tetradecanoylphorbol-13-acetate-responsive element, which overlaps with a Pit-1/GHF-1 binding site. A mutually exclusive binding of the activator protein-1 (AP-1) and Pit-1/GHF-1 has been observed on this composite site, and AP-1 was shown to down-regulate PIT1/GHF1 transcription.

Searching for low-penetrance genes involved in breast cancer susceptibility has been a field of interest in the last few years. Recently, the CHEK 2 gene, involved in DNA damage and replication checkpoints, has been pointed out as a good candidate; moreover, a specific variant in this gene,1100delC, has been found to increase breast cancer susceptibility among familial breast cancer cases not attributable to mutations in BRCA1 or BRCA2 genes. In our present study, we evaluated the role of the 1100delC variant as a susceptibility allele in breast cancer in the Spanish population. However, our results suggest that this variant is absent or very infrequent in our population, making its screening irrelevant from the practical point of view. © 2003 Wiley-Liss, Inc.

BRCA1-associated breast and ovarian cancer risks can be modified by common genetic variants. To identify further cancer risk-modifying loci, we performed a multi-stage GWAS of 11,705 BRCA1 carriers (of whom 5,920 were diagnosed with breast and 1,839 were diagnosed with ovarian cancer), with a further replication in an additional sample of 2,646 BRCA1 carriers. We identified a novel breast cancer risk modifier locus at 1q32 for BRCA1 carriers (rs2290854, P = 2.7×10−8, HR = 1.14, 95% CI: 1.09–1.20). In addition, we identified two novel ovarian cancer risk modifier loci: 17q21.31 (rs17631303, P = 1.4×10−8, HR = 1.27, 95% CI: 1.17–1.38) and 4q32.3 (rs4691139, P = 3.4×10−8, HR = 1.20, 95% CI: 1.17–1.38). The 4q32.3 locus was not associated with ovarian cancer risk in the general population or BRCA2 carriers, suggesting a BRCA1-specific association. The 17q21.31 locus was also associated with ovarian cancer risk in 8,211 BRCA2 carriers (P = 2×10−4). These loci may lead to an improved understanding of the etiology of breast and ovarian tumors in BRCA1 carriers. Based on the joint distribution of the known BRCA1 breast cancer risk-modifying loci, we estimated that the breast cancer lifetime risks for the 5% of BRCA1 carriers at lowest risk are 28%–50% compared to 81%–100% for the 5% at highest risk. Similarly, based on the known ovarian cancer risk-modifying loci, the 5% of BRCA1 carriers at lowest risk have an estimated lifetime risk of developing ovarian cancer of 28% or lower, whereas the 5% at highest risk will have a risk of 63% or higher. Such differences in risk may have important implications for risk prediction and clinical management for BRCA1 carriers., Author Summary BRCA1 mutation carriers have increased and variable risks of breast and ovarian cancer. To identify modifiers of breast and ovarian cancer risk in this population, a multi-stage GWAS of 14,351 BRCA1 mutation carriers was performed. Loci 1q32 and TCF7L2 at 10q25.3 were associated with breast cancer risk, and two loci at 4q32.2 and 17q21.31 were associated with ovarian cancer risk. The 4q32.3 ovarian cancer locus was not associated with ovarian cancer risk in the general population or in BRCA2 carriers and is the first indication of a BRCA1-specific risk locus for either breast or ovarian cancer. Furthermore, modeling the influence of these modifiers on cumulative risk of breast and ovarian cancer in BRCA1 mutation carriers for the first time showed that a wide range of individual absolute risks of each cancer can be estimated. These differences suggest that genetic risk modifiers may be incorporated into the clinical management of BRCA1 mutation carriers.

Fanconi anemia is a genetically heterogeneous autosomal recessive disorder characterized by development abnormalities, bone marrow failure, and childhood cancers. Compelling evidence indicates a common genetic basis for FA and breast/ovarian cancer susceptibility. Recently, biallelic germ-line mutations in SLX4 have been demonstrated to cause a previously unknown FA subtype (FA-P). We address the role of SLX4/FANCP in breast/ovarian cancer susceptibility by conducting a comprehensive mutation scanning in 486 index cases from non-BRCA1/BRCA2 multiple-case breast and/or ovarian cancer families (non-BRCA1/2 families) from Spain. We detected one unequivocal loss-of-function mutation (p.Glu1517X). In addition, one missense change (p.Arg372Trp) predicted to be pathogenic by in silico analysis co-segregates with disease in one family. Overall, the study indicates that SLX4 mutation screening will have a very low impact (if any) in the genetic counseling of non-BRCA1/2 families.

Germline mutations in BRCA1 and BRCA2 are associated with increased risks of breast and ovarian cancer. A genome-wide association study (GWAS) identified six alleles associated with risk of ovarian cancer for women in the general population. We evaluated four of these loci as potential modifiers of ovarian cancer risk for BRCA1 and BRCA2 mutation carriers. Four single-nucleotide polymorphisms (SNPs), rs10088218 (at 8q24), rs2665390 (at 3q25), rs717852 (at 2q31), and rs9303542 (at 17q21), were genotyped in 12,599 BRCA1 and 7,132 BRCA2 carriers, including 2,678 ovarian cancer cases. Associations were evaluated within a retrospective cohort approach. All four loci were associated with ovarian cancer risk in BRCA2 carriers; rs10088218 per-allele hazard ratio (HR) = 0.81 (95% CI: 0.67-0.98) P-trend = 0.033, rs2665390 HR = 1.48 (95% CI: 1.21-1.83) P-trend = 1.8 x 10(-4), rs717852 HR = 1.25 (95% CI: 1.10-1.42) P-trend = 6.6 x 10(-4), rs9303542 HR = 1.16 (95% CI: 1.02-1.33) P-trend = 0.026. Two loci were associated with ovarian cancer risk in BRCA1 carriers; rs10088218 per-allele HR = 0.89 (95% CI: 0.81-0.99) P-trend = 0.029, rs2665390 HR = 1.25 (95% CI: 1.10-1.42) P-trend = 6.1 x 10(-4). The HR estimates for the remaining loci were consistent with odds ratio estimates for the general population. The identification of multiple loci modifying ovarian cancer risk may be useful for counseling women with BRCA1 and BRCA2 mutations regarding their risk of ovarian cancer., link_to_OA_fulltext

RAD51C was defined by Meindl et al. in 2010 as a high-risk gene involved in hereditary breast and ovarian cancers. Although this role seems to be clear, nowadays there is controversy about the indication of including the gene in routine clinical genetic testing, due to the lower prevalence or the absence of mutations found in subsequent studies. Here, we present the results of a comprehensive mutational screening of the RAD51C gene in a large series of 785 Spanish breast and/or ovarian cancer families, which, in contrast to the various subsequent studies published to date, includes the functional characterization of suspicious missense variants as reported in the initial study. We have detected 1.3% mutations of RAD51C in breast and ovarian cancer families, while mutations in breast cancer only families seem to be very rare. More than half of the deleterious variants detected were of missense type, which highlights their significance in the gene, and suggest that RAD51C mutations may have been so far partially disregarded and their prevalence underestimated due to the lack of functional complementation assays. Our results provide new evidences, suggesting that the genetic testing of RAD51C should be considered for inclusion into the clinical setting, at least for breast and ovarian cancer families, and encourage re-evaluating its role incorporating functional assays.

INTRODUCTION: Several common alleles have been shown to be associated with breast and/or ovarian cancer risk for BRCA1 and BRCA2 mutation carriers. Recent genome-wide association studies of breast cancer have identified eight additional breast cancer susceptibility loci: rs1011970 (9p21, CDKN2A/B), rs10995190 (ZNF365), rs704010 (ZMIZ1), rs2380205 (10p15), rs614367 (11q13), rs1292011 (12q24), rs10771399 (12p11 near PTHLH) and rs865686 (9q31.2). METHODS: To evaluate whether these single nucleotide polymorphisms (SNPs) are associated with breast cancer risk for BRCA1 and BRCA2 carriers, we genotyped these SNPs in 12,599 BRCA1 and 7,132 BRCA2 mutation carriers and analysed the associations with breast cancer risk within a retrospective likelihood framework. RESULTS: Only SNP rs10771399 near PTHLH was associated with breast cancer risk for BRCA1 mutation carriers (per-allele hazard ratio (HR) = 0.87, 95% CI: 0.81 to 0.94, P-trend = 3 x 10-4). The association was restricted to mutations proven or predicted to lead to absence of protein expression (HR = 0.82, 95% CI: 0.74 to 0.90, P-trend = 3.1 x 10-5, P-difference = 0.03). Four SNPs were associated with the risk of breast cancer for BRCA2 mutation carriers: rs10995190, P-trend = 0.015; rs1011970, P-trend = 0.048; rs865686, 2df-P = 0.007; rs1292011 2df-P = 0.03. rs10771399 (PTHLH) was predominantly associated with estrogen receptor (ER)-negative breast cancer for BRCA1 mutation carriers (HR = 0.81, 95% CI: 0.74 to 0.90, P-trend = 4 x 10-5) and there was marginal evidence of association with ER-negative breast cancer for BRCA2 mutation carriers (HR = 0.78, 95% CI: 0.62 to 1.00, P-trend = 0.049). CONCLUSIONS: The present findings, in combination with previously identified modifiers of risk, will ultimately lead to more accurate risk prediction and an improved understanding of the disease etiology in BRCA1 and BRCA2 mutation carriers., published_or_final_version

[Background]: Alterations in telomere maintenance mechanisms leading to short telomeres underlie different genetic disorders of ageing and cancer predisposition syndromes. It is known that short telomeres and subsequent genomic instability contribute to malignant transformation, and it is therefore likely that people with shorter telomeres are at higher risk for different types of cancer. Recently, the authors demonstrated that the genes BRCA1 and BRCA2 are modifiers of telomere length (TL) in familial breast cancer. The present study analysed TL in peripheral blood leucocytes of hereditary and sporadic ovarian cancer cases, as well as in female controls, to evaluate whether TL contributes to ovarian cancer risk. [Methods]: TL was measured by quantitative PCR in 178 sporadic and 168 hereditary ovarian cases (46 BRCA1, 12 BRCA2, and 110 BRCAX) and compared to TL in 267 controls. [Results]: Both sporadic and hereditary cases showed significantly shorter age adjusted TLs than controls. Unconditional logistic regression analysis revealed an association between TL and ovarian cancer risk with a significant interaction with age (p, This work was supported by Genetic Counseling Programme in Hereditary Cancer (Junta de Castilla y León) grant number FIS PI10/00219 (RGS); the Spanish Association Against Cancer (AECC), FIS PI08-1120 and by Red Tematica de investigacion Cooperativa en Cancer grant number RETICC RD06/0020/1060 (JB), and RETICC 06/0020/0021 (TC and MH); by the Xunta de Galicia grant number 10PXIB 9101297PR and Fundación Mutua Madrileña (AV).

et al., It has been demonstrated that monoallelic PALB2 (Partner and Localizer of BRCA2) gene mutations predispose to familial breast cancer. Some of the families reported with germline PALB2 mutations presented male breast cancer as a characteristic clinical feature. Therefore, we wanted to investigate the contribution of germline PALB2 mutations in a set of 131 Spanish BRCA1/BRCA2-negative breast/ovarian cancer families with at least one male breast cancer case. The analysis included direct sequencing of all coding exons and intron/exon boundaries as well as a Multiplex Ligation-dependent Probe Amplification-based analysis of genomic rearrangements. For the first time we have identified a genomic rearrangement of PALB2 gene involving a large deletion from exon 7 to 11 in a breast cancer family. We have also identified several PALB2 variants, but no other obvious deleterious PALB2 mutation has been found. Thus, our study does not support an enrichment of PALB2 germline mutations in the subset of breast cancer families with male breast cancer cases. The identification of intronic and exonic variants indicates the necessity of assessing the implications of variants that do not lead to PALB2 truncation in the pathoghenicity of the PALB2 gene., This study was supported by grants from the Xunta de Galicia (10PXIB 9101297PR) and FMM Foundation given to AV. TC, M de H, and PPS were supported by PS09/00859, RD06/0020/0021 from RTICC, Instituto de Salud Carlos III. JB and AO were supports by the AECC, and RD06/0020/1060 from RTICC ICO: Contract grant sponsor: Asociación Española Contra el Cáncer, Spanish Health Research Fund; Carlos III Health Institute; Catalan Health Institute and Autonomous Government of Catalonia. Contract grant numbers: ISCIIIRETIC RD06/0020/1051, PI10/01422, PI10/ 31488, and 2009SGR290. E.V. grants, CSI004A10-2 (Consejería de Educación, Junta de Castilla y León) and BIO39/VA27/10 (Consejería de Sanidad, Junta de Castilla y León).

Growth hormone (GH) transcription factor 1 (GHF-1) or pituitary transcription factor 1 (Pit-1) is a pituitary gland-specific homeodomain protein of the POU subclass. POU proteins exert critical developmental and transcriptional functions. Two functional regions, the DNA-binding or POU domain and the transcriptional serine-threonine activation domain (STA) are highly conserved between fishes and primates. However, a variability in the length of the STA domain (between 71 and 128 amino acid residues) is found in different species as well as isoforms generated by alternative splicing.

Large genomic rearrangements (LGRs) at the BRCA2 locus explain a non-negligible proportion of hereditary breast and ovarian cancer (HBOC) syndromes. The multiplex ligation and probe amplification (MLPA) assay has permitted in recent years to identify several families carrying LGRs at this locus, but very few such alterations have been fully characterized at the molecular level. Yet, molecular characterization is essential to identify recurrent alterations, to analyze the genetic mechanisms underlying such alterations, or to investigate potential genotype/phenotype relationships. We have used MLPA to identify BRCA2 LGRs in 7 out of 813 Spanish HBOC families previously tested negative for BRCA1 and BRCA2 small genomic alterations (substitutions and indels) and BRCA1 LGRs. We used a combination of long-range PCR, restriction mapping, and cDNA analysis to characterize the alterations at the molecular level. We found that Del Exon1-Exon2, Del Exon12-Exon16 and Del Exon22-Exon24 explain one family each, while Del Exon2 appears to be a Spanish founder mutation explaining four independent families. Finally, we have combined our data with a comprehensive review of the literature to reevaluate the genetic mechanisms underlying LGRs at the BRCA2 locus. Our study substantially increases the spectrum of BRCA2 LGRs fully characterized at the molecular level. Further on, we provide data to suggest that non-allelic homologous recombination has been overestimated as a mechanism underlying these alterations, while the opposite might be true for microhomology-mediated events.

Although BRCA1 gene mutations have been associated with breast cancer, BRCA1 mutations have been also involved in other functions. Thrombosis and coagulation are novel mechanisms recently associated with cancer. The aims of the present study were (a) to evaluate, using proteomics, if BRCA1 mutation carriers have a different plasma proteins expression related to thrombosis and coagulation profile than non-mutant BRCA1 women and (b) to analyze if the expression of these proteins may be different among BRCA1 mutation carriers with and without breast cancer.Proteomic study was based on 2-dimensional electrophoresis and mass spectrometry. The study was performed in 10 BRCA1 non-mutant controls and 21 women with BRCA1 mutations (with breast cancer (n = 8) and breast cancer-free (n = 13)), all of them free of family history or diagnosis of ovarian cancer.Proteomic study showed that fibrinogen gamma chain isotypes 2 and 3, serotransferrin isotype 4, and convertase C3/C5 isotypes 1-5 were significantly increased in plasma from BRCA1 mutation carriers with respect to BRCA1 non-mutant controls. Plasma levels of alpha-1 antitrypsin isotypes 2-5, apolipoprotein A-IV, and vitamin D-binding protein isotypes 1 and 2 were significantly reduced in BRCA1 mutation carriers with respect to non-mutant controls. Only apolipoprotein A-IV plasma levels were significantly higher in cancer-free BRCA1 mutations carriers compared with BRCA1 mutations carriers who developed breast cancer.It is suggested that independently of breast cancer generation, BRCA1-encoded gene alterations are associated with changes in the expression of circulating proteins associated with thrombosis and coagulation.

The RAD51C gene has been recently proposed as a high-penetrance breast and ovarian cancer gene. However, early replication studies have failed to confirm the finding. Thus, further studies in larger cohorts should be conducted in order to clarify the role of RAD51C as a cancer susceptibility gene. Here, we describe a high-resolution melting analysis (HRMA)-based method developed for presequence screening of RAD51C sequence variants. We have screened RAD51C sequence variants by HRMA in 492 breast cancer patients with family history of breast and/or ovarian cancer that were previously tested negative for BRCA1/2. All variants were confirmed by direct sequencing. We have detected 12 different RAD51C germ-line sequence variants, including eight transitions, two transversion, and two indels (insA, and delT). All these variants generated melting profiles which differ from wild type homozygous controls. Interestingly, we have identified one clearly pathogenic mutation (c.774delT) in the subset of 101 breast and ovarian cancer families, supporting that RAD51C is a human breast and ovarian cancer susceptibility gene.

Intracellular signaling mediated by the receptor activator of nuclear factor-κB [Rank, encoded by the tumor necrosis factor receptor superfamily, member 11a (Tnfrsf11a) gene] is fundamental for mammary gland development in mice, regulating the expansion of stem and progenitor cell compartments. Conversely, Rank overexpression in mice promotes abnormal proliferation and impairs differentiation, leading to an increased incidence of tumorigenesis. Here, we show that a common genetic variant near the 5′-end of TNFRSF11A, rs7226991, is associated with breast cancer risk in the general population and among carriers of mutations in the breast cancer 2, early onset (BRCA2) gene. Akin to the results of the Cancer and Genetics Markers of Susceptibility initiative, combined analysis of rs7226991 in two Spanish case–control studies (1,365 controls and 1,323 cases in total) revealed a significant association with risk: odds ratio (OR) = 0.88, 95% confidence interval (CI) 0.78–0.98, P trend = 0.025. Subsequent examination of BRCA1 (n = 1,017) and BRCA2 (n = 885) mutation carriers revealed a consistent association in the latter group: weighted hazard ratio (wHR) = 0.70; 95% CI 0.55–0.88; and P trend = 0.003; compared to BRCA1 mutation carriers, wHR = 0.91; 95% CI 0.76–1.10; and P trend = 0.33. The results of this study need to be replicated in other populations and with larger numbers of BRCA1/2 mutation carriers.

[Background]: Germline mutations in the BRCA1 and BRCA2 genes are associated with increased risks of breast and ovarian cancers. Although several common variants have been associated with breast cancer susceptibility in mutation carriers, none have been associated with ovarian cancer susceptibility. A genome-wide association study recently identified an association between the rare allele of the single-nucleotide polymorphism (SNP) rs3814113 (ie, the C allele) at 9p22.2 and decreased risk of ovarian cancer for women in the general population. We evaluated the association of this SNP with ovarian cancer risk among BRCA1 or BRCA2 mutation carriers by use of data from the Consortium of Investigators of Modifiers of BRCA1/2. [Methods]: We genotyped rs3814113 in 10 029 BRCA1 mutation carriers and 5837 BRCA2 mutation carriers. Associations with ovarian and breast cancer were assessed with a retrospective likelihood approach. All statistical tests were two-sided. [Results]: The minor allele of rs3814113 was associated with a reduced risk of ovarian cancer among BRCA1 mutation carriers (per-allele hazard ratio of ovarian cancer = 0.78, 95% confidence interval = 0.72 to 0.85; P = 4.8 × 10-9) and BRCA2 mutation carriers (hazard ratio of ovarian cancer = 0.78, 95% confidence interval = 0.67 to 0.90; P = 5.5 × 10-4). This SNP was not associated with breast cancer risk among either BRCA1 or BRCA2 mutation carriers. BRCA1 mutation carriers with the TT genotype at SNP rs3814113 were predicted to have an ovarian cancer risk to age 80 years of 48%, and those with the CC genotype were predicted to have a risk of 33%. [Conclusion]: Common genetic variation at the 9p22.2 locus was associated with decreased risk of ovarian cancer for carriers of a BRCA1 or BRCA2 mutation., Spanish National Cancer Center (CNIO) and the Spanish Consortium: Partially supported by Fundación Mutua Madrileña, Asociación Española Contra el Cáncer, and the Spanish Ministry of Science and Innovation (FIS PI08 1120).

5 páginas, 1 figura, 1 tabla.-- et al.-- El pdf del artículo es el manuscrito de autor., The mutation spectrum of BRCA1 and BRCA2 presents a wide range of unique mutations in breast/ovarian cancer patients but recurrent mutations with founder effects have also been described. BRCA2 5344delAATA and 9538delAA are recurrent mutations in Castilla-Leo´n (Spain) representing 10.6% of BRCA2 positive families. By genotyping eleven chromosome 13 markers (4.3 Mb) we demonstrate that each mutation shows core haplotypes of 1.66 and 0.87 Mb, respectively, supporting a common ancestor in Castilla-Leo´n. Furthermore, both mutations are associated with earlier onset of breast cancer (5344delAATA: 37.4 years, P = 0.033; 9538delAA: 39.4 years, P = 0.008). The identification of founder effects improves the genetic screening strategy to be followed and facilitates the clinical management of asymptomatic carriers., This work has been supported by the Regional Government of Castilla y León, and grants PI061102 (Instituto de Salud Carlos III, Ministerio de Ciencia e Innovación) and 200820I135 (Consejo Superior de Investigaciones Científicas, Ministerio de Ciencia e Innovación).

Recent reports have shown that mutations in the FANCJ/BRIP1 and FANCN/PALB2 Fanconi Anemia (FA) genes confer a moderate breast cancer risk. Discussion has been raised on the phenotypic characteristics of the PALB2-associated families and tumors. The role of FANCB in breast cancer susceptibility has not been tested to date. Likewise PALB2 mutation frequency has not been studied in Spanish population. We analyzed the complete coding sequence and splicing sites of FANCB and PALB2 in 95 index cases of BRCA1/2-negative Spanish breast cancer families. We also performed an exhaustive screening of three previously described rare but recurrent PALB2 mutations in 725 additional probands. Pathogenic changes were not detected in FANCB. We found a novel PALB2 truncating mutation c.1056_1057delGA (p.K353IfsX7) in one of the 95 screened patients, accounting for a mutation frequency of 1% in our series. Further comprehensive screening of the novel mutation and of previously reported rare but recurrent PALB2 mutations did not reveal any carrier patient. We report the first example of LOH occurring in a PALB2-associated tumor. Our results rule out a major contribution of FANCB to hereditary breast cancer. Our data are consistent with the notion of individually rare PALB2 mutations, lack of mutational hot-spots in the gene and existence of between-population disease-allele heterogeneity. We show evidence that PALB2 loss of function might also conform to the inactivation model of a classic tumor-suppressor gene and present data that adds to the clinically relevant discussion about the existence of a PALB2-breast cancer phenotype.

9 páginas, 1 figura, 4 tablas.-- et al., [Purpose]: It is not clear that the published estimates of the breast and ovarian cancer penetrances of mutations in BRCA1 and BRCA2 can be used in genetic counseling in countries such as Spain, where the incidence of breast cancer in the general population is considerably lower, the prevalence of BRCA2 mutations seems to be higher, and a distinct spectrum of recurrent mutations exists for both genes. We aimed to estimate these penetrances for women attending genetic counseling units in Spain. [Experimental Design]: We collected phenotype and genotype data on 155 BRCA1 and 164 BRCA2 mutation carrier families from 12 centers across the country. Average age-specific cumulative risks of breast cancer and ovarian cancer were estimated using a modified segregation analysis method. [Results]: The estimated average cumulative risk of breast cancer to age 70 years was estimated to be 52% [95% confidence interval (95% CI), 26-69%] for BRCA1 mutation carriers and 47% (95% CI, 29-60%) for BRCA2 mutation carriers. The corresponding estimates for ovarian cancer were 22% (95% CI, 0-40%) and 18% (95% CI, 0-35%), respectively. There was some evidence (two-sided P = 0.09) that 330A>G (R71G) in BRCA1 may have lower breast cancer penetrance. [Conclusions]: These results are consistent with those from a recent meta-analysis of practically all previous penetrance studies, suggesting that women with BRCA1 and BRCA2 mutations attending genetic counseling services in Spain have similar risks of breast and ovarian cancer to those published for other Caucasian populations. Carriers should be fully informed of their mutation- and age-specific risks to make appropriate decisions regarding prophylactic interventions such as oophorectomy.

Purpose: A subset of colorectal cancers (CRC) arises in families that, despite fulfilling clinical criteria for hereditary nonpolyposis colorectal cancer (HNPCC), do not show evidence of a mismatch repair (MMR) deficiency. The main objective of this study was to characterize these tumors at the molecular level. Experimental Design: After comprehensive germ line mutation scanning, microsatellite analysis, and MMR protein expressions, we selected a well-defined cohort of 57 colorectal tumors with no evidence of MMR defects. In this group of tumors, we analyzed KRAS, BRAF, and APC somatic mutations, as well as methylguanine methyltransferase (MGMT) and β-catenin expression. We correlated these alterations with clinicopathologic data and explored the relationship between KRAS G > A transitions and lack of MGMT expression. Results: The mutation profile at the RAS/RAF/MAPK pathway mimics sporadic microsatellite-stable CRCs. We found an average age of diagnosis 10 years older in KRAS-mutated patients (P = 0.001). In addition, we show that KRAS G > A transitions are actively selected by tumors, regardless of MGMT status. Similarities with HNPCC high–microsatellite instability tumors are observed when APC data are analyzed. The APC mutation rate was low and small insertions/deletions accounted for 70% of the alterations. In addition, we found a low frequency of β-catenin nuclear staining. Finally, we did not find evidence of tumors arising in individuals from the same family sharing molecular features. Conclusions: We show evidence that CRC tumors arising in HNPCC families without MMR alterations have distinctive molecular features. Overall, our work shows that systematic analysis of somatic alterations in a well-defined subset of CRCs is a good approach to provide new insights into the mechanisms of colorectal carcinogenesis.

Breast cancer (BC) is the most commonly diagnosed cancer among women, with 1 in every 7 women in the U.S. developing BC in their lifetime. While BC may not be the leading cause of cancer incidence in many minority populations, such as Hispanics, it is the leading cause of cancer death, highlighting a cancer disparity. Moreover, the contribution of mutations in BC susceptibility genes remains poorly investigated in Hispanic populations. To begin to address these voids, we screened Colombian BC patients for common BRCA1 and BRCA2 mutations using the KASP genotyping system. Strikingly, 27 of 722 unselected cases (4%) harbored the same BRCA1 3450del4 mutation. Clinical data and family history indicate that these individuals originate from a distinct geographic region in Colombia, Neiva. Significantly, 10% of the unselected BC cases in Neiva and the surrounding region harbor the 3450del4 mutation, potentially representing one of the most profound founder effects reported in human populations. Interesting, this BRCA1 mutation has also been reported in other countries, including Portugal, Spain, and Chile. To determine whether this mutation stems from a single origin, mutation carriers from each of these countries (n = 26), along with mutation carriers from Colombia (n = 27), were subjected to the Affymetrix Axiom Human UK Biobank Array (>800 thousand markers). Haplotypes in which the BRCA1 mutation resides were estimated by SHAPEIT, and pairwise segmental sharing was determined using GERMLINE. Our data suggest that the mutation carriers, although from different countries and continents, share a core haplotype, likely to have originated from Spain. Additionally, the mutation seems to be fairly new to Colombia, with individuals sharing up to a 40Mb haplotype comprising the mutation. We are currently estimating the age of the mutation using the bioinformatic software DMLE+, which exploits the rate of linkage disequilibrium decay due to recombination. By understanding the prevalence of mutations in known breast cancer risk genes in minority populations, cancer disparities can be better addressed and breast cancer screening can be improved. Furthermore, these findings have direct implications in robust and cost-effective targeted screening in regions where there is a high prevalence of the BRCA1 3450del4 mutation. Citation Format: Anna Marie De Asis Tuazon, Carolina Ramirez, Mabel Bohorquez, Rodrigo Prieto, Paul Lott, Angel Criollo, Ana Estrada, Gillbert Mateus, Alejandro Velez, Justo Ramirez, COLUMBUS Consortium, Manuel Teixeira, Ana Vega, Conxi Lazaro, Eva Tornero, Cristina Martinez, Mar Infante, Miguel De La Hoya, Orland Diez, Pilar Carvallo, Magdalena Echeverry, Luis Carvajal-Carmona. Transcontinental characterization of the Hispanic BRCA1 3450del4 breast cancer founder mutation. [abstract]. In: Proceedings of the 106th Annual Meeting of the American Association for Cancer Research; 2015 Apr 18-22; Philadelphia, PA. Philadelphia (PA): AACR; Cancer Res 2015;75(15 Suppl):Abstract nr 2739. doi:10.1158/1538-7445.AM2015-2739

6 páginas, 2 tablas.-- et al., [Background]: Large genomic rearrangements (LGRs) account for a substantial proportion of the BRCA1 disease-causing changes, or variations, identified in families with hereditary breast/ovarian cancer [HB(O)C]. Great differences in the spectrum and prevalence of BRCA1 LGR have been observed among populations. Here we report the first comprehensive analysis of BRCA1 LGRs conducted in Spain. [Methods]: We used multiplex ligation-dependent probe amplification (MLPA) to screen for BRCA1 LGRs in the index case individuals of 384 HB(O)C families who previously tested negative for BRCA1 and BRCA2 point variations, small insertions, and deletions. An alternative set of MLPA probes, long-range PCR, and real-time PCR were used to confirm positive results. [Results]: We have identified 8 different BRCA1 rearrangements (del exon 1–24, del exon 8–13, del exon 11–15, del exon 14, dup exon 19–20, dup exon 20, exon 21–22 amplification, and del exon 23–24). With the exception of del exon 8–13, they are novel alterations. Overall, BRCA1 LGRs explain 1.4% of the Spanish HB(O)C families, and they account for 8.2% of all BRCA1 pathogenic variations identified in our study population. BRCA1 genetic variants affecting hybridization of commercially available MLPA probes are very rare in our population. [Conclusions]: Screening for BRCA1 LGRs should be mandatory in Spanish HB(O)C families. A high proportion of country-specific rearrangements are scattered along the gene. MLPA is a robust method to screen for LGRs in our population. MLPA analysis of positive samples with an alternative set of probes, together with long-range PCR and real-time PCR, is a feasible approach to confirm results in cases in which LGR breakpoints have not been characterized., This work was supported by grants from Instituto de Salud Carlos III (FIS 01/3040, FIS 04/1832, FIS RTICC C03/10, and Xunta de Galicia (PGIDIT02PXIC20804PN). Sara Gutierrez-Enriquez is supported by a contract financed by Red Genómica del Cáncer del Instituto de Salud Carlos III (2003–2005).

The genetic factors that cause clustering of colorectal cancers (CRCs) other than mutations in the mismatch repair (MMR) genes are not well understood. Clustering in families who lack MMR gene mutations may be attributable to low-penetrance mutations. Hypothetically, mono-allelic MYH mutations could contribute to the risk of CRC in these families. Using Fisher's exact test and logistic regression, we compared the frequency of the known disease-causing MYH mutations Y165C, G382D and 466delE in 137 probands (117 cases with CRC and 20 cases diagnosed on the basis of adenomatous polyps only) from families with three or more CRCs but negative for mutations in the MMR genes and in 967 healthy controls with comparable ethnic backgrounds. Of 137 cases, 6 (4.4%) carried mono-allelic MYH mutations compared with 16 of 967 (1.6%) controls. In addition, three bi-allelic MYH mutation carriers, who eventually developed MYH-associated polyposis, were also identified in families with pedigree structures consistent with dominant inheritance of CRC susceptibility. By Fisher's exact tests, there was a statistically different frequency of cases with any MYH mutation (mono- or bi-allelic carriers; P-value = 0.002) and of cases with mono-allelic MYH mutation (P = 0.04) compared with the controls. Using a logistic regression model, the unadjusted odds ratio associated with any MYH mutation was 4.14 (P-value < 0.001); for mono-allelic carriers, it was 2.79 (P-value = 0.04). Adjusting for ethnic backgrounds, gender and age, the odds ratio associated with any disease-causing MYH mutation was 3.23 (P-value = 0.01); for mono-allelic carriers, it was 1.99 (P-value = 0.20). Overall, the results support previous studies suggesting that mono-allelic mutations of MYH constitute low-penetrance CRC-causing alleles. These data further support a model in which low-penetrance alleles are enriched in MMR gene mutation-negative CRC families.

The frame-shift mutation 1100delC in the cell-cycle-checkpoint kinase 2 gene (CHEK2) has been reported to be a low penetrance breast cancer gene in Northern European populations. However, the variant may be relevant for breast cancer risk in other populations, due to its low prevalence. Recent studies have proposed a role for the mutation in colorectal cancer, finding a strong association between the CHEK21100delC mutation and hereditary breast and colorectal cancer (HBCC). A previous study suggested that the CHEK21100delC variant was not of clinical relevance in Spanish breast/ovarian cancer families. Here, we demonstrate that this genetic variant is not of clinical relevance for HNPCC and HBCC Spanish families.

Six SNPs have been detected in the DNA repair genes RAD51C and RAD51D, not previously characterized. The novel variant E233G in RAD51D is more highly represented in high-risk, site-specific, familial breast cancer cases that are not associated with the BRCA1/2 genes, with a frequency of 5.74% (n = 174) compared to a control population (n = 567) and another subset of breast cancer patients (n = 765) with a prevalence of around 2% only (comparison to controls, OR = 2.6, 95% CI 1.12-6.03; p0.021). We found that the immunohistochemical profile detected in available tumors from these patients differs slightly from those described in non-BRCA1/2 tumors. Finally, the structural prediction of the putative functional consequence of this change indicates that it can diminish protein stability and structure. This suggests a role for E233G as a low-penetrance susceptibility gene in the specific subgroup of high-risk familial breast cancer cases that are not related to BRCA1/2.

Searching for low-penetrance genes involved in breast cancer susceptibility has been a field of interest in the last few years. Recently, the CHEK 2 gene, involved in DNA damage and replication checkpoints, has been pointed out as a good candidate; moreover, a specific variant in this gene,1100delC, has been found to increase breast cancer susceptibility among familial breast cancer cases not attributable to mutations in BRCA1 or BRCA2 genes. In our present study, we evaluated the role of the 1100delC variant as a susceptibility allele in breast cancer in the Spanish population. However, our results suggest that this variant is absent or very infrequent in our population, making its screening irrelevant from the practical point of view.

We screened index cases from 410 Spanish breast/ovarian cancer families and 214 patients (19 of them males) with breast cancer for germ-line mutations in the BRCA1 and BRCA2 genes, using SSCP, PTT, CSGE, DGGE, and direct sequencing. We identified 60 mutations in BRCA1 and 53 in BRCA2. Of the 53 distinct mutations observed, 11 are novel and 12 have been reported only in Spanish families (41.5%). The prevalence of mutations in this set of families was 26.3%, but the percentage was higher in the families with breast and ovarian cancer (52.1%). The lowest proportion of mutations was found in the site-specific female breast cancer families (15.4%). Of the families with male breast cancer cases, 59.1% presented mutations in the BRCA2 gene. We found a higher frequency of ovarian cancer associated with mutations localized in the 5' end of the BRCA1 gene, but there was no association between the prevalence of this type of cancer and mutations situated in the ovarian cancer cluster region (OCCR) region of exon 11 of the BRCA2 gene. The mutations 187_188delAG, 330AG, 5236GA, 5242CA, and 589_590del (numbered after GenBank U14680) account for 46.6% of BRCA1 detected mutations whereas 3036_3039del, 6857_6858del, 9254_9258del, and 9538_9539del (numbered after GenBank U43746) account for 56.6% of the BRCA2 mutations. The BRCA1 330AG has a Galician origin (northwest Spain), and BRCA2 6857_6858del and 9254_9258del probably originated in Catalonia (northeast Spain). Knowledge of the spectrum of mutations and their geographical distribution in Spain will allow a more effective detection strategy in countries with large Spanish populations.

Defects in X-chromosome inactivation distort sex ratio in mice. The BRCA1 gene is also involved in X-chromosome inactivation, suggesting the possibility that some sex-ratio distortion may be associated with BRCA1-related human cancer syndromes.To determine whether BRCA1 mutations are associated with distortion of the sex ratio of births in families with breast cancer, ovarian cancer, or both.Analysis of germline mutations in participants from Spain who had been screened for BRCA between 1998 and 2002.Sixty-eight families with at least 3 breast cancer cases or ovarian cancer cases, or both types of cancer in 2 generations (germline mutations: BRCA1, n = 17; BRCA2, n = 15; and BRCA unrelated, n = 36). An average of 4 relatives per family were tested for the corresponding BRCA mutation.Male and female births registered in breast and/or ovarian pedigrees tested for the presence of BRCA1 and BRCA2 germline mutations.Of BRCA1-related breast and/or ovarian cancer pedigrees, there was a 2-fold excess of female births (218 female vs 109 male births). Of BRCA2-related or BRCA-unrelated breast and/or ovarian cancer pedigrees, there was not an excess of female births (175 female/150 male and 344 female/315 male, respectively). Of 327 BRCA1 births, 218 (67%) were female births compared with 54% among BRCA2 pedigrees (175/327; P.001) and 52% among BRCA-unrelated pedigrees (344/659; P.001). Female births increased in the offspring of BRCA1 carriers compared with BRCA2 carriers (67% vs 52%; P =.004).In these families with breast and/or ovarian cancer, mutations in BRCA1 but not BRCA2 were associated with a sex ratio skewed against male births.

The BRCA1 gene is included in a 200-400 kb region that is subjected to a recombination suppression mechanism; this region shows nearly complete linkage disequilibrium for a series of common biallelic polymorphisms, all of them with rarer allele frequency close to 0.4. These series of SNPs define two major haplotypes designated as class I and class II. In the present study, we have determined haplotype classes in the index case of 106 breast/ovarian cancer families previously screened for mutations in the BRCA genes and we have found that haplotype II (the less frequent in the control population) is over-represented among chromosomes harbouring mutations in BRCA1. In addition, we have defined a subtype of chromosomes characterized by haplotype I and one specific allele for the microsatellite marker D17S855, which are also more frequently associated with BRCA1 mutations. These findings may have important consequences for the selection of families with higher probabilities of carrying mutations in the BRCA1 gene.

The aim of this study was to explore the usefulness of a human monocyte cell line in the development of in vitro models for predictive testing of contact sensitizers. Several studies have shown that contact sensitizers induce CD86 expression and enhanced internalization of MHC class II molecules in dendritic cells (DCs). We used THP-1, a human monocyte cell line, as a replacement for DCs for evaluation of these phenotypical alterations as predictive endpoints for contact sensitizers. Known sensitizers and irritants were evaluated. After 24-h exposure to samples, the expression of CD86 on THP-1 cells was measured by flow cytometry. Sensitizers such as dinitrochlorobenzene (DNCB), 2-mercaptobenzothiazole (MBT), eugenol, p-phenylenediamine (PPDA) and ammonium tetrachloroplatinate (Pt) enhanced CD86 expression on THP-1 cells, while nickel sulfate, cobalt sulfate and irritants such as methylsalicylate (MS), sodium dodecyl sulfate (SDS) and dimethyl sulfoxide (DMSO) did not augment CD86 expression. A synergistic effect was observed when DNCB and IFN-alpha were added simultaneously to a culture of THP-1 cells. Furthermore, internalization of MHC class II molecules was observed when the cells were treated with some of sensitizers for 2 h. The inducing effects of chemicals on the two phenotypical alterations were the same. These results suggest that these test systems can be used to predict contact-sensitizing ability of chemicals as an in vitro sensitization assay.

We have observed that the frequency of D17S855 short alleles (139 bp and 141 bp) in individuals carrying BRCA1 germline mutations is higher than in controls (54% vs. 31%, p = 0.0004). By unambiguously establishing mutation/D17S855 phase in 18 BRCA1-positive families, we find that most (11 of 15 different mutations) BRCA1 defects are linked to chromosomes with short alleles (OR = 8.21, 95% CI 1.97–39.32, p = 0.0007). We suggest that BRCA1 mutations are not randomly distributed but clustered in a subset of BRCA1 alleles that can be identified by D17S855 genotyping. Further analysis involving a larger set of mutations and different populations are needed to clarify the relevance of this unexpected finding. © 2002 Wiley-Liss, Inc.