RESUMO
Co-observation of a gene variant with a pathogenic variant in another gene that explains the disease presentation has been designated as evidence against pathogenicity for commonly used variant classification guidelines. Multiple variant curation expert panels have specified, from consensus opinion, that this evidence type is not applicable for the classification of breast cancer predisposition gene variants. Statistical analysis of sequence data for 55,815 individuals diagnosed with breast cancer from the BRIDGES sequencing project was undertaken to formally assess the utility of co-observation data for germline variant classification. Our analysis included expected loss-of-function variants in 11 breast cancer predisposition genes and pathogenic missense variants in BRCA1, BRCA2, and TP53. We assessed whether co-observation of pathogenic variants in two different genes occurred more or less often than expected under the assumption of independence. Co-observation of pathogenic variants in each of BRCA1, BRCA2, and PALB2 with the remaining genes was less frequent than expected. This evidence for depletion remained after adjustment for age at diagnosis, study design (familial versus population-based), and country. Co-observation of a variant of uncertain significance in BRCA1, BRCA2, or PALB2 with a pathogenic variant in another breast cancer gene equated to supporting evidence against pathogenicity following criterion strength assignment based on the likelihood ratio and showed utility in reclassification of missense BRCA1 and BRCA2 variants identified in BRIDGES. Our approach has applicability for assessing the value of co-observation as a predictor of variant pathogenicity in other clinical contexts, including for gene-specific guidelines developed by ClinGen Variant Curation Expert Panels.
Assuntos
Neoplasias da Mama , Predisposição Genética para Doença , Mutação em Linhagem Germinativa , Humanos , Neoplasias da Mama/genética , Mutação em Linhagem Germinativa/genética , Feminino , Proteína BRCA2/genética , Proteína BRCA1/genética , Proteína do Grupo de Complementação N da Anemia de Fanconi/genética , Pessoa de Meia-Idade , Mutação de Sentido Incorreto/genética , Adulto , Proteína Supressora de Tumor p53/genéticaRESUMO
PURPOSE: To investigate frequency of germline pathogenic variants (PVs) in women with ductal carcinoma in situ (DCIS) and grade 1 invasive breast cancer (G1BC). METHODS: We undertook BRCA1/2 analysis in 311 women with DCIS and 392 with G1BC and extended panel testing (non-BRCA1/2) in 176/311 with DCIS and 156/392 with G1BC. We investigated PV detection by age at diagnosis, Manchester Score (MS), DCIS grade and receptor status. RESULTS: 30/311 (9.6%) with DCIS and 16/392 with G1BC (4.1%) had a BRCA1/2 PV (p=0.003), and 24/176-(13.6%) and 7/156-(4.5%), respectively, a non-BRCA1/2 PV (p=0.004). Increasing MS was associated with increased likelihood of BRCA1/2 PV in both DCIS and G1BC, although the 10% threshold was not predictive for G1GB. 13/32 (40.6%) DCIS and 0/17 with G1BC <40 years had a non-BRCA1/2 PV (p<0.001). 0/16 DCIS G1 had a PV. For G2 and G3 DCIS, PV rates were 10/98 (BRCA1/2) and 9/90 (non-BRCA1/2), and 8/47 (BRCA1/2) and 8/45 (non-BRCA1/2), respectively. 6/9 BRCA1 and 3/26 BRCA2-associated DCIS were oestrogen receptor negative-(p=0.003). G1BC population testing showed no increased PV rate (OR=1.16, 95% CI 0.28 to 4.80). CONCLUSION: DCIS is more likely to be associated with both BRCA1/2 and non-BRCA1/2 PVs than G1BC. Extended panel testing ought to be offered in young-onset DCIS where PV detection rates are highest.
Assuntos
Neoplasias da Mama , Carcinoma Intraductal não Infiltrante , Feminino , Humanos , Carcinoma Intraductal não Infiltrante/diagnóstico , Carcinoma Intraductal não Infiltrante/genética , Carcinoma Intraductal não Infiltrante/patologia , Neoplasias da Mama/diagnóstico , Neoplasias da Mama/genética , Neoplasias da Mama/epidemiologia , Proteína BRCA1/genética , Proteína BRCA2/genética , Mutação em Linhagem Germinativa/genética , Genes BRCA2 , Células Germinativas/patologiaRESUMO
BACKGROUND: Polygenic risk score (PRS), calculated based on genome-wide association studies (GWASs), can improve breast cancer (BC) risk assessment. To date, most BC GWASs have been performed in individuals of European (EUR) ancestry, and the generalisation of EUR-based PRS to other populations is a major challenge. In this study, we examined the performance of EUR-based BC PRS models in Ashkenazi Jewish (AJ) women. METHODS: We generated PRSs based on data on EUR women from the Breast Cancer Association Consortium (BCAC). We tested the performance of the PRSs in a cohort of 2161 AJ women from Israel (1437 cases and 724 controls) from BCAC (BCAC cohort from Israel (BCAC-IL)). In addition, we tested the performance of these EUR-based BC PRSs, as well as the established 313-SNP EUR BC PRS, in an independent cohort of 181 AJ women from Hadassah Medical Center (HMC) in Israel. RESULTS: In the BCAC-IL cohort, the highest OR per 1 SD was 1.56 (±0.09). The OR for AJ women at the top 10% of the PRS distribution compared with the middle quintile was 2.10 (±0.24). In the HMC cohort, the OR per 1 SD of the EUR-based PRS that performed best in the BCAC-IL cohort was 1.58±0.27. The OR per 1 SD of the commonly used 313-SNP BC PRS was 1.64 (±0.28). CONCLUSIONS: Extant EUR GWAS data can be used for generating PRSs that identify AJ women with markedly elevated risk of BC and therefore hold promise for improving BC risk assessment in AJ women.
Assuntos
Neoplasias da Mama , Humanos , Feminino , Neoplasias da Mama/epidemiologia , Neoplasias da Mama/genética , Estudo de Associação Genômica Ampla , Judeus/genética , Israel/epidemiologia , Predisposição Genética para Doença , Fatores de Risco , Herança Multifatorial/genética , Fatores de TranscriçãoRESUMO
PURPOSE: Screening with low-dose computed tomography reduces lung cancer (LC) mortality. Risk prediction models used for screening selection do not include genetic variables. Here, we investigated the performance of previously published polygenic risk scores (PRSs) for LC, considering their potential to improve screening selection. METHODS: We validated 9 PRSs in a high-risk case-control cohort, comprising genotype data from 652 surgical patients with LC and 550 cancer-free, high-risk (PLCOM2012 score ≥ 1.51%) participants of the Manchester Lung Health Check, a community-based LC screening program (n = 550). Discrimination (area under the curve [AUC]) between cases and controls was assessed for each PRS independently and alongside clinical risk factors. RESULTS: Median age was 67 years, 53% were female, 46% were current smokers, and 76% were National Lung Screening Trial eligible. Median PLCOM2012 score among controls was 3.4%, 80% of cases were early stage. All PRSs significantly improved discrimination, AUC increased between +0.002 (P = .02) and +0.015 (P < .0001), compared with clinical risk factors alone. The best-performing PRS had an independent AUC of 0.59. Two novel loci, in the DAPK1 and MAGI2 genes, were significantly associated with LC risk. CONCLUSION: PRSs may improve LC risk prediction and screening selection. Further research, particularly examining clinical utility and cost-effectiveness, is required.
Assuntos
Neoplasias Pulmonares , Humanos , Feminino , Idoso , Masculino , Medição de Risco/métodos , Fatores de Risco , Neoplasias Pulmonares/diagnóstico , Neoplasias Pulmonares/genética , Genótipo , Estudos de Casos e ControlesRESUMO
PURPOSE: Polygenic risk scores (PRSs) are a major component of accurate breast cancer (BC) risk prediction but require ethnicity-specific calibration. Ashkenazi Jewish (AJ) population is assumed to be of White European (WE) origin in some commercially available PRSs despite differing effect allele frequencies (EAFs). We conducted a case-control study of WE and AJ women from the Predicting Risk of Cancer at Screening Study. The Breast Cancer in Northern Israel Study provided a separate AJ population-based case-control validation series. METHODS: All women underwent Illumina OncoArray single-nucleotide variation (SNV; formerly single-nucleotide polymorphism [SNP]) analysis. Two PRSs were assessed, SNV142 and SNV78. A total of 221 of 2243 WE women (discovery: cases = 111; controls = 110; validation: cases = 651; controls = 1772) and 221 AJ women (cases = 121; controls = 110) were included from the UK study; the Israeli series consisted of 2045 AJ women (cases = 1331; controls = 714). EAFs were obtained from the Genome Aggregation Database. RESULTS: In the UK study, the mean SNV142 PRS demonstrated good calibration and discrimination in WE population, with mean PRS of 1.33 (95% CI 1.18-1.48) in cases and 1.01 (95% CI 0.89-1.13) in controls. In AJ women from Manchester, the mean PRS of 1.54 (1.38-1.70) in cases and 1.20 (1.08-1.32) in controls demonstrated good discrimination but overestimation of BC relative risk. After adjusting for EAFs for the AJ population, mean risk was corrected (mean SNV142 PRS cases = 1.30 [95% CI 1.16-1.44] and controls = 1.02 [95% CI 0.92-1.12]). This was recapitulated in the larger Israeli data set with good discrimination (area under the curve = 0.632 [95% CI 0.607-0.657] for SNV142). CONCLUSION: AJ women should not be given BC relative risk predictions based on PRSs calibrated to EAFs from the WE population. PRSs need to be recalibrated using AJ-derived EAFs. A simple recalibration using the mean PRS adjustment ratio likely performs well.
Assuntos
Neoplasias da Mama , Predisposição Genética para Doença , Judeus , Feminino , Humanos , Neoplasias da Mama/diagnóstico , Neoplasias da Mama/etnologia , Neoplasias da Mama/genética , Estudos de Casos e Controles , Judeus/genética , Polimorfismo de Nucleotídeo Único , Fatores de Risco , População Branca/genética , Herança MultifatorialRESUMO
BACKGROUND: While the likelihood of identifying constitutional breast cancer-associated BRCA1, BRCA2 and TP53 pathogenic variants (PVs) increases with earlier diagnosis age, little is known about the correlation with age at diagnosis in other predisposition genes. Here, we assessed the contribution of known breast cancer-associated genes to very early onset disease. METHODS: Sequencing of BRCA1, BRCA2, TP53 and CHEK2 c.1100delC was undertaken in women with breast cancer diagnosed ≤30 years. Those testing negative were screened for PVs in a minimum of eight additional breast cancer-associated genes. Rates of PVs were compared with cases ≤30 years from the Prospective study of Outcomes in Sporadic vs Hereditary breast cancer (POSH) study. RESULTS: Testing 379 women with breast cancer aged ≤30 years identified 75 PVs (19.7%) in BRCA1, 35 (9.2%) in BRCA2, 22 (5.8%) in TP53 and 2 (0.5%) CHEK2 c.1100delC. Extended screening of 184 PV negative women only identified eight additional actionable PVs. BRCA1/2 PVs were more common in women aged 26-30 years than in younger women (p=0.0083) although the younger age group had rates more similar to those in the POSH cohort. Out of 26 women with ductal carcinoma in situ (DCIS) alone, most were high-grade and 11/26 (42.3%) had a PV (TP53=6, BRCA2=2, BRCA1=2, PALB2=1). This PV yield is similar to the 61 (48.8%) BRCA1/2 PVs identified in 125 women with triple-negative breast cancer. The POSH cohort specifically excluded pure DCIS which may explain lower TP53 PV rates in this group (1.7%). CONCLUSION: The rates of BRCA1, BRCA2 and TP53 PVs are high in very early onset breast cancer, with limited benefit from testing of additional breast cancer-associated genes.
Assuntos
Neoplasias da Mama/genética , Quinase do Ponto de Checagem 2/genética , Genes BRCA1 , Genes BRCA2 , Mutação , Adulto , Idade de Início , DNA de Neoplasias , Feminino , Genes p53 , Humanos , Análise de Sequência de DNARESUMO
Polygenic risk scores (PRS) for disease risk stratification show great promise for application in general populations, but most are based on data from individuals of White European origin. We assessed two well validated PRS (SNP18, SNP143) in the Predicting-Risk-of-Cancer-At-Screening (PROCAS) study in North-West England for breast cancer prediction based on ethnicity. Overall, 9475 women without breast cancer at study entry, including 645 who subsequently developed invasive breast cancer or ductal carcinoma in situ provided DNA. All were genotyped for SNP18 and a subset of 1868 controls were genotyped for SNP143. For White Europeans both PRS discriminated well between individuals with and without cancer. For n = 395 Black (n = 112), Asian (n = 119), mixed (n = 44) or Jewish (n = 120) women without cancer both PRS overestimated breast cancer risk, being most marked for women of Black and Jewish origin (P < .001). SNP143 resulted in a potential mean 40% breast cancer risk overestimation in the combined group of non-White/non-European origin. SNP-PRS that has been normalized based on White European ethnicity for breast cancer should not be used to predict risk in women of other ethnicities. There is an urgent need to develop PRS specific for other ethnicities, in order to widen access of this technology.
Assuntos
Biomarcadores Tumorais/genética , Neoplasias da Mama/epidemiologia , Carcinoma Ductal de Mama/epidemiologia , Carcinoma Intraductal não Infiltrante/epidemiologia , Etnicidade/genética , Polimorfismo de Nucleotídeo Único , População Branca/genética , Adulto , Idoso , Densidade da Mama , Neoplasias da Mama/genética , Neoplasias da Mama/patologia , Carcinoma Ductal de Mama/genética , Carcinoma Ductal de Mama/patologia , Carcinoma Intraductal não Infiltrante/genética , Carcinoma Intraductal não Infiltrante/patologia , Estudos de Casos e Controles , Inglaterra/epidemiologia , Feminino , Seguimentos , Predisposição Genética para Doença , Humanos , Pessoa de Meia-Idade , Prognóstico , Fatores de RiscoRESUMO
PURPOSE: There is great promise in breast cancer risk stratification to target screening and prevention. It is unclear whether adding gene panels to other risk tools improves breast cancer risk stratification and adds discriminatory benefit on a population basis. METHODS: In total, 10,025 of 57,902 women aged 46 to 73 years in the Predicting Risk of Cancer at Screening study provided DNA samples. A case-control study was used to evaluate breast cancer risk assessment using polygenic risk scores (PRSs), cancer gene panel (n = 33), mammographic density (density residual [DR]), and risk factors collected using a self-completed 2-page questionnaire (Tyrer-Cuzick [TC] model version 8). In total, 525 cases and 1410 controls underwent gene panel testing and PRS calculation (18, 143, and/or 313 single-nucleotide polymorphisms [SNPs]). RESULTS: Actionable pathogenic variants (PGVs) in BRCA1/2 were found in 1.7% of cases and 0.55% of controls, and overall PGVs were found in 6.1% of cases and 1.3% of controls. A combined assessment of TC8-DR-SNP313 and gene panel provided the best risk stratification with 26.1% of controls and 9.7% of cases identified at <1.4% 10-year risk and 9.01% of controls and 23.3% of cases at ≥8% 10-year risk. Because actionable PGVs were uncommon, discrimination was identical with/without gene panel (with/without: area under the curve = 0.67, 95% CI = 0.64-0.70). Only 7 of 17 PGVs in cases resulted in actionable risk category change. Extended case (n = 644)-control (n = 1779) series with TC8-DR-SNP143 identified 18.9% of controls and only 6.4% of stage 2+ cases at <1.4% 10-year risk and 20.7% of controls and 47.9% of stage 2+ cases at ≥5% 10-year risk. CONCLUSION: Further studies and economic analysis will determine whether adding panels to PRS is a cost-effective strategy for risk stratification.
Assuntos
Densidade da Mama , Neoplasias da Mama , Densidade da Mama/genética , Neoplasias da Mama/diagnóstico por imagem , Neoplasias da Mama/genética , Estudos de Casos e Controles , Detecção Precoce de Câncer , Feminino , Predisposição Genética para Doença , Humanos , Polimorfismo de Nucleotídeo Único/genética , Medição de Risco/métodos , Fatores de RiscoRESUMO
Pathogenic variants in BRCA1 or BRCA2 are identified in â¼20% of families with multiple individuals affected by early-onset breast and/or ovarian cancer. Extensive searches for additional highly penetrant genes or alternative mutational mechanisms altering BRCA1 or BRCA2 have not explained the missing heritability. Here, we report a dominantly inherited 5' UTR variant associated with epigenetic BRCA1 silencing due to promoter hypermethylation in two families affected by breast and ovarian cancer. BRCA1 promoter methylation of ten CpG dinucleotides in families who are affected by breast and/or ovarian cancer but do not have germline BRCA1 or BRCA2 pathogenic variants was assessed by pyrosequencing and clonal bisulfite sequencing. RNA and DNA sequencing of BRCA1 from lymphocytes was undertaken to establish allelic expression and the presence of germline variants. BRCA1 promoter hypermethylation was identified in 2 of 49 families in which multiple women are affected by grade 3 breast cancer or high-grade serous ovarian cancer. Soma-wide BRCA1 promoter hypermethylation was confirmed in blood, buccal mucosa, and hair follicles. Pyrosequencing showed that DNA was â¼50% methylated, consistent with the silencing of one allele, which was confirmed by clonal bisulfite sequencing. RNA sequencing revealed the allelic loss of BRCA1 expression in both families and that this loss of expression segregated with the heterozygous variant c.-107A>T in the BRCA1 5' UTR. Our results establish a mechanism whereby familial breast and ovarian cancer is caused by an in cis 5' UTR variant associated with epigenetic silencing of the BRCA1 promoter in two independent families. We propose that methylation analyses be undertaken to establish the frequency of this mechanism in families affected by early-onset breast and/or ovarian cancer without a BRCA1 or BRCA2 pathogenic variant.
Assuntos
Regiões 5' não Traduzidas/genética , Proteína BRCA1/genética , Neoplasias da Mama/genética , Metilação de DNA/genética , Mutação em Linhagem Germinativa/genética , Neoplasias Ovarianas/genética , Adulto , Idoso , Idoso de 80 Anos ou mais , Proteína BRCA2/genética , Epigênese Genética/genética , Feminino , Predisposição Genética para Doença/genética , Humanos , Pessoa de Meia-Idade , Regiões Promotoras Genéticas/genéticaRESUMO
PURPOSE: To investigate the contribution of PALB2 pathogenic gene variants (PGVs, PALB2_PGV) and the CHEK2 c.1100delC (CHEK2_1100delC) PGV to familial breast and ovarian cancer, and PALB2_PGV associated breast cancer pathology. METHODS: Outcomes of germline PALB2_PGV and CHEK2_1100delC testing were recorded in 3,127 women with histologically confirmed diagnoses of invasive breast cancer, carcinoma in situ, or epithelial nonmucinous ovarian cancer, and 1,567 female controls. Breast cancer pathology was recorded in PALB2_PGV cases from extended families. RESULTS: Thirty-five PALB2 and 44 CHEK2_1100delC PGVs were detected in patients (odds ratio [OR] PALB2 breast-ovarian = 5.90 [95% CI: 1.92-18.36], CHEK2 breast-ovarian = 4.46 [95% CI: 1.86-10.46], PALB2 breast = 6.16 [95% CI: 1.98-19.21], CHEK2 breast = 4.89 [95% CI: 2.01-11.34]). Grade 3 ER-positive HER2-negative, grade 3 and triple negative (TN) tumors were enriched in cases with PALB2 PGVs compared with all breast cancers known to our service (respectively: 15/43, 254/1,843, P = 0.0005; 28/37, 562/1,381, P = 0.0001; 12/43, 204/1,639, P < 0.0001). PALB2_PGV likelihood increased with increasing Manchester score (MS) (MS < 15 = 17/1,763, MS 20-39 = 11/520, P = 0.04) but not for CHEK2_1100delC (MS < 15 = 29/1,762, MS 20-39 = 4/520). PALB2 PGVs showed perfect segregation in 20/20 first-degree relatives with breast cancer, compared with 7/13 for CHEK2_1100delC (P = 0.002). CONCLUSION: PALB2 PGVs and CHEK2_1100delC together account for ~2.5% of familial breast/ovarian cancer risk. PALB2 PGVs are associated with grade 3, TN, and grade 3 ER-positive HER2-negative breast tumors.
Assuntos
Neoplasias da Mama , Quinase do Ponto de Checagem 2 , Proteína do Grupo de Complementação N da Anemia de Fanconi , Neoplasias Ovarianas , Neoplasias da Mama/diagnóstico , Neoplasias da Mama/genética , Quinase do Ponto de Checagem 2/genética , Proteína do Grupo de Complementação N da Anemia de Fanconi/genética , Feminino , Predisposição Genética para Doença , Humanos , Razão de Chances , Neoplasias Ovarianas/diagnóstico , Neoplasias Ovarianas/genéticaRESUMO
Panels of single nucleotide polymorphisms (SNPs) stratify risk for breast cancer in women from the general population, but studies are needed assess their use in a fully comprehensive model including classical risk factors, mammographic density and more than 100 SNPs associated with breast cancer. A case-control study was designed (1,668 controls, 405 cases) in women aged 47-73 years attending routine screening in Manchester UK, and enrolled in a wider study to assess methods for risk assessment. Risk from classical questionnaire risk factors was assessed using the Tyrer-Cuzick model; mean percentage visual mammographic density was scored by two independent readers. DNA extracted from saliva was genotyped at selected SNPs using the OncoArray. A predefined polygenic risk score based on 143 SNPs was calculated (SNP143). The odds ratio (OR, and 95% confidence interval, CI) per interquartile range (IQ-OR) of SNP143 was estimated unadjusted and adjusted for Tyrer-Cuzick and breast density. Secondary analysis assessed risk by oestrogen receptor (ER) status. The primary polygenic risk score was well calibrated (O/E OR 1.10, 95% CI 0.86-1.34) and accuracy was retained after adjustment for Tyrer-Cuzick risk and mammographic density (IQ-OR unadjusted 2.12, 95% CI% 1.75-2.42; adjusted 2.06, 95% CI 1.75-2.42). SNP143 was a risk factor for ER+ and ER- breast cancer (adjusted IQ-OR, ER+ 2.11, 95% CI 1.78-2.51; ER- 1.81, 95% CI 1.16-2.84). In conclusion, polygenic risk scores based on a large number of SNPs improve risk stratification in combination with classical risk factors and mammographic density, and SNP143 was similarly predictive for ER-positive and ER-negative disease.
Assuntos
Neoplasias da Mama/genética , Neoplasias da Mama/patologia , Idoso , Densidade da Mama , Neoplasias da Mama/diagnóstico por imagem , Estudos de Casos e Controles , Feminino , Predisposição Genética para Doença , Humanos , Mamografia , Pessoa de Meia-Idade , Sobrepeso/genética , Sobrepeso/patologia , Polimorfismo de Nucleotídeo Único , RiscoRESUMO
PURPOSE: To improve breast cancer risk stratification to enable more targeted early detection/prevention strategies that will better balance risks and benefits of population screening programmes. METHODS: 9362 of 57,902 women in the Predicting-Risk-Of-Cancer-At-Screening (PROCAS) study who were unaffected by breast cancer at study entry and provided DNA for a polygenic risk score (PRS). The PRS was analysed alongside mammographic density (density-residual-DR) and standard risk factors (Tyrer-Cuzick-model) to assess future risk of breast cancer based on tumour stage receptor expression and pathology. RESULTS: 195 prospective incident breast cancers had a prediction based on TC/DR/PRS which was informative for subsequent breast cancer overall [IQ-OR 2.25 (95% CI 1.89-2.68)] with excellent calibration-(0.99). The model performed particularly well in predicting higher stage stage 2+ IQ-OR 2.69 (95% CI 2.02-3.60) and ER + BCs (IQ-OR 2.36 (95% CI 1.93-2.89)). DR was most predictive for HER2+ and stage 2+ cancers but did not discriminate as well between poor and extremely good prognosis BC as either Tyrer-Cuzick or PRS. In contrast, PRS gave the highest OR for incident stage 2+ cancers, [IQR-OR 1.79 (95% CI 1.30-2.46)]. CONCLUSIONS: A combined approach using Tyrer-Cuzick/DR/PRS provides accurate risk stratification, particularly for poor prognosis cancers. This provides support for reducing the screening interval in high-risk women and increasing the screening interval in low-risk women defined by this model.
Assuntos
Biomarcadores Tumorais , Densidade da Mama , Neoplasias da Mama/diagnóstico , Neoplasias da Mama/genética , Variação Genética , Mamografia , Idoso , Neoplasias da Mama/epidemiologia , Detecção Precoce de Câncer , Feminino , Humanos , Incidência , Pessoa de Meia-Idade , Gradação de Tumores , Estadiamento de Neoplasias , Razão de Chances , Polimorfismo de Nucleotídeo Único , Prognóstico , Medição de Risco , Fatores de RiscoRESUMO
BACKGROUND: Breast cancer familial risk clinics offer screening and preventive strategies. While BRCA1/BRCA2 genetic testing provides important risk information for some women, panels of more common breast cancer risk genetic variants may have relevance to greater numbers of women with familial risk. METHODS: Three polygenic risk scores (PRS) based on 18 SNPs were investigated in a case-control study of women attending a familial risk clinic. PRS were derived from published general European population allele ORs and frequencies (18-SNPs (SNP18)). In women with BRCA1/BRCA2 mutations, 3 SNPs/13 SNPs, respectively, generated the PRS estimates. In total, 364 incident breast cancer cases (112 with BRCA1/2 mutations) were matched with 1605 controls (691 BRCA1/2) by age last mammogram and BRCA1/2 genetic test result. 87 women with cancer before attendance were also considered. Logistic regression was used to measure PRS performance through ORs per IQR and calibration of the observed to expected (O/E) logarithm relative risk when unadjusted and adjusted for phenotypic risk factors assessed by the Tyrer-Cuzick (TC) model. RESULTS: SNP18 was predictive for non-carriers of BRCA1/2 mutations (IQR OR 1.55, 95% CI 1.29 to 1.87, O/E 96%). Findings were unaffected by adjustment from TC (IQR OR 1.56, 95% CI 1.29 to 1.89) or when prior cancers were included (IQR OR 1.55, 95% CI 1.30 to 1.87). There was some evidence to support polygenic scores with weights for individuals with BRCA1/2 mutations (BRCA1 IQR OR 1.44, 95% CI 1.17 to 1.76; BRCA2 IQ OR 1.44, 95% CI 0.90 to 2.31). CONCLUSIONS: PRS may be used to refine risk assessment for women at increased familial risk who test negative/have low likelihood of BRCA1/2 mutations. They may alter the recommended prevention strategy for many women attending family history clinics.
Assuntos
Proteína BRCA1/genética , Proteína BRCA2/genética , Neoplasias da Mama/genética , Predisposição Genética para Doença , Adulto , Densidade da Mama/genética , Neoplasias da Mama/diagnóstico , Neoplasias da Mama/diagnóstico por imagem , Neoplasias da Mama/patologia , Feminino , Testes Genéticos , Heterozigoto , Humanos , Pessoa de Meia-Idade , Herança Multifatorial/genética , Proteínas de Neoplasias/genética , Polimorfismo de Nucleotídeo Único , Medição de Risco , Fatores de RiscoRESUMO
Heterozygous whole gene deletions (WGDs), and intragenic microdeletions, account for a significant proportion of mutations underlying cancer predisposition syndromes. We analyzed the frequency and genotype-phenotype correlations of microdeletions in 12 genes (BRCA1, BRCA2, TP53, MSH2, MLH1, MSH6, PMS2, NF1, NF2, APC, PTCH1, and VHL) representing seven tumor predisposition syndromes in 5,897 individuals (2,611 families) from our center. Overall, microdeletions accounted for 14% of identified mutations. As expected, smaller deletions or duplications were more common (12%) than WGDs (2.2%). Where a WGD was identified in the germline in NF2, the mechanism of somatic second hit was not deletion, as previously described for NF1. For neurofibromatosis type 1 and 2, we compared the mechanism of germline deletion. Unlike NF1, where three specific deletion sizes account for most germline WGDs, NF2 deletion breakpoints were different across seven samples tested. One of these deletions was 3.93 Mb and conferred a severe phenotype, thus refining the region for a potential NF2 modifier gene to a 2.04-Mb region on chromosome 22. The milder phenotype of NF2 WGDs may be due to the apparent absence of chromosome 22 loss as the second hit. These observations of WGD phenotypes will be helpful for interpreting incidental findings from microarray analysis and next-generation sequencing.
Assuntos
Cromossomos Humanos Par 22/genética , Deleção de Genes , Adulto , Proteína BRCA1/genética , Proteína BRCA2/genética , Proteínas de Ligação a DNA/genética , Feminino , Genótipo , Mutação em Linhagem Germinativa/genética , Humanos , Pessoa de Meia-Idade , Proteína 2 Homóloga a MutS/genética , Mutação/genética , Proteína Supressora de Tumor p53/genéticaRESUMO
A case-control study from two randomised breast cancer prevention trials of tamoxifen and raloxifene (P-1 and P-2) identified single-nucleotide polymorphisms (SNPs) in or near genes ZNF423 and CTSO as factors which predict which women will derive most anti-cancer benefit from selective oestrogen receptor modulator (SERM) therapy. In this article, we further examine this question using blood samples from two randomised tamoxifen prevention trials: the International Breast Cancer Intervention Study I (IBIS-I) and the Royal Marsden trial (Marsden). A nested case-control study was designed with 2:1 matching in IBIS-I and 1:1 matching in Marsden. The OncoArray was used for genotyping and included two SNPs previously identified (rs8060157 in ZNF423 and rs10030044 near CTSO), and 102 further SNPs within the same regions. Overall, there were 369 cases and 662 controls, with 148 cases and 268 controls from the tamoxifen arms. Odds ratios were estimated by conditional logistic regression, with Wald 95 % confidence intervals. In the tamoxifen arms, the per-allele odds ratio for rs8060157 was 0.99 (95 %CI 0.73-1.34) and 1.00 (95 %CI 0.76-1.33) for rs10030044. In the placebo arm, the odds ratio was 1.10 (95 %CI 0.87-1.40) for rs8060157 and 1.01 (95 %CI 0.79-1.29) for rs10030044. There was no evidence to suggest that other SNPs in the surrounding regions of these SNPs might predict response to tamoxifen. Results from these two prevention trials do not support the earlier findings. rs8060157 in ZNF423 and rs10030044 near CTSO do not appear to predict response to tamoxifen.
Assuntos
Antineoplásicos Hormonais/uso terapêutico , Neoplasias da Mama/prevenção & controle , Catepsinas/genética , Proteínas de Ligação a DNA/genética , Polimorfismo de Nucleotídeo Único , Tamoxifeno/uso terapêutico , Neoplasias da Mama/genética , Estudos de Casos e Controles , Feminino , Humanos , Modelos Logísticos , Pessoa de Meia-Idade , Razão de Chances , Proteínas , Ensaios Clínicos Controlados Aleatórios como AssuntoRESUMO
Previous studies have suggested an association between a variant in the promoter region of the FSHR gene and diminished response to controlled ovarian hyperstimulation (COH) in women undergoing assisted reproduction. FSHR -29G>A was genotyped in 559 women undergoing their first cycle of COH for IVF/intracytoplasmic sperm injection (ICSI) using TaqMan allelic discrimination assay. Correlation and regression analysis was performed to assess the relationship between FSHR promoter genotypes and markers of ovarian reserve and measures of response to COH, including the number of oocytes retrieved, gonadotrophin dose used and the live-birth rate. There were no statistically significant differences between the genotype frequencies and the markers of ovarian reserve or the early measures of response to COH. However, the live-birth rate was higher for women carrying the variant A allele (odds ratio [OR] 1.37; 95% confidence interval [CI] 1.02-1.84 per allele). This relationship did not reach statistical significance after adjustment for the number of embryos transferred (OR 1.33; 95% CI 0.98-1.83 per allele). Results from this study do not provide evidence that the FSHR -29G>A variant can be used in the individualization of the treatment protocol for women undergoing IVF/ICSI.
Assuntos
Reserva Ovariana/genética , Indução da Ovulação , Polimorfismo Genético , Regiões Promotoras Genéticas , Receptores do FSH/genética , Adulto , Feminino , Genótipo , Haplótipos , Humanos , Razão de Chances , Receptores do FSH/química , Análise de Regressão , Técnicas de Reprodução AssistidaRESUMO
PURPOSE: Genetic variation may influence women's response to ovarian stimulation therapy. The purpose of this study was to investigate any effects of genetic variants in the anti-Müllerian hormone (AMH) and AMH type II receptor genes on ovarian response/treatment outcomes and on current markers of ovarian reserve in individuals undergoing in vitro fertilisation (IVF) treatment. METHODS: In this prospective observational study, we genotyped the AMH c.146G>T, p.(Ile49Ser) and AMHR2 -482A>G variants in 603 unrelated women undergoing their first cycle of controlled ovarian stimulation for IVF and ICSI (intracytoplasmic sperm injection) using gonadotrophins at a tertiary referral centre for reproductive medicine. Pelvic ultrasound and blood hormone levels were taken on days 2-3 of the cycle. Genotypes were determined using TaqMan allelic discrimination assay. Regression analysis was performed to assess the relationship between the genotypes and the ovarian reserve markers (FSH, AMH, antral follicle count) and the early outcomes of response (number of oocytes retrieved and gonadotropin dose) as well as the treatment outcome (live birth). RESULTS: There were no significant associations between the variants AMH c.146G>T and AMHR2 -482A>G with ovarian response in terms of number of oocytes retrieved (p = 0.08 and p = 0.64, respectively), live births (p = 0.28 and p = 0.52) and/or markers of ovarian reserve. CONCLUSIONS: Genotyping of the AMH c.146G>T and AMHR2 -482A>G polymorphisms does not provide additional useful information as a predictor of ovarian reserve or ovarian response and treatment outcomes.
Assuntos
Hormônio Antimülleriano/genética , Reserva Ovariana/genética , Indução da Ovulação/métodos , Receptores de Peptídeos/genética , Receptores de Fatores de Crescimento Transformadores beta/genética , Adulto , Feminino , Hormônio Foliculoestimulante/metabolismo , Gonadotrofos/metabolismo , Humanos , Polimorfismo Genético/genética , Gravidez , Resultado da Gravidez , Estudos Prospectivos , Injeções de Esperma Intracitoplásmicas , Resultado do TratamentoRESUMO
The deficiency of ubiquitously expressed glucose-6-phosphatase (G6PC3) enzyme is known to result in a syndrome characterized by severe congenital neutropenia, prominent superficial venous pattern, congenital heart defects and genito-urinary malformations. Here, we describe four patients from three families with non-syndromic severe congenital neutropenia and identify four G6PC3 mutations as causative in these cases. Thus we demonstrate that G6PC3 mutations also result in a non-syndromic form of severe congenital neutropenia. We propose that G6PC3 deficiency should be considered as part of the differential diagnoses in any patient with unexplained congenital neutropenia. Additionally, we show a relationship between the genotype and non-hematological phenotype of G6PC3 deficiency. These findings may provide an insight into the role of the G6PC3 enzyme and glucose metabolism in developmental pathways.
Assuntos
Glucose-6-Fosfatase/genética , Mutação , Neutropenia/congênito , Adolescente , Sequência de Aminoácidos , Sequência de Bases , Criança , Síndrome Congênita de Insuficiência da Medula Óssea , Éxons , Feminino , Genótipo , Humanos , Neutropenia/genética , Alinhamento de SequênciaRESUMO
The objective of this study was to assess the role of the variant p.Asn680Ser in the FSH receptor gene (FSHR) in determining oocyte maturity. It also assessed the relationship between this FSHR variant with metaphase-II oocyte output rate (MOR) and the fertilization rate. This was a prospective observational study based at a tertiary referral centre for reproductive medicine. Women (n=212) undergoing their first cycle of ovarian stimulation for IVF with intracytoplasmic sperm injection (ICSI) were included in the study. Baseline pelvic ultrasound and blood tests were taken on day 2 or 3 of the cycle for assessment of baseline hormones and for DNA extraction. Genotypes for FSHR p.Asn680Ser was determined using TaqMan allelic discrimination assay. The outcome measures were the total dose of exogenous gonadotrophins used, antral follicle count (AFC), number of mature (metaphase-II) oocytes retrieved, MOR and fertilization rate. No statistically significant differences were found between the number of mature oocytes retrieved, MOR or fertilization rates among the patients with different p.Asn680Ser FSHR genotypes. No significant difference was noted in the clinical pregnancy rates per transfer. There is no evidence that the p.Asn680Ser FSHR genotype predicts oocyte maturity.