Reclassification of BRCA1 and BRCA2 variants of uncertain significance: a multifactorial analysis of multicentre prospective cohort

2018 ◽  
Vol 55 (12) ◽  
pp. 794-802 ◽  
Author(s):  
Jee-Soo Lee ◽  
Sohee Oh ◽  
Sue Kyung Park ◽  
Min-Hyuk Lee ◽  
Jong Won Lee ◽  
...  

BackgroundBRCA1 and BRCA2 (BRCA1/2) variants classified ambiguously as variants of uncertain significance (VUS) are a major challenge for clinical genetic testing in breast cancer; their relevance to the cancer risk is unclear and the association with the response to specific BRCA1/2-targeted agents is uncertain. To minimise the proportion of VUS in BRCA1/2, we performed the multifactorial likelihood analysis and validated this method using an independent cohort of patients with breast cancer.MethodsWe used a data set of 2115 patients with breast cancer from the nationwide multicentre prospective Korean Hereditary Breast Cancer study. In total, 83 BRCA1/2 VUSs (BRCA1, n=26; BRCA2, n=57) were analysed. The multifactorial probability was estimated by combining the prior probability with the overall likelihood ratio derived from co-occurrence of each VUS with pathogenic variants, personal and family history, and tumour characteristics. The classification was compared with the interpretation according to the American College of Medical Genetics and Genomics–Association for Molecular Pathology (ACMG/AMP) guidelines. An external validation was conducted using independent data set of 810 patients.ResultsWe were able to redefine 38 VUSs (BRCA1, n=10; BRCA2, n=28). The revised classification was highly correlated with the ACMG/AMP guideline-based interpretation (BRCA1, p for trend=0.015; BRCA2, p=0.001). Our approach reduced the proportion of VUS from 19% (154/810) to 8.9% (72/810) in the retrospective validation data set.ConclusionThe classification in this study would minimise the ‘uncertainty’ in clinical interpretation, and this validated multifactorial model can be used for the reliable annotation of BRCA1/2 VUSs.

2020 ◽  
pp. 163-175
Author(s):  
Laura Cifuentes-C ◽  
Ana Lucia Rivera-Herrera ◽  
Guillermo Barreto

Introduction: Breast cancer is the most common neoplasia of women from all over the world especially women from Colombia. 5%­10% of all cases are caused by hereditary factors, 25% of those cases have mutations in the BRCA1/BRCA2 genes. Objective: The purpose of this study was to identify the mutations associated with the risk of familial breast and/or ovarian cancer in a population of Colombian pacific. Methods: 58 high-risk breast and/or ovarian cancer families and 20 controls were screened for germline mutations in BRCA1 and BRCA2, by Single Strand Conformation Polymorphism (SSCP) and sequencing. Results: Four families (6.9%) were found to carry BRCA1 mutations and eight families (13.8%) had mutations in BRCA2. In BRCA1, we found three Variants of Uncertain Significance (VUS), of which we concluded, using in silico tools, that c.81­12C>G and c.3119G>A (p.Ser1040Asn) are probably deleterious, and c.3083G>A (p.Arg1028His) is probably neutral. In BRCA2, we found three variants of uncertain significance: two were previously described and one novel mutation. Using in silico analysis, we concluded that c.865A>G (p.Asn289Asp) and c.6427T>C (p.Ser2143Pro) are probably deleterious and c.125A>G (p.Tyr42Cys) is probably neutral. Only one of them has previously been reported in Colombia. We also identified 13 polymorphisms (4 in BRCA1 and 9 in BRCA2), two of them are associated with a moderate increase in breast cancer risk (BRCA2 c.1114A>C and c.8755­66T>C). Conclusion: According to our results, the Colombian pacific population presents diverse mutational spectrum for BRCA genes that differs from the findings in other regions in the country.


2021 ◽  
Vol 11 ◽  
Author(s):  
Daniele Fanale ◽  
Alessia Fiorino ◽  
Lorena Incorvaia ◽  
Alessandra Dimino ◽  
Clarissa Filorizzo ◽  
...  

About 10–20% of breast/ovarian (BC/OC) cancer patients undergoing germline BRCA1/2 genetic testing have been shown to harbor Variants of Uncertain Significance (VUSs). Since little is known about the prevalence of germline BRCA1/2 VUS in Southern Italy, our study aimed at describing the spectrum of these variants detected in BC/OC patients in order to improve the identification of potentially high-risk BRCA variants helpful in patient clinical management. Eight hundred and seventy-four BC or OC patients, enrolled from October 2016 to December 2020 at the “Sicilian Regional Center for the Prevention, Diagnosis and Treatment of Rare and Heredo-Familial Tumors” of University Hospital Policlinico “P. Giaccone” of Palermo, were genetically tested for germline BRCA1/2 variants through Next-Generation Sequencing analysis. The mutational screening showed that 639 (73.1%) out of 874 patients were BRCA-w.t., whereas 67 (7.7%) were carriers of germline BRCA1/2 VUSs, and 168 (19.2%) harbored germline BRCA1/2 pathogenic/likely pathogenic variants. Our analysis revealed the presence of 59 different VUSs detected in 67 patients, 46 of which were affected by BC and 21 by OC. Twenty-one (35.6%) out of 59 variants were located on BRCA1 gene, whereas 38 (64.4%) on BRCA2. We detected six alterations in BRCA1 and two in BRCA2 with unclear interpretation of clinical significance. Familial anamnesis of a patient harboring the BRCA1-c.3367G>T suggests for this variant a potential of pathogenicity, therefore it should be carefully investigated. Understanding clinical significance of germline BRCA1/2 VUS could improve, in future, the identification of potentially high-risk variants useful for clinical management of BC or OC patients and family members.


Cancers ◽  
2019 ◽  
Vol 11 (2) ◽  
pp. 151 ◽  
Author(s):  
Laura Caleca ◽  
Mara Colombo ◽  
Thomas van Overeem Hansen ◽  
Conxi Lázaro ◽  
Siranoush Manoukian ◽  
...  

Genetic testing for BRCA1 and BRCA2 genes has led to the identification of many unique variants of uncertain significance (VUS). Multifactorial likelihood models that predict the odds ratio for VUS in favor or against cancer causality, have been developed, but their use is conditioned by the amount of necessary data, which are difficult to obtain if a variant is rare. As an alternative, variants mapping to the coding regions can be examined using in vitro functional assays. BRCA1 and BRCA2 proteins promote genome protection by interacting with different proteins. In this study, we assessed the functional effect of two sets of variants in BRCA genes by exploiting the green fluorescent protein (GFP)-reassembly in vitro assay, which was set-up to test the BRCA1/BARD1, BRCA1/UbcH5a, and BRCA2/DSS1 interactions. Based on the findings observed for the validation panels of previously classified variants, BRCA1/UbcH5a and BRCA2/DSS1 binding assays showed 100% sensitivity and specificity in identifying pathogenic and non-pathogenic variants. While the actual efficiency of these assays in assessing the clinical significance of BRCA VUS has to be verified using larger validation panels, our results suggest that the GFP-reassembly assay is a robust method to identify variants affecting normal protein functioning and contributes to the classification of VUS.


2020 ◽  
Vol 21 (1) ◽  
Author(s):  
Erik Gustavsson ◽  
Giovanni Galvis ◽  
Niklas Juth

Abstract Background Genetic testing is moving from targeted investigations of monogenetic diseases to broader testing that may provide more information. For example, recent health economic studies of genetic testing for an increased risk of breast cancer suggest that it is associated with higher cost-effectiveness to screen for pathogenic variants in a seven gene panel rather than the usual two gene test for variants in BRCA1 and BRCA2. However, irrespective of the extent to which the screening of the panel is cost-effective, there may be ethical reasons to not screen for pathogenic variants in a panel, or to revise the way in which testing and disclosing of results are carried out. Main text In this paper we discuss the ethical aspects of genetic testing for an increased risk of breast cancer with a special focus on the ethical differences between screening for pathogenic variants in BRCA1/2 and a seven gene panel. The paper identifies that the panel increases the number of secondary findings as well as the number of variants of uncertain significance as two specific issues that call for ethical reflection. Conclusions We conclude that while the problem of handling secondary findings should not be overstated with regard to the panel, the fact that the panel also generate more variants of uncertain significance, give rise to a more complex set of problems that relate to the value of health as well as the value of autonomy. Therefore, it is insufficient to claim that the seven gene panel is preferable by only referring to the higher cost effectiveness of the panel.


2020 ◽  
Vol 112 (12) ◽  
pp. 1275-1279 ◽  
Author(s):  
Anne S Reiner ◽  
Mark E Robson ◽  
Lene Mellemkjær ◽  
Marc Tischkowitz ◽  
Esther M John ◽  
...  

Abstract Whether radiation therapy (RT) affects contralateral breast cancer (CBC) risk in women with pathogenic germline variants in moderate- to high-penetrance breast cancer–associated genes is unknown. In a population-based case-control study, we examined the association between RT; variants in ATM, BRCA1/2, or CHEK2*1100delC; and CBC risk. We analyzed 708 cases of women with CBC and 1399 controls with unilateral breast cancer, all diagnosed with first invasive breast cancer between 1985 and 2000 and aged younger than 55 years at diagnosis and screened for variants in breast cancer–associated genes. Rate ratios (RR) and 95% confidence intervals (CIs) were estimated using multivariable conditional logistic regression. RT did not modify the association between known pathogenic variants and CBC risk (eg, BRCA1/2 pathogenic variant carriers without RT: RR = 3.52, 95% CI = 1.76 to 7.01; BRCA1/2 pathogenic variant carriers with RT: RR = 4.46, 95% CI = 2.96 to 6.71), suggesting that modifying RT plans for young women with breast cancer is unwarranted. Rare ATM missense variants, not currently identified as pathogenic, were associated with increased risk of RT-associated CBC (carriers of ATM rare missense variants of uncertain significance without RT: RR = 0.38, 95% CI = 0.09 to 1.55; carriers of ATM rare missense variants of uncertain significance with RT: RR = 2.98, 95% CI = 1.31 to 6.80). Further mechanistic studies will aid clinical decision-making related to RT.


Cancers ◽  
2020 ◽  
Vol 12 (5) ◽  
pp. 1286 ◽  
Author(s):  
Concetta Santonocito ◽  
Roberta Rizza ◽  
Ida Paris ◽  
Laura De Marchis ◽  
Carmela Paolillo ◽  
...  

Pathogenic variants (PVs) carriers in BRCA1 or BRCA2 are associated with an elevated lifetime risk of developing breast cancer (BC) and/or ovarian cancer (OC). The prevalence of BRCA1 and BRCA2 germline alterations is extremely variable among different ethnic groups. Particularly, the rate of variants in Italian BC and/or OC families is rather controversial and ranges from 8% to 37%, according to different reports. By In Vitro Diagnostic (IVD) next generation sequencing (NGS)-based pipelines, we routinely screened thousands of patients with either sporadic or cancer family history. By NGS, we identified new PVs and some variants of uncertain significance (VUS) which were also evaluated in silico using dedicated tools. We report in detail data regarding BRCA1/2 variants identified in 517 out of 2351 BC and OC patients. The aim of this study was to report the incidence and spectrum of BRCA1/2 variants observed in BC and/or OC patients, tested in at Policlinico Gemelli Foundation Hospital, the origin of which is mainly from Central and Southern Italy. This study provides an overview of the variant frequency in these geographic areas of Italy and provides data that could be used in the clinical management of patients.


2020 ◽  
Author(s):  
Joo Heung Kim ◽  
Sunggyun Park ◽  
Hyung Seok Park ◽  
Ji Soo Park ◽  
Seung-Tae Lee ◽  
...  

Abstract Background Genetic testing for BRCA1 and BRCA2 genes is crucial for diagnosing hereditary breast and ovarian cancer syndromes (HBOC). Testing for such genes has been on the rise due to the development of multigene panel tests. However, results classified as variants of uncertain significance (VUS) present challenges to clinicians trying to interpret their functions and choose appropriate management plans.Methods We reviewed a total of 676 breast cancer patients who had VUS on BRCA mutation tests between November 2007 and April 2013 in the KOHBRA study. These results were compared to the ClinVar database. We calculated the incidence and odds ratios for these variants using the Korean Reference Genome Database (KRGDB).Results A total of 58 and 91 distinct VUS in BRCA1 and 2 were identified in the KOHBRA study (comprising 258 and 453 patients, respectively). A total of 27 variants in the KOHBRA study were not registered in the SNP database. Of the BRCA1 VUS, 20 variants were reclassified as benign or likely benign, 4 variants were reclassified as pathogenic or likely pathogenic, and 8 variants remained as VUS according to the ClinVar database. Of the BRCA2 VUS variants, 25 variants were reclassified as benign or likely benign, two variants were reclassified as pathogenic or likely pathogenic, and 33 variants remained as VUS according to the Clinvar database. There were 12 variants with conflicting interpretations of pathogenicity for BRCA1 and 18 variants for BRCA2. Among them, p.Leu1780Pro showed a particularly high odds ratio.Conclusions Six pathogenic variants and one conflicting variant identified using ClinVar could be reclassified as pathogenic variants in this study. Using updated ClinVar and calculating odds ratios can be helpful when reclassifying VUS in BRCA1/2.


2020 ◽  
Vol 38 (15_suppl) ◽  
pp. 1531-1531
Author(s):  
Shijie Wu ◽  
Jiaojiao Zhou ◽  
Yiding Chen

1531 Background: Inherited PALB2 pathogenic variants are associated with an increased lifetime risk for breast cancer development. However, the interpretation of numerous PALB2 missense variants of uncertain significance (VUS) identified in germline genetic testing remains a challenge. Here, we assessed the impact of breast cancer patient-derived VUS on PALB2 function and identified pathogenic PALB2 missense variants that may increase cancer risk. Methods: A total of seven potentially pathogenic PALB2 VUS identified in 2,279 breast cancer patients were selected for functional analysis. All these selected VUS were assessed by SIFT, Align-GVGD, and PolyPhen2 in silico and were predicted to be deleterious by at least two in silico algorithms. The p.L35P [c.104T > C] variant was also included, for which pathogenicity has been recently confirmed. The effects of the VUS on the homologous recombination (HR) activity of PALB2 were tested by U2OS/DR-GFP reporting system. Functional characterization was further validated by protein co-immunoprecipitation and RAD51 recruitment assay. Results: PALB2 variants p.L24F [c.72G > C] and p.L35P [c.104T > C] showed the most significant disruption to the HR activity of PALB2 relative to the wild-type condition, retaining only 52.2% ( p = 0.0013) and 8.5% ( p < 0.0001) of HR activity respectively. Moderate but statistically significant HR deficiency was observed for four other variants (p.P405A [c.1213C > G], p.T1012I [c.3035C > T], p.E1018D [c.3054G > C], and p.T1099M [c.3296C > T]). We found no statistical differences for the p.K628N [c.1884G > T] and p.R663C [c.1987C > T] in the HR activity compared to wild-type PALB2. The p.L24F and p.L35P variants compromised the BRCA1-PALB2 interaction and reduced RAD51 foci formation in response to DNA damage. Conclusions: We have identified a novel patient-derived pathogenic PALB2 missense variant, p.L24F [c.72G > C], that compromises PALB2-mediated HR activity. We suggest the integration of the identified pathogenic variants into breast cancer genetic counseling and individualized treatment regimens for better clinical outcomes.


BMJ Open ◽  
2021 ◽  
Vol 11 (1) ◽  
pp. e040778
Author(s):  
Vineet Kumar Kamal ◽  
Ravindra Mohan Pandey ◽  
Deepak Agrawal

ObjectiveTo develop and validate a simple risk scores chart to estimate the probability of poor outcomes in patients with severe head injury (HI).DesignRetrospective.SettingLevel-1, government-funded trauma centre, India.ParticipantsPatients with severe HI admitted to the neurosurgery intensive care unit during 19 May 2010–31 December 2011 (n=946) for the model development and further, data from same centre with same inclusion criteria from 1 January 2012 to 31 July 2012 (n=284) for the external validation of the model.Outcome(s)In-hospital mortality and unfavourable outcome at 6 months.ResultsA total of 39.5% and 70.7% had in-hospital mortality and unfavourable outcome, respectively, in the development data set. The multivariable logistic regression analysis of routinely collected admission characteristics revealed that for in-hospital mortality, age (51–60, >60 years), motor score (1, 2, 4), pupillary reactivity (none), presence of hypotension, basal cistern effaced, traumatic subarachnoid haemorrhage/intraventricular haematoma and for unfavourable outcome, age (41–50, 51–60, >60 years), motor score (1–4), pupillary reactivity (none, one), unequal limb movement, presence of hypotension were the independent predictors as its 95% confidence interval (CI) of odds ratio (OR)_did not contain one. The discriminative ability (area under the receiver operating characteristic curve (95% CI)) of the score chart for in-hospital mortality and 6 months outcome was excellent in the development data set (0.890 (0.867 to 912) and 0.894 (0.869 to 0.918), respectively), internal validation data set using bootstrap resampling method (0.889 (0.867 to 909) and 0.893 (0.867 to 0.915), respectively) and external validation data set (0.871 (0.825 to 916) and 0.887 (0.842 to 0.932), respectively). Calibration showed good agreement between observed outcome rates and predicted risks in development and external validation data set (p>0.05).ConclusionFor clinical decision making, we can use of these score charts in predicting outcomes in new patients with severe HI in India and similar settings.


Sign in / Sign up

Export Citation Format

Share Document