BRCA1 p.His1673del is a pathogenic mutation associated with a predominant ovarian cancer phenotype

Clinical genetic services in the Emilia-Romagna region, Italy: current activity and open issues: a mixed-method study

In 2002, in the Emilia-Romagna region of Italy, a comprehensive strategic plan was developed with the aim of improving the integration and efficiency of the genetic services. Two decades later, this report aims to explore the current functioning of the regional network, with special focus on clinical genetics in the evolving scenarios. To this aim, we analyzed the activity data of the medical genetics services in the region, to identify and possibly improve currently open issues. This is a mixed-method study, analyzing quantitatively and qualitatively the activities of seven medical genetics services in Emilia-Romagna region. Quantitative analysis considered the number of consultations and the composition of the staff in the year 2021. Qualitative analysis examined a focus group of directors of the services through reflexive thematic analysis. A total of 14,925 counseling sessions have been delivered by the medical genetics services, staffed with 22.4 full-time equivalent clinical geneticists. A physician performed an average of 14.5 consultations per week and approximately 1166 h of patient care per year. The clinical geneticists/inhabitants ratio was 0.54 per 100,000 inhabitants, and it is estimated that one every 278 inhabitants, on average, underwent a genetic counseling session in 2021. Qualitative analysis highlighted issues concerning patients' access to service, general organization and staff composition. In order to meet the growing demand for genetic counseling services, expansion of the workforce and adjustment of current practice models are required to increase the access to genetic services and the application of test results to clinical management.

Molecular analysis of BRCA1 and BRCA2 genes in La Rioja (Spain): five new variants

BACKGROUND

To study BRCA1/2 gene variants in La Rioja in the northcentral area of Spain.

METHODS

We performed a molecular analysis of BRCA1 and BRCA2 in 642 individuals from 427 different families from June 2008 to December 2019.

RESULTS

We identified 71 families with pathogenic variants in these genes, 32 families with BRCA1 variants and 39 families with BRCA2 variants. The pathogenic variants c.959delG in BRCA1 and c.1363_1369delTCAGAGA, c.1397dupA, c.4234_4236delACTinsC and c.8387delC in BRCA2 have not been previously described. The c.81-2 A > T variant in BRCA1, detected in two unrelated families, has not been reported previously in the Spanish population. Two large genomic deletions were found in the BRCA1 gene in exons (Ex) 23-24 and Ex1A-1B-2, and one deletion was found in the BRCA2 gene in Ex2. The pathogenic variant c.5123 C > A in BRCA1 was detected in 8 unrelated families and was the most frequent pathogenic variant in our population. The c.6024dupG mutation in BRCA2 was detected in 6 unrelated families; the c.2808_2011delACAA mutation in BRCA2 was found in 5 different families; the c.211 A > G mutation in BRCA1 was found in three different families; and the c.68_69delAG, c81-2 A > T, c.4038_4039delAA, and c.5266dupC variants in BRCA1 and the c.2457delA, c.2701delC, c.5116_5119delAATA, c.6275delTT, c.7558 C > T and c.7617 + 1G > A variants in BRCA2 were found in two different families.

CONCLUSIONS

The spectrum of pathogenic variants in the BRCA1/2 genes in La Rioja is similar to that in other Spanish regions, with some unique characteristics. The pathogenic c.6024dupG variant in the BRCA2 gene was detected in a large number of families and could have a founding effect in the Ebro riverside areas in the regions of La Rioja and Navarra.

TRIAL REGISTRATION

Not applicable.

Atypical cancer risk profile in carriers of Italian founder BRCA1 variant p.His1673del: Implications for classification and clinical management

BACKGROUND

BRCA1:c.5017_5019del (p.His1673del) is a founder variant relatively frequent in Northern Italy. Despite previous suggestion of pathogenicity, variant classification in public databases is still conflicting, needing additional evidence.

METHODS

Maximum likelihood penetrance of breast/ovarian and other cancer types was estimated using full pedigree data from 53 informative Italian families. The effect of the variant on BRCA1-ABRAXAS1 interaction was assessed using a GFP-fragment reassembly-based PPI assay. Results were combined with additional data from multiple sources to classify the variant according to ACMG/AMP classification rules specified for BRCA1/2.

RESULTS

Variant-carriers displayed increased risk for ovarian cancer (HR = 33.0, 95% CI = 7.0-155.0; cumulative risk at age 70 = 27.6%, 95% CI = 12.6-40.0%) but not for breast cancer (HR = 0.7, 95% CI = 0.2-2.2). An increased risk of uterine cancer (HR = 8.0, 95% CI = 1.03-61.6) emerged, warranting further evaluation. Likelihood-ratio in favor of pathogenicity was 98898642.82 under assumption of standard BRCA1 breast and ovarian penetrance, and 104240832.84 after excluding breast cancer diagnoses (based on penetrance results). Functional analysis demonstrated that the variant abrogates the BRCA1-ABRAXAS1 binding, supporting the PS3 code assignment within the ACMG/AMP rule-based model. Collectively, these findings allowed to classify the variant as pathogenic.

CONCLUSION

Pathogenicity of BRCA1:c.5017_5019del(p.His1673del) has been confirmed; however, breast cancer risk in Italian families is not increased, unlike in families from other countries and in carriers of most BRCA1 pathogenic variants. The knowledge of atypical risk profiles for this and other variants will pave the way for personalized management based on specific genotype.

Clinical implications of VUS reclassification in a single-centre series from application of ACMG/AMP classification rules specified for BRCA1/2

BACKGROUND

BRCA1/2 testing is crucial to guide clinical decisions in patients with hereditary breast/ovarian cancer, but detection of variants of uncertain significance (VUSs) prevents proper management of carriers. The ENIGMA (Evidence-based Network for the Interpretation of Germline Mutant Alleles) BRCA1/2 Variant Curation Expert Panel (VCEP) has recently developed BRCA1/2 variant classification guidelines consistent with ClinGen processes, specified against the ACMG/AMP (American College of Medical Genetics and Genomics/Association for Molecular-Pathology) classification framework.

METHODS

The ClinGen-approved BRCA1/2-specified ACMG/AMP classification guidelines were applied to BRCA1/2 VUSs identified from 2011 to 2022 in a series of patients, retrieving information from the VCEP documentation, public databases, literature and ENIGMA unpublished data. Then, we critically re-evaluated carrier families based on new results and checked consistency of updated classification with main sources for clinical interpretation of BRCA1/2 variants.

RESULTS

Among 166 VUSs detected in 231 index cases, 135 (81.3%) found in 197 index cases were classified by applying BRCA1/2-specified ACMG/AMP criteria: 128 (94.8%) as Benign/Likely Benign and 7 (5.2%) as Pathogenic/Likely Pathogenic. The average time from the first report as 'VUS' to classification using this approach was 49.4 months. Considering that 15 of these variants found in 64 families had already been internally reclassified prior to this work, this study provided 121 new reclassifications among the 151 (80.1%) remaining VUSs, relevant to 133/167 (79.6%) families.

CONCLUSIONS

These results demonstrated the effectiveness of new BRCA1/2 ACMG/AMP classification guidelines for VUS classification within a clinical cohort, and their important clinical impact. Furthermore, they suggested a cadence of no more than 3 years for regular review of VUSs, which however requires time, expertise and resources.

The emergence of Fanconi anaemia type S: a phenotypic spectrum of biallelic BRCA1 mutations

BRCA1 is involved in the Fanconi anaemia (FA) pathway, which coordinates repair of DNA interstrand cross-links. FA is a rare genetic disorder characterised by bone marrow failure, cancer predisposition and congenital abnormalities, caused by biallelic mutations affecting proteins in the FA pathway. Germline monoallelic pathogenic BRCA1 mutations are known to be associated with hereditary breast/ovarian cancer, however biallelic mutations of BRCA1 were long predicted to be incompatible with embryonic viability, hence BRCA1 was not considered to be a canonical FA gene. Despite this, several patients with biallelic pathogenic BRCA1 mutations and FA-like phenotypes have been identified - defining a new FA type (FA-S) and designating BRCA1 as an FA gene. This report presents a scoping review of the cases of biallelic BRCA1 mutations identified to date, discusses the functional effects of the mutations identified, and proposes a phenotypic spectrum of BRCA1 mutations based upon available clinical and genetic data. We report that this FA-S cohort phenotype includes short stature, microcephaly, facial dysmorphisms, hypo/hyperpigmented lesions, intellectual disability, chromosomal sensitivity to crosslinking agents and predisposition to breast/ovarian cancer and/or childhood cancers, with some patients exhibiting sensitivity to chemotherapy. Unlike most other types of FA, FA-S patients lack bone marrow failure.

Comprehensive clinical characterization of patients with BRCA1: c.5017_5019del germline variant

Purpose

We provide evidence for the reclassification of the BRCA1:c.5017_5019del variant by presenting the clinicopathological characteristics, clinical outcomes, and family history of breast or ovarian cancer in 17 patients with this variant.

Methods

This study included breast or ovarian cancer patients tested for BRCA1/2 genes between January 2008 and June 2020 at 10 medical centers in Korea. We retrospectively reviewed 17 probands from 15 families who had the BRCA1:c.5017_5019del variant according to the electronic medical records.

Results

We present 10 breast cancer patients and 7 ovarian cancer patients from 15 families identified as having BRCA1:c.5017_5019del and a total of 19 cases of breast cancer and 14 cases of ovarian cancer in these families. The ratio of breast-to-ovarian cancer was 1.3:1. Breast cancer patients with this variant showed a rich family history of breast or ovarian cancer, 8 patients (80.0%). The mean age at diagnosis was 45.4 years and 6 patients (60.0%) were categorized into hormone-receptor-negative breast cancer. Also, the ovarian cancer patients with this variant showed strong family histories of breast and/or ovarian cancer in 4 patients (57.1%).

Conclusion

We presented clinical evidence for the reclassification of BRCA1:c.5017_5019del as a likely pathogenic variant (LPV). Reclassification as LPV could result in the prophylactic treatment and medical surveillance of probands, family testing recommendations, and appropriate genetic counseling of their families.

Identification of Eleven Novel BRCA Mutations in Tunisia: Impact on the Clinical Management of BRCA Related Cancers

Background

Breast cancer is the world's most common cancer among women. It is becoming an increasingly urgent problem in low- and middle-income countries (LMICs) where a large fraction of women is diagnosed with advanced-stage disease and have no access to treatment or basic palliative care. About 5-10% of all breast cancers can be attributed to hereditary genetic components and up to 25% of familial cases are due to mutations in BRCA1/2 genes. Since their discovery in 1994 and 1995, as few as 18 mutations have been identified in BRCA genes in the Tunisian population. The aim of this study is to identify additional BRCA mutations, to estimate their contribution to the hereditary breast and ovarian cancers in Tunisia and to investigate the clinicopathological signatures associated with BRCA mutations.

Methods

A total of 354 patients diagnosed with breast and ovarian cancers, including 5 male breast cancer cases, have been investigated for BRCA1/2 mutations using traditional and/or next generation sequencing technologies. Clinicopathological signatures associated with BRCA mutations have also been investigated.

Results

In the current study, 16 distinct mutations were detected: 10 in BRCA1 and 6 in BRCA2, of which 11 are described for the first time in Tunisia including 3 variations that have not been reported previously in public databases namely BRCA1_c.915T>A; BRCA2_c.-227-?_7805+? and BRCA2_c.249delG. Early age at onset, family history of ovarian cancer and high tumor grade were significantly associated with BRCA status. BRCA1 carriers were more likely to be triple negative breast cancer compared to BRCA2 carriers. A relatively high frequency of contralateral breast cancer and ovarian cancer occurrence was observed among BRCA carriers and was more frequent in patients carrying BRCA1 mutations.

Conclusion

Our study provides new insights into breast and ovarian cancer genetic landscape in the under-represented North African populations. The prevalence assessment of novel and recurrent BRCA1/2 pathogenic mutations will enhance the use of personalized treatment and precise screening strategies by both affected and unaffected North African cancer cases.

Reclassification of BRCA1 and BRCA2 variants found in ovarian epithelial, fallopian tube, and primary peritoneal cancers

Objective

We investigated the proportions of and reclassified BRCA1/2 variants of unknown significance (VUS) in Korean patients with epithelial ovarian, tubal, and primary peritoneal cancers.

Methods

Data from 805 patients who underwent genetic testing for BRCA1/2 from January 1, 2006 to August 31, 2018 were included. The VUS in BRCA1/2 were reclassified using the 2015 American College of Medical Genetics and Genomics and the Association for Molecular Pathology standards and guidelines.

Results

A BRCA1 pathogenic variant was found in 17.0% (137/805) of the patients, and BRCA1 VUS were found in 15.9% (128/805) of the patients. Further, 8.7% (69/805) of the patients possessed a BRCA2 pathogenic variant and 18.4% (148/805) of the patients possessed BRCA2 VUS. Fifty-three specific BRCA1 VUS were found and 20 were further reclassified as benign (n=11), likely benign (n=5), likely pathogenic (n=3), and pathogenic (n=1). The remaining 33 remained classified as VUS. For BRCA2, 55 specific VUS were detected; among these, 14 were reclassified as benign or likely benign, and 2 were reclassified as likely pathogenic. Among the 805 patients, 195 were found to have only VUS and no pathogenic variants (PV), and 41.5% (81/195) were reclassified as benign or likely benign, and 10.3% (20/195) as pathogenic or likely pathogenic variants.

Conclusions

Approximately 33.3% (36/108) of the specific BRCA1/2 variants analyzed in this study that were initially classified as VUS over a 13-year period were reclassified. Among these, 5.6% (6/108) were reclassified as pathogenic or likely pathogenic variants.

Analysis of BRCA1/2 variants of unknown significance in the prospective Korean Hereditary Breast Cancer study

Genetic testing for BRCA1 and BRCA2 is crucial in diagnosing hereditary breast and ovarian cancer syndromes and has increased with the development of multigene panel tests. However, results classified as variants of uncertain significance (VUS) present challenges to clinicians in attempting to choose an appropriate management plans. We reviewed a total of 676 breast cancer patients included in the Korean Hereditary Breast Cancer (KOHBRA) study with a VUS on BRCA mutation tests between November 2007 and April 2013. These results were compared to the ClinVar database. We calculated the incidence and odds ratios for these variants using the Korean Reference Genome Database. A total of 58 and 91 distinct VUS in BRCA1 and BRCA2 were identified in the KOHBRA study (comprising 278 and 453 patients, respectively). A total of 27 variants in the KOHBRA study were not registered in the Single Nucleotide Polymorphism database. Among BRCA1 VUSs, 20 were reclassified as benign or likely benign, four were reclassified as pathogenic or likely pathogenic, and eight remained as VUSs according to the ClinVar database. Of the BRCA2 VUSs, 25 were reclassified as benign or likely benign, two were reclassified as pathogenic or likely pathogenic, and 33 remained as VUS according to the ClinVar database. There were 12 variants with conflicting interpretations of pathogenicity for BRCA1 and 18 for BRCA2. Among them, p.Leu1780Pro showed a particularly high odds ratio. Six pathogenic variants and one conflicting variant identified using ClinVar could be reclassified as pathogenic variants in this study. Using updated ClinVar information and calculating odds ratios can be helpful when reclassifying VUSs in BRCA1/2.

Reinterpretation of BRCA1 and BRCA2 variants of uncertain significance in patients with hereditary breast/ovarian cancer using the ACMG/AMP 2015 guidelines

BACKGROUND

Although BRCA1 or BRCA2 (BRCA1/2) genetic testing plays an important role in determining treatment modalities in patients with hereditary breast and ovarian cancer, sequence variants with unknown clinical significance or variant of uncertain significance (VUS) have limited use in medical decision-making. With vast quantities of gene-related data being updated, the clinical significance of VUS may change over time. We reinterpreted the sequence variant previously reported as BRCA1/2 VUS results in patients with breast or ovarian cancer and assessed whether the clinical significance of VUS was changed.

METHODS

We retrospectively reviewed medical records of 423 breast or ovarian cancer patients who underwent BRCA1/2 genetic testing from 2010 to 2017. The VUSs in BRCA1/2 were reanalyzed using the 2015 American College of Medical Genetics and Genomics and the Association for Molecular Pathology standards and guidelines (ACMG/AMP 2015 guidelines) and the VUS was reclassified into five categories: "pathogenic", "likely pathogenic", "VUS", "likely benign", and "benign".

RESULTS

A total of 75 patients (48 sequence types of VUS) were identified as carrying either one or more VUS in BRCA1/2. Among the 75 patients, two patients (2.7%) were reclassified as "likely pathogenic", 30 patients (40.0%) were reclassified as either "benign" or "likely benign", and the remaining 43 patients (57.3%) were still classified as VUS category.

CONCLUSIONS

Since the clinical significance of VUS in BRCA1/2 may vary from time to time, reinterpretation of the VUS results could contribute to clinical decision-making.

Dealing With BRCA1/2 Unclassified Variants in a Cancer Genetics Clinic: Does Cosegregation Analysis Help?

Background: Detection of variants of uncertain significance (VUSs) in BRCA1 and BRCA2 genes poses relevant challenges for counseling and managing patients. VUS carriers should be managed similarly to probands with no BRCA1/2 variants detected, and predictive genetic testing in relatives is discouraged. However, miscomprehension of VUSs is common and can lead to inaccurate risk perception and biased decisions about prophylactic surgery. Therefore, efforts are needed to improve VUS evaluation and communication at an individual level.

Aims: We aimed at investigating whether cosegregation analysis, integrated with a careful review of available functional data and in silico predictions, may improve VUSs interpretation and counseling in individual families.

Methods: Patients with Breast Cancer (BC) and/or Ovarian Cancer (OC) fulfilling established criteria were offered genetic counseling and BRCA1/2 testing; VUSs identified in index cases were checked in other relatives affected by BC/OC whenever possible. As an alternative, if BC/OC clustered only in one branch of the family, the parental origin of the VUS was investigated. Public prediction tools and databases were used to collect additional information on the variants analyzed.

Results: Out of 1045 patients undergoing BRCA1/2 testing in the period October 2011–April 2018, 66 (6.3%) carried class 3 VUSs. Cosegregation analysis was performed for 13 VUSs in 11 kindreds. Seven VUSs (53.8%) did not cosegregate with breast/ovarian cancer in the family, which provided evidence against their role in cancer clustering in those families. Among the 6 cosegregating VUSs, for two (BRCA1 c.5152+2T>G and BRCA2 c.7975A>G) additional evidence exists from databases and in silico tools supporting their pathogenicity, which reinforces the hypothesis they may have had a predisposing effect in respective families. For the remaining four VUSs (31%), cosegregation analysis failed to provide relevant information.

Conclusion: Our findings suggest that cosegregation analysis in a clinical context may be helpful to improve test result interpretation in the specific family and, therefore, should be offered whenever possible. Besides, obtaining and sharing cosegregation data helps gathering evidence that may eventually contribute to VUS classification.

Effects of Endocrine-Disrupting Chemicals and Epigenetic Modifications in Ovarian Cancer: A Review

Ovarian cancer (OC) is a relatively fatal female reproductive malignancy. Since the underlying causes are uncertain, it brings us to believe that both genetic and external factors contribute toward development of this lethal disorder. Exposure to endocrine-disrupting chemicals (EDCs) in the form of occupational usage of pesticides, fungicides, herbicides, plasticizers, cosmetics, and so on is potentially carcinogenic and their ability to cause epigenetic modifications has led us to hypothesize that they may play a catalytic role in OC progression. In response to synthetic chemicals, animal models have demonstrated disturbances in the development of ovaries and steroid hormonal levels but in humans, more research is required. The present review is an attempt to address the impact of EDCs on the hormonal system and gene methylation levels that may lead to malfunctioning of the ovaries which may consequently develop in the form of cancer. It can be concluded that endocrine disruptors do have a potential carcinogenicity and their high proportions in human body may cause epigenetic modifications, prompting ovarian surface epithelium to grow in an abnormal manner.