Publications by authors named "Maaike Vreeswijk"

Article Synopsis
  • The ENIGMA research consortium focuses on determining the clinical significance of variants in hereditary breast and ovarian cancer genes, specifically BRCA1 and BRCA2, and evolved from an external expert panel to an internal Variant Curation Expert Panel (VCEP) to enhance alignment with FDA recognized classification processes.
  • The VCEP reviewed existing classification criteria and utilized statistical methods to assess evidence strength, testing new specifications on variants and updating documentation for better user clarity.
  • Analysis led to refined classifications for variants—resolving uncertainties and maintaining confidence in others—while revealing gaps in both ENIGMA's research and ACMG/AMP criteria, ultimately improving the classification process for BRCA1 and BRCA2 variants.
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Background: Disrupted pre-mRNA splicing is a frequent deleterious mechanism in hereditary cancer. We aimed to functionally analyze candidate spliceogenic variants of the breast cancer susceptibility gene CHEK2 by splicing reporter minigenes.

Methods: A total of 128 CHEK2 splice-site variants identified in the Breast Cancer After Diagnostic Gene Sequencing (BRIDGES) project (https://cordis.

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Purpose: BRCA-deficient breast cancers (BC) are highly sensitive to platinum-based chemotherapy and PARP inhibitors due to their deficiency in the homologous recombination (HR) pathway. However, HR deficiency (HRD) extends beyond BRCA-associated BC, highlighting the need for a sensitive method to enrich for HRD tumors in an alternative way. A promising approach is the use of functional HRD tests which evaluate the HR capability of tumor cells by measuring RAD51 protein accumulation at DNA damage sites.

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  • The RAD51 test is being explored as a potential biomarker for assessing homologous recombination deficiency (HRD) in ovarian cancer, but its reliability across different labs hasn't been fully assessed.
  • In a study involving four European laboratories, slight differences in staining techniques led to low variability in RAD51 and γH2AX scores, but some samples showed significant scoring variability due to technical and biological issues.
  • The findings highlight the importance of improving quality control and potentially automating image analysis for the RAD51 test to better identify HRD in high-grade serous ovarian carcinoma (HGSOC) patients, which is crucial for personalized treatment approaches.
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  • - The study investigated the links between genetic variants in breast cancer susceptibility genes (besides BRCA1, BRCA2, and CHEK2) and risks of developing contralateral breast cancer (CBC) and breast cancer-specific survival (BCSS) in 34,401 women of European ancestry who had been diagnosed with breast cancer.
  • - Significant findings revealed that protein-truncating variants (PTVs) and certain missense variants (MSVs) in genes like BRCA1, BRCA2, TP53, CHEK2, and PALB2 were associated with higher CBC risk and negative impacts on BCSS, indicating that these genetic factors play a crucial role in cancer outcomes.
  • - The results showed minimal
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  • Many variants found in disease susceptibility genes are classified as variants of uncertain significance (VUS), making their interpretation critical for clinical decisions.
  • This study introduces a new likelihood ratio-based method that takes into account gene-specific age-related penetrance to better analyze the pathogenicity of these variants.
  • The method outperformed traditional approaches in simulated and real datasets, allowing for clearer classifications of variants as pathogenic or non-pathogenic for conditions like breast cancer, and includes user-friendly tools for researchers.
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Skipping of BRCA2 exon 3 (∆E3) is a naturally occurring splicing event, complicating clinical classification of variants that may alter ∆E3 expression. This study used multiple evidence types to assess pathogenicity of 85 variants in/near BRCA2 exon 3. Bioinformatically predicted spliceogenic variants underwent mRNA splicing analysis using minigenes and/or patient samples.

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The ataxia telangiectasia-mutated (ATM) protein is a major coordinator of the DNA damage response pathway. ATM loss-of-function variants are associated with 2-fold increased breast cancer risk. We aimed at identifying and classifying spliceogenic ATM variants detected in subjects of the large-scale sequencing project BRIDGES.

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Protein-truncating variants in the breast cancer susceptibility gene CHEK2 are associated with a moderately increased risk of breast cancer. By contrast, for missense variants of uncertain significance (VUS) in CHEK2 the associated breast cancer risk is often unclear. To facilitate their classification, functional assays that determine the impact of missense VUS on CHK2 protein function have been performed.

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Article Synopsis
  • Protein truncating variants in genes like ATM and BRCA1 are linked to higher breast cancer risk, but the risks of missense variants remain unclear.
  • A study involving over 59,000 breast cancer cases analyzed the impact of rare missense variants across several genes using advanced prediction techniques and statistical models.
  • The analysis indicated that some missense variants in genes like ATM and BRCA1 could carry risks similar to truncating variants, while CHEK2 showed a different risk profile, and PALB2 variants had minimal association with breast cancer risk.
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  • Rare germline genetic variants in specific genes are linked to increased breast cancer risk, but their impact on different subtypes of the disease is not fully understood.
  • The BRIDGES study analyzed data from 42,680 breast cancer patients and 46,387 controls, focusing on specific genetic mutations and their associations with tumor characteristics.
  • Results showed that certain gene variants (like RAD51C, RAD51D, and BARD1) are primarily linked to triple-negative breast cancer, while others (like CHEK2) are associated with various subtypes, indicating varied genetic influence on breast cancer types.
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Introduction: Carcinomas with defects in the homologous recombination (HR) pathway are sensitive to PARP inhibitors (PARPi). A robust method to identify HR-deficient (HRD) carcinomas is therefore of utmost clinical importance. Currently, available DNA-based HRD tests either scan HR-related genes such as and for the presence of pathogenic variants or identify HRD-related genomic scars or mutational signatures by using whole-exome or whole-genome sequencing data.

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Unlabelled: Heterozygous carriers of germline loss-of-function variants in the tumor suppressor gene checkpoint kinase 2 (CHEK2) are at an increased risk for developing breast and other cancers. While truncating variants in CHEK2 are known to be pathogenic, the interpretation of missense variants of uncertain significance (VUS) is challenging. Consequently, many VUS remain unclassified both functionally and clinically.

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PALB2 loss-of-function variants confer high risk of developing breast cancer. Here we present a systematic functional analysis of PALB2 splice-site variants detected in approximately 113,000 women in the large-scale sequencing project Breast Cancer After Diagnostic Gene Sequencing (BRIDGES; https://bridges-research.eu/).

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PARP inhibitor (PARPi) sensitivity is related to tumor-specific defects in homologous recombination (HR). Therefore, there is great clinical interest in tests that can rapidly and reliably identify HR deficiency (HRD). Functional HRD tests determine the actual HR status by using the (dis)ability to accumulate RAD51 protein at sites of DNA damage as read-out.

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loss-of-function variants increase lifetime risk of breast and ovarian cancer. Splicing disruption is a frequent pathogenic mechanism associated with variants in susceptibility genes. Herein, we have assessed the splicing and clinical impact of splice-site and exonic splicing enhancer (ESE) variants identified through the study of ~113,000 women of the BRIDGES cohort.

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Background: Genetic testing for breast cancer susceptibility is widely used, but for many genes, evidence of an association with breast cancer is weak, underlying risk estimates are imprecise, and reliable subtype-specific risk estimates are lacking.

Methods: We used a panel of 34 putative susceptibility genes to perform sequencing on samples from 60,466 women with breast cancer and 53,461 controls. In separate analyses for protein-truncating variants and rare missense variants in these genes, we estimated odds ratios for breast cancer overall and tumor subtypes.

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Hereditary breast and/or ovarian cancer is a highly heterogeneous disease with more than 10 known disease-associated genes. In the framework of the BRIDGES project (Breast Cancer Risk after Diagnostic Gene Sequencing), the gene has been sequenced in 60,466 breast cancer patients and 53,461 controls. We aimed at functionally characterizing all the identified genetic variants that are predicted to disrupt the splicing process.

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In recent years it has become clear that pathogenic variants in are associated with a high risk for breast, ovarian and pancreatic cancer. However, the clinical relevance of variants of uncertain significance (VUS) in , which are increasingly identified through clinical genetic testing, is unclear. Here we review recent advances in the functional characterization of VUS in .

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Recent studies have shown that the efficacy of PARP inhibitors in epithelial ovarian carcinoma (EOC) is related to tumor-specific defects in homologous recombination (HR) and extends beyond deficient EOC. A robust method with which to identify HR-deficient (HRD) carcinomas is therefore of utmost clinical importance. In this study, we investigated the proficiency of a functional HR assay based on the detection of RAD51 foci, the REcombination CAPacity (RECAP) test, in identifying HRD tumors in a cohort of prospectively collected epithelial ovarian carcinomas (EOCs).

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Short-term fasting protects tumor-bearing mice against the toxic effects of chemotherapy while enhancing therapeutic efficacy. We randomized 131 patients with HER2-negative stage II/III breast cancer, without diabetes and a BMI over 18 kg m, to receive either a fasting mimicking diet (FMD) or their regular diet for 3 days prior to and during neoadjuvant chemotherapy. Here we show that there was no difference in toxicity between both groups, despite the fact that dexamethasone was omitted in the FMD group.

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Purpose: Because is a high-risk breast/ovarian cancer susceptibility gene, sequence variants of uncertain clinical significance (VUS) complicate genetic counseling. As most VUS are rare, reliable classification based on clinical and genetic data is often impossible. However, all pathogenic variants analyzed result in defective homologous recombination DNA repair (HRR).

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Purpose: Current interpretation guidelines for germline variants in high-risk cancer susceptibility genes consider predicted loss-of-function (LoF) variants, such as nonsense variants and variants in the canonical splice site sequences ofBRCA2, to be associated with high cancer risk. However, some variant alleles produce alternative transcripts that encode (partially) functional protein isoforms leading to possible incorrect risk estimations. For accurate classification of variants it is therefore essential that alternative transcripts are identified and functionally characterized.

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