Systematic Minigene-Based Splicing Analysis and Tentative Clinical Classification of 52 CHEK2 Splice-Site Variants.

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.

Performance of a RAD51-based functional HRD test on paraffin-embedded breast cancer tissue.

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.

Clinical, splicing, and functional analysis to classify BRCA2 exon 3 variants: Application of a points-based ACMG/AMP approach.

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.

CHEK2 variants: linking functional impact to cancer risk.

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.

RAD51 as a functional biomarker for homologous recombination deficiency in cancer: a promising addition to the HRD toolbox?

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.

Functional Analysis Identifies Damaging CHEK2 Missense Variants Associated with Increased Cancer Risk.

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.

The RAD51-FFPE Test; Calibration of a Functional Homologous Recombination Deficiency Test on Diagnostic Endometrial and Ovarian Tumor Blocks.

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.

Aberrant Splicing in Breast Cancer: Identification of Splicing Regulatory Elements and Minigene-Based Evaluation of 53 DNA Variants.

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.

Breast Cancer Risk Genes - Association Analysis in More than 113,000 Women.

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.

Comprehensive Functional Characterization and Clinical Interpretation of 20 Splice-Site Variants of the Gene.

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.

Functional Characterization of Variants of Uncertain Significance: Toward Cancer Risk and Therapy Response Prediction.

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 .

The RECAP Test Rapidly and Reliably Identifies Homologous Recombination-Deficient Ovarian Carcinomas.

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).

Correction: Alternative mRNA splicing can attenuate the pathogenicity of presumed loss-of-function variants in BRCA2.

An amendment to this paper has been published and can be accessed via a link at the top of the paper.

Fasting mimicking diet as an adjunct to neoadjuvant chemotherapy for breast cancer in the multicentre randomized phase 2 DIRECT trial.

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.

Functional Categorization of Variants of Uncertain Clinical Significance in Homologous Recombination Repair Complementation Assays.

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).

Alternative mRNA splicing can attenuate the pathogenicity of presumed loss-of-function variants in BRCA2.

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.

Variants of uncertain clinical significance in hereditary breast and ovarian cancer genes: best practices in functional analysis for clinical annotation.

Germline DNA tests to identify pathogenic variants in genes linked to hereditary breast and ovarian cancer susceptibility have become widely available. However, the clinical utility of genetic testing depends on reliable evidence-based classification of sequence variants. Determination of pathogenicity traditionally relies on painstaking pedigree-based segregation analyses.

Skipping Nonsense to Maintain Function: The Paradigm of Exon 12.

Germline nonsense and canonical splice site variants identified in disease-causing genes are generally considered as loss-of-function (LoF) alleles and classified as pathogenic. However, a fraction of such variants could maintain function through their impact on RNA splicing. To test this hypothesis, we used the alternatively spliced exon 12 (E12) as a model system because its in-frame skipping leads to a potentially functional protein.

Functional analysis of genetic variants in the high-risk breast cancer susceptibility gene PALB2.

Heterozygous carriers of germ-line loss-of-function variants in the DNA repair gene PALB2 are at a highly increased lifetime risk for developing breast cancer. While truncating variants in PALB2 are known to increase cancer risk, the interpretation of missense variants of uncertain significance (VUS) is in its infancy. Here we describe the development of a relatively fast and easy cDNA-based system for the semi high-throughput functional analysis of 48 VUS in human PALB2.