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Yin X, Richardson M, Laner A, Shi X, Ognedal E, Vasta V, Hansen TVO, Pineda M, Ritter D, den Dunnen JT, Hassanin E, Lyman Lin W, Borras E, Krahn K, Nordling M, Martins A, Mahmood K, Nadeau EAW, Beshay V, Tops C, Genuardi M, Pesaran T, Frayling IM, Capellá G, Latchford A, Tavtigian SV, Maj C, Plon SE, Greenblatt MS, Macrae FA, Spier I, Aretz S. Systematic large-scale application of ClinGen InSiGHT APC -specific ACMG/AMP variant classification criteria substantially alleviates the burden of variants of uncertain significance in ClinVar and LOVD databases. MEDRXIV : THE PREPRINT SERVER FOR HEALTH SCIENCES 2024:2024.05.03.24306761. [PMID: 38746299 PMCID: PMC11092726 DOI: 10.1101/2024.05.03.24306761] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/16/2024]
Abstract
Background Pathogenic constitutional APC variants underlie familial adenomatous polyposis, the most common hereditary gastrointestinal polyposis syndrome. To improve variant classification and resolve the interpretative challenges of variants of uncertain significance (VUS), APC-specific ACMG/AMP variant classification criteria were developed by the ClinGen-InSiGHT Hereditary Colorectal Cancer/Polyposis Variant Curation Expert Panel (VCEP). Methods A streamlined algorithm using the APC -specific criteria was developed and applied to assess all APC variants in ClinVar and the InSiGHT international reference APC LOVD variant database. Results A total of 10,228 unique APC variants were analysed. Among the ClinVar and LOVD variants with an initial classification of (Likely) Benign or (Likely) Pathogenic, 94% and 96% remained in their original categories, respectively. In contrast, 41% ClinVar and 61% LOVD VUS were reclassified into clinically actionable classes, the vast majority as (Likely) Benign. The total number of VUS was reduced by 37%. In 21 out of 36 (58%) promising APC variants that remained VUS despite evidence for pathogenicity, a data mining-driven work-up allowed their reclassification as (Likely) Pathogenic. Conclusions The application of APC -specific criteria substantially reduced the number of VUS in ClinVar and LOVD. The study also demonstrated the feasibility of a systematic approach to variant classification in large datasets, which might serve as a generalisable model for other gene-/disease-specific variant interpretation initiatives. It also allowed for the prioritization of VUS that will benefit from in-depth evidence collection. This subset of APC variants was approved by the VCEP and made publicly available through ClinVar and LOVD for widespread clinical use.
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Spier I, Yin X, Richardson M, Pineda M, Laner A, Ritter D, Boyle J, Mur P, Hansen TVO, Shi X, Mahmood K, Plazzer JP, Ognedal E, Nordling M, Farrington SM, Yamamoto G, Baert-Desurmont S, Martins A, Borras E, Tops C, Webb E, Beshay V, Genuardi M, Pesaran T, Capellá G, Tavtigian SV, Latchford A, Frayling IM, Plon SE, Greenblatt M, Macrae FA, Aretz S. Gene-specific ACMG/AMP classification criteria for germline APC variants: Recommendations from the ClinGen InSiGHT Hereditary Colorectal Cancer/Polyposis Variant Curation Expert Panel. Genet Med 2024; 26:100992. [PMID: 37800450 PMCID: PMC10922469 DOI: 10.1016/j.gim.2023.100992] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/14/2023] [Revised: 09/25/2023] [Accepted: 09/27/2023] [Indexed: 10/07/2023] Open
Abstract
PURPOSE The Hereditary Colorectal Cancer/Polyposis Variant Curation Expert Panel (VCEP) was established by the International Society for Gastrointestinal Hereditary Tumours and the Clinical Genome Resource, who set out to develop recommendations for the interpretation of germline APC variants underlying Familial Adenomatous Polyposis, the most frequent hereditary polyposis syndrome. METHODS Through a rigorous process of database analysis, literature review, and expert elicitation, the APC VCEP derived gene-specific modifications to the ACMG/AMP (American College of Medical Genetics and Genomics and Association for Molecular Pathology) variant classification guidelines and validated such criteria through the pilot classification of 58 variants. RESULTS The APC-specific criteria represented gene- and disease-informed specifications, including a quantitative approach to allele frequency thresholds, a stepwise decision tool for truncating variants, and semiquantitative evaluations of experimental and clinical data. Using the APC-specific criteria, 47% (27/58) of pilot variants were reclassified including 14 previous variants of uncertain significance (VUS). CONCLUSION The APC-specific ACMG/AMP criteria preserved the classification of well-characterized variants on ClinVar while substantially reducing the number of VUS by 56% (14/25). Moving forward, the APC VCEP will continue to interpret prioritized lists of VUS, the results of which will represent the most authoritative variant classification for widespread clinical use.
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Affiliation(s)
- Isabel Spier
- Institute of Human Genetics, Medical Faculty, University of Bonn, Bonn, Germany; National Center for Hereditary Tumor Syndromes, University Hospital Bonn, Bonn, Germany; European Reference Network on Genetic Tumour Risk Syndromes (ERN GENTURIS) - Project ID No 739547
| | - Xiaoyu Yin
- Institute of Human Genetics, Medical Faculty, University of Bonn, Bonn, Germany; Department of Colorectal Medicine and Genetics, Royal Melbourne Hospital, Parkville, Australia; Department of Medicine, University of Melbourne, Parkville, Australia.
| | | | - Marta Pineda
- European Reference Network on Genetic Tumour Risk Syndromes (ERN GENTURIS) - Project ID No 739547; Hereditary Cancer Program, Catalan Institute of Oncology - ONCOBELL, IDIBELL, Barcelona, Spain; Centro de Investigación Biomédica en Red de Cáncer (CIBERONC), Instituto Salud Carlos III, Madrid, Spain
| | | | - Deborah Ritter
- Baylor College of Medicine, Houston, TX; Texas Children's Cancer Center, Texas Children's Hospital, Houston, TX
| | - Julie Boyle
- Department of Oncological Sciences, School of Medicine, University of Utah, Salt Lake City, UT
| | - Pilar Mur
- Hereditary Cancer Program, Catalan Institute of Oncology - ONCOBELL, IDIBELL, Barcelona, Spain; Centro de Investigación Biomédica en Red de Cáncer (CIBERONC), Instituto Salud Carlos III, Madrid, Spain
| | - Thomas V O Hansen
- Department of Clinical Genetics, Rigshospitalet, Copenhagen University Hospital, Copenhagen, Denmark; Department of Clinical Medicine, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark
| | | | - Khalid Mahmood
- Colorectal Oncogenomics Group, Department of Clinical Pathology, University of Melbourne, Parkville, Australia; Melbourne Bioinformatics, University of Melbourne, Parkville, Australia
| | - John-Paul Plazzer
- Department of Colorectal Medicine and Genetics, Royal Melbourne Hospital, Parkville, Australia
| | | | - Margareta Nordling
- Department of Biomedical and Clinical Sciences, Linköping University, Linköping, Sweden; Department of Clinical Genetics, Linköping University Hospital, Linköping, Sweden
| | - Susan M Farrington
- Cancer Research UK Edinburgh Centre, the University of Edinburgh, Edinburgh, United Kingdom
| | - Gou Yamamoto
- Department of Molecular Diagnosis and Cancer Prevention, Saitama Cancer Center, Saitama, Japan
| | | | | | | | - Carli Tops
- Department of Clinical Genetics, Leiden University Medical Center, Leiden, The Netherlands
| | | | | | - Maurizio Genuardi
- Fondazione Policlinico Universitario A. Gemelli IRCCS, and Dipartimento di Scienze della Vita e Sanità Pubblica, Università Cattolica del Sacro Cuore, Rome, Italy
| | | | - Gabriel Capellá
- European Reference Network on Genetic Tumour Risk Syndromes (ERN GENTURIS) - Project ID No 739547; Hereditary Cancer Program, Catalan Institute of Oncology - ONCOBELL, IDIBELL, Barcelona, Spain; Centro de Investigación Biomédica en Red de Cáncer (CIBERONC), Instituto Salud Carlos III, Madrid, Spain
| | - Sean V Tavtigian
- Department of Oncological Sciences, School of Medicine, University of Utah, Salt Lake City, UT; Huntsman Cancer Institute, University of Utah, Salt Lake City, UT
| | - Andrew Latchford
- Polyposis Registry, St. Mark's Hospital, London, United Kingdom; Department of Surgery and Cancer, Imperial College, London, United Kingdom
| | - Ian M Frayling
- Polyposis Registry, St. Mark's Hospital, London, United Kingdom; Inherited Tumour Syndromes Research Group, Institute of Cancer & Genetics, Cardiff University, United Kingdom
| | - Sharon E Plon
- Baylor College of Medicine, Houston, TX; Texas Children's Cancer Center, Texas Children's Hospital, Houston, TX
| | - Marc Greenblatt
- Larner College of Medicine, University of Vermont, Burlington, VT
| | - Finlay A Macrae
- Department of Colorectal Medicine and Genetics, Royal Melbourne Hospital, Parkville, Australia; Department of Medicine, University of Melbourne, Parkville, Australia
| | - Stefan Aretz
- Institute of Human Genetics, Medical Faculty, University of Bonn, Bonn, Germany; National Center for Hereditary Tumor Syndromes, University Hospital Bonn, Bonn, Germany; European Reference Network on Genetic Tumour Risk Syndromes (ERN GENTURIS) - Project ID No 739547
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Horton C, Hoang L, Zimmermann H, Young C, Grzybowski J, Durda K, Vuong H, Burks D, Cass A, LaDuca H, Richardson ME, Harrison S, Chao EC, Karam R. Diagnostic Outcomes of Concurrent DNA and RNA Sequencing in Individuals Undergoing Hereditary Cancer Testing. JAMA Oncol 2024; 10:212-219. [PMID: 37924330 PMCID: PMC10625669 DOI: 10.1001/jamaoncol.2023.5586] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/12/2023] [Accepted: 09/04/2023] [Indexed: 11/06/2023]
Abstract
Importance Personalized surveillance, prophylaxis, and cancer treatment options for individuals with hereditary cancer predisposition are informed by results of germline genetic testing. Improvements to genomic technology, such as the availability of RNA sequencing, may increase identification of individuals eligible for personalized interventions by improving the accuracy and yield of germline testing. Objective To assess the cumulative association of paired DNA and RNA testing with detection of disease-causing germline genetic variants and resolution of variants of uncertain significance (VUS). Design, Setting, and Participants Paired DNA and RNA sequencing was performed on individuals undergoing germline testing for hereditary cancer indication at a single diagnostic laboratory from March 2019 through April 2020. Demographic characteristics, clinical data, and test results were curated as samples were received, and changes to variant classification were assessed over time. Data analysis was performed from May 2020 to June 2023. Main Outcomes and Measures Main outcomes were increase in diagnostic yield, decrease in VUS rate, the overall results by variant type, the association of RNA evidence with variant classification, and the corresponding predicted effect on cancer risk management. Results A total of 43 524 individuals were included (median [range] age at testing, 54 [2-101] years; 37 373 female individuals [85.7%], 6224 male individuals [14.3%], and 2 individuals of unknown sex [<0.1%]), with 43 599 tests. A total of 2197 (5.0%) were Ashkenazi Jewish, 1539 (3.5%) were Asian, 3077 (7.1%) were Black, 2437 (5.6%) were Hispanic, 27 793 (63.7%) were White, and 2049 (4.7%) were other race, and for 4507 individuals (10.3%), race and ethnicity were unknown. Variant classification was impacted in 549 individuals (1.3%). Medically significant upgrades were made in 97 individuals, including 70 individuals who had a variant reclassified from VUS to pathogenic/likely pathogenic (P/LP) and 27 individuals who had a novel deep intronic P/LP variant that would not have been detected using DNA sequencing alone. A total of 93 of 545 P/LP splicing variants (17.1%) were dependent on RNA evidence for classification, and 312 of 439 existing splicing VUS (71.1%) were resolved by RNA evidence. Notably, the increase in positive rate (3.1%) and decrease in VUS rate (-3.9%) was higher in Asian, Black, and Hispanic individuals combined compared to White individuals (1.6%; P = .02; and -2.5%; P < .001). Conclusions and Relevance Findings of this diagnostic study demonstrate that the ability to perform RNA sequencing concurrently with DNA sequencing represents an important advancement in germline genetic testing by improving detection of novel variants and classification of existing variants. This expands the identification of individuals with hereditary cancer predisposition and increases opportunities for personalization of therapeutics and surveillance.
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Affiliation(s)
| | | | | | | | | | | | - Huy Vuong
- Ambry Genetics, Aliso Viejo, California
| | | | | | | | | | | | - Elizabeth C Chao
- Ambry Genetics, Aliso Viejo, California
- University of California, Irvine, School of Medicine
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Valle L, Monahan KJ. Genetic predisposition to gastrointestinal polyposis: syndromes, tumour features, genetic testing, and clinical management. Lancet Gastroenterol Hepatol 2024; 9:68-82. [PMID: 37931640 DOI: 10.1016/s2468-1253(23)00240-6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/06/2023] [Revised: 07/19/2023] [Accepted: 07/20/2023] [Indexed: 11/08/2023]
Abstract
Gastrointestinal tract polyposis is characterised by the presence of multiple polyps, particularly in the colorectum, and encompasses both cancer predisposition genetic syndromes and non-syndromic clinical manifestations. The sources of the heterogeneity observed in polyposis syndromes relate to genetic cause, mode of inheritance, polyp burden and histological type, and spectrum and frequency of extracolonic manifestations. These features determine the clinical management of carriers, including strategies for cancer prevention and early detection, and oncological treatments. Despite substantial progress in identifying the genetic causes of polyposis, a large proportion of cases remain genetically unexplained. Although some of these cases might be due to lifestyle, environmental factors, or cancer treatments, it is likely that additional polyposis predisposition genes will be identified. This Review provides an overview of the known syndromes and genes, genetic testing, and clinical management of patients with polyposis, and recent advances and challenges in the field of gastrointestinal polyposis.
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Affiliation(s)
- Laura Valle
- Hereditary Cancer Programme, Catalan Institute of Oncology, Oncobell Programme, IDIBELL, Hospitalet de Llobregat, Barcelona, Spain; Centro de Investigación Biomédica en Red de Cáncer (CIBERONC), Madrid, Spain.
| | - Kevin J Monahan
- The St Mark's Centre for Familial Intestinal Cancer Lynch Syndrome & Family Cancer Clinic & Polyposis Registry, St Mark's Hospital, London, UK; Imperial College, London, UK.
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Fillman C, Anantharajah A, Marmelstein B, Dillon M, Horton C, Peterson C, Lopez J, Tondon R, Brannan T, Katona BW. Combining clinical and molecular characterization of CDH1: a multidisciplinary approach to reclassification of a splicing variant. Fam Cancer 2023; 22:521-526. [PMID: 37540482 DOI: 10.1007/s10689-023-00346-z] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/02/2023] [Accepted: 07/25/2023] [Indexed: 08/05/2023]
Abstract
Pathogenic germline variants (PGVs) in the CDH1 gene are associated with diffuse gastric and lobular breast cancer syndrome (DGLBC) and can increase the lifetime risk for both diffuse gastric cancer and lobular breast cancer. Given the risk for diffuse gastric cancer among individuals with CDH1 PGVs is up to 30-40%, prophylactic total gastrectomy is often recommended to affected individuals. Therefore, accurate interpretation of CDH1 variants is of the utmost importance for proper clinical decision-making. Herein we present a 45-year-old female, with lobular breast cancer and a father with gastric cancer of unknown pathology at age 48, who was identified to have an intronic variant of uncertain significance in the CDH1 gene, specifically c.833-9 C > G. Although the proband did not meet the International Gastric Cancer Linkage Consortium (IGCLC) criteria for gastric surveillance, she elected to pursue an upper endoscopy where non-targeted gastric biopsies identified a focus of signet ring cell carcinoma (SRCC). The proband then underwent a total gastrectomy, revealing numerous SRCC foci, but no invasive diffuse gastric cancer. Simultaneously, a genetic testing laboratory performed RNA sequencing to further analyze the CDH1 intronic variant, identifying an abnormal transcript from a novel acceptor splice site. The RNA analysis in conjunction with the patient's gastric foci of SRCC and family history was sufficient evidence for reclassification of the variant from uncertain significance to likely pathogenic. In conclusion, we report the first case of the CDH1 c.833-9 C > G intronic variant being associated with DGLBC and illustrate how collaboration among clinicians, laboratory personnel, and patients is crucial for variant resolution.
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Affiliation(s)
- Corrine Fillman
- Cancer Risk and Genetics Program, St. Luke's University Health Network, Bethlehem, PA, USA
| | | | - Briana Marmelstein
- Cancer Risk and Genetics Program, St. Luke's University Health Network, Bethlehem, PA, USA
| | - Monica Dillon
- Cancer Risk and Genetics Program, St. Luke's University Health Network, Bethlehem, PA, USA
| | | | | | - Joseph Lopez
- Cancer Risk and Genetics Program, St. Luke's University Health Network, Bethlehem, PA, USA
| | - Rashmi Tondon
- University of Pennsylvania Perelman School of Medicine, Philadelphia, PA, USA
| | | | - Bryson W Katona
- University of Pennsylvania Perelman School of Medicine, Philadelphia, PA, USA.
- Division of Gastroenterology and Hepatology, University of Pennsylvania Perelman School of Medicine, 3400 Civic Center Blvd. 751 South Pavilion, Philadelphia, PA, 19104, USA.
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Alimohamed MZ, Boven LG, van Dijk KK, Vos YJ, Hoedemaekers YM, van der Zwaag PA, Sijmons RH, Jongbloed JD, Sikkema-Raddatz B, Westers H. SEPT–GD: A decision tree to prioritise potential RNA splice variants in cardiomyopathy genes for functional splicing assays in diagnostics. Gene 2023; 851:146984. [DOI: 10.1016/j.gene.2022.146984] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/20/2022] [Revised: 08/09/2022] [Accepted: 10/13/2022] [Indexed: 11/06/2022]
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Postel MD, Culver JO, Ricker C, Craig DW. Transcriptome analysis provides critical answers to the "variants of uncertain significance" conundrum. Hum Mutat 2022; 43:1590-1608. [PMID: 35510381 PMCID: PMC9560997 DOI: 10.1002/humu.24394] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/22/2021] [Revised: 03/16/2022] [Accepted: 04/26/2022] [Indexed: 12/30/2022]
Abstract
While whole-genome and exome sequencing have transformed our collective understanding of genetics' role in disease pathogenesis, there are certain conditions and populations for whom DNA-level data fails to identify the underlying genetic etiology. Specifically, patients of non-White race and non-European ancestry are disproportionately affected by "variants of unknown/uncertain significance" (VUS), limiting the scope of precision medicine for minority patients and perpetuating health disparities. VUS often include deep intronic and splicing variants which are difficult to interpret from DNA data alone. RNA analysis can illuminate the consequences of VUS, thereby allowing for their reclassification as pathogenic versus benign. Here we review the critical role transcriptome analysis plays in clarifying VUS in both neoplastic and non-neoplastic diseases.
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Affiliation(s)
- Mackenzie D. Postel
- Department of Translational GenomicsUniversity of Southern CaliforniaLos AngelesCaliforniaUSA
- Keck School of Medicine of USCUniversity of Southern CaliforniaLos AngelesCaliforniaUSA
| | - Julie O. Culver
- Keck School of Medicine of USCUniversity of Southern CaliforniaLos AngelesCaliforniaUSA
| | - Charité Ricker
- Keck School of Medicine of USCUniversity of Southern CaliforniaLos AngelesCaliforniaUSA
| | - David W. Craig
- Department of Translational GenomicsUniversity of Southern CaliforniaLos AngelesCaliforniaUSA
- Keck School of Medicine of USCUniversity of Southern CaliforniaLos AngelesCaliforniaUSA
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Azadifar S, Rostami M, Berahmand K, Moradi P, Oussalah M. Graph-based relevancy-redundancy gene selection method for cancer diagnosis. Comput Biol Med 2022; 147:105766. [PMID: 35779479 DOI: 10.1016/j.compbiomed.2022.105766] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/10/2022] [Revised: 06/12/2022] [Accepted: 06/18/2022] [Indexed: 11/26/2022]
Abstract
Nowadays, microarray data processing is one of the most important applications in molecular biology for cancer diagnosis. A major task in microarray data processing is gene selection, which aims to find a subset of genes with the least inner similarity and most relevant to the target class. Removing unnecessary, redundant, or noisy data reduces the data dimensionality. This research advocates a graph theoretic-based gene selection method for cancer diagnosis. Both unsupervised and supervised modes use well-known and successful social network approaches such as the maximum weighted clique criterion and edge centrality to rank genes. The suggested technique has two goals: (i) to maximize the relevancy of the chosen genes with the target class and (ii) to reduce their inner redundancy. A maximum weighted clique is chosen in a repetitive way in each iteration of this procedure. The appropriate genes are then chosen from among the existing features in this maximum clique using edge centrality and gene relevance. In the experiment, several datasets consisting of Colon, Leukemia, SRBCT, Prostate Tumor, and Lung Cancer, with different properties, are used to demonstrate the efficacy of the developed model. Our performance is compared to that of renowned filter-based gene selection approaches for cancer diagnosis whose results demonstrate a clear superiority.
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Affiliation(s)
- Saeid Azadifar
- Department of Computer Engineering, University of Khajeh Nasir Toosi, Tehran, Iran
| | - Mehrdad Rostami
- Centre for Machine Vision and Signal Processing, University of Oulu, Oulu, Finland.
| | - Kamal Berahmand
- School of Computer Science, Faculty of Science, Queensland University of Technology (QUT), Brisbane, Australia
| | - Parham Moradi
- Department of Computer Engineering, University of Kurdistan, Sanandaj, Iran
| | - Mourad Oussalah
- Centre for Machine Vision and Signal Processing, University of Oulu, Oulu, Finland; Research Unit of Medical Imaging, Physics, and Technology, Faculty of Medicine, University of Oulu, Finland
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9
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Rofes P, Pineda M, Feliubadaló L, Menéndez M, de Cid R, Gómez C, Montes E, Capellá G, Brunet J, Del Valle J, Lázaro C. RNA assay identifies a previous misclassification of BARD1 c.1977A>G variant. Sci Rep 2021; 11:22948. [PMID: 34824355 PMCID: PMC8617171 DOI: 10.1038/s41598-021-02465-y] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/22/2021] [Accepted: 11/15/2021] [Indexed: 11/22/2022] Open
Abstract
Case–control studies have shown an association of BARD1 with hereditary breast and/or ovarian cancer (HBOC) predisposition. BARD1 alternatively spliced isoforms are abundant and some are highly expressed in different cancer types. In addition, a number of BARD1 germline pathogenic variants have been reported among HBOC patients. In previous reports, BARD1 c.1977A>G variant has been classified as pathogenic since it produces a frameshift transcript lacking exons 2 to 9. In the present study, we sought to validate the mRNA splicing results previously published and to contribute with new evidence to refine the classification of this substitution according to ACMG/AMP guidelines. The presence of the variant was screened in patients and controls. RT-PCR was performed in order to compare the transcriptional profiles of two variant carriers and ten non-carrier controls. In addition, allele-specific expression was assessed. No differences in variant frequency were detected between patients and controls. The RNA assay confirmed the presence of the shorter transcript lacking exons 2–9, but it was detected both in carriers and non-carriers. Furthermore, allelic imbalance was discarded and no significant differences in the proportion of full-length and shorter transcript were detected between carriers and controls. The shorter transcript detected corresponds to BARD1 isoform η, constituted by exons 1, 10 and 11. Our results support that this transcript is a constitutive splicing product rather than an aberrant transcript caused by BARD1 c.1977A>G variant, and for this reason this variant should be considered as likely benign following ACMG/AMP guidelines.
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Affiliation(s)
- Paula Rofes
- Hereditary Cancer Program, Molecular Mechanisms and Experimental Therapy in Oncology (Oncobell) Program, Catalan Institute of Oncology, IDIBELL, Av. Gran Via 199-203, 08908, L'Hospitalet de Llobregat, Spain.,Centro de Investigación Biomédica en Red de Cáncer (CIBERONC), 28029, Madrid, Spain
| | - Marta Pineda
- Hereditary Cancer Program, Molecular Mechanisms and Experimental Therapy in Oncology (Oncobell) Program, Catalan Institute of Oncology, IDIBELL, Av. Gran Via 199-203, 08908, L'Hospitalet de Llobregat, Spain.,Centro de Investigación Biomédica en Red de Cáncer (CIBERONC), 28029, Madrid, Spain
| | - Lídia Feliubadaló
- Hereditary Cancer Program, Molecular Mechanisms and Experimental Therapy in Oncology (Oncobell) Program, Catalan Institute of Oncology, IDIBELL, Av. Gran Via 199-203, 08908, L'Hospitalet de Llobregat, Spain.,Centro de Investigación Biomédica en Red de Cáncer (CIBERONC), 28029, Madrid, Spain
| | - Mireia Menéndez
- Hereditary Cancer Program, Molecular Mechanisms and Experimental Therapy in Oncology (Oncobell) Program, Catalan Institute of Oncology, IDIBELL, Av. Gran Via 199-203, 08908, L'Hospitalet de Llobregat, Spain.,Centro de Investigación Biomédica en Red de Cáncer (CIBERONC), 28029, Madrid, Spain
| | - Rafael de Cid
- Genomes for Life-GCAT Lab Group, Institut Germans Trias i Pujol (IGTP) (on behalf of the GCAT project), 08916, Badalona, Spain
| | - Carolina Gómez
- Hereditary Cancer Program, Molecular Mechanisms and Experimental Therapy in Oncology (Oncobell) Program, Catalan Institute of Oncology, IDIBELL, Av. Gran Via 199-203, 08908, L'Hospitalet de Llobregat, Spain
| | - Eva Montes
- Hereditary Cancer Program, Molecular Mechanisms and Experimental Therapy in Oncology (Oncobell) Program, Catalan Institute of Oncology, IDIBELL, Av. Gran Via 199-203, 08908, L'Hospitalet de Llobregat, Spain
| | - Gabriel Capellá
- Hereditary Cancer Program, Molecular Mechanisms and Experimental Therapy in Oncology (Oncobell) Program, Catalan Institute of Oncology, IDIBELL, Av. Gran Via 199-203, 08908, L'Hospitalet de Llobregat, Spain.,Centro de Investigación Biomédica en Red de Cáncer (CIBERONC), 28029, Madrid, Spain
| | - Joan Brunet
- Hereditary Cancer Program, Molecular Mechanisms and Experimental Therapy in Oncology (Oncobell) Program, Catalan Institute of Oncology, IDIBELL, Av. Gran Via 199-203, 08908, L'Hospitalet de Llobregat, Spain.,Centro de Investigación Biomédica en Red de Cáncer (CIBERONC), 28029, Madrid, Spain
| | - Jesús Del Valle
- Hereditary Cancer Program, Molecular Mechanisms and Experimental Therapy in Oncology (Oncobell) Program, Catalan Institute of Oncology, IDIBELL, Av. Gran Via 199-203, 08908, L'Hospitalet de Llobregat, Spain.,Centro de Investigación Biomédica en Red de Cáncer (CIBERONC), 28029, Madrid, Spain
| | - Conxi Lázaro
- Hereditary Cancer Program, Molecular Mechanisms and Experimental Therapy in Oncology (Oncobell) Program, Catalan Institute of Oncology, IDIBELL, Av. Gran Via 199-203, 08908, L'Hospitalet de Llobregat, Spain. .,Centro de Investigación Biomédica en Red de Cáncer (CIBERONC), 28029, Madrid, Spain.
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