1
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Paulo P, Cardoso M, Brandão A, Pinto P, Falconi A, Pinheiro M, Cerveira N, Silva R, Santos C, Pinto C, Peixoto A, Maia S, Teixeira MR. Genetic landscape of homologous recombination repair genes in early-onset/familial prostate cancer patients. Genes Chromosomes Cancer 2023; 62:710-720. [PMID: 37436117 DOI: 10.1002/gcc.23190] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/28/2023] [Revised: 06/19/2023] [Accepted: 06/28/2023] [Indexed: 07/13/2023] Open
Abstract
Prostate cancer (PrCa) is one of the three most frequent and deadliest cancers worldwide. The discovery of PARP inhibitors for the treatment of tumors with deleterious variants in homologous recombination repair (HRR) genes has placed PrCa on the roadmap of precision medicine. However, the overall contribution of HRR genes to the 10%-20% of carcinomas arising in men with early-onset/familial PrCa has not been fully clarified. We used targeted next-generation sequencing (T-NGS) covering eight HRR genes (ATM, BRCA1, BRCA2, BRIP1, CHEK2, NBN, PALB2, and RAD51C) and an analysis pipeline querying both small and large genomic variations to clarify their global and relative contribution to hereditary PrCa predisposition in a series of 462 early-onset/familial PrCa cases. Deleterious variants were found in 3.9% of the patients, with CHEK2 and ATM being the most frequently mutated genes (38.9% and 22.2% of the carriers, respectively), followed by PALB2 and NBN (11.1% of the carriers, each), and finally by BRCA2, RAD51C, and BRIP1 (5.6% of the carriers, each). Using the same NGS data, exonic rearrangements were found in two patients, one pathogenic in BRCA2 and one of unknown significance in BRCA1. These results contribute to clarify the genetic heterogeneity that underlies PrCa predisposition in the early-onset and familial disease, respectively.
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Affiliation(s)
- Paula Paulo
- Cancer Genetics Group, IPO Porto Research Center (CI-IPOP) /RISE@CI-IPOP (Health Research Network), Portuguese Oncology Institute of Porto (IPO Porto) /Porto Comprehensive Cancer Center, Porto, Portugal
| | - Marta Cardoso
- Cancer Genetics Group, IPO Porto Research Center (CI-IPOP) /RISE@CI-IPOP (Health Research Network), Portuguese Oncology Institute of Porto (IPO Porto) /Porto Comprehensive Cancer Center, Porto, Portugal
| | - Andreia Brandão
- Cancer Genetics Group, IPO Porto Research Center (CI-IPOP) /RISE@CI-IPOP (Health Research Network), Portuguese Oncology Institute of Porto (IPO Porto) /Porto Comprehensive Cancer Center, Porto, Portugal
| | - Pedro Pinto
- Cancer Genetics Group, IPO Porto Research Center (CI-IPOP) /RISE@CI-IPOP (Health Research Network), Portuguese Oncology Institute of Porto (IPO Porto) /Porto Comprehensive Cancer Center, Porto, Portugal
| | - Ariane Falconi
- Cancer Genetics Group, IPO Porto Research Center (CI-IPOP) /RISE@CI-IPOP (Health Research Network), Portuguese Oncology Institute of Porto (IPO Porto) /Porto Comprehensive Cancer Center, Porto, Portugal
| | - Manuela Pinheiro
- Cancer Genetics Group, IPO Porto Research Center (CI-IPOP) /RISE@CI-IPOP (Health Research Network), Portuguese Oncology Institute of Porto (IPO Porto) /Porto Comprehensive Cancer Center, Porto, Portugal
| | - Nuno Cerveira
- Cancer Genetics Group, IPO Porto Research Center (CI-IPOP) /RISE@CI-IPOP (Health Research Network), Portuguese Oncology Institute of Porto (IPO Porto) /Porto Comprehensive Cancer Center, Porto, Portugal
- Department of Laboratory Genetics, Portuguese Oncology Institute of Porto (IPO Porto)/Porto Comprehensive Cancer Center, Porto, Portugal
| | - Rui Silva
- Cancer Genetics Group, IPO Porto Research Center (CI-IPOP) /RISE@CI-IPOP (Health Research Network), Portuguese Oncology Institute of Porto (IPO Porto) /Porto Comprehensive Cancer Center, Porto, Portugal
| | - Catarina Santos
- Cancer Genetics Group, IPO Porto Research Center (CI-IPOP) /RISE@CI-IPOP (Health Research Network), Portuguese Oncology Institute of Porto (IPO Porto) /Porto Comprehensive Cancer Center, Porto, Portugal
- Department of Laboratory Genetics, Portuguese Oncology Institute of Porto (IPO Porto)/Porto Comprehensive Cancer Center, Porto, Portugal
| | - Carla Pinto
- Cancer Genetics Group, IPO Porto Research Center (CI-IPOP) /RISE@CI-IPOP (Health Research Network), Portuguese Oncology Institute of Porto (IPO Porto) /Porto Comprehensive Cancer Center, Porto, Portugal
- Department of Laboratory Genetics, Portuguese Oncology Institute of Porto (IPO Porto)/Porto Comprehensive Cancer Center, Porto, Portugal
| | - Ana Peixoto
- Cancer Genetics Group, IPO Porto Research Center (CI-IPOP) /RISE@CI-IPOP (Health Research Network), Portuguese Oncology Institute of Porto (IPO Porto) /Porto Comprehensive Cancer Center, Porto, Portugal
- Department of Laboratory Genetics, Portuguese Oncology Institute of Porto (IPO Porto)/Porto Comprehensive Cancer Center, Porto, Portugal
| | - Sofia Maia
- Cancer Genetics Group, IPO Porto Research Center (CI-IPOP) /RISE@CI-IPOP (Health Research Network), Portuguese Oncology Institute of Porto (IPO Porto) /Porto Comprehensive Cancer Center, Porto, Portugal
- Medical Genetics Unit, Hospital Pediátrico de Coimbra, Centro Hospitalar e Universitário de Coimbra, Coimbra, Portugal
| | - Manuel R Teixeira
- Cancer Genetics Group, IPO Porto Research Center (CI-IPOP) /RISE@CI-IPOP (Health Research Network), Portuguese Oncology Institute of Porto (IPO Porto) /Porto Comprehensive Cancer Center, Porto, Portugal
- Department of Laboratory Genetics, Portuguese Oncology Institute of Porto (IPO Porto)/Porto Comprehensive Cancer Center, Porto, Portugal
- School of Medicine and Biomedical Sciences (ICBAS), University of Porto, Porto, Portugal
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Kechin A, Boyarskikh U, Borobova V, Khrapov E, Subbotin S, Filipenko M. BRACNAC: A BRCA1 and BRCA2 Copy Number Alteration Caller from Next-Generation Sequencing Data. Int J Mol Sci 2023; 24:16630. [PMID: 38068953 PMCID: PMC10706169 DOI: 10.3390/ijms242316630] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/26/2023] [Revised: 11/17/2023] [Accepted: 11/21/2023] [Indexed: 12/18/2023] Open
Abstract
Detecting copy number variations (CNVs) and alterations (CNAs) in the BRCA1 and BRCA2 genes is essential for testing patients for targeted therapy applicability. However, the available bioinformatics tools were initially designed for identifying CNVs/CNAs in whole-genome or -exome (WES) NGS data or targeted NGS data without adaptation to the BRCA1/2 genes. Most of these tools were tested on sample cohorts of limited size, with their use restricted to specific library preparation kits or sequencing platforms. We developed BRACNAC, a new tool for detecting CNVs and CNAs in the BRCA1 and BRCA2 genes in NGS data of different origin. The underlying mechanism of this tool involves various coverage normalization steps complemented by CNV probability evaluation. We estimated the sensitivity and specificity of our tool to be 100% and 94%, respectively, with an area under the curve (AUC) of 94%. The estimation was performed using the NGS data obtained from 213 ovarian and prostate cancer samples tested with in-house and commercially available library preparation kits and additionally using multiplex ligation-dependent probe amplification (MLPA) (12 CNV-positive samples). Using freely available WES and targeted NGS data from other research groups, we demonstrated that BRACNAC could also be used for these two types of data, with an AUC of up to 99.9%. In addition, we determined the limitations of the tool in terms of the minimum number of samples per NGS run (≥20 samples) and the minimum expected percentage of CNV-negative samples (≥80%). We expect that our findings will improve the efficacy of BRCA1/2 diagnostics. BRACNAC is freely available at the GitHub server.
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Affiliation(s)
- Andrey Kechin
- Institute of Chemical Biology and Fundamental Medicine, Novosibirsk 630090, Russia
- Faculty of Natural Sciences, Novosibirsk State University, Novosibirsk 630090, Russia
| | - Ulyana Boyarskikh
- Institute of Chemical Biology and Fundamental Medicine, Novosibirsk 630090, Russia
| | - Viktoriya Borobova
- Institute of Chemical Biology and Fundamental Medicine, Novosibirsk 630090, Russia
- Faculty of Natural Sciences, Novosibirsk State University, Novosibirsk 630090, Russia
| | - Evgeniy Khrapov
- Institute of Chemical Biology and Fundamental Medicine, Novosibirsk 630090, Russia
| | - Sergey Subbotin
- Institute of Chemical Biology and Fundamental Medicine, Novosibirsk 630090, Russia
| | - Maxim Filipenko
- Institute of Chemical Biology and Fundamental Medicine, Novosibirsk 630090, Russia
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3
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Loboda AP, Adonin LS, Zvereva SD, Guschin DY, Korneenko TV, Telegina AV, Kondratieva OK, Frolova SE, Pestov NB, Barlev NA. BRCA Mutations-The Achilles Heel of Breast, Ovarian and Other Epithelial Cancers. Int J Mol Sci 2023; 24:ijms24054982. [PMID: 36902416 PMCID: PMC10003548 DOI: 10.3390/ijms24054982] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/11/2023] [Revised: 02/27/2023] [Accepted: 03/02/2023] [Indexed: 03/08/2023] Open
Abstract
Two related tumor suppressor genes, BRCA1 and BRCA2, attract a lot of attention from both fundamental and clinical points of view. Oncogenic hereditary mutations in these genes are firmly linked to the early onset of breast and ovarian cancers. However, the molecular mechanisms that drive extensive mutagenesis in these genes are not known. In this review, we hypothesize that one of the potential mechanisms behind this phenomenon can be mediated by Alu mobile genomic elements. Linking mutations in the BRCA1 and BRCA2 genes to the general mechanisms of genome stability and DNA repair is critical to ensure the rationalized choice of anti-cancer therapy. Accordingly, we review the literature available on the mechanisms of DNA damage repair where these proteins are involved, and how the inactivating mutations in these genes (BRCAness) can be exploited in anti-cancer therapy. We also discuss a hypothesis explaining why breast and ovarian epithelial tissues are preferentially susceptible to mutations in BRCA genes. Finally, we discuss prospective novel therapeutic approaches for treating BRCAness cancers.
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Affiliation(s)
- Anna P. Loboda
- Laboratory of Molecular Oncology, Phystech School of Biological and Medical Physics, Moscow Institute of Physics and Technology, 141701 Dolgoprudny, Russia
| | | | - Svetlana D. Zvereva
- Laboratory of Molecular Oncology, Phystech School of Biological and Medical Physics, Moscow Institute of Physics and Technology, 141701 Dolgoprudny, Russia
| | - Dmitri Y. Guschin
- School of Medicine, Nazarbayev University, Astana 010000, Kazakhstan
| | - Tatyana V. Korneenko
- Group of Cross-Linking Enzymes, Shemyakin-Ovchinnikov Institute of Bioorganic Chemistry, 117997 Moscow, Russia
| | | | | | | | - Nikolay B. Pestov
- Institute of Biomedical Chemistry, 119121 Moscow, Russia
- Group of Cross-Linking Enzymes, Shemyakin-Ovchinnikov Institute of Bioorganic Chemistry, 117997 Moscow, Russia
- Chumakov Federal Scientific Center for Research and Development of Immune-and-Biological Products, 108819 Moscow, Russia
- Correspondence: (N.B.P.); (N.A.B.)
| | - Nick A. Barlev
- Institute of Biomedical Chemistry, 119121 Moscow, Russia
- School of Medicine, Nazarbayev University, Astana 010000, Kazakhstan
- Chumakov Federal Scientific Center for Research and Development of Immune-and-Biological Products, 108819 Moscow, Russia
- Institute of Cytology, Tikhoretsky ave 4, 194064 St-Petersburg, Russia
- Correspondence: (N.B.P.); (N.A.B.)
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4
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Kwong A, Au CH, Shin VY, Ho DN, Wong EYL, Ho CYS, Chung Y, Chan TL, Ma ESK. Rapid Breakpoint Mapping of a Novel Germline PALB2 Duplication by PCR-Free Long-Read Sequencing for Interpretation of Its Pathogenicity. JCO Precis Oncol 2022; 5:1044-1047. [PMID: 34994627 DOI: 10.1200/po.20.00454] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023] Open
Affiliation(s)
- Ava Kwong
- Department of Surgery, The University of Hong Kong and The University of Hong Kong-Shenzhen Hospital, Hong Kong, China.,Department of Surgery and Cancer Genetics Centre, Hong Kong Sanatorium and Hospital, Hong Kong, China.,Hong Kong Hereditary Breast Cancer Family Registry, Hong Kong Sanatorium and Hospital, Hong Kong, China
| | - Chun Hang Au
- Division of Molecular Pathology, Department of Pathology, Hong Kong Sanatorium and Hospital, Hong Kong, China
| | - Vivian Y Shin
- Department of Surgery, The University of Hong Kong and The University of Hong Kong-Shenzhen Hospital, Hong Kong, China
| | - Dona N Ho
- Division of Molecular Pathology, Department of Pathology, Hong Kong Sanatorium and Hospital, Hong Kong, China
| | - Elaine Y L Wong
- Division of Molecular Pathology, Department of Pathology, Hong Kong Sanatorium and Hospital, Hong Kong, China
| | - Cecilia Y S Ho
- Division of Molecular Pathology, Department of Pathology, Hong Kong Sanatorium and Hospital, Hong Kong, China
| | - Yvonne Chung
- Division of Molecular Pathology, Department of Pathology, Hong Kong Sanatorium and Hospital, Hong Kong, China
| | - Tsun Leung Chan
- Hong Kong Hereditary Breast Cancer Family Registry, Hong Kong Sanatorium and Hospital, Hong Kong, China.,Division of Molecular Pathology, Department of Pathology, Hong Kong Sanatorium and Hospital, Hong Kong, China
| | - Edmond S K Ma
- Hong Kong Hereditary Breast Cancer Family Registry, Hong Kong Sanatorium and Hospital, Hong Kong, China.,Division of Molecular Pathology, Department of Pathology, Hong Kong Sanatorium and Hospital, Hong Kong, China
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5
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Caputo SM, Telly D, Briaux A, Sesen J, Ceppi M, Bonnet F, Bourdon V, Coulet F, Castera L, Delnatte C, Hardouin A, Mazoyer S, Schultz I, Sevenet N, Uhrhammer N, Bonnet C, Tilkin-Mariamé AF, Houdayer C, Moncoutier V, Andrieu C, Bièche I, Stern MH, Stoppa-Lyonnet D, Lidereau R, Toulas C, Rouleau E. 5' Region Large Genomic Rearrangements in the BRCA1 Gene in French Families: Identification of a Tandem Triplication and Nine Distinct Deletions with Five Recurrent Breakpoints. Cancers (Basel) 2021; 13:cancers13133171. [PMID: 34202044 PMCID: PMC8268747 DOI: 10.3390/cancers13133171] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/30/2021] [Revised: 06/11/2021] [Accepted: 06/17/2021] [Indexed: 12/28/2022] Open
Abstract
Simple Summary Large genomic rearrangements in BRCA1 consisting of deletions/duplications of one or several exons are complex events, often occurring in the 5′ region. We characterized 10 events in 20 families: one large triplication classified as benign and nine large deletions classified as pathogenic. The breakpoint localization will certainly help to further understand the chromatin structure in regions sensitive to rearrangement. Abstract Background: Large genomic rearrangements (LGR) in BRCA1 consisting of deletions/duplications of one or several exons have been found throughout the gene with a large proportion occurring in the 5′ region from the promoter to exon 2. The aim of this study was to better characterize those LGR in French high-risk breast/ovarian cancer families. Methods: DNA from 20 families with one apparent duplication and nine deletions was analyzed with a dedicated comparative genomic hybridization (CGH) array, high-resolution BRCA1 Genomic Morse Codes analysis and Sanger sequencing. Results: The apparent duplication was in fact a tandem triplication of exons 1 and 2 and part of intron 2 of BRCA1, fully characterized here for the first time. We calculated a causality score with the multifactorial model from data obtained from six families, classifying this variant as benign. Among the nine deletions detected in this region, eight have never been identified. The breakpoints fell in six recurrent regions and could confirm some specific conformation of the chromatin. Conclusions: Taken together, our results firmly establish that the BRCA1 5′ region is a frequent site of different LGRs and highlight the importance of the segmental duplication and Alu sequences, particularly the very high homologous region, in the mechanism of a recombination event. This also confirmed that those events are not systematically deleterious.
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Affiliation(s)
- Sandrine M. Caputo
- Department of Genetics, Institut Curie, F-75248 Paris, France; (S.M.C.); (A.B.); (V.M.); (C.A.); (I.B.); (M.-H.S.); (D.S.-L.); (R.L.)
- Institut Curie, PSL Research University, F-75005 Paris, France
| | - Dominique Telly
- Laboratoire d’Oncogénétique, Institut Claudius Regaud, IUCT-O, F-31059 Toulouse, France;
| | - Adrien Briaux
- Department of Genetics, Institut Curie, F-75248 Paris, France; (S.M.C.); (A.B.); (V.M.); (C.A.); (I.B.); (M.-H.S.); (D.S.-L.); (R.L.)
- Institut Curie, PSL Research University, F-75005 Paris, France
| | - Julie Sesen
- Department of Neurosurgery, Boston Children’s Hospital, Boston, MA 02115, USA;
| | - Maurizio Ceppi
- Roche Innovation Center Basel (RICB), Roche Pharma Research and Early Development, CH-4052 Basel, Switzerland;
| | - Françoise Bonnet
- Laboratoire de Génétique Constitutionnelle et INSERM U916 VINCO, Institut Bergonié, CEDEX, F-33076 Bordeaux, France; (F.B.); (N.S.)
| | - Violaine Bourdon
- Laboratoire d’Oncogénétique Moléculaire, Département de Biologie du Cancer, Institut Paoli-Calmettes, F-13273 Marseille, France;
| | - Florence Coulet
- Department of Genetics, Pitié-Salpêtriere Hospital, Assistance Publique-Hopitaux de Paris, Sorbonne University, F-75013 Paris, France;
| | - Laurent Castera
- Laboratoire de Biologie et de Génétique du Cancer, CLCC François Baclesse, INSERM 1079 Centre Normand de Génomique et de Médecine Personnalisée, F-14076 Caen, France; (L.C.); (A.H.)
| | - Capucine Delnatte
- Service de Génétique Médicale, Unité de Génétique Moléculaire, CHU Nantes, F-44093 Nantes, France;
| | - Agnès Hardouin
- Laboratoire de Biologie et de Génétique du Cancer, CLCC François Baclesse, INSERM 1079 Centre Normand de Génomique et de Médecine Personnalisée, F-14076 Caen, France; (L.C.); (A.H.)
| | - Sylvie Mazoyer
- Centre de Recherche en Neurosciences de Lyon, INSERM, U1028, CNRS, UMR5292, Université de Lyon, F-69008 Lyon, France;
| | - Inès Schultz
- Centre Paul Strauss, Laboratoire de Biologie Tumorale—Oncogénétique, F-67000 Strasbourg, France;
| | - Nicolas Sevenet
- Laboratoire de Génétique Constitutionnelle et INSERM U916 VINCO, Institut Bergonié, CEDEX, F-33076 Bordeaux, France; (F.B.); (N.S.)
| | - Nancy Uhrhammer
- Biologie Clinique et Oncologique, Biologie Moléculaire—Centre Jean Perrin, F-63000 Clermont-Ferrand, France;
| | - Céline Bonnet
- Institut de Cancérologie, 6 Avenue de Bourgogne, F-54519 Vandœuvre-lès-Nancy, France;
| | - Anne-Françoise Tilkin-Mariamé
- Cancer Research Center of Toulouse (CRCT), Institut National de la Santé et de la Recherche Médicale (INSERM) UMR 1037, F-31000 Toulouse, France;
| | - Claude Houdayer
- Inserm U1245, UNIROUEN, Normandie University, Normandy Centre for Genomic and Personalized Medicine, F-76183 Rouen, France;
- Normandy Centre for Genomic and 41 Personalized Medicine, Department of Genetics, University Hospital, F-76183 Rouen, France
| | - Virginie Moncoutier
- Department of Genetics, Institut Curie, F-75248 Paris, France; (S.M.C.); (A.B.); (V.M.); (C.A.); (I.B.); (M.-H.S.); (D.S.-L.); (R.L.)
- Institut Curie, PSL Research University, F-75005 Paris, France
| | - Catherine Andrieu
- Department of Genetics, Institut Curie, F-75248 Paris, France; (S.M.C.); (A.B.); (V.M.); (C.A.); (I.B.); (M.-H.S.); (D.S.-L.); (R.L.)
- Institut Curie, PSL Research University, F-75005 Paris, France
| | | | - Ivan Bièche
- Department of Genetics, Institut Curie, F-75248 Paris, France; (S.M.C.); (A.B.); (V.M.); (C.A.); (I.B.); (M.-H.S.); (D.S.-L.); (R.L.)
- Faculty of Pharmaceutical and Biological Sciences, University of Paris, F-75006 Paris, France
| | - Marc-Henri Stern
- Department of Genetics, Institut Curie, F-75248 Paris, France; (S.M.C.); (A.B.); (V.M.); (C.A.); (I.B.); (M.-H.S.); (D.S.-L.); (R.L.)
- Institut Curie, INSERM U830, DNA Repair and Uveal Melanoma (D.R.U.M.), PSL Research University, F-75005 Paris, France
| | - Dominique Stoppa-Lyonnet
- Department of Genetics, Institut Curie, F-75248 Paris, France; (S.M.C.); (A.B.); (V.M.); (C.A.); (I.B.); (M.-H.S.); (D.S.-L.); (R.L.)
- Institut Curie, INSERM U830, DNA Repair and Uveal Melanoma (D.R.U.M.), PSL Research University, F-75005 Paris, France
- Faculty of Medicine, University of Paris, F-75005 Paris, France
| | - Rosette Lidereau
- Department of Genetics, Institut Curie, F-75248 Paris, France; (S.M.C.); (A.B.); (V.M.); (C.A.); (I.B.); (M.-H.S.); (D.S.-L.); (R.L.)
- Institut Curie, PSL Research University, F-75005 Paris, France
| | - Christine Toulas
- Laboratoire d’Oncogénétique, Institut Claudius Regaud, IUCT-O, F-31059 Toulouse, France;
- Correspondence: (C.T.); (E.R.)
| | - Etienne Rouleau
- Department of Biology, Gustave Roussy, Université Paris-Saclay, F-94805 Villejuif, France
- Correspondence: (C.T.); (E.R.)
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6
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Pócza T, Grolmusz VK, Papp J, Butz H, Patócs A, Bozsik A. Germline Structural Variations in Cancer Predisposition Genes. Front Genet 2021; 12:634217. [PMID: 33936164 PMCID: PMC8081352 DOI: 10.3389/fgene.2021.634217] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/27/2020] [Accepted: 03/08/2021] [Indexed: 12/14/2022] Open
Abstract
In addition to single nucleotide variations and small-scale indels, structural variations (SVs) also contribute to the genetic diversity of the genome. SVs, such as deletions, duplications, amplifications, or inversions may also affect coding regions of cancer-predisposing genes. These rearrangements may abrogate the open reading frame of these genes or adversely affect their expression and may thus act as germline mutations in hereditary cancer syndromes. With the capacity of disrupting the function of tumor suppressors, structural variations confer an increased risk of cancer and account for a remarkable fraction of heritability. The development of sequencing techniques enables the discovery of a constantly growing number of SVs of various types in cancer predisposition genes (CPGs). Here, we provide a comprehensive review of the landscape of germline SV types, detection methods, pathomechanisms, and frequency in CPGs, focusing on the two most common cancer syndromes: hereditary breast- and ovarian cancer and gastrointestinal cancers. Current knowledge about the possible molecular mechanisms driving to SVs is also summarized.
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Affiliation(s)
- Tímea Pócza
- Department of Molecular Genetics, National Institute of Oncology, Budapest, Hungary
| | - Vince Kornél Grolmusz
- Department of Molecular Genetics, National Institute of Oncology, Budapest, Hungary.,Hereditary Cancers Research Group, Hungarian Academy of Sciences, Semmelweis University, Budapest, Hungary
| | - János Papp
- Department of Molecular Genetics, National Institute of Oncology, Budapest, Hungary.,Hereditary Cancers Research Group, Hungarian Academy of Sciences, Semmelweis University, Budapest, Hungary
| | - Henriett Butz
- Department of Molecular Genetics, National Institute of Oncology, Budapest, Hungary.,Hereditary Cancers Research Group, Hungarian Academy of Sciences, Semmelweis University, Budapest, Hungary.,Department of Laboratory Medicine, Semmelweis University, Budapest, Hungary
| | - Attila Patócs
- Department of Molecular Genetics, National Institute of Oncology, Budapest, Hungary.,Hereditary Cancers Research Group, Hungarian Academy of Sciences, Semmelweis University, Budapest, Hungary.,Department of Laboratory Medicine, Semmelweis University, Budapest, Hungary
| | - Anikó Bozsik
- Department of Molecular Genetics, National Institute of Oncology, Budapest, Hungary.,Hereditary Cancers Research Group, Hungarian Academy of Sciences, Semmelweis University, Budapest, Hungary
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7
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Complex Characterization of Germline Large Genomic Rearrangements of the BRCA1 and BRCA2 Genes in High-Risk Breast Cancer Patients-Novel Variants from a Large National Center. Int J Mol Sci 2020; 21:ijms21134650. [PMID: 32629901 PMCID: PMC7370166 DOI: 10.3390/ijms21134650] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/20/2020] [Revised: 06/19/2020] [Accepted: 06/27/2020] [Indexed: 12/23/2022] Open
Abstract
Large genomic rearrangements (LGRs) affecting one or more exons of BRCA1 and BRCA2 constitute a significant part of the mutation spectrum of these genes. Since 2004, the National Institute of Oncology, Hungary, has been involved in screening for LGRs of breast or ovarian cancer families enrolled for genetic testing. LGRs were detected by multiplex ligation probe amplification method, or next-generation sequencing. Where it was possible, transcript-level characterization of LGRs was performed. Phenotype data were collected and analyzed too. Altogether 28 different types of LGRs in 51 probands were detected. Sixteen LGRs were novel. Forty-nine cases were deletions or duplications in BRCA1 and two affected BRCA2. Rearrangements accounted for 10% of the BRCA1 mutations. Three exon copy gains, two complex rearrangements, and 23 exon losses were characterized by exact breakpoint determinations. The inferred mechanisms for LGR formation were mainly end-joining repairs utilizing short direct homologies. Comparing phenotype features of the LGR-carriers to that of the non-LGR BRCA1 mutation carriers, revealed no significant differences. Our study is the largest comprehensive report of LGRs of BRCA1/2 in familial breast and ovarian cancer patients in the Middle and Eastern European region. Our data add novel insights to genetic interpretation associated to the LGRs.
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8
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van der Merwe NC, Oosthuizen J, Theron M, Chong G, Foulkes WD. The contribution of large genomic rearrangements in BRCA1 and BRCA2 to South African familial breast cancer. BMC Cancer 2020; 20:391. [PMID: 32375709 PMCID: PMC7203887 DOI: 10.1186/s12885-020-06917-y] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/06/2019] [Accepted: 04/30/2020] [Indexed: 12/15/2022] Open
Abstract
BACKGROUND Pathogenic variants that occur in the familial breast cancer genes (BRCA1/2) lead to truncated ineffective proteins in the majority of cases. These variants are mostly represented by small deletions/insertions, nonsense- and splice-site variants, although some larger pathogenic rearrangements occur. Currently, their contribution to familial breast cancer (BC) and ovarian cancer (OVC) in South Africa (SA) is unknown. METHODS Seven hundred and forty-four patients affected with BC or OVC were screened for larger genomic rearrangements (LGRs) by means of multiplex ligation-dependent probe amplification or Next Generation Sequencing using the Oncomine™ BRCA research assay. RESULTS The patients represented mostly medium to high-risk families, but also included lower risk patients without a family history of the disease, diagnosed at an early age of onset (< 40 years). Eight LGRs were detected (1.1%); seven in BRCA1 with a single whole gene deletion (WGD) detected for BRCA2. These eight LGRs accounted for 8.7% of the 92 BRCA1/2 pathogenic variants identified in the 744 cases. The pathogenic LGRs ranged from WGDs to the duplication of a single exon. CONCLUSIONS Larger rearrangements in BRCA1/2 contributed to the overall mutational burden of familial BC and OVC in SA. Almost a quarter of all pathogenic variants in BRCA1 were LGRs (7/30, 23%). The spectrum observed included two WGDs, one each for BRCA1 and BRCA2.
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Affiliation(s)
- Nerina C. van der Merwe
- Division of Human Genetics, Faculty of Health Sciences, University of the Free State, Bloemfontein, South Africa
- Division of Human Genetics, National Health Laboratory Services, Universitas Academic Hospital, Bloemfontein, South Africa
| | - Jaco Oosthuizen
- Division of Human Genetics, Faculty of Health Sciences, University of the Free State, Bloemfontein, South Africa
- Division of Human Genetics, National Health Laboratory Services, Universitas Academic Hospital, Bloemfontein, South Africa
| | - Magdalena Theron
- Division of Human Genetics, Faculty of Health Sciences, University of the Free State, Bloemfontein, South Africa
- Division of Human Genetics, National Health Laboratory Services, Universitas Academic Hospital, Bloemfontein, South Africa
| | - George Chong
- Lady Davis Institute and Segal Cancer Centre, Jewish General Hospital, Montréal, QC Canada
| | - William D. Foulkes
- Lady Davis Institute and Segal Cancer Centre, Jewish General Hospital, Montréal, QC Canada
- Research Institute of the McGill University Health Centre, Montréal, QC Canada
- Program in Cancer Genetics, Departments of Oncology and Human Genetics, McGill University, Montréal, QC Canada
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9
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Concolino P, Capoluongo E. Detection of BRCA1/2 large genomic rearrangements in breast and ovarian cancer patients: an overview of the current methods. Expert Rev Mol Diagn 2019; 19:795-802. [PMID: 31429350 DOI: 10.1080/14737159.2019.1657011] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/07/2023]
Abstract
Introduction: Currently, genetic testing of BRCA1/2 genes includes screening for single-nucleotide variants, small insertions/deletions, and copy number variations (CNVs). In fact, many studies document the involvement of BRCA1/2 gene rearrangements in genetic predisposition to breast and ovarian cancer. Large genomic rearrangements (LGRs) of BRCA1 may account for up to one-third of all disease-causing alterations in various populations, while LGRs in BRCA2 are less frequently observed. Areas covered: We aimed to present an overview of current technologies employed in molecular diagnosis of BRCA1/2 LGRs. The most relevant literature papers, showing the application of new strategies, were considered. Expert opinion: Currently, the progress of next-generation sequencing (NGS) technologies allows for the validation of new pipelines able to provide rapid and effective results, ensuring the sensitivity and specificity requested for the detection of BRCA1/2 LGRs. Multiplex ligation-dependent probe amplification remains the gold standard to confirm NGS CNVs results and to perform fast screening in families where a pathogenic rearrangement has been detected in a proband.
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Affiliation(s)
- Paola Concolino
- Dipartimento Scienze di Laboratorio e Infettivologiche, Fondazione Policlinico Universitario A. Gemelli - IRCCS , Roma , Italia
| | - Ettore Capoluongo
- Dipartimento di Medicina Molecolare e Biotecnologie Mediche, Università Federico II , Napoli , Italia
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10
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Richardson ME, Chong H, Mu W, Conner BR, Hsuan V, Willett S, Lam S, Tsai P, Pesaran T, Chamberlin AC, Park MS, Gray P, Karam R, Elliott A. DNA breakpoint assay reveals a majority of gross duplications occur in tandem reducing VUS classifications in breast cancer predisposition genes. Genet Med 2018; 21:683-693. [PMID: 30054569 PMCID: PMC6752314 DOI: 10.1038/s41436-018-0092-7] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/07/2018] [Accepted: 06/04/2018] [Indexed: 01/17/2023] Open
Abstract
PURPOSE Gross duplications are ambiguous in terms of clinical interpretation due to the limitations of the detection methods that cannot infer their context, namely, whether they occur in tandem or are duplicated and inserted elsewhere in the genome. We investigated the proportion of gross duplications occurring in tandem in breast cancer predisposition genes with the intent of informing their classifications. METHODS The DNA breakpoint assay (DBA) is a custom, paired-end, next-generation sequencing (NGS) method designed to capture and detect deep-intronic DNA breakpoints in gross duplications in BRCA1, BRCA2, ATM, CDH1, PALB2, and CHEK2. RESULTS DBA allowed us to ascertain breakpoints for 44 unique gross duplications from 147 probands. We determined that the duplications occurred in tandem in 114 (78%) carriers from this cohort, while the remainder have unknown tandem status. Among the tandem gross duplications that were eligible for reclassification, 95% of them were upgraded to pathogenic. CONCLUSION DBA is a novel, high-throughput, NGS-based method that informs the tandem status, and thereby the classification of, gross duplications. This method revealed that most gross duplications in the investigated genes occurred in tandem and resulted in a pathogenic classification, which helps to secure the necessary treatment options for their carriers.
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Affiliation(s)
- Marcy E Richardson
- Department of Clinical Genomics, Ambry Genetics, 15 Argonaut Drive, Aliso Viejo, California, 92656, USA.
| | - Hansook Chong
- Department of Clinical Genomics, Ambry Genetics, 15 Argonaut Drive, Aliso Viejo, California, 92656, USA
| | - Wenbo Mu
- Department of Clinical Genomics, Ambry Genetics, 15 Argonaut Drive, Aliso Viejo, California, 92656, USA
| | - Blair R Conner
- Department of Clinical Genomics, Ambry Genetics, 15 Argonaut Drive, Aliso Viejo, California, 92656, USA
| | - Vickie Hsuan
- Department of Clinical Genomics, Ambry Genetics, 15 Argonaut Drive, Aliso Viejo, California, 92656, USA
| | - Sara Willett
- Department of Clinical Genomics, Ambry Genetics, 15 Argonaut Drive, Aliso Viejo, California, 92656, USA
| | - Stephanie Lam
- Department of Clinical Genomics, Ambry Genetics, 15 Argonaut Drive, Aliso Viejo, California, 92656, USA
| | - Pei Tsai
- Department of Clinical Genomics, Ambry Genetics, 15 Argonaut Drive, Aliso Viejo, California, 92656, USA
| | - Tina Pesaran
- Department of Clinical Genomics, Ambry Genetics, 15 Argonaut Drive, Aliso Viejo, California, 92656, USA
| | - Adam C Chamberlin
- Department of Clinical Genomics, Ambry Genetics, 15 Argonaut Drive, Aliso Viejo, California, 92656, USA
| | - Min-Sun Park
- Department of Clinical Genomics, Ambry Genetics, 15 Argonaut Drive, Aliso Viejo, California, 92656, USA
| | - Phillip Gray
- Department of Clinical Genomics, Ambry Genetics, 15 Argonaut Drive, Aliso Viejo, California, 92656, USA
| | - Rachid Karam
- Department of Clinical Genomics, Ambry Genetics, 15 Argonaut Drive, Aliso Viejo, California, 92656, USA
| | - Aaron Elliott
- Department of Clinical Genomics, Ambry Genetics, 15 Argonaut Drive, Aliso Viejo, California, 92656, USA
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11
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Torres D, Bermejo JL, Rashid MU, Briceño I, Gil F, Beltran A, Ariza V, Hamann U. Prevalence and Penetrance of BRCA1 and BRCA2 Germline Mutations in Colombian Breast Cancer Patients. Sci Rep 2017; 7:4713. [PMID: 28680148 PMCID: PMC5498630 DOI: 10.1038/s41598-017-05056-y] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/28/2017] [Accepted: 05/23/2017] [Indexed: 12/01/2022] Open
Abstract
Pathogenic BRCA1/2 germline mutations confer high risks of breast and ovarian cancer to women of European ancestry. Characterization of BRCA1/2 mutations in other ethnic groups is also medically important. We comprehensively screened 68 Colombian breast/ovarian cancer families for small-range mutations, 221 families for large-genomic rearrangements, and 1,022 unselected breast cancer cases for Colombian founder mutations in BRCA1/2. The risk of cancer among relatives of mutation carriers and the mutation penetrance were estimated by survival analysis. Identified BRCA2 mutations included 6310delGA and the recurrent 1991del4 mutations. A novel large BRCA2 deletion was found in 0.9% of the screened families. Among unselected breast cancer cases, 3.3% tested positive for BRCA1/3450del4, 2.2% for BRCA1/A1708E, 1.1% for BRCA2/3034del4, and 0.4% for BRCA2/1991del4. Female relatives of carriers of BRCA1/2 founder mutations showed a 5.90 times higher risk of breast cancer, when the woman herself carried a BRCA1 mutation compared to a non-carrier (95% CI 2.01–17.3). The estimated cumulative risk of breast cancer by age 70 years for BRCA1 mutations carriers was 14% (95% CI 5–38) compared to 3% for the general Colombian population (relative risk of breast cancer 4.05). Together with known founder mutations, reported novel variants may ease a cost-effective BRCA1/2 screening in women with Colombian ancestry.
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Affiliation(s)
- D Torres
- Molecular Genetics of Breast Cancer, German Cancer Research Center (DKFZ), Heidelberg, Germany.,Institute of Human Genetics, Pontificia Universidad Javeriana, Bogota, Colombia
| | - J Lorenzo Bermejo
- Institute of Medical Biometry and Informatics, University of Heidelberg, Heidelberg, Germany
| | - M U Rashid
- Molecular Genetics of Breast Cancer, German Cancer Research Center (DKFZ), Heidelberg, Germany.,Department of Basic Sciences Research, Shaukat Khanum Memorial Cancer Hospital and Research Centre (SKMCH & RC), Lahore, Pakistan
| | - I Briceño
- Institute of Human Genetics, Pontificia Universidad Javeriana, Bogota, Colombia.,Universidad de la Sabana, Bogota, Colombia
| | - F Gil
- Unit of Clinical Epidemiology and Biostatistics, Pontificia Universidad Javeriana, Bogota, Colombia
| | - A Beltran
- Universidad Nacional, Bogota, Colombia
| | - V Ariza
- Universidad Nacional, Bogota, Colombia
| | - U Hamann
- Molecular Genetics of Breast Cancer, German Cancer Research Center (DKFZ), Heidelberg, Germany.
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12
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Cruz-Correa M, Pérez-Mayoral J, Dutil J, Echenique M, Mosquera R, Rivera-Román K, Umpierre S, Rodriguez-Quilichini S, Gonzalez-Pons M, Olivera MI, Pardo S. Hereditary cancer syndromes in Latino populations: genetic characterization and surveillance guidelines. Hered Cancer Clin Pract 2017; 15:3. [PMID: 28127413 PMCID: PMC5251307 DOI: 10.1186/s13053-017-0063-z] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/02/2016] [Accepted: 01/05/2017] [Indexed: 12/17/2022] Open
Abstract
Hereditary cancer predisposition syndromes comprise approximately 10% of diagnosed cancers; however, familial forms are believed to account for up to 30% of some cancers. In Hispanics, the most commonly diagnosed hereditary cancers include colorectal cancer syndromes such as, Lynch Syndrome, Familial Adenomatous Polyposis, and hereditary breast and ovarian cancer syndromes. Although the incidence of hereditary cancers is low, patients diagnosed with hereditary cancer syndromes are at high-risk for developing secondary cancers. Furthermore, the productivity loss that occurs after cancer diagnosis in these high-risk patients has a negative socio-economic impact. This review summarizes the genetic basis, phenotype characteristics, and the National Comprehensive Cancer Network's screening, testing, and surveillance guidelines for the leading hereditary cancer syndromes. The aim of this review is to promote a better understanding of cancer genetics and genetic testing in Hispanic patients.
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Affiliation(s)
- Marcia Cruz-Correa
- Department of Cancer Biology, University of Puerto Rico Comprehensive Cancer Center, San Juan, PR USA
- University of Puerto Rico Medical Sciences Campus, School of Medicine, San Juan, PR USA
- University of Puerto Rico Comprehensive Cancer Center, PMB711 Ave. De Diego 89 Ste. 105, San Juan, PR 00927-6346 USA
| | - Julyann Pérez-Mayoral
- Department of Cancer Biology, University of Puerto Rico Comprehensive Cancer Center, San Juan, PR USA
- University of Puerto Rico Medical Sciences Campus, School of Medicine, San Juan, PR USA
| | - Julie Dutil
- Ponce Health Sciences University, Ponce Research Institute, Ponce, PR USA
| | | | | | - Keila Rivera-Román
- Department of Pediatrics, University of Puerto Rico School of Medicine, San Juan, PR USA
| | - Sharee Umpierre
- Department of Cancer Biology, University of Puerto Rico Comprehensive Cancer Center, San Juan, PR USA
| | | | - Maria Gonzalez-Pons
- Department of Cancer Biology, University of Puerto Rico Comprehensive Cancer Center, San Juan, PR USA
- University of Puerto Rico Medical Sciences Campus, School of Medicine, San Juan, PR USA
| | - Myrta I. Olivera
- Department of Cancer Biology, University of Puerto Rico Comprehensive Cancer Center, San Juan, PR USA
- University of Puerto Rico Medical Sciences Campus, School of Medicine, San Juan, PR USA
| | - Sherly Pardo
- Department of Pathology, University of Puerto Rico School of Medicine, San Juan, PR USA
| | - on behalf of the Puerto Rico Clinical Cancer Genetics Consortia
- Department of Cancer Biology, University of Puerto Rico Comprehensive Cancer Center, San Juan, PR USA
- University of Puerto Rico Medical Sciences Campus, School of Medicine, San Juan, PR USA
- Ponce Health Sciences University, Ponce Research Institute, Ponce, PR USA
- Cancer Center, Auxilio Mutuo Hospital, San Juan, PR USA
- Puerto Rico Gastroenterology Association, San Juan, PR USA
- Department of Pediatrics, University of Puerto Rico School of Medicine, San Juan, PR USA
- Department of Pathology, University of Puerto Rico School of Medicine, San Juan, PR USA
- University of Puerto Rico Comprehensive Cancer Center, PMB711 Ave. De Diego 89 Ste. 105, San Juan, PR 00927-6346 USA
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13
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Contribution of BRCA1 large genomic rearrangements to early-onset and familial breast/ovarian cancer in Pakistan. Breast Cancer Res Treat 2016; 161:191-201. [PMID: 27826754 DOI: 10.1007/s10549-016-4044-0] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/07/2016] [Accepted: 11/01/2016] [Indexed: 10/20/2022]
Abstract
BACKGROUND Germline mutations in BRCA1 and BRCA2 (BRCA1/2) account for the majority of hereditary breast and/or ovarian cancers. Pakistan has one of the highest rates of breast cancer incidence in Asia, where BRCA1/2 small-range mutations account for 17% of early-onset and familial breast/ovarian cancer patients. We report the first study from Pakistan evaluating the prevalence of BRCA1/2 large genomic rearrangements (LGRs) in breast and/or ovarian cancer patients who do not harbor small-range BRCA1/2 mutations. MATERIALS AND METHODS Both BRCA1/2 genes were comprehensively screened for LGRs using multiplex ligation-dependent probe amplification in 120 BRCA1/2 small-range mutations negative early-onset or familial breast/ovarian cancer patients from Pakistan (Group 1). The breakpoints were characterized by long-range PCR- and DNA-sequencing analyses. An additional cohort of 445 BRCA1/2 negative high-risk patients (Group 2) was analyzed for the presence of LGRs identified in Group 1. RESULTS Three different BRCA1 LGRs were identified in Group 1 (4/120; 3.3%), two of these were novel. Exon 1-2 deletion was observed in two unrelated patients: an early-onset breast cancer patient and another bilateral breast cancer patient from a hereditary breast cancer (HBC) family. Novel exon 20-21 deletion was detected in a 29-year-old breast cancer patient from a HBC family. Another novel exon 21-24 deletion was identified in a breast-ovarian cancer patient from a hereditary breast and ovarian cancer family. The breakpoints of all deletions were characterized. Screening of the 445 patients in Group 2 for the three LGRs revealed ten additional patients harboring exon 1-2 deletion or exon 21-24 deletion (10/445; 2.2%). No BRCA2 LGRs were identified. CONCLUSIONS LGRs in BRCA1 are found with a considerable frequency in Pakistani breast/ovarian cancer cases. Our findings suggest that BRCA1 exons 1-2 deletion and exons 21-24 deletion should be included in the recurrent BRCA1/2 mutations panel for genetic testing of high-risk Pakistani breast/ovarian cancer patients.
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14
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Abstract
Increased demand for BRCA testing is placing pressures on diagnostic laboratories to raise their mutation screening capacity and handle the challenges associated with classifying BRCA sequence variants for clinical significance, for example interpretation of pathogenic mutations or variants of unknown significance, accurate determination of large genomic rearrangements and detection of somatic mutations in DNA extracted from formalin-fixed, paraffin-embedded tumour samples. Many diagnostic laboratories are adopting next-generation sequencing (NGS) technology to increase their screening capacity and reduce processing time and unit costs. However, migration to NGS introduces complexities arising from choice of components of the BRCA testing workflow, such as NGS platform, enrichment method and bioinformatics analysis process. An efficient, cost-effective accurate mutation detection strategy and a standardised, systematic approach to the reporting of BRCA test results is imperative for diagnostic laboratories. This review covers the challenges of BRCA testing from the perspective of a diagnostics laboratory.
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Affiliation(s)
- Andrew J Wallace
- Genomic Diagnostics Laboratory, Manchester Centre for Genomic Medicine, St Mary's Hospital, Manchester, UK
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15
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Kwong A, Chen J, Shin VY, Ho JCW, Law FBF, Au CH, Chan TL, Ma ESK, Ford JM. The importance of analysis of long-range rearrangement of BRCA1 and BRCA2 in genetic diagnosis of familial breast cancer. Cancer Genet 2015; 208:448-54. [PMID: 26271414 DOI: 10.1016/j.cancergen.2015.05.031] [Citation(s) in RCA: 39] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/20/2015] [Revised: 05/11/2015] [Accepted: 05/12/2015] [Indexed: 12/30/2022]
Abstract
Germline BRCA gene mutations are reportedly associated with hereditary breast and ovarian cancers. Identification of BRCA mutations greatly improves the preventive strategies and management of breast cancer. Sanger sequencing has been the gold standard in identifying these mutations. However, 4-28% of inherited BRCA mutations may be due to large genomic rearrangements (LGRs), which could be missed by using Sanger sequencing alone. Our aim is to evaluate the pick-up rate of LGRs in our cohort. A total of 1,236 clinically high-risk patients with breast and/or ovarian cancers were recruited through The Hong Kong Hereditary Breast Cancer Family Registry from 2007 to 2014. Full gene sequencing (either Sanger or next generation sequencing) and multiplex ligation-dependent probe amplification (MLPA) were performed. We identified 120 deleterious BRCA mutations: 57 (4.61%) were in BRCA1 and 63 (5.10%) were in BRCA2. LGRs accounted for 6.67% (8 of 120) of all BRCA mutations, whereas 8.77 % (5 of 57) were BRCA1 mutations and 4.76% (3 of 63) were BRCA2 mutations. Through this integrated approach, both small nucleotide variations and LGRs could be detected. We suggest that MLPA should be incorporated into the standard practice for genetic testing to avoid false-negative results, which would greatly affect the management of these high-risk families.
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Affiliation(s)
- Ava Kwong
- Department of Surgery, The University of Hong Kong, Hong Kong SAR, China; Hong Kong Hereditary Breast Cancer Family Registry, Hong Kong Sanatorium and Hospital, Hong Kong SAR, China; Department of Oncology, Stanford University School of Medicine, Stanford, California, USA; Department of Surgery, Hong Kong Sanatorium and Hospital, Hong Kong SAR, China.
| | - Jiawei Chen
- Department of Surgery, The University of Hong Kong, Hong Kong SAR, China
| | - Vivian Y Shin
- Department of Surgery, The University of Hong Kong, Hong Kong SAR, China
| | - John C W Ho
- Department of Surgery, The University of Hong Kong, Hong Kong SAR, China; Department of Molecular Pathology, Hong Kong Sanatorium and Hospital, Hong Kong SAR, China
| | - Fian B F Law
- Hong Kong Hereditary Breast Cancer Family Registry, Hong Kong Sanatorium and Hospital, Hong Kong SAR, China; Department of Molecular Pathology, Hong Kong Sanatorium and Hospital, Hong Kong SAR, China
| | - Chun Hang Au
- Department of Molecular Pathology, Hong Kong Sanatorium and Hospital, Hong Kong SAR, China
| | - Tsun-Leung Chan
- Hong Kong Hereditary Breast Cancer Family Registry, Hong Kong Sanatorium and Hospital, Hong Kong SAR, China; Department of Molecular Pathology, Hong Kong Sanatorium and Hospital, Hong Kong SAR, China
| | - Edmond S K Ma
- Hong Kong Hereditary Breast Cancer Family Registry, Hong Kong Sanatorium and Hospital, Hong Kong SAR, China; Department of Molecular Pathology, Hong Kong Sanatorium and Hospital, Hong Kong SAR, China
| | - James M Ford
- Department of Oncology, Stanford University School of Medicine, Stanford, California, USA
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