1
|
Jayasekera LP, Ranasinghe R, Senathilake KS, Kotelawala JT, de Silva K, Abeygunasekara PH, Goonesinghe R, Tennekoon KH. Mitochondrial genome in sporadic breast cancer: A case control study and a proteomic analysis in a Sinhalese cohort from Sri Lanka. PLoS One 2023; 18:e0281620. [PMID: 36758048 PMCID: PMC9910733 DOI: 10.1371/journal.pone.0281620] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/22/2022] [Accepted: 01/27/2023] [Indexed: 02/10/2023] Open
Abstract
Breast cancer is the commonest malignancy in women and the majority occurs sporadically with no hereditary predisposition. However, sporadic breast cancer has been studied less intensively than the hereditary form and to date hardly any predictive biomarkers exist for the former. Furthermore, although mitochondrial DNA variants have been reported to be associated with breast cancer, findings have been inconsistent across populations. Thus we carried out a case control study on sporadic breast cancer patients and healthy controls of Sinhalese ethnicity (N = 60 matched pairs) in order to characterize coding region variants associated with the disease and to identify any potential biomarkers. Mitochondrial genome was fully sequenced in 30 pairs and selected regions were sequenced in the remaining 30 pairs. Several in-silico tools were used to assess functional significance of the variants observed. A number of variants were identified among the patients and the controls. Missense variants identified were either polymorphisms or rare variants. Their prevalence did not significantly differ between patients and the healthy controls (matched for age, body mass index and menopausal status). MT-CYB, MT-ATP6 and MT-ND2 genes showed a higher mutation rate. A higher proportion of pre-menopausal patients carried missense and pathogenic variants. Unique combinations of missense variants were seen within genes and these occurred mostly in MT-ATP6 and MT-CYB genes. Such unique combinations that occurred exclusively among the patients were common in obese patients. Mitochondrial DNA variants may have a role in breast carcinogenesis in obesity and pre-menopause. Molecular dynamic simulations suggested the mutants, G78S in MT-CO3 gene and T146A in MT-ATP6 gene are likely to be more stable than their wild type counterparts.
Collapse
Affiliation(s)
- Lakshika P. Jayasekera
- Institute of Biochemistry, Molecular Biology and Biotechnology, University of Colombo, Colombo, Sri Lanka
| | - Ruwandi Ranasinghe
- Institute of Biochemistry, Molecular Biology and Biotechnology, University of Colombo, Colombo, Sri Lanka
| | - Kanishka S. Senathilake
- Institute of Biochemistry, Molecular Biology and Biotechnology, University of Colombo, Colombo, Sri Lanka
| | - Joanne T. Kotelawala
- Institute of Biochemistry, Molecular Biology and Biotechnology, University of Colombo, Colombo, Sri Lanka
| | | | | | | | - Kamani H. Tennekoon
- Institute of Biochemistry, Molecular Biology and Biotechnology, University of Colombo, Colombo, Sri Lanka
| |
Collapse
|
2
|
Kharel S, Shrestha S, Yadav S, Shakya P, Baidya S, Hirachan S. BRCA1/ BRCA2 mutation spectrum analysis in South Asia: a systematic review. J Int Med Res 2022; 50:3000605211070757. [PMID: 35000471 PMCID: PMC8753086 DOI: 10.1177/03000605211070757] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022] Open
Abstract
Objective Breast cancer (BC) is the most common form of cancer among Asian females. Mutations in the BRCA1/BRCA2 genes are often observed in BC cases and largely increase the lifetime risk of having BC. Because of the paucity of high-quality data on the molecular spectrum of BRCA mutations in South Asian populations, we aimed to explore these mutations among South Asian countries. Methods A systematic literature search was performed for the BRCA1 and BRCA2 gene mutation spectrum using electronic databases such as PubMed, EMBASE, and Google Scholar. Twenty studies were selected based on specific inclusion and exclusion criteria. Results The 185delAG (c.68_69del) mutation in exon 2 of BRCA1 was the most common recurrent mutation and founder mutation found. Various intronic variants, variants of unknown significance, large genomic rearrangements, and polymorphisms were also described in some studies. Conclusions The South Asian population has a wide variety of genetic mutations of BRCA1 and BRCA2 that differ according to countries and ethnicities. A stronger knowledge of various population-specific mutations in these cancer susceptibility genes can help provide efficient strategies for genetic testing.
Collapse
Affiliation(s)
- Sanjeev Kharel
- Maharajgunj Medical Campus, Institute of Medicine, Kathmandu, Nepal
| | - Suraj Shrestha
- Maharajgunj Medical Campus, Institute of Medicine, Kathmandu, Nepal
| | | | - Prafulla Shakya
- Department of Surgery, National Cancer Hospital and Research Center, Harisiddhi, Lalitpur, Nepal
| | - Sujita Baidya
- Kathmandu University School of Medical Sciences, Panauti, Nepal
| | - Suzita Hirachan
- Department of Surgery, Tribhuvan University Teaching Hospital, Kathmandu, Nepal
| |
Collapse
|
3
|
Kim HN, Shin MH, Lee R, Park MH, Kweon SS. Novel Germline Mutations of BRCA1 and BRCA2 in Korean Familial Breast Cancer Patients. Chonnam Med J 2019; 55:99-103. [PMID: 31161121 PMCID: PMC6536435 DOI: 10.4068/cmj.2019.55.2.99] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/23/2019] [Revised: 05/03/2019] [Accepted: 05/07/2019] [Indexed: 12/03/2022] Open
Abstract
Breast cancer is the second most common cancer in Korean women. Germline mutations in the BRCA1 and BRCA2 genes cause hereditary breast cancer and are detected in 15–20% of hereditary breast cancer. We investigated the BRCA1 and BRCA2 mutations in 114 familial breast cancer patients using next-generation sequencing. We confirmed 20 different mutations of BRCA1 and BRCA2 in 25 subjects (21.9%). Two such mutations in eight patients were novel (not reported in any variant database or previous study). Six mutations have been reported as disease-causing mutations in public databases. Seven mutations were found only in a single nucleotide polymorphism database and one mutation has been reported in Korea. The BRCA1/2 mutation frequency was similar to that of other studies on familial breast cancer patients in the Korean population. Further studies should examine more cases and mutations of whole exons.
Collapse
Affiliation(s)
- Hee Nam Kim
- Department of Preventive Medicine, Chonnam National University Medical School, Hwasun, Korea
| | - Min-Ho Shin
- Department of Preventive Medicine, Chonnam National University Medical School, Hwasun, Korea
| | - Ran Lee
- Department of Preventive Medicine, Chonnam National University Medical School, Hwasun, Korea
| | - Min-Ho Park
- Department of Surgery, Chonnam National University Medical School, Hwasun, Korea
| | - Sun-Seog Kweon
- Department of Preventive Medicine, Chonnam National University Medical School, Hwasun, Korea.,Jeonnam Regional Cancer Center, Chonnam National University Hwasun Hospital, Hwasun, Korea
| |
Collapse
|
4
|
Sirisena ND, Adeyemo A, Kuruppu AI, Neththikumara N, Samaranayake N, Dissanayake VHW. Genetic determinants of sporadic breast cancer in Sri Lankan women. BMC Cancer 2018; 18:180. [PMID: 29433565 PMCID: PMC5809862 DOI: 10.1186/s12885-018-4112-4] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/07/2017] [Accepted: 02/09/2018] [Indexed: 11/25/2022] Open
Abstract
Background While a range of common genetic variants have been identified to be associated with risk of sporadic breast cancer in several Western studies, little is known about their role in South Asian populations. Our objective was to examine the association between common genetic variants in breast cancer related genes and risk of breast cancer in a cohort of Sri Lankan women. Methods A case-control study of 350 postmenopausal women with breast cancer and 350 healthy postmenopausal women was conducted. Genotyping using the iPLEX GOLD assay was done for 56 haplotype-tagging single nucleotide polymorphisms (SNPs) in 36 breast cancer related genes. Testing for association was done using an additive genetic model. Odds ratios and 95% confidence intervals were calculated using adjusted logistic regression models. Results Four SNPs [rs3218550 (XRCC2), rs6917 (PHB), rs1801516 (ATM), and rs13689 (CDH1)] were significantly associated with risk of breast cancer. The rs3218550 T allele and rs6917 A allele increased breast cancer risk by 1.5-fold and 1.4-fold, respectively. The CTC haplotype defined by the SNPs rs3218552|rs3218550|rs3218536 on chromosome 7 (P = 0.0088) and the CA haplotype defined by the SNPs rs1049620|rs6917 on chromosome 17 (P = 0.0067) were significantly associated with increased risk of breast cancer. The rs1801516 A allele and the rs13689 C allele decreased breast cancer risk by 0.6-fold and 0.7-fold, respectively. Conclusions These findings suggest that common genetic polymorphisms in the XRCC2, PHB, CDH1 and ATM genes are associated with risk of breast cancer among Sri Lankan postmenopausal women. The exact biological mechanisms of how these variants regulate overall breast cancer risk need further evaluation using functional studies. Electronic supplementary material The online version of this article (10.1186/s12885-018-4112-4) contains supplementary material, which is available to authorized users.
Collapse
Affiliation(s)
| | - Adebowale Adeyemo
- Center for Research on Genomics and Global Health, National Human Genome Research Institute, Bethesda, MD, USA
| | - Anchala I Kuruppu
- Human Genetics Unit, Faculty of Medicine, University of Colombo, Kynsey Road, Colombo 8, Sri Lanka
| | - Nilaksha Neththikumara
- Human Genetics Unit, Faculty of Medicine, University of Colombo, Kynsey Road, Colombo 8, Sri Lanka
| | - Nilakshi Samaranayake
- Department of Parasitology, Faculty of Medicine, University of Colombo, Colombo, Sri Lanka
| | - Vajira H W Dissanayake
- Human Genetics Unit, Faculty of Medicine, University of Colombo, Kynsey Road, Colombo 8, Sri Lanka
| |
Collapse
|
5
|
De Silva S, Tennekoon KH, Dissanayake A, De Silva K, Jayasekara L. Novel and reported pathogenic variants in exon 11 of BRCA2 gene in a cohort of Sri Lankan young breast cancer patients. Fam Cancer 2018; 16:329-338. [PMID: 28039656 DOI: 10.1007/s10689-016-9962-9] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
Women with breast carcinoma diagnosed before 40 years of age with a strong familial risk have a greater prevalence of germline BRCA1 or BRCA2 variants than late onset breast cancer. Previously germline variants in BRCA1 and BRCA2 genes were characterized in a cohort of Sri Lankan breast cancer patients unselected for age of onset. This study focused on young breast cancer patients who were screened for previously identified hotspot regions in BRCA2 gene. A total of 48 young breast cancer patients with family history of cancer and 25 healthy controls were studied. Direct sequencing was used to detect pathogenic and other sequence variants in the hotspot regions of BRCA2 gene. Thirty-six sequence variants including seven pathogenic (c.2411_2412delAA/p.Glu804Valfs*2, c.2500_2501insG/p.Leu834Cysfs*4, c.3881T>G/p.Leu1294*, c.4768A>T/p.Lys1590*, c.5645C>G/p.Ser1882*, c.5747delC/p.His1916Phefs*3, c.6728C>T/p.Ser2243Phe) and two likely pathogenic (c.1922C>T and c.3378A>T) variants, two intronic variants of unknown significance (c.1910-74T>C, c.1910-51G>T), two variants of uncertain significance (c.2324C>T c.5104C>T) and 23 benign variants were detected. Among them, seven were novel (pathogenic 5 and likely pathogenic 2). Prevalence of pathogenic and likely pathogenic variants in the hotspots regions of BRCA2 was 23 and 6.3 % respectively in this cohort. This justifies BRCA2 variant testing in young breast cancer patients with family history of cancer in Sri Lanka.
Collapse
Affiliation(s)
- Sumadee De Silva
- Institute of Biochemistry, Molecular Biology and Biotechnology, University of Colombo, 90, Cumaratunga Munidasa Mawatha, Colombo, 00300, Sri Lanka.
| | - Kamani Hemamala Tennekoon
- Institute of Biochemistry, Molecular Biology and Biotechnology, University of Colombo, 90, Cumaratunga Munidasa Mawatha, Colombo, 00300, Sri Lanka
| | - Aravinda Dissanayake
- National Cancer Research, Maharagama, Sri Lanka.,Teaching Hospital Jaffna, Jaffna, Sri Lanka
| | | | - Lakshika Jayasekara
- Institute of Biochemistry, Molecular Biology and Biotechnology, University of Colombo, 90, Cumaratunga Munidasa Mawatha, Colombo, 00300, Sri Lanka
| |
Collapse
|
6
|
Sharma B, Preet Kaur R, Raut S, Munshi A. BRCA1 mutation spectrum, functions, and therapeutic strategies: The story so far. Curr Probl Cancer 2018; 42:189-207. [PMID: 29452958 DOI: 10.1016/j.currproblcancer.2018.01.001] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/14/2017] [Revised: 12/19/2017] [Accepted: 01/04/2018] [Indexed: 02/07/2023]
Abstract
BRCA1 gene mutations account for about 25-28% of hereditary Breast Cancer as BRCA1 is included in the category of high penetrance genes. Except for few commonmutations, there is a heterogenous spectrum of BRCA1 mutations in various ethnic groups. 185AGdel and 5382ins Care the most common BRCA1 alterations (founder mutations) which have been identified in most of the population. This review has been compiled with an aim to consolidate the information on genetic variants reported in BRCA1 found in various ethnic groups, their functional implications if known; involvement of BRCA1 in various cellular pathways/processes and potential BRCA1 targeted therapies. The pathological variations of BRCA1 vary among different ethical groups. A systematic search in PubMed and Google scholar for the literature on BRCA1 gene was carried out to figure out structure and function of BRCA1 gene. BRCA1 is a large protein having 1863 amino acids with multiple functional domains and interacts with multiple proteins to carry out various crucial cellular processes. BRCA1 plays a major role in maintaining genome integrity, transcription regulation, chromatin remodeling, cell cycle checkpoint control, DNA damage repair, chromosomal segregation, and apoptosis. Studies investigating the phenotypic response of mutant BRCA1 protein and comparing it to wildtype BRCA1 protein are clinically important as they are involved in homologous recombination and other repair mechanisms. These studies may help in developing more targetted therapies, detecting novel interacting partners, identification of new signaling pathways that BRCA1 is a part of or downstream target genes that BRCA1 affects.
Collapse
Affiliation(s)
- Babita Sharma
- Department of Human Genetics and Molecular Medicine, Central University of Punjab, Bathinda, Punjab, India
| | - Raman Preet Kaur
- Department of Human Genetics and Molecular Medicine, Central University of Punjab, Bathinda, Punjab, India
| | - Sonali Raut
- Department of Human Genetics and Molecular Medicine, Central University of Punjab, Bathinda, Punjab, India
| | - Anjana Munshi
- Department of Human Genetics and Molecular Medicine, Central University of Punjab, Bathinda, Punjab, India.
| |
Collapse
|
7
|
Kwong A, Shin VY, Ho JCW, Kang E, Nakamura S, Teo SH, Lee ASG, Sng JH, Ginsburg OM, Kurian AW, Weitzel JN, Siu MT, Law FBF, Chan TL, Narod SA, Ford JM, Ma ESK, Kim SW. Comprehensive spectrum of BRCA1 and BRCA2 deleterious mutations in breast cancer in Asian countries. J Med Genet 2015; 53:15-23. [PMID: 26187060 DOI: 10.1136/jmedgenet-2015-103132] [Citation(s) in RCA: 64] [Impact Index Per Article: 7.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/16/2015] [Accepted: 07/02/2015] [Indexed: 12/20/2022]
Abstract
Approximately 5%-10% of breast cancers are due to genetic predisposition caused by germline mutations; the most commonly tested genes are BRCA1 and BRCA2 mutations. Some mutations are unique to one family and others are recurrent; the spectrum of BRCA1/BRCA2 mutations varies depending on the geographical origins, populations or ethnic groups. In this review, we compiled data from 11 participating Asian countries (Bangladesh, Mainland China, Hong Kong SAR, Indonesia, Japan, Korea, Malaysia, Philippines, Singapore, Thailand and Vietnam), and from ethnic Asians residing in Canada and the USA. We have additionally conducted a literature review to include other Asian countries mainly in Central and Western Asia. We present the current pathogenic mutation spectrum of BRCA1/BRCA2 genes in patients with breast cancer in various Asian populations. Understanding BRCA1/BRCA2 mutations in Asians will help provide better risk assessment and clinical management of breast cancer.
Collapse
Affiliation(s)
- Ava Kwong
- Department of Surgery, The University of Hong Kong, Hong Kong, Hong Kong Hong Kong Hereditary Breast Cancer Family Registry, Hong Kong, Hong Kong Departments of Medicine (Oncology) and Genetics, Stanford University School of Medicine, Stanford, California, USA Department of Surgery, Hong Kong Sanatorium & Hospital, Hong Kong, Hong Kong
| | - Vivian Y Shin
- Department of Surgery, The University of Hong Kong, Hong Kong, Hong Kong
| | - John C W Ho
- Department of Surgery, The University of Hong Kong, Hong Kong, Hong Kong Department of Molecular Pathology, Hong Kong Sanatorium & Hospital, Hong Kong, Hong Kong
| | - Eunyoung Kang
- Department of Surgery, Seoul National University Bundang Hospital, Seoul National University College of Medicine, Seongnam, Korea
| | - Seigo Nakamura
- Department of Surgery, Division of Breast Surgical Oncology, Showa University School of Medicine, Tokyo, Japan
| | - Soo-Hwang Teo
- Cancer Research Initiatives Foundation, Sime Darby Medical Centre, Subang Jaya, Selangor, Malaysia Faculty of Medicine, University Malaya Cancer Research Institute, University Malaya, Subang Jaya, Malaysia
| | - Ann S G Lee
- Division of Medical Sciences, National Cancer Centre, Singapore, Singapore Department of Physiology, Yong Loo Lin School of Medicine, National University of Singapore, Singapore, Singapore Office of Clinical & Academic Faculty Affairs, Duke-NUS Graduate Medical School, Singapore, Singapore
| | - Jen-Hwei Sng
- Department of Surgery, Yong Loo Lin School of Medicine, National University of Singapore, Singapore, Singapore
| | - Ophira M Ginsburg
- Women's College Research Institute, University of Toronto, Toronto, Ontario, Canada
| | - Allison W Kurian
- Departments of Medicine (Oncology) and Genetics, Stanford University School of Medicine, Stanford, California, USA
| | - Jeffrey N Weitzel
- Division of Clinical Cancer Genetics, City of Hope National Medical Center, Duarte, California, USA
| | - Man-Ting Siu
- Department of Surgery, The University of Hong Kong, Hong Kong, Hong Kong
| | - Fian B F Law
- Hong Kong Hereditary Breast Cancer Family Registry, Hong Kong, Hong Kong Department of Molecular Pathology, Hong Kong Sanatorium & Hospital, Hong Kong, Hong Kong
| | - Tsun-Leung Chan
- Hong Kong Hereditary Breast Cancer Family Registry, Hong Kong, Hong Kong Department of Molecular Pathology, Hong Kong Sanatorium & Hospital, Hong Kong, Hong Kong
| | - Steven A Narod
- Women's College Research Institute, University of Toronto, Toronto, Ontario, Canada
| | - James M Ford
- Departments of Medicine (Oncology) and Genetics, Stanford University School of Medicine, Stanford, California, USA
| | - Edmond S K Ma
- Hong Kong Hereditary Breast Cancer Family Registry, Hong Kong, Hong Kong Department of Molecular Pathology, Hong Kong Sanatorium & Hospital, Hong Kong, Hong Kong
| | - Sung-Won Kim
- Department of Surgery, Seoul National University Bundang Hospital, Seoul National University College of Medicine, Seongnam, Korea
| |
Collapse
|
8
|
De Silva S, Tennekoon KH, Karunanayake EH, Amarasinghe I, Angunawela P. Analysis of BRCA1and BRCA2 large genomic rearrangements in Sri Lankan familial breast cancer patients and at risk individuals. BMC Res Notes 2014; 7:344. [PMID: 24906410 PMCID: PMC4057568 DOI: 10.1186/1756-0500-7-344] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/21/2013] [Accepted: 05/29/2014] [Indexed: 11/10/2022] Open
Abstract
Background Majority of mutations found to date in the BRCA1/BRCA2 genes in breast and/or ovarian cancer families are point mutations or small insertions and deletions scattered over the coding sequence and splice junctions. Such mutations and sequence variants of BRCA1 and BRCA2 genes were previously identified in a group of Sri Lankan breast cancer patients. Large genomic rearrangements have been characterized in BRCA1 and BRCA2 genes in several populations but these have not been characterized in Sri Lankan breast cancer patients. Findings A cohort of familial breast cancer patients (N = 57), at risk individuals (N = 25) and healthy controls (N = 23) were analyzed using multiplex ligation-dependent probe amplification method to detect BRCA1 and BRCA2 large genomic rearrangements. One familial breast cancer patient showed an ambiguous deletion in exon 6 of BRCA1 gene. Full sequencing of the ambiguous region was used to confirm MLPA results. Ambiguous deletion detected by MLPA was found to be a false positive result confirming that BRCA1 large genomic rearrangements were absent in the subjects studied. No BRCA2 rearrangement was also identified in the cohort. Conclusion Thus this study demonstrates that BRCA1 and BRCA2 large genomic rearrangements are unlikely to make a significant contribution to aetiology of breast cancer in Sri Lanka.
Collapse
Affiliation(s)
| | - Kamani Hemamala Tennekoon
- Institute of Biochemistry, Molecular Biology and Biotechnology, University of Colombo, Colombo, Sri Lanka.
| | | | | | | |
Collapse
|
9
|
Karami F, Mehdipour P. A comprehensive focus on global spectrum of BRCA1 and BRCA2 mutations in breast cancer. BIOMED RESEARCH INTERNATIONAL 2013; 2013:928562. [PMID: 24312913 PMCID: PMC3838820 DOI: 10.1155/2013/928562] [Citation(s) in RCA: 106] [Impact Index Per Article: 9.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 04/17/2013] [Revised: 07/31/2013] [Accepted: 08/15/2013] [Indexed: 02/05/2023]
Abstract
Breast cancer (BC) is the most common cancer of women all over the world. BRCA1 and BRCA2 gene mutations comprise the most important genetic susceptibility of BC. Except for few common mutations, the spectrum of BRCA1 and BRCA2 mutations is heterogeneous in diverse populations. 185AGdel and 5382insC are the most important BRCA1 and BRCA2 alterations which have been encountered in most of the populations. After those Ashkenazi founder mutations, 300T>G also demonstrated sparse frequency in African American and European populations. This review affords quick access to the most frequent alterations among various populations which could be helpful in BRCA screening programs.
Collapse
Affiliation(s)
- Fatemeh Karami
- Department of Medical Genetics, Tehran University of Medical Sciences, School of Medicine, Tehran, Iran
| | - Parvin Mehdipour
- Department of Medical Genetics, Tehran University of Medical Sciences, School of Medicine, Tehran, Iran
- *Parvin Mehdipour:
| |
Collapse
|
10
|
BRCA1 And BRCA2 analysis of Argentinean breast/ovarian cancer patients selected for age and family history highlights a role for novel mutations of putative south-American origin. SPRINGERPLUS 2012; 1:20. [PMID: 23961350 PMCID: PMC3725882 DOI: 10.1186/2193-1801-1-20] [Citation(s) in RCA: 37] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 08/17/2012] [Accepted: 08/30/2012] [Indexed: 01/05/2023]
Abstract
Background The spectrum of BRCA1/2 genetic variation in breast-ovarian cancer patients has been scarcely investigated outside Europe and North America, with few reports for South America, where Amerindian founder effects and recent multiracial immigration are predicted to result in high genetic diversity. We describe here the results of BRCA1/BRCA2 germline analysis in an Argentinean series of breast/ovarian cancer patients selected for young age at diagnosis or breast/ovarian cancer family history. Methods The study series (134 patients) included 37 cases diagnosed within 40 years of age and no family history (any ethnicity, fully-sequenced), and 97 cases with at least 2 affected relatives (any age), of which 57 were non-Ashkenazi (fully-sequenced) and 40 Ashkenazi (tested only for the founder mutations c.66_67delAG and c.5263insC in BRCA1 and c.5946delT in BRCA2). Discussion We found 24 deleterious mutations (BRCA1:16; BRCA2: 8) in 38/134 (28.3%) patients, of which 6/37 (16.2%) within the young age group, 15/57 (26.3%) within the non-Ahkenazi positive for family history; and 17/40 (42.5%) within the Ashkenazi. Seven pathogenetic mutations were novel, five in BRCA1: c.1502_1505delAATT, c.2626_2627delAA c.2686delA, c.2728 C > T, c.3758_3759delCT, two in BRCA2: c.7105insA, c.793 + 1delG. We also detected 72 variants of which 54 previously reported and 17 novel, 33 detected in an individual patient. Four missense variants of unknown clinical significance, identified in 5 patients, are predicted to affect protein function. While global and European variants contributed near 45% of the detected BRCA1/2 variation, the significant fraction of new variants (25/96, 26%) suggests the presence of a South American genetic component. This study, the first conducted in Argentinean patients, highlights a significant impact of novel BRCA1/2 mutations and genetic variants, which may be regarded as putatively South American, and confirms the important role of founder BRCA1 and BRCA2 mutations in Argentinean Ashkenazi Jews. Electronic supplementary material The online version of this article (doi:10.1186/2193-1801-1-20) contains supplementary material, which is available to authorized users.
Collapse
|
11
|
Keshavarzi F, Javadi GR, Zeinali S. BRCA1 and BRCA2 germline mutations in 85 Iranian breast cancer patients. Fam Cancer 2012; 11:57-67. [PMID: 21918854 DOI: 10.1007/s10689-011-9477-3] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
Breast cancer is the most common cancer in Iranian women (Mousavi et al in Asian Pac J Cancer Prev 9(2):275-278, 2008). Genetic predisposition accounts for 15% of all breast cancers and germline mutations in breast cancer susceptibility genes, BRCA1 and BRCA2 are responsible for a substantial proportion of high-risk breast and breast/ovarian cancer families (Collaborative Group on Hormonal Factors in Breast Cancer in Lancet 350:1047-1059, 1997; Lee et al in Int Nurs Rev 55:355-359, 2008; Hulka and Stark in Lancet 346:883-887, 1995; Kelsey in Epidemiol Rev 15:256-263, 1993; Tischer et al in J Biol Chem 266:11947-11954, 1991; Newman et al in: Proc Natl Acad Sci USA 85:3044-3048, 1988). Therefore, the aim of this study was to investigate mutations of BRCA1/2 in high risk Iranian families. We screened 85 patients who met our minimal criteria. The entire coding sequences and each intron/exon boundaries of BRCA1/2 genes were screened by direct sequencing. In the present study, we could detect the novel following mutations: p.Glu1735 p.Gly1140Ser, p.Ile26Val, p.Leu1418X, p.Glu23Gln, p.Leu3X, p.Asn1403His, p.Lys581X, p.Pro938Arg, p.Thr77Arg, p.Arg7Cys, p.Ser177Thr, IVS7+83(TT), IVS8-70(-CATT), IVS2+9(-GC), IVS1-20(-GA), IVS1-8(-AG), IVS2+24(AG), IVS5-8 (A-G), IVS2(35-39)TTcctatGAT in BRCA1 and p.Glu1391Gly, 1994_1995 (Ins A), IVS6-70-T>G in BRCA2. In agreement with findings in other populations, we found that family history is a good predictor of being a mutation carrier. Five pathogenic BRCA1 mutations and one pathogenic BRCA2 mutation were detected in 85 index cases.
Collapse
Affiliation(s)
- Fatemeh Keshavarzi
- Department of Biology, Sanandaj Branch, Islamic Azad University, Sanandaj, Iran.
| | | | | |
Collapse
|
12
|
BRCA1/BRCA2 gene mutations/SNPs and BRCA1 haplotypes in early-onset breast cancer patients of Indian ethnicity. Med Oncol 2012; 29:3272-81. [PMID: 22752604 DOI: 10.1007/s12032-012-0294-9] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/31/2012] [Accepted: 06/19/2012] [Indexed: 10/28/2022]
Abstract
We examined BRCA1/2 mutations and single nucleotide polymorphisms (SNPs) for identification of BRCA1 haplotypes, in early-onset breast cancer patients and their relatives, sporadic breast cancer patients, and unrelated normal healthy females, of Indian ethnicity. Peripheral blood DNA was amplified by polymerase chain reaction, at BRCA1/2 coding exons and subject to nucleotide sequencing using ABI 3100 Genetic Analyzer. We observed BRCA1/BRCA2 mutations in 52 % early-onset breast cancer patients and in 57 % relatives. Deleterious mutations detected in early-onset patients and relatives were 187delAG, 632insT, 1052delT, Q759X, Q780X, R1203X, 5154delC, IVS14 + 1G > A, IVS17 + 1G > T, and 632insT in BRCA1 gene; and 4075delGT, 5076delAA, 6079delAGTT, and W3127X in BRCA2 gene. A high degree of penetrance of BRCA1/2 gene mutations was observed in the relatives. BRCA1/2 SNPs were identified in the Indian population, and association of BRCA1 haplotypes with breast cancer was investigated. A significantly increased frequency of the SNPs 203G/A, 3624A/G and 7470A/G SNPs in BRCA2 gene was observed in normal controls indicative of a protective effect of the SNPs. BRCA1 haplotype 2 was most frequently observed in our population. Our study indicates a high incidence of BRCA1/BRCA2 gene mutations in the Indian patients. The BRCA1/2 mutations and SNPs are detailed on our website http://relibrca.rellife.com .
Collapse
|
13
|
DE Silva S, Tennekoon KH, Karunanayake EH, DE Silva W, Amarasinghe I, Angunawela P. Novel sequence variants and common recurrent polymorphisms of BRCA2 in Sri Lankan breast cancer patients and a family with BRCA1 mutations. Exp Ther Med 2011; 2:1163-1170. [PMID: 22977638 DOI: 10.3892/etm.2011.337] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/28/2011] [Accepted: 08/02/2011] [Indexed: 01/25/2023] Open
Abstract
We previously reported BRCA1 mutations and sequence variants in Sri Lankan breast cancer patients. Mutations and sequence variants of the BRCA2 gene were studied in 149 study participants from the same cohort. There were 55 familial and 54 sporadic breast cancer patients, 20 at-risk individuals and 20 healthy controls. Direct sequencing (exon 11) and sequencing of abnormal bands after screening with single-strand conformation polymorphism (remaining exons) were used to detect mutations and sequence variants. Twenty-three sequence variants were found in the BRCA2 gene. Two novel pathogenic frame-shift additions resulting in a premature stop codon (c.2403 insA/exon 11, c.2667 insT/exon 11) were identified. Possibly pathogenic two novel missense mutations (c.1191 A>C/exon 10, c.5695 A>C/exon 11) one novel intronic variant (IVS15-21 insTT), four novel silent mutations (c.969 C>T/exon 9, c.1353 C>T/exon 10, c.2766 A>C/exon 11 and c.7452 A>G/exon 14) and one novel missense mutation (c.971 C>G/exon 9) were observed. One previously reported possibly pathogenic intronic variant (IVS81 G>C) and several previously reported silent mutations, missense mutations, and one 5' UTR polymorphism were detected. Pathogenic and possibly pathogenic mutations were more frequent in the BRCA2 gene among Sri Lankan familial breast cancer patients when compared to our previous findings for the BRCA1 gene.
Collapse
Affiliation(s)
- Sumadee DE Silva
- Institute of Biochemistry, Molecular Biology and Biotechnology, University of Colombo, Colombo 03
| | | | | | | | | | | |
Collapse
|
14
|
Sequence Variants of BRCA1 and BRCA2 Genes in Four Iranian Families with Breast and Ovarian Cancer. IRANIAN JOURNAL OF PUBLIC HEALTH 2011; 40:57-66. [PMID: 23113073 PMCID: PMC3481774] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 06/24/2010] [Accepted: 02/03/2011] [Indexed: 11/24/2022]
Abstract
BACKGROUND BRCA1 and BRCA2 genes have been recognized to be responsible for 20-30% of hereditary breast cancers and approximately 50% of familial breast and ovarian cancers. Therefore, the demand for BRCA1 and BRCA2 mutation screening is rapidly increasing as their identification will affect medical management of people at increased risk. Because of high costs involved in analysis of BRCA1 and 2 genes, contribution of different mutation types in BRCA1 and 2 and not knowing who should be tested has hampered wide spread use of molecular testing of high -risk families. There is a need to identify the genes and types of mutations involved in breast or ovarian cancers at different age of onsets and polymorphism and polymorphic variations in our population. METHODS Twenty-seven patients with either early onset breast cancer (at age≤ 35 years) or a personal and/or family history of breast or ovarian cancer and 50 control subjects participated in this study. After collecting blood samples and extracting DNA, BRCA1 and BRCA2 genes were fully sequenced. RESULTS Thirteen missense substitutions in BRCA1 and BRCA2 (9 and 4, respectively) were revealed. Two nucleotide substitutions were novel (Gly1140Ser in BRCA1 and Glu1391Gly in BRCA2). The Glu1038Pro and Gly1140Ser were found in large series of breast and ovarian cancer and matched controls. CONCLUSION Some nucleotide substitutions were seen only in single families and other in several. In other cases, mutations were seen in both BRCA1 and BRCA2 genes. Clinical significance of these mutations was evaluated comparing with normal controls.
Collapse
|