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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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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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Kour A, Sambyal V, Guleria K, Singh NR, Uppal MS, Manjari M, Sudan M. Screening of BRCA1 variants c.190T>C, 1307delT, g.5331G>A and c.2612C>T in breast cancer patients from North India. Genet Mol Biol 2020; 43:e20190014. [PMID: 32453341 PMCID: PMC7250277 DOI: 10.1590/1678-4685-gmb-2019-0014] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/16/2019] [Accepted: 06/22/2019] [Indexed: 12/01/2022] Open
Abstract
The polymorphic variants of BRCA1, which lead to amino acid
substitutions, have a known pathogenic role in breast cancer. The present study
investigated in North Indian breast cancer patients the association of risk with
four reported pathogenic variants of BRCA1: c.190T>C
(p.Cys64Arg), 1307delT, g.5331G>A (p.G1738R) and c.2612C>T (p.Pro871Leu).
Genotyping was done by PCR-RFLP method in 255 clinically confirmed breast cancer
patients and 255 age and gender matched healthy individuals. For c.190T>C,
1307delT and g.5331G>A, all the patients and controls had the wild-type
genotype indicating no association with breast cancer risk. For c.2612C>T
polymorphism, the frequency of the CC, CT, and TT genotypes was 14.5 vs 15.7%,
59.6 vs 53.7% and 25.9 vs 30.6% in breast cancer patients and controls
respectively. The frequency of heterozygotes (CT genotype) was higher in cases
than controls but the difference was not statistically significant. Genetic
model analysis showed no association of the four analyzed BRCA1
variants with breast cancer risk with any model. The studied variants were not
associated with the risk of breast cancer in Punjab, North west India,
suggesting a need for further screening of other BRCA1
variants. It is the first reported study on these 4 variants from India.
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Affiliation(s)
- Akeen Kour
- Guru Nanak Dev University, Department of Human Genetics, Human Cytogenetics Laboratory, Amritsar, Punjab, India
| | - Vasudha Sambyal
- Guru Nanak Dev University, Department of Human Genetics, Human Cytogenetics Laboratory, Amritsar, Punjab, India
| | - Kamlesh Guleria
- Guru Nanak Dev University, Department of Human Genetics, Human Cytogenetics Laboratory, Amritsar, Punjab, India
| | - Neeti Rajan Singh
- Sri Guru Ram Das Institute of Medical Sciences and Research, Vallah,Department of Surgery, Amritsar, Punjab, India
| | - Manjit Singh Uppal
- Sri Guru Ram Das Institute of Medical Sciences and Research, Vallah,Department of Surgery, Amritsar, Punjab, India
| | - Mridu Manjari
- Sri Guru Ram Das Institute of Medical Sciences and Research, Vallah,Department of Pathology, Amritsar, Punjab, India
| | - Meena Sudan
- Sri Guru Ram Das Institute of Medical Sciences and Research, Vallah, Department of Radiotherapy, Amritsar, Punjab, India
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Nicolussi A, Belardinilli F, Silvestri V, Mahdavian Y, Valentini V, D'Inzeo S, Petroni M, Zani M, Ferraro S, Di Giulio S, Fabretti F, Fratini B, Gradilone A, Ottini L, Giannini G, Coppa A, Capalbo C. Identification of novel BRCA1 large genomic rearrangements by a computational algorithm of amplicon-based Next-Generation Sequencing data. PeerJ 2019; 7:e7972. [PMID: 31741787 PMCID: PMC6859874 DOI: 10.7717/peerj.7972] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/29/2019] [Accepted: 10/01/2019] [Indexed: 12/30/2022] Open
Abstract
Background Genetic testing for BRCA1/2 germline mutations in hereditary breast/ovarian cancer patients requires screening for single nucleotide variants, small insertions/deletions and large genomic rearrangements (LGRs). These studies have long been run by Sanger sequencing and multiplex ligation-dependent probe amplification (MLPA). The recent introduction of next-generation sequencing (NGS) platforms dramatically improved the speed and the efficiency of DNA testing for nucleotide variants, while the possibility to correctly detect LGRs by this mean is still debated. The purpose of this study was to establish whether and to which extent the development of an analytical algorithm could help us translating NGS sequencing via an Ion Torrent PGM platform into a tool suitable to identify LGRs in hereditary breast-ovarian cancer patients. Methods We first used NGS data of a group of three patients (training set), previously screened in our laboratory by conventional methods, to develop an algorithm for the calculation of the dosage quotient (DQ) to be compared with the Ion Reporter (IR) analysis. Then, we tested the optimized pipeline with a consecutive cohort of 85 uncharacterized probands (validation set) also subjected to MLPA analysis. Characterization of the breakpoints of three novel BRCA1 LGRs was obtained via long-range PCR and direct sequencing of the DNA products. Results In our cohort, the newly defined DQ-based algorithm detected 3/3 BRCA1 LGRs, demonstrating 100% sensitivity and 100% negative predictive value (NPV) (95% CI [87.6–99.9]) compared to 2/3 cases detected by IR (66.7% sensitivity and 98.2% NPV (95% CI [85.6–99.9])). Interestingly, DQ and IR shared 12 positive results, but exons deletion calls matched only in five cases, two of which confirmed by MLPA. The breakpoints of the 3 novel BRCA1 deletions, involving exons 16–17, 21–22 and 20, have been characterized. Conclusions Our study defined a DQ-based algorithm to identify BRCA1 LGRs using NGS data. Whether confirmed on larger data sets, this tool could guide the selection of samples to be subjected to MLPA analysis, leading to significant savings in time and money.
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Affiliation(s)
- Arianna Nicolussi
- Department of Experimental Medicine, University of Roma "La Sapienza", Roma, Italy
| | | | - Valentina Silvestri
- Department of Molecular Medicine, University of Roma "La Sapienza", Roma, Italy
| | - Yasaman Mahdavian
- Department of Molecular Medicine, University of Roma "La Sapienza", Roma, Italy
| | - Virginia Valentini
- Department of Molecular Medicine, University of Roma "La Sapienza", Roma, Italy
| | - Sonia D'Inzeo
- U.O.C. Microbiology and Virology Laboratory, A.O. San Camillo Forlanini, Roma, Italy
| | - Marialaura Petroni
- Istituto Italiano di Tecnologia, Center for Life Nano Science @ Sapienza, Roma, Italy
| | - Massimo Zani
- Department of Molecular Medicine, University of Roma "La Sapienza", Roma, Italy
| | - Sergio Ferraro
- Department of Molecular Medicine, University of Roma "La Sapienza", Roma, Italy
| | - Stefano Di Giulio
- Department of Molecular Medicine, University of Roma "La Sapienza", Roma, Italy
| | - Francesca Fabretti
- Department of Molecular Medicine, University of Roma "La Sapienza", Roma, Italy
| | - Beatrice Fratini
- Department of Experimental Medicine, University of Roma "La Sapienza", Roma, Italy
| | - Angela Gradilone
- Department of Molecular Medicine, University of Roma "La Sapienza", Roma, Italy
| | - Laura Ottini
- Department of Molecular Medicine, University of Roma "La Sapienza", Roma, Italy
| | - Giuseppe Giannini
- Department of Molecular Medicine, University of Roma "La Sapienza", Roma, Italy.,Istituto Pasteur-Fondazione Cenci Bolognetti, Roma, Italy
| | - Anna Coppa
- Department of Experimental Medicine, University of Roma "La Sapienza", Roma, Italy
| | - Carlo Capalbo
- Department of Molecular Medicine, University of Roma "La Sapienza", Roma, Italy
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5
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Nishat L, Yesmin ZA, Arjuman F, Rahman SHZ, Banu LA. Identification of Mutation in Exon11 of BRCA1 Gene in Bangladeshi Patients with Breast Cancer. Asian Pac J Cancer Prev 2019; 20:3515-3519. [PMID: 31759379 PMCID: PMC7063022 DOI: 10.31557/apjcp.2019.20.11.3515] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/08/2019] [Indexed: 12/24/2022] Open
Abstract
Background: Worldwide, breast cancer is the leading cause of cancer death in female, in Bangladesh breast cancer is the second leading cancer in both sexes, and in women it occupied the top position. Highly penetrant mutations in BRCA1 gene constitute high risk of breast cancer. The spectrum of BRCA1 gene mutations varies in different population. The objective of this study was to identify mutation in exon11 of BRCA1 gene in Bangladeshi breast cancer patients. Methods: Genomic DNA was extracted from the histopathologically diagnosed formalin fixed paraffin embedded (FFPE) breast cancer tissues of 65 adult female patients. Two regions of exon11 of the BRCA1 gene were amplified and the amplicons were sequenced using Sanger sequencing. The sequenced nucleotides were analyzed and blast using NCBI nucleoblast. Selected demographic, reproductive and medical histories were collected and analyzed using SPSS version 20. Results: The mean age of the patients was 46 years and the mean age at diagnosis was 44.64 years. The patients were married and had 2.65 ± 1.22 children except one was nulliparous, the mean age of menarche was 12.67 years. All patients had children, breastfed the babies for an average 1.5 years. Only 13.6% of the patients had hypertension and the rest had no comorbidity. The family history for cancer (breast and other cancer) was negative. Three novel mutations were found in a patient. Two among the three mutant sequences had effect on amino acid coding (DNA sequence change g.852G>C and g.709G>A and amino acid changes p.Gln284His and p.Glu237Lys respectively). Conclusion: We found three novel mutations in Bangladeshi breast cancer patients. This finding indicates the necessity to study the mutation profile of whole BRCA1 gene in our population for cancer risk prediction.
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Affiliation(s)
- Latifa Nishat
- Department of Anatomy, Bangabandhu Sheikh Mujib Medical University, Shahbagh, Dhaka, Bangladesh
| | - Zinnat Ara Yesmin
- Department of Anatomy, Bangabandhu Sheikh Mujib Medical University, Shahbagh, Dhaka, Bangladesh
| | - Farida Arjuman
- Department of Histopathology, National Institute of Cancer Research and Hospital, Mohakhali, Dhaka, Bangladesh
| | - Sufi Hannan Zulfiqar Rahman
- Department of Immunology and Molecular Biology, National Institute of Cancer Research and Hospital, Mohakhali, Dhaka, Bangladesh
| | - Laila Anjuman Banu
- Department of Anatomy, Bangabandhu Sheikh Mujib Medical University, Shahbagh, Dhaka, Bangladesh
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6
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Apessos A, Agiannitopoulos K, Pepe G, Tsaousis GN, Papadopoulou E, Metaxa-Mariatou V, Tsirigoti A, Efstathiadou C, Markopoulos C, Xepapadakis G, Venizelos V, Tsiftsoglou A, Natsiopoulos I, Nasioulas G. Comprehensive BRCA mutation analysis in the Greek population. Experience from a single clinical diagnostic center. Cancer Genet 2018; 220:1-12. [DOI: 10.1016/j.cancergen.2017.10.002] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/22/2016] [Revised: 10/09/2017] [Accepted: 10/12/2017] [Indexed: 12/28/2022]
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7
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Bhatta B, Thapa R, Shahi S, Bhatta Y, Pandeya DR, Poudel BH. A Pilot Study on Screening of BRCA1 Mutations (185delAG, 1294del40) in Nepalese Breast Cancer Patients. Asian Pac J Cancer Prev 2017; 17:1829-32. [PMID: 27221860 DOI: 10.7314/apjcp.2016.17.4.1829] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND Breast cancer is the second most common malignancy among Nepalese women, accounting for 60% of the total cancer cases in females. Women diagnosed with germline mutations in BRCA1 like 185delAG, 1294del40 develop breast and/or ovarian cancer with a lifelong likelihood of up to 85% whereas presence of a mutation increases the risk for mutations to occur in other genes. The major objective of this study was to find the prevalence of these mutations in Nepalese cancer patients. MATERIALS AND METHODS This prospective study was carried out at two cancer hospitals in the Kathmandu valley over a period of 11 months. Irrespective of age group and stage of canceran appropriate amount of blood was withdrawn from 50 breast cancer patients and 20 controls. DNA was extracted manually and subjected to PCR using primers for 185delAG and 1294del40 mutations. PCR products were then digested with restriction enzyme (DdeII) followed by electrophoresis. RESULTS Prevalence of 185delAG in reference breast cancer patients was found to be 4/50 (8%) but no 1294del40 was apparent. CONCLUSIONS Several mutations occurring in different exons of BRCA1 as well as mutations in other genes like BRCA2, for example, should also be taken in account.
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Affiliation(s)
- Bibek Bhatta
- Department of Clinical Microbiology, Nobel College, Nepalese Army Institute of Health Science, College of Medicine, Kathmandu, Nepal E-mail :
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8
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Tsigginou A, Vlachopoulos F, Arzimanoglou I, Zagouri F, Dimitrakakis C. Cumulative BRCA mutation analysis in the Greek population confirms that homogenous ethnic background facilitates genetic testing. Hered Cancer Clin Pract 2015; 13:17. [PMID: 26300996 PMCID: PMC4545329 DOI: 10.1186/s13053-015-0037-y] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/23/2015] [Accepted: 07/14/2015] [Indexed: 11/10/2022] Open
Abstract
Screening for BRCA 1 and BRCA 2 mutations has long moved from the research lab to the clinic as a routine clinical genetic testing. BRCA molecular alteration pattern varies among ethnic groups which makes it already a less straightforward process to select the appropriate mutations for routine genetic testing on the basis of known clinical significance. The present report comprises an in depth literature review of the so far reported BRCA 1 and BRCA 2 molecular alterations in Greek families. Our analysis of Greek cumulative BRCA 1 and 2 molecular data, produced by several independent groups, confirmed that six recurrent deleterious mutations account for almost 60 % and 70 % of all BRCA 1 and 2 and BRCA 1 mutations, respectively. As a result, it makes more sense to perform BRCA mutation analysis in the clinic in two sequential steps, first conventional analysis for the six most prevalent pathogenic mutations and if none identified, a second step of New Generation Sequencing-based whole genome or whole exome sequencing would follow. Our suggested approach would enable more clinically meaningful, considerably easier and less expensive BRCA analysis in the Greek population which is considered homogenous.
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Affiliation(s)
- Alexandra Tsigginou
- Breast Unit of the 1st Department of Obstetrics and Gynecology, Athens University Medical School, Athens, Greece
| | - Fotios Vlachopoulos
- Breast Unit of the 1st Department of Obstetrics and Gynecology, Athens University Medical School, Athens, Greece
| | | | - Flora Zagouri
- Department of Clinical Therapeutics, Alexandra Hospital, Athens University Medical School, Athens, Greece
| | - Constantine Dimitrakakis
- Breast Unit of the 1st Department of Obstetrics and Gynecology, Athens University Medical School, Athens, Greece
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9
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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.
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Affiliation(s)
- Fatemeh Keshavarzi
- Department of Biology, Sanandaj Branch, Islamic Azad University, Sanandaj, Iran.
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10
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Stuppia L, Antonucci I, Palka G, Gatta V. Use of the MLPA assay in the molecular diagnosis of gene copy number alterations in human genetic diseases. Int J Mol Sci 2012; 13:3245-3276. [PMID: 22489151 PMCID: PMC3317712 DOI: 10.3390/ijms13033245] [Citation(s) in RCA: 156] [Impact Index Per Article: 13.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/30/2011] [Revised: 02/28/2012] [Accepted: 02/29/2012] [Indexed: 11/16/2022] Open
Abstract
Multiplex Ligation-dependent Probe Amplification (MLPA) assay is a recently developed technique able to evidence variations in the copy number of several human genes. Due to this ability, MLPA can be used in the molecular diagnosis of several genetic diseases whose pathogenesis is related to the presence of deletions or duplications of specific genes. Moreover, MLPA assay can also be used in the molecular diagnosis of genetic diseases characterized by the presence of abnormal DNA methylation. Due to the large number of genes that can be analyzed by a single technique, MLPA assay represents the gold standard for molecular analysis of all pathologies derived from the presence of gene copy number variation. In this review, the main applications of the MLPA technique for the molecular diagnosis of human diseases are described.
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Affiliation(s)
- Liborio Stuppia
- Department of Oral Sciences, Nano and Biotechnologies, “G. d’Annunzio” University, Via dei Vestini 31, 66013 Chieti, Italy; E-Mails: (I.A.); (G.P.); (V.G.)
| | - Ivana Antonucci
- Department of Oral Sciences, Nano and Biotechnologies, “G. d’Annunzio” University, Via dei Vestini 31, 66013 Chieti, Italy; E-Mails: (I.A.); (G.P.); (V.G.)
| | - Giandomenico Palka
- Department of Oral Sciences, Nano and Biotechnologies, “G. d’Annunzio” University, Via dei Vestini 31, 66013 Chieti, Italy; E-Mails: (I.A.); (G.P.); (V.G.)
| | - Valentina Gatta
- Department of Oral Sciences, Nano and Biotechnologies, “G. d’Annunzio” University, Via dei Vestini 31, 66013 Chieti, Italy; E-Mails: (I.A.); (G.P.); (V.G.)
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Koumpis C, Dimitrakakis C, Antsaklis A, Royer R, Zhang S, Narod SA, Kotsopoulos J. Prevalence of BRCA1 and BRCA2 mutations in unselected breast cancer patients from Greece. Hered Cancer Clin Pract 2011; 9:10. [PMID: 22085629 PMCID: PMC3240809 DOI: 10.1186/1897-4287-9-10] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/20/2011] [Accepted: 11/15/2011] [Indexed: 12/24/2022] Open
Abstract
BACKGROUND Inheritance of a mutation in either BRCA1 or BRCA2 accounts for approximately 5% of all breast cancer cases, but varies by country. Investigations into the contribution of BRCA mutations to breast cancer incidence in Greece have been, for the most part, limited by small sample sizes and by the use of cases selected for their family history of cancer. The aim of the current study was to estimate BRCA mutation frequencies in breast cancer patients unselected for family history. METHODS To do so, we enrolled 127 unselected women with breast cancer from the Alexandra Hospital in Athens, Greece, a large public hospital in the city. Mutations in BRCA1 and BRCA2 were detected using a combination of techniques and were confirmed by direct sequencing. Two large genomic deletions were sought using mutation-specific assays. A detailed family history of cancer was obtained from each patient. RESULTS We were able to successfully complete testing on samples from 127 women. Among these, six mutations were identified (four in BRCA1 and two in BRCA2) representing 4.7% of the total or 9.5% of cases diagnosed before age forty. None of the mutation carriers had a family history of breast or ovarian cancer. Three of the four BRCA1 mutations were in exon 20: two were a G5331A mutation and the third was a 3.2 kb deletion. The fourth BRCA1 mutation was the 3819delGTAAA in exon 11. The two BRCA2 mutations were in exon 11 (3782del10 and 4512insT). CONCLUSIONS The G5331A mutation in BRCA1 appears to be a founder mutation in the Greek population.
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12
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Pertesi M, Konstantopoulou I, Yannoukakos D. Haplotype analysis of two recurrent genomic rearrangements in the BRCA1 gene suggests they are founder mutations for the Greek population. Clin Genet 2010; 80:375-82. [DOI: 10.1111/j.1399-0004.2010.01532.x] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
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13
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Large genomic rearrangements of the BRCA1 and BRCA2 genes: review of the literature and report of a novel BRCA1 mutation. Breast Cancer Res Treat 2010; 125:325-49. [PMID: 20232141 DOI: 10.1007/s10549-010-0817-z] [Citation(s) in RCA: 100] [Impact Index Per Article: 7.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/26/2010] [Accepted: 02/22/2010] [Indexed: 10/19/2022]
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14
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Fazza AC, Sabino FC, de Setta N, Bordin NA, da Silva EHT, Carareto CMA. Estimating genomic instability mediated by Alu retroelements in breast cancer. Genet Mol Biol 2009; 32:25-31. [PMID: 21637642 PMCID: PMC3032955 DOI: 10.1590/s1415-47572009005000018] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/18/2008] [Accepted: 08/11/2008] [Indexed: 11/21/2022] Open
Abstract
Alu-PCR is a relatively simple technique that can be used to investigate genomic instability in cancer. This technique allows identification of the loss, gain or amplification of gene sequences based on the analysis of segments between two Alu elements coupled with quantitative and qualitative analyses of the profiles obtained from tumor samples, surgical margins and blood. In this work, we used Alu-PCR to identify gene alterations in ten patients with invasive ductal breast cancer. Several deletions and insertions were identified, indicating genomic instability in the tumor and adjacent normal tissue. Although not associated with specific genes, the alterations, which involved chromosomal bands 1p36.23, 1q41, 11q14.3, 13q14.2, occurred in areas of well-known genomic instability in breast and other types of cancer. These results indicate the potential usefulness of Alu-PCR in identifying altered gene sequences in breast cancer. However, caution is required in its application since the Alu primer can produce non-specific amplification.
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Affiliation(s)
- Ana Cristina Fazza
- Departamento de Biologia, Instituto de Biociências, Letras e Ciências Exatas, Universidade Estadual Paulista Júlio De Mesquita Filho, São José Rio Preto, SPBrazil
| | - Flavia Cal Sabino
- Departamento de Biologia, Instituto de Biociências, Letras e Ciências Exatas, Universidade Estadual Paulista Júlio De Mesquita Filho, São José Rio Preto, SPBrazil
| | - Nathalia de Setta
- Departamento de Biologia, Instituto de Biociências, Letras e Ciências Exatas, Universidade Estadual Paulista Júlio De Mesquita Filho, São José Rio Preto, SPBrazil
| | - Newton Antonio Bordin
- Departamento de Ginecologia e Obstetrícia, Faculdade de Medicina, São José do Rio Preto, SPBrazil
| | | | - Claudia Marcia Aparecida Carareto
- Departamento de Biologia, Instituto de Biociências, Letras e Ciências Exatas, Universidade Estadual Paulista Júlio De Mesquita Filho, São José Rio Preto, SPBrazil
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15
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Analysis of BRCA1/BRCA2 genes' contribution to breast cancer susceptibility in high risk Jewish Ashkenazi women. Fam Cancer 2008; 8:127-33. [PMID: 18798010 DOI: 10.1007/s10689-008-9216-6] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2008] [Accepted: 09/03/2008] [Indexed: 10/21/2022]
Abstract
BACKGROUND Three mutations in BRCA1 (185delAG 5382InsC) and BRCA2 (6174delT) can be detected in a substantial proportion of Jewish Ashkenazi breast/ovarian cancer families. Family-specific pathogenic mutations in both genes can be detected in up to 5% of high risk Ashkenazim. The contribution of major gene rearrangements and seemingly pathogenic missense mutations to inherited breast cancer predisposition has never been systematically evaluated in Ashkenazim. MATERIAL AND METHODS High risk, Jewish Ashkenazi women, non-carriers of the predominant Jewish BRCA1/BRCA2 mutations, were genotyped for major gene rearrangements in BRCA1/BRCA2 using Multiplex ligation-dependent probe amplification (MLPA), and for the occurrence rate of 6 seemingly pathogenic missense mutations in BRCA1 (R866C, R331S, R841W, Y179C, C61G, M1008I) using a modified restriction enzyme assay. RESULTS Overall, 105 Jewish Ashkenazi high risk women, participated in the study: 104 with breast cancer [age at diagnosis (mean +/- SD) 51.05 +/- 11.13 years], one was affected with ovarian cancer (61 years). Two were found to carry the M1008I mutation in BRCA1 and none harbored any of the other missense mutations. MLPA reveled four changes (amplifications of exons 5, 17, 19 and 21) in BRCA1 in five patients, and six patients exhibited 4 MLPA-detectable abnormalities in BRCA2 (amplifications in exons 1b, 2, and deletions in exons 11a and 25). None of these abnormalities could be confirmed using quantitative PCR (qPCR) analysis. CONCLUSIONS Major gene rearrangements involving BRCA1 BRCA2 contribute little to the burden of inherited predisposition of breast cancer in Ashkenazi Jews.
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De Silva W, Karunanayake EH, Tennekoon KH, Allen M, Amarasinghe I, Angunawala P, Ziard MH. Novel sequence variants and a high frequency of recurrent polymorphisms in BRCA1 gene in Sri Lankan breast cancer patients and at risk individuals. BMC Cancer 2008; 8:214. [PMID: 18662409 PMCID: PMC2519088 DOI: 10.1186/1471-2407-8-214] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/07/2008] [Accepted: 07/29/2008] [Indexed: 12/14/2022] Open
Abstract
BACKGROUND Breast Cancer is the most commonly diagnosed cancer among Sri Lankan women. Germline mutations in the susceptibility genes BRCA1 and BRCA2 in hereditary breast/ovarian cancer, though low in prevalence, are highly penetrant and show geographical variations. There have been only a few reports from Asia on mutations in BRCA1/2 genes and none from Sri Lanka. METHODS A total of 130 patients with (N = 66) and without (N = 64) a family history of breast cancer, 70 unaffected individuals with a family history of breast cancer and 40 control subjects were analysed for BRCA1 mutations. All but exon 11 were screened by single strand conformation analysis (SSCP) and heteroduplex analysis. PCR products which showed abnormal patterns in SSCP were sequenced. Exon 11 was directly sequenced. RESULTS Nineteen sequence variants were found in BRCA1 gene. Two novel deleterious frame-shift mutations; c.3086delT/exon11 (in one patient) and c.5404delG/exon21 (in one patient and two of her family members) were identified. A possibly pathogenic novel missense mutation (c.856T>G/exon 11) and three novel intronic variants (IVS7+36C>T, IVS7+41C>T, IVS7+49del15) were characterised. Ten previously reported common polymorphisms and three previously reported intronic variants were also observed. CONCLUSION After screening of 66 patients with family history and 64 sporadic breast cancer patients, 2 deleterious mutations (c.3086delT and c.5404delG) in two families were identified and two more possibly pathogenic mutations (c.856T>G and IVS17-2A>T) in two families were identified. DATA BASE BRCA1--Gene Bank: Accession # U14680 Version # 14680.1.
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Affiliation(s)
- Wasanthi De Silva
- Institute of Biochemistry Molecular Biology and Biotechnology, University of Colombo, 90, Cumaratunga Munidasa Mawatha, Colombo 03, Sri Lanka
| | - Eric H Karunanayake
- Institute of Biochemistry Molecular Biology and Biotechnology, University of Colombo, 90, Cumaratunga Munidasa Mawatha, Colombo 03, Sri Lanka
| | - Kamani H Tennekoon
- Institute of Biochemistry Molecular Biology and Biotechnology, University of Colombo, 90, Cumaratunga Munidasa Mawatha, Colombo 03, Sri Lanka
| | - Marie Allen
- Department of Genetics and Pathology, Rudbeck Laboratory, University of Uppsala, Sweden
| | | | - Preethika Angunawala
- Department of Pathology, Faculty of Medicine, Kynsey Road, Colombo 08, University of Colombo, Sri Lanka
| | - Mohamed H Ziard
- Institute of Biochemistry Molecular Biology and Biotechnology, University of Colombo, 90, Cumaratunga Munidasa Mawatha, Colombo 03, Sri Lanka
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17
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Cvok ML, Cretnik M, Musani V, Ozretic P, Levanat S. New sequence variants in BRCA1 and BRCA2 genes detected by high-resolution melting analysis in an elderly healthy female population in Croatia. Clin Chem Lab Med 2008; 46:1376-83. [PMID: 18844490 DOI: 10.1515/cclm.2008.307] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
Abstract
BACKGROUND Mutations in BRCA1 and BRCA2 genes are associated with family predisposition to breast and ovarian cancer. Novel screening methods are required for efficient and rapid detection of sequence variants in cancer patients and their family members. METHODS The screening for variants in the breast and ovarian cancer susceptibility genes BRCA1 and BRCA2 in Croatia was performed by a high-resolution melting approach, which is based on differences in melting curves caused by variations in nucleotide sequence. This is the first screening in Croatia on elderly healthy women with no family history of cancer. BRCA1 screening was performed on 220 and BRCA2 screening on 115 samples. RESULTS In a population well beyond the average age of breast/ovarian cancer onset, 21 different sequence variants in the BRCA1 gene (one novel: c.5193+49_50delTA) and 36 variants in the BRCA2 gene (7 novel: c.459A>C, c.3318C>A, c.4412_ 4414delGAA, c.4790C>A, c.6264T>C, c.9087G>A, and c.9864A>G) were detected. CONCLUSIONS Nine BRCA1 and seven BRCA2 known variants appeared with such high frequencies that they could be declared as harmless in this population. Eight BRCA1 high frequency variants, located further from the promoter region, appear to be strongly correlated. Three novel variants that changed the amino acid sequence of the BRCA2 protein (two missense base substitutions, c.3318C>A and c.4790C>A, and one codon deletion c.4412_4414delGAA), appearing only once, were predicted to have no potential effect on protein structure and function.
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18
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Identification of a novel BRCA1 large genomic rearrangement in a Spanish breast/ovarian cancer family. Breast Cancer Res Treat 2007; 112:63-7. [DOI: 10.1007/s10549-007-9839-6] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/21/2007] [Accepted: 11/21/2007] [Indexed: 10/22/2022]
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19
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Lim YK, Lau PTC, Ali AB, Lee SC, Wong JEL, Putti TC, Sng JH. Identification of novel BRCA large genomic rearrangements in Singapore Asian breast and ovarian patients with cancer. Clin Genet 2007; 71:331-42. [PMID: 17470134 DOI: 10.1111/j.1399-0004.2007.00773.x] [Citation(s) in RCA: 45] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/01/2022]
Abstract
Large genomic rearrangements have been reported to account for about 10-15% of BRCA1 gene mutations. Approximately, 90 BRCA rearrangements have been described to date, all of which but one have been reported in Caucasian populations of predominantly Western European descent. Knowledge of BRCA genomic rearrangements in Asian populations is still largely unknown. In this study, we have investigated for the presence of BRCA rearrangements among Asian patients with early onset or familial history of breast or ovarian cancer. Using multiplex ligation-dependent probe amplification (MLPA), we have analyzed 100 Singapore patients who previously tested negative for deleterious BRCA mutations by the conventional polymerase chain reaction-based mutation detection methods. Three novel BRCA rearrangements were detected, two of which were characterized. The patients with the rearrangements, a BRCA1 exon 13 duplication, a BRCA1 exon 13-15 deletion and a BRCA2 exon 4-11 duplication, comprise 3% of those previously tested negative for BRCA mutations. Of the BRCA1 and BRCA2 pathogenic mutations identified in our studies on Asian high-risk breast and ovarian patients with cancer to date, these rearrangements constitute 2/19 and 1/2 of the BRCA1 and BRCA2 pathogenic mutations, respectively. Given the increasing number of rearrangements reported in recent years and their contribution to the BRCA mutation spectrum, the presence of BRCA large exon rearrangements in Asian populations should be investigated where clinical, diagnostic service is recommended.
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Affiliation(s)
- Y K Lim
- Department of Surgery, Yong Loo Lin School of Medicine, National University of Singapore, Singapore
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20
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Vasickova P, Machackova E, Lukesova M, Damborsky J, Horky O, Pavlu H, Kuklova J, Kosinova V, Navratilova M, Foretova L. High occurrence of BRCA1 intragenic rearrangements in hereditary breast and ovarian cancer syndrome in the Czech Republic. BMC MEDICAL GENETICS 2007; 8:32. [PMID: 17561994 PMCID: PMC1904436 DOI: 10.1186/1471-2350-8-32] [Citation(s) in RCA: 39] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 11/07/2006] [Accepted: 06/11/2007] [Indexed: 01/07/2023]
Abstract
Background Alterations in the highly penetrant cancer susceptibility gene BRCA1 are responsible for the majority of hereditary breast and/or ovarian cancers. However, the number of detected germline mutations has been lower than expected based upon genetic linkage data. Undetected deleterious mutations in the BRCA1 gene in some high-risk families could be due to the presence of intragenic rearrangements as deletions, duplications or insertions spanning whole exons. Standard PCR-based screening methods are mainly focused on detecting point mutations and small insertions/deletions, but large rearrangements might escape detection. The purpose of this study was to determine the type and frequency of large genomic rearrangements in the BRCA1 gene in hereditary breast and ovarian cancer cases in the Czech Republic. Methods Multiplex ligation-dependent probe amplification (MLPA) was used to examine BRCA1 rearrangements in 172 unrelated patients with hereditary breast and/or ovarian cancer syndrome without finding deleterious mutation after complete screening of whole coding regions of BRCA1/2 genes. Positive MLPA results were confirmed and located by long-range PCR. The breakpoints of detected rearrangements were characterized by sequencing. Results Six different large deletions in the BRCA1 gene were identified in 10 out of 172 unrelated high-risk patients: exons 1A/1B and 2 deletion; partial deletion of exon 11 and exon 12; exons 18 and 19 deletion; exon 20 deletion; exons 21 and 22 deletion; and deletion of exons 5 to 14. The breakpoint junctions were localized and further characterized. Destabilization and global unfolding of the mutated BRCT domains explain the molecular and genetic defects associated with the exon 20 in-frame deletion and the exon 21 and 22 in-frame deletion, respectively. Conclusion Using MLPA, mutations were detected in 6% of high-risk patients previously designated as BRCA1/2 mutation-negative. The breakpoints of five out of six large deletions detected in Czech patients are novel. Screening for large genomic rearrangements in the BRCA1 gene in the Czech high-risk patients is highly supported by this study.
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Affiliation(s)
| | | | | | - Jiri Damborsky
- Loschmidt Laboratories, Faculty of Science, Masaryk University, Brno, Czech Republic
| | - Ondrej Horky
- Center of Molecular Biology and Gene Therapy, University Hospital, Brno, Czech Republic
| | - Hana Pavlu
- Masaryk Memorial Cancer Institute, Brno, Czech Republic
| | - Jitka Kuklova
- Masaryk Memorial Cancer Institute, Brno, Czech Republic
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Konstantopoulou I, Rampias T, Ladopoulou A, Koutsodontis G, Armaou S, Anagnostopoulos T, Nikolopoulos G, Kamakari S, Nounesis G, Stylianakis A, Karanikiotis C, Razis E, Gogas H, Keramopoulos A, Gaki V, Markopoulos C, Skarlos D, Pandis N, Bei T, Arzimanoglou I, Fountzilas G, Yannoukakos D. Greek BRCA1 and BRCA2 mutation spectrum: two BRCA1 mutations account for half the carriers found among high-risk breast/ovarian cancer patients. Breast Cancer Res Treat 2007; 107:431-41. [PMID: 17453335 DOI: 10.1007/s10549-007-9571-2] [Citation(s) in RCA: 34] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/12/2007] [Accepted: 03/16/2007] [Indexed: 12/17/2022]
Abstract
127 Greek breast/ovarian cancer families were screened for germline BRCA1/2 mutations by dHPLC followed by direct sequencing. Our results indicated 16 and 5 breast/ovarian cancer families bearing deleterious mutations in the BRCA1 and BRCA2 genes, respectively. Two novel BRCA2 germline mutations (G4X and 3783del10) are reported here for the first time. Subsequent compilation of our present findings with previously reported mutation data reveals that in a total of 287 Greek breast/ovarian cancer families, 46 and 13 carry a deleterious mutation in BRCA1 and BRCA2, respectively. It should be noted that two BRCA1 mutations, 5382insC and G1738R, both located in exon 20, account for 46% of the families found to carry a mutation. Based on our mutation analysis results, we propose here a hierarchical, cost-effective BRCA1/2 mutation screening protocol for individuals of Greek ethnic origin. The suggested protocol can impact on the clinical management of breast-ovarian cancer families on a national healthcare system level.
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Affiliation(s)
- Irene Konstantopoulou
- Molecular Diagnostics Laboratory, I/R-RP, National Center for Scientific Research "Demokritos", Athens, Greece
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22
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Armaou S, Konstantopoulou I, Anagnostopoulos T, Razis E, Boukovinas I, Xenidis N, Fountzilas G, Yannoukakos D. Novel genomic rearrangements in the BRCA1 gene detected in Greek breast/ovarian cancer patients. Eur J Cancer 2006; 43:443-53. [PMID: 17174087 DOI: 10.1016/j.ejca.2006.09.021] [Citation(s) in RCA: 39] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2006] [Revised: 09/12/2006] [Accepted: 09/16/2006] [Indexed: 11/30/2022]
Abstract
The identification of genomic rearrangements in breast/ovarian cancer families has widened the mutational spectrum of the BRCA1 gene, increasing the number of patients who can benefit from molecular screening. More than 60 different BRCA1 genomic rearrangements with mapped breakpoints have been reported up to date, in all exons of the gene. The proportion of BRCA1 mutations due to genomic rearrangements varies from 8 to 27% in different populations, probably due to both ethnic diversity and the technical approach employed. In order to estimate the contribution of BRCA1 genomic rearrangements to hereditary breast/ovarian cancer (HBOC) predisposition in Greek families, probands from 95 families with breast/ovarian history but negative for point mutations or small insertions/deletions in BRCA1 and BRCA2 genes, were screened using Quantitative Multiplex PCR of Short Fluorescent Fragments (QMPSF). Two large deletions of 4.2 and 4.4 kb were identified in exons 20 and 24 respectively. Additional screening, using diagnostic primers for the above deletions in exons 20 and 24, performed on another 86 probands from families with breast/ovarian cancer history and 210 cases of sporadic breast/ovarian cancer resulted in the identification of two more large genomic rearrangements. One, identified in a familial case, identical to the previous exon 24 deletion and a second, identified in a case reported as sporadic, 3.2 kb deletion involving exon 20 and reported elsewhere in another Greek patient. Three out of four genomic rearrangements described in this study were detected in patients who had developed both breast and ovarian cancer; thus suggesting a correlation between the specific phenotype and the high probability of detecting inherited rearrangements in BRCA1.
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Affiliation(s)
- Sophia Armaou
- Molecular Diagnostics Laboratory, I/R-RP, National Centre for Scientific Research Demokritos, Athens, Greece
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23
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Agata S, Viel A, Della Puppa L, Cortesi L, Fersini G, Callegaro M, Dalla Palma M, Dolcetti R, Federico M, Venuta S, Miolo G, D'Andrea E, Montagna M. Prevalence of BRCA1 genomic rearrangements in a large cohort of Italian breast and breast/ovarian cancer families without detectable BRCA1 and BRCA2 point mutations. Genes Chromosomes Cancer 2006; 45:791-7. [PMID: 16715518 DOI: 10.1002/gcc.20342] [Citation(s) in RCA: 45] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022] Open
Abstract
The presence of genomic rearrangements of the BRCA1 gene in breast and/or ovarian cancer families has been intensively investigated in patients from various countries over the last years. A number of different rearrangements have been reported by several studies that clearly document the involvement of this mutation type in genetic predisposition to breast and ovarian cancer. Population-specific studies are now needed to evaluate the prevalence of genomic rearrangements before deciding whether to include ad hoc screening procedures into standard diagnostic mutation detection approaches. Indeed, the vast majority of the studies have been performed on small, highly selected, sample sets because of the limitations imposed by the laborious technical approaches. Moreover, prevalence figures are likely to differ across different countries according to the ethnic origin of each specific population. Here we analyze a large cohort of 653 Italian probands, negative for BRCA1 and BRCA2 point mutations, gathered from four National Institutions. We report the identification of BRCA1 genomic rearrangements in 12 independent families. Noteworthy, half of the probands carry mutations that recur in more than one Italian family. Considering the whole spectrum of Italian BRCA1 gene rearrangements identified thus far in consecutive patients, we estimate that alterations of this type account for 19% (95% CI: 0.11 < 0.19 < 0.28) of the BRCA1 mutation positive families. We conclude that the search for major genomic rearrangements is essential for an accurate and comprehensive BRCA1 mutation detection strategy in Italy.
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Affiliation(s)
- Simona Agata
- Department of Oncology and Surgical Sciences, Oncology Section, University of Padua, Padua, Italy
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24
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Yap KPL, Ang P, Lim IHK, Ho GH, Lee ASG. Detection of a novel Alu-mediated BRCA1 exon 13 duplication in Chinese breast cancer patients and implications for genetic testing. Clin Genet 2006; 70:80-2. [PMID: 16813611 DOI: 10.1111/j.1399-0004.2006.00637.x] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
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25
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Mihalatos M, Apessos A, Dauwerse H, Velissariou V, Psychias A, Koliopanos A, Petropoulos K, Triantafillidis JK, Danielidis I, Fountzilas G, Agnantis NJ, Nasioulas G. Rare mutations predisposing to familial adenomatous polyposis in Greek FAP patients. BMC Cancer 2005; 5:40. [PMID: 15833136 PMCID: PMC1097718 DOI: 10.1186/1471-2407-5-40] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/20/2005] [Accepted: 04/15/2005] [Indexed: 12/21/2022] Open
Abstract
BACKGROUND Familial Adenomatous Polyposis (FAP) is caused by germline mutations in the APC (Adenomatous Polyposis Coli) gene. The vast majority of APC mutations are point mutations or small insertions/deletions which lead to truncated protein products. Splicing mutations or gross genomic rearrangements are less common inactivating events of the APC gene. METHODS In the current study genomic DNA or RNA from ten unrelated FAP suspected patients was examined for germline mutations in the APC gene. Family history and phenotype were used in order to select the patients. Methods used for testing were dHPLC (denaturing High Performance Liquid Chromatography), sequencing, MLPA (Multiplex Ligation - dependent Probe Amplification), Karyotyping, FISH (Fluorescence In Situ Hybridization) and RT-PCR (Reverse Transcription - Polymerase Chain Reaction). RESULTS A 250 Kbp deletion in the APC gene starting from intron 5 and extending beyond exon 15 was identified in one patient. A substitution of the +5 conserved nucleotide at the splice donor site of intron 9 in the APC gene was shown to produce frameshift and inefficient exon skipping in a second patient. Four frameshift mutations (1577insT, 1973delAG, 3180delAAAA, 3212delA) and a nonsense mutation (C1690T) were identified in the rest of the patients. CONCLUSION Screening for APC mutations in FAP patients should include testing for splicing defects and gross genomic alterations.
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Affiliation(s)
- Markos Mihalatos
- Molecular Biology Research Center HYGEIA – «Antonis Papayiannis», Athens
| | - Angela Apessos
- Molecular Biology Research Center HYGEIA – «Antonis Papayiannis», Athens
| | - Hans Dauwerse
- Center for Human and Clinical Genetics, Leiden University Medical Center, The Netherlands
| | - Voula Velissariou
- Cytogenetics Laboratory, Department of Genetics and Molecular Biology, Mitera Maternity and Surgical Center, Athens, Greece
| | - Aristidis Psychias
- Hygeia Ofthalmos, Diagnostic and Therapeutic Center of Athens HYGEIA S.A., Athens, Greece
| | - Alexander Koliopanos
- Surgical Clinic, General State Hospital of Athens "G. Gennimatas", Athens, Greece
| | | | | | - Ioannis Danielidis
- Gastroenterology Department Diagnostic and Therapeutic Center of Athens HYGEIA S.A., Athens Greece
| | - George Fountzilas
- AHEPA Hospital, Aristotle University of Thessaloniki, Thessaloniki Greece
| | - Niki J Agnantis
- Department of Pathology, Medical School, University of Ioannina, Ioannina, Greece
| | - Georgios Nasioulas
- Molecular Biology Research Center HYGEIA – «Antonis Papayiannis», Athens
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