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Discovery of BRCA1/BRCA2 Founder Variants by Haplotype Analysis. Cancer Genet 2022; 266-267:19-27. [DOI: 10.1016/j.cancergen.2022.05.042] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/09/2021] [Revised: 05/22/2022] [Accepted: 05/26/2022] [Indexed: 11/20/2022]
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Gomes R, Soares BL, Felicio PS, Michelli R, Netto CBO, Alemar B, Ashton-Prolla P, Palmero EI, Moreira MÂM. Haplotypic characterization of BRCA1 c.5266dupC, the prevailing mutation in Brazilian hereditary breast/ovarian cancer. Genet Mol Biol 2020. [PMID: 32453342 PMCID: PMC7250276 DOI: 10.1590//1678-4685-gmb-2019-0072] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
Specific pathogenic mutations associated with breast cancer development can vary between ethnical groups. One example is BRCA1 c.5266dupC that was first described as a founder mutation in the Ashkenazi Jewish population, but was later also found in other populations. In Brazil, this mutation corresponds to 20% of pathogenic BRCA1 variants reported. Our objective was to investigate the haplotype component of a group of Brazilian families who inherited c.5266dupC in the BRCA1 gene and to verify the ancestry contribution from European, African, and Amerindian origins. Fourteen probands carrying c.5266dupC and 16 relatives (carriers and non-carriers) were investigated. The same haplotype was observed segregating within all the families analyzed, revealing no recombinants in a region of 0.68 Mb. Ancestry analysis demonstrated that the European component was predominant among probands. The BRCA1 c.5266dupC analysis indicates that there was a founder effect in the Brazilian population.
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Affiliation(s)
- Renan Gomes
- Instituto Nacional de Câncer, Programa de Genética, Rio de Janeiro, RJ, Brazil
| | | | - Paula Silva Felicio
- Hospital de Cancer de Barretos, Centro de Pesquisa em Oncologia Molecular, Barretos, SP, Brazil
| | - Rodrigo Michelli
- Hospital de Cancer de Barretos, Centro de Pesquisa em Oncologia Molecular, Barretos, SP, Brazil
| | - Cristina B O Netto
- Hospital de Clínicas de Porto Alegre, Serviço de Genética Médica, Porto Alegre, RS, Brazil
| | - Barbara Alemar
- Hospital de Clínicas de Porto Alegre, Laboratório de Medicina Genômica, Porto Alegre, RS, Brazil.,Universidade Federal do Rio Grande do Sul (UFRGS), Departamento de Genética, Programa de Pós-Graduação em Genética e Biologia Molecular, Porto Alegre, RS, Brazil
| | - Patrícia Ashton-Prolla
- Hospital de Clínicas de Porto Alegre, Laboratório de Medicina Genômica, Porto Alegre, RS, Brazil.,Universidade Federal do Rio Grande do Sul (UFRGS), Departamento de Genética, Programa de Pós-Graduação em Genética e Biologia Molecular, Porto Alegre, RS, Brazil
| | - Edenir Inêz Palmero
- Hospital de Cancer de Barretos, Centro de Pesquisa em Oncologia Molecular, Barretos, SP, Brazil.,Faculdade de Ciências de Saúde de Barretos Dr. Paulo Prata (FACISB), Barretos, SP, Brazil
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Enyedi MZ, Jaksa G, Pintér L, Sükösd F, Gyuris Z, Hajdu A, Határvölgyi E, Priskin K, Haracska L. Simultaneous detection of BRCA mutations and large genomic rearrangements in germline DNA and FFPE tumor samples. Oncotarget 2018; 7:61845-61859. [PMID: 27533253 PMCID: PMC5308695 DOI: 10.18632/oncotarget.11259] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/31/2016] [Accepted: 07/19/2016] [Indexed: 11/25/2022] Open
Abstract
The development of breast and ovarian cancer is strongly connected to the inactivation of the BRCA1 and BRCA2 genes by different germline and somatic alterations, and their diagnosis has great significance in targeted tumor therapy, since recently approved PARP inhibitors show high efficiency in the treatment of BRCA-deficient tumors. This raises the need for new diagnostic methods that are capable of performing an integrative mutation analysis of the BRCA genes not only from germline DNA but also from formalin-fixed and paraffin-embedded (FFPE) tumor samples. Here we describe the development of such a methodology based on next-generation sequencing and a new bioinformatics software for data analysis. The diagnostic method was initially developed on an Illumina MiSeq NGS platform using germline-mutated stem cell lines and then adapted for the Ion Torrent PGM NGS platform as well. We also investigated the usability of NGS coverage data for the detection of copy number variations and exon deletions as a replacement of the conventional MLPA technique. Finally, we tested the developed workflow on FFPE samples from breast and ovarian cancer patients. Our method meets the sensitivity and specificity requirements for the genetic diagnosis of breast and ovarian cancers both from germline and FFPE samples.
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Affiliation(s)
- Márton Zsolt Enyedi
- Institute of Genetics, Biological Research Centre of the Hungarian Academy of Sciences, Szeged 6726, Hungary
| | | | | | - Farkas Sükösd
- Department of Pathology, Faculty of Medicine, University of Szeged, Szeged 6720, Hungary
| | | | - Adrienn Hajdu
- Delta Bio 2000 Ltd., Szeged 6726, Hungary.,Department of Pathology, Faculty of Medicine, University of Szeged, Szeged 6720, Hungary
| | | | | | - Lajos Haracska
- Institute of Genetics, Biological Research Centre of the Hungarian Academy of Sciences, Szeged 6726, Hungary
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4
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Oglesbee D, Cowan TM, Pasquali M, Wood TC, Weck KE, Long T, Palomaki GE. CAP/ACMG proficiency testing for biochemical genetics laboratories: a summary of performance. Genet Med 2017; 20:83-90. [PMID: 28661487 PMCID: PMC5763156 DOI: 10.1038/gim.2017.61] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/20/2017] [Accepted: 03/31/2017] [Indexed: 11/19/2022] Open
Abstract
Purpose Testing for inborn errors of metabolism is performed by clinical laboratories worldwide, each utilizing laboratory-developed procedures. We sought to summarize performance in the College of American Pathologists’ (CAP) proficiency testing (PT) program and identify opportunities for improving laboratory quality. When evaluating PT data, we focused on a subset of laboratories that have participated in at least one survey since 2010. Methods An analysis of laboratory performance (2004 to 2014) on the Biochemical Genetics PT Surveys, a program administered by CAP and the American College of Medical Genetics and Genomics. Analytical and interpretive performance was evaluated for four tests: amino acids, organic acids, acylcarnitines, and mucopolysaccharides. Results Since 2010, 150 laboratories have participated in at least one of four PT surveys. Analytic sensitivities ranged from 88.2 to 93.4%, while clinical sensitivities ranged from 82.4 to 91.0%. Performance was higher for US participants and for more recent challenges. Performance was lower for challenges with subtle findings or complex analytical patterns. Conclusion US clinical biochemical genetics laboratory proficiency is satisfactory, with a minority of laboratories accounting for the majority of errors. Our findings underscore the complex nature of clinical biochemical genetics testing and highlight the necessity of continuous quality management.
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Affiliation(s)
- Devin Oglesbee
- Department of Laboratory Medicine and Pathology, Mayo Clinic College of Medicine, Rochester, Minnesota, USA
| | - Tina M Cowan
- Department of Pathology, Stanford University, School of Medicine, Palo Alto, California, USA
| | - Marzia Pasquali
- Department of Pathology, University of Utah School of Medicine, Salt Lake City, Utah, USA
| | - Timothy C Wood
- Greenwood Genetics Center, Greenwood, South Carolina, USA
| | - Karen E Weck
- Department of Pathology and Laboratory Medicine, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina, USA
| | - Thomas Long
- Department of Biostatistics, College of American Pathologists, Northfield, Illinois, USA
| | - Glenn E Palomaki
- Department of Pathology and Laboratory Medicine, Women and Infants Hospital, Alpert Medical School of Brown University, Providence, Rhode Island, USA
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Hwang SM, Lee KC, Lee MS, Park KU. Comparison of Ion Personal Genome Machine Platforms for the Detection of Variants in BRCA1 and BRCA2. Cancer Res Treat 2017; 50:255-264. [PMID: 28392550 PMCID: PMC5784618 DOI: 10.4143/crt.2017.062] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/01/2017] [Accepted: 04/03/2017] [Indexed: 11/26/2022] Open
Abstract
Purpose Transition to next generation sequencing (NGS) for BRCA1/BRCA2 analysis in clinical laboratories is ongoing but different platforms and/or data analysis pipelines give different results resulting in difficulties in implementation. We have evaluated the Ion Personal Genome Machine (PGM) Platforms (Ion PGM, Ion PGM Dx, Thermo Fisher Scientific) for the analysis of BRCA1/2. Materials and Methods The results of Ion PGM with OTG-snpcaller, a pipeline based on Torrent mapping alignment program and Genome Analysis Toolkit, from 75 clinical samples and 14 reference DNA samples were compared with Sanger sequencing for BRCA1/BRCA2. Ten clinical samples and 14 reference DNA samples were additionally sequenced by Ion PGM Dx with Torrent Suite. Results Fifty types of variants including 18 pathogenic or variants of unknown significance were identified from 75 clinical samples and known variants of the reference samples were confirmed by Sanger sequencing and/or NGS. One false-negative results were present for Ion PGM/OTG-snpcaller for an indel variant misidentified as a single nucleotide variant. However, eight discordant results were present for Ion PGM Dx/Torrent Suite with both false-positive and -negative results. A 40-bp deletion, a 4-bp deletion and a 1-bp deletion variant was not called and a false-positive deletion was identified. Four other variants were misidentified as another variant. Conclusion Ion PGM/OTG-snpcaller showed acceptable performance with good concordance with Sanger sequencing. However, Ion PGM Dx/Torrent Suite showed many discrepant results not suitable for use in a clinical laboratory, requiring further optimization of the data analysis for calling variants.
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Affiliation(s)
- Sang Mee Hwang
- Department of Laboratory Medicine, Seoul National University Bundang Hospital, Seongnam, Korea.,Department of Laboratory Medicine, Seoul National University College of Medicine, Seoul, Korea
| | - Ki Chan Lee
- Eone-Diagnomics Genome Center, Incheon, Korea
| | | | - Kyoung Un Park
- Department of Laboratory Medicine, Seoul National University Bundang Hospital, Seongnam, Korea.,Department of Laboratory Medicine, Seoul National University College of Medicine, Seoul, Korea
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Weck KE, Schrijver I. A panoramic view of the accuracy of molecular genetic testing. Genet Med 2016; 18:1188-1189. [PMID: 27537703 DOI: 10.1038/gim.2016.116] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2016] [Accepted: 07/07/2016] [Indexed: 11/09/2022] Open
Affiliation(s)
- Karen E Weck
- Department of Pathology & Laboratory Medicine, University of North Carolina, Chapel Hill, North Carolina, USA.,Department of Genetics, University of North Carolina, Chapel Hill, North Carolina, USA
| | - Iris Schrijver
- Department of Pathology, Stanford University School of Medicine, Stanford, California, USA
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Payne DA, Baluchova K, Peoc'h KH, van Schaik RHN, Chan KCA, Maekawa M, Mamotte C, Russomando G, Rousseau F, Ahmad-Nejad P. Pre-examination factors affecting molecular diagnostic test results and interpretation: A case-based approach. Clin Chim Acta 2016; 467:59-69. [PMID: 27321365 DOI: 10.1016/j.cca.2016.06.018] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/21/2015] [Revised: 06/13/2016] [Accepted: 06/15/2016] [Indexed: 12/13/2022]
Abstract
BACKGROUND Multiple organizations produce guidance documents that provide opportunities to harmonize quality practices for diagnostic testing. The International Organization for Standardization ISO 15189 standard addresses requirements for quality in management and technical aspects of the clinical laboratory. One technical aspect addresses the complexities of the pre-examination phase prior to diagnostic testing. METHODS The Committee for Molecular Diagnostics of the International Federation for Clinical Chemistry and Laboratory Medicine (also known as, IFCC C-MD) conducted a survey of international molecular laboratories and determined ISO 15189 to be the most referenced guidance document. In this review, the IFCC C-MD provides case-based examples illustrating the value of select pre-examination processes as these processes relate to molecular diagnostic testing. Case-based examples in infectious disease, oncology, inherited disease and pharmacogenomics address the utility of: 1) providing information to patients and users, 2) designing requisition forms, 3) obtaining informed consent and 4) maintaining sample integrity prior to testing. CONCLUSIONS The pre-examination phase requires extensive and consistent communication between the laboratory, the healthcare provider and the end user. The clinical vignettes presented in this paper illustrate the value of applying select ISO 15189 recommendations for general laboratory to the more specialized area of Molecular Diagnostics.
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Affiliation(s)
- Deborah A Payne
- Molecular Services, APP-UniPath LLC, American Pathology Partners-UniPath, 6116 East Warren Ave., Denver, CO, USA.
| | - Katarina Baluchova
- Comenius University in Bratislava, Jessenius Faculty of Medicine in Martin, Biomedical Center Martin, Division of Oncology, Mala Hora 4C, 036 01 Martin, Slovakia; Comenius University in Bratislava, Jessenius Faculty of Medicine in Martin, Department of Molecular Biology, Mala Hora 4C, 036 01 Martin, Slovakia
| | - Katell H Peoc'h
- AP-HP Hôpital Beaujon, Service de Biochimie clinique, Clichy F-92118, France; Université Paris Diderot, UFR de Médecine site Bichat, INSERM UMRs-1149, Paris, France
| | - Ron H N van Schaik
- Department Clinical Chemistry, Erasmus University Medical Center, Rotterdam, The Netherlands
| | - K C Allen Chan
- Department of Chemical Pathology, Li Ka Shing Institute of Health Sciences, The Chinese University of Hong Kong, Prince of Wales Hospital, Shatin, Hong Kong
| | - Masato Maekawa
- Department of Laboratory Medicine, Hamamatsu University School of Medicine, Hamamatsu, Japan
| | - Cyril Mamotte
- School of Biomedical Sciences and CHIRI Biosciences, Curtin University, Perth, Australia
| | - Graciela Russomando
- Molecular Biology and Biotechnology Department, Instituto de Investigaciones en Ciencias de la Salud, Universidad Nacional de Asunción, Paraguay
| | - François Rousseau
- Department of Medical Biology, Direction médicale des services hospitaliers, CHU de Québec - Université Laval, Québec City, Canada; Department of Molecular Biology, Medical Biochemistry and Pathology, Faculty of Medicine, Université Laval, Québec City, Canada
| | - Parviz Ahmad-Nejad
- Institute for Medical Laboratory Diagnostics, Centre for Clinical and Translational Research (CCTR), HELIOS Hospital, Heusnerstraße 40, 42283 Wuppertal, Witten/Herdecke University, Germany
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Results from an external proficiency testing program: 11 years of molecular genetics testing for myotonic dystrophy type 1. Genet Med 2016; 18:1290-1294. [PMID: 27253733 DOI: 10.1038/gim.2016.59] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/02/2015] [Accepted: 03/28/2016] [Indexed: 01/10/2023] Open
Abstract
PURPOSE The aim of this study was to examine the performance of laboratories offering assessment for myotonic dystrophy type 1 (DM1) using external proficiency testing samples. DM1, a dominant disorder, has a prevalence of 1:20,000 due to the expansion of CTG trinucleotide repeats in the DMPK gene. METHODS External proficiency testing administered by the College of American Pathologists/American College of Medical Genetics and Genomics distributes three samples twice yearly. Responses from 2003 through the first distribution of 2013 were analyzed after stratification by location (United States/international). Both the repeat sizes (analytic validity) and clinical interpretations were assessed. RESULTS Over the 21 distributions, 45 US and 29 international laboratories participated. Analytic sensitivity for detecting and reporting expanded repeats (≥50) was 99.2% (382/385 challenges) and 97.1% (133/137 challenges), respectively. Analytic specificity (to within two repeats of the consensus) was 99.2% (1,790/1,805 alleles) and 98.6% (702/712 alleles), respectively. Clinical interpretations were correct for 99.3% (450/453) and 98.2% (224/228) of positive challenges and in 99.9% (936/937) and 99.6% (455/457) of negative challenges, respectively. Of four incorrect interpretations made in the United States, two were probably due to sample mix-up. CONCLUSION This review of laboratory performance regarding laboratory-developed genetic tests indicates very high performance for both the analytic and interpretative challenges for DM1.Genet Med 18 12, 1290-1294.
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Improvements in CYP2C9 Genotyping Accuracy Are Needed: A Report of the First Proficiency Testing for Warfarin-related CYP2C9 and VKORC1 Genotyping in China. J Cardiovasc Pharmacol 2016; 66:129-34. [PMID: 25815675 DOI: 10.1097/fjc.0000000000000254] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
Warfarin is the most commonly used oral anticoagulant in clinical practice. The cytochrome P450 2C9 (CYP2C9) and vitamin K epoxide reductase complex 1 (VKORC1) genotypes have been confirmed to be associated with warfarin dose requirements. Accurate genotyping results are of particular importance for obtaining reliable genotype-guided warfarin dosing information. This study aims to determine analytic performance of laboratories offering CYP2C9 and VKORC1 testing in China. A proficiency panel of 15 validated cell samples covering common CYP2C9 and VKORC1 genetic polymorphisms was provided to 31 participating laboratories, and their genotyping results were evaluated. Fourteen data sets (45.2%) performed well with the entire panel of samples, and 17 data sets (54.8%) reported at least one genotyping error. For VKORC1 (-1639G>A), participating laboratories were 100% successful in detecting genotypes of GG, GA, and AA. For CYP2C9, participants were greater than 90% successful in detecting genotypes of *1/*1, *1/*2, *1/*3, *2/*3, and *3/*3. However, 15 laboratories failed to detect rarely encountered variant genotype *2/*2. The poor performance of CYP2C9 genotyping may be because of the limitation of methodologies used for detecting CYP2C9*2 allele. The proficiency testing survey highlighted the need for improving genotyping accuracy for some laboratories in this field.
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Highly accurate molecular genetic testing for HFE hereditary hemochromatosis: results from 10 years of blinded proficiency surveys by the College of American Pathologists. Genet Med 2016; 18:1206-1213. [PMID: 27124787 DOI: 10.1038/gim.2016.34] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/14/2015] [Accepted: 01/26/2016] [Indexed: 01/26/2023] Open
Abstract
PURPOSE The College of American Pathologists offers blinded proficiency testing (PT) for laboratories performing HFE genetic tests for hereditary hemochromatosis (common C282Y and H63D variants). This study used 10 years of PT data to determine laboratory performance for HFE analytical genotyping and clinical interpretation. METHODS Laboratories were graded for accuracy of genotype determination (six possible C282Y/H63D genotypes) and clinical interpretation regarding whether the genotype was likely to have contributed to iron overload in a hypothetical patient. RESULTS The analytical genotyping error rate was low (0.73%) in 7,663 results (from 257 unique laboratories). Genotyping errors were significantly higher in C282Y heterozygous, H63D homozygous, and C282Y homozygous samples, in non-American laboratories, and in laboratories with lower testing volume. Analytical sensitivity and specificity were >98.5 and >99.5%. The interpretive error rate (4.3%) was higher than the genotyping error rate, with two problematic genotypes (C282Y heterozygous and H63D homozygous) accounting for 77% of total interpretive errors. There was a time-dependent improvement in the interpretation of the clinical significance of HFE genotypes. CONCLUSIONS HFE molecular genetic testing, performed by non-US Food and Drug Administration-approved laboratory-developed tests, demonstrated excellent accuracy, sensitivity, and specificity. Clinical interpretations were more heterogeneous, probably owing to the low clinical penetrance of some common HFE genotypes.Genet Med 18 12, 1206-1213.
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Lee SH, Zhou S, Zhou T, Hong G. Sanger Sequencing for BRCA1 c.68_69del, BRCA1 c.5266dup and BRCA2 c.5946del Mutation Screen on Pap Smear Cytology Samples. Int J Mol Sci 2016; 17:229. [PMID: 26867194 PMCID: PMC4783961 DOI: 10.3390/ijms17020229] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/06/2015] [Revised: 02/01/2016] [Accepted: 02/04/2016] [Indexed: 01/06/2023] Open
Abstract
Three sets of polymerase chain reaction (PCR) primers were designed for heminested PCR amplification of the target DNA fragments in the human genome which include the site of BRCA1 c.68_69del, BRCA1 c.5266dup and BRCA2 c.5946del respectively, to prepare the templates for direct Sanger sequencing screen of these three founder mutations. With a robust PCR mixture, crude proteinase K digestate of the fixed cervicovaginal cells in the liquid-based Papanicolaou (Pap) cytology specimens can be used as the sample for target DNA amplification without pre-PCR DNA extraction, purification and quantitation. The post-PCR products can be used directly as the sequencing templates without further purification or quantitation. By simplifying the frontend procedures for template preparation, the cost for screening these three founder mutations can be reduced to about US $200 per test when performed in conjunction with human papillomavirus (HPV) assays now routinely ordered for cervical cancer prevention. With this projected price structure, selective patients in a high-risk population can be tested and each provided with a set of DNA sequencing electropherograms to document the absence or presence of these founder mutations in her genome to help assess inherited susceptibility to breast and ovarian cancer in this era of precision molecular personalized medicine.
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Affiliation(s)
- Sin Hang Lee
- Milford Hospital and Milford Molecular Diagnostics Laboratory, 2044 Bridgeport Avenue, Milford, CT 06460, USA.
| | - Shaoxia Zhou
- State Key Laboratory of Molecular Biology, Institute of Biochemistry and Cell Biology, Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences, 320 Yueyang Road, Shanghai 200031, China.
- College of Plant Protection, Nanjing Agricultural University, Nanjing 210095, China.
| | - Tianjun Zhou
- State Key Laboratory of Molecular Biology, Institute of Biochemistry and Cell Biology, Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences, 320 Yueyang Road, Shanghai 200031, China.
| | - Guofan Hong
- State Key Laboratory of Molecular Biology, Institute of Biochemistry and Cell Biology, Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences, 320 Yueyang Road, Shanghai 200031, China.
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Abstract
The current standard model for identifying carriers of high-risk mutations in cancer-susceptibility genes (CSGs) generally involves a process that is not amenable to population-based testing: access to genetic tests is typically regulated by health-care providers on the basis of a labour-intensive assessment of an individual's personal and family history of cancer, with face-to-face genetic counselling performed before mutation testing. Several studies have shown that application of these selection criteria results in a substantial proportion of mutation carriers being missed. Population-based genetic testing has been proposed as an alternative approach to determining cancer susceptibility, and aims for a more-comprehensive detection of mutation carriers. Herein, we review the existing data on population-based genetic testing, and consider some of the barriers, pitfalls, and challenges related to the possible expansion of this approach. We consider mechanisms by which population-based genetic testing for cancer susceptibility could be delivered, and suggest how such genetic testing might be integrated into existing and emerging health-care structures. The existing models of genetic testing (including issues relating to informed consent) will very likely require considerable alteration if the potential benefits of population-based genetic testing are to be fully realized.
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Nogueiro I, Teixeira JC, Amorim A, Gusmão L, Alvarez L. Portuguese crypto-Jews: the genetic heritage of a complex history. Front Genet 2015; 6:12. [PMID: 25699075 PMCID: PMC4313780 DOI: 10.3389/fgene.2015.00012] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/18/2014] [Accepted: 01/11/2015] [Indexed: 11/22/2022] Open
Abstract
The first documents mentioning Jewish people in Iberia are from the Visigothic period. It was also in this period that the first documented anti-Judaic persecution took place. Other episodes of persecution would happen again and again during the long troubled history of the Jewish people in Iberia and culminated with the Decrees of Expulsion and the establishment of the Inquisition: some Jews converted to Catholicism while others resisted and were forcedly baptized, becoming the first Iberian Crypto-Jews. In the 18th century the official discrimination and persecution carried out by the Inquisition ended and several Jewish communities emerged in Portugal. From a populational genetics point of view, the worldwide Diaspora of contemporary Jewish communities has been intensely studied. Nevertheless, very little information is available concerning Sephardic and Iberian Crypto-Jewish descendants. Data from the Iberian Peninsula, the original geographic source of Sephardic Jews, is limited to two populations in Portugal, Belmonte, and Bragança district, and the Chueta community from Mallorca. Belmonte was the first Jewish community studied for uniparental markers. The construction of a reference model for the history of the Portuguese Jewish communities, in which the genetic and classical historical data interplay dynamically, is still ongoing. Recently an enlarged sample covering a wide region in the Northeast Portugal was undertaken, allowing the genetic profiling of male and female lineages. A Jewish specific shared female lineage (HV0b) was detected between the community of Belmonte and Bragança. In contrast to what was previously described as a hallmark of the Portuguese Jews, an unexpectedly high polymorphism of lineages was found in Bragança, showing a surprising resistance to the erosion of genetic diversity typical of small-sized isolate populations, as well as signs of admixture with the Portuguese host population.
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Affiliation(s)
- Inês Nogueiro
- Institute of Molecular Pathology and Immunology of the University of Porto Porto, Portugal ; Faculty of Sciences, University of Porto Porto, Portugal ; Instituto de Investigaç ao e Inovaç ao em Saúde, Universidade do Porto Porto, Portugal
| | - João C Teixeira
- Department of Evolutionary Genetics, Max Planck Institute for Evolutionary Anthropology Leipzig, Germany
| | - António Amorim
- Institute of Molecular Pathology and Immunology of the University of Porto Porto, Portugal ; Faculty of Sciences, University of Porto Porto, Portugal ; Instituto de Investigaç ao e Inovaç ao em Saúde, Universidade do Porto Porto, Portugal
| | - Leonor Gusmão
- Institute of Molecular Pathology and Immunology of the University of Porto Porto, Portugal ; Instituto de Investigaç ao e Inovaç ao em Saúde, Universidade do Porto Porto, Portugal ; DNA Diagnostic Laboratory, State University of Rio de Janeiro Rio de Janeiro, Brazil
| | - Luis Alvarez
- Institute of Molecular Pathology and Immunology of the University of Porto Porto, Portugal ; Faculty of Sciences, University of Porto Porto, Portugal ; Instituto de Investigaç ao e Inovaç ao em Saúde, Universidade do Porto Porto, Portugal
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