1
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Pinheiro M, Francisco I, Pinto C, Peixoto A, Veiga I, Filipe B, Santos C, Maia S, Silva J, Pinto P, Santos R, Claro I, Lage P, Lopes P, Ferreira S, Rosa I, Fonseca R, Rodrigues P, Henrique R, Chaves P, Pereira AD, Brandão C, Albuquerque C, Teixeira MR. The nonsense mutation MSH2 c.2152C>T shows a founder effect in Portuguese Lynch syndrome families. Genes Chromosomes Cancer 2019; 58:657-664. [PMID: 30968502 DOI: 10.1002/gcc.22759] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/13/2019] [Revised: 04/05/2019] [Accepted: 04/08/2019] [Indexed: 12/27/2022] Open
Abstract
The mutational spectrum of the MMR genes is highly heterogeneous, but specific mutations are observed at high frequencies in well-defined populations or ethnic groups, due to founder effects. The MSH2 mutation c.2152C>T, p.(Gln718*), has occasionally been described in Lynch families worldwide, including in Portuguese Lynch syndrome families. During genetic testing for Lynch syndrome at the Portuguese Oncology Institutes of Porto and Lisbon, this mutation was identified in 28 seemingly unrelated families. In order to evaluate if this alteration is a founder mutation, haplotype analysis using microsatellite and SNP markers flanking the MSH2 gene was performed in the 28 probands and 87 family members. Additionally, the geographic origin of these families was evaluated and the age of the mutation estimated. Twelve different haplotypes were phased for 13 out of the 28 families and shared a conserved region of ∼3.6 Mb. Based on the mutation and recombination events observed in the microsatellite haplotypes and assuming a generation time of 25 years, the age estimate for the MSH2 mutation was 273 ± 64 years. The geographic origins of these families were mostly from the Northern region of Portugal. Concluding, these results suggest that the MSH2 c.2152C>T alteration is a founder mutation in Portugal with a relatively recent origin. Furthermore, its high proportion indicates that screening for this mutation as a first step, together with the previously reported Portuguese founder mutations, may be cost-effective in genetic testing of Lynch syndrome suspects of Portuguese ancestry.
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Affiliation(s)
- Manuela Pinheiro
- Department of Genetics, Portuguese Oncology Institute of Porto, Porto, Portugal
| | - Inês Francisco
- Molecular Pathobiology Research Unit, Portuguese Oncology Institute of Lisbon, Lisbon, Portugal
| | - Carla Pinto
- Department of Genetics, Portuguese Oncology Institute of Porto, Porto, Portugal
| | - Ana Peixoto
- Department of Genetics, Portuguese Oncology Institute of Porto, Porto, Portugal
| | - Isabel Veiga
- Department of Genetics, Portuguese Oncology Institute of Porto, Porto, Portugal
| | - Bruno Filipe
- Molecular Pathobiology Research Unit, Portuguese Oncology Institute of Lisbon, Lisbon, Portugal
| | - Catarina Santos
- Department of Genetics, Portuguese Oncology Institute of Porto, Porto, Portugal
| | - Sofia Maia
- Department of Genetics, Portuguese Oncology Institute of Porto, Porto, Portugal
| | - João Silva
- Department of Genetics, Portuguese Oncology Institute of Porto, Porto, Portugal
| | - Pedro Pinto
- Department of Genetics, Portuguese Oncology Institute of Porto, Porto, Portugal
| | - Rui Santos
- Department of Genetics, Portuguese Oncology Institute of Porto, Porto, Portugal
| | - Isabel Claro
- Department of Gastroenterology, Portuguese Oncology Institute of Lisbon, Lisbon, Portugal.,Familial Risk Clinic, Portuguese Oncology Institute of Lisbon, Lisbon, Portugal
| | - Pedro Lage
- Department of Gastroenterology, Portuguese Oncology Institute of Lisbon, Lisbon, Portugal.,Familial Risk Clinic, Portuguese Oncology Institute of Lisbon, Lisbon, Portugal
| | - Paula Lopes
- Department of Pathology, Portuguese Oncology Institute of Porto, Porto, Portugal
| | - Sara Ferreira
- Department of Gastroenterology, Portuguese Oncology Institute of Lisbon, Lisbon, Portugal.,Familial Risk Clinic, Portuguese Oncology Institute of Lisbon, Lisbon, Portugal
| | - Isadora Rosa
- Department of Gastroenterology, Portuguese Oncology Institute of Lisbon, Lisbon, Portugal.,Familial Risk Clinic, Portuguese Oncology Institute of Lisbon, Lisbon, Portugal
| | - Ricardo Fonseca
- Department of Pathology, Portuguese Oncology Institute of Lisbon, Lisbon, Portugal
| | - Paula Rodrigues
- Familial Risk Clinic, Portuguese Oncology Institute of Lisbon, Lisbon, Portugal
| | - Rui Henrique
- Department of Pathology, Portuguese Oncology Institute of Porto, Porto, Portugal.,Institute of Biomedical Sciences Abel Salazar (ICBAS), University of Porto, Porto, Portugal
| | - Paula Chaves
- Department of Pathology, Portuguese Oncology Institute of Lisbon, Lisbon, Portugal
| | - António Dias Pereira
- Department of Gastroenterology, Portuguese Oncology Institute of Lisbon, Lisbon, Portugal
| | - Catarina Brandão
- Department of Gastroenterology, Portuguese Oncology Institute of Porto, Porto, Portugal
| | - Cristina Albuquerque
- Molecular Pathobiology Research Unit, Portuguese Oncology Institute of Lisbon, Lisbon, Portugal
| | - Manuel R Teixeira
- Department of Genetics, Portuguese Oncology Institute of Porto, Porto, Portugal.,Institute of Biomedical Sciences Abel Salazar (ICBAS), University of Porto, Porto, Portugal
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Natarajan P, Gold NB, Bick AG, McLaughlin H, Kraft P, Rehm HL, Peloso GM, Wilson JG, Correa A, Seidman JG, Seidman CE, Kathiresan S, Green RC. Aggregate penetrance of genomic variants for actionable disorders in European and African Americans. Sci Transl Med 2017; 8:364ra151. [PMID: 27831900 DOI: 10.1126/scitranslmed.aag2367] [Citation(s) in RCA: 52] [Impact Index Per Article: 7.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/23/2016] [Accepted: 09/30/2016] [Indexed: 12/21/2022]
Abstract
In populations that have not been selected for family history of disease, it is unclear how commonly pathogenic variants (PVs) in disease-associated genes for rare Mendelian conditions are found and how often they are associated with clinical features of these conditions. We conducted independent, prospective analyses of participants in two community-based epidemiological studies to test the hypothesis that persons carrying PVs in any of 56 genes that lead to 24 dominantly inherited, actionable conditions are more likely to exhibit the clinical features of the corresponding diseases than those without PVs. Among 462 European American Framingham Heart Study (FHS) and 3223 African-American Jackson Heart Study (JHS) participants who were exome-sequenced, we identified and classified 642 and 4429 unique variants, respectively, in these 56 genes while blinded to clinical data. In the same participants, we ascertained related clinical features from the participants' clinical history of cancer and most recent echocardiograms, electrocardiograms, and lipid measurements, without knowledge of variant classification. PVs were found in 5 FHS (1.1%) and 31 JHS (1.0%) participants. Carriers of PVs were more likely than expected, on the basis of incidence in noncarriers, to have related clinical features in both FHS (80.0% versus 12.4%) and JHS (26.9% versus 5.4%), yielding standardized incidence ratios of 6.4 [95% confidence interval (CI), 1.7 to 16.5; P = 7 × 10-4) in FHS and 4.7 (95% CI, 1.9 to 9.7; P = 3 × 10-4) in JHS. Individuals unselected for family history who carry PVs in 56 genes for actionable conditions have an increased aggregated risk of developing clinical features associated with the corresponding diseases.
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Affiliation(s)
- Pradeep Natarajan
- Center for Human Genetic Research, Cardiovascular Research Center, and Cardiology Division, Department of Medicine, Massachusetts General Hospital, Boston, MA 02114, USA.,Harvard Medical School, Boston, MA 02115, USA.,Broad Institute of Harvard and Massachusetts Institute of Technology, Cambridge, MA 02142, USA
| | - Nina B Gold
- Harvard Medical School, Boston, MA 02115, USA.,Boston Children's Hospital, Boston, MA 02115, USA
| | - Alexander G Bick
- Harvard Medical School, Boston, MA 02115, USA.,Broad Institute of Harvard and Massachusetts Institute of Technology, Cambridge, MA 02142, USA.,Department of Genetics, Harvard Medical School, Boston, MA 02115, USA
| | - Heather McLaughlin
- Harvard Medical School, Boston, MA 02115, USA.,Department of Pathology, Brigham and Women's Hospital, Boston, MA 02115, USA.,Partners HealthCare Personalized Medicine, Boston, MA 02115, USA
| | - Peter Kraft
- Departments of Epidemiology and Biostatistics, Harvard T.H. Chan School of Public Health, Boston, MA 02115, USA
| | - Heidi L Rehm
- Harvard Medical School, Boston, MA 02115, USA.,Department of Pathology, Brigham and Women's Hospital, Boston, MA 02115, USA.,Partners HealthCare Personalized Medicine, Boston, MA 02115, USA
| | - Gina M Peloso
- Harvard Medical School, Boston, MA 02115, USA.,Broad Institute of Harvard and Massachusetts Institute of Technology, Cambridge, MA 02142, USA
| | - James G Wilson
- Department of Physiology and Biophysics, University of Mississippi Medical Center, Jackson, MS 39216, USA
| | - Adolfo Correa
- Departments of Pediatrics and Medicine, University of Mississippi Medical Center, Jackson, MS 39216, USA
| | - Jonathan G Seidman
- Harvard Medical School, Boston, MA 02115, USA.,Department of Genetics, Harvard Medical School, Boston, MA 02115, USA
| | - Christine E Seidman
- Harvard Medical School, Boston, MA 02115, USA.,Department of Genetics, Harvard Medical School, Boston, MA 02115, USA.,Department of Medicine, Brigham and Women's Hospital, Boston, MA 02115, USA.,Howard Hughes Medical Institute, Harvard Medical School, Boston, MA 02115, USA
| | - Sekar Kathiresan
- Center for Human Genetic Research, Cardiovascular Research Center, and Cardiology Division, Department of Medicine, Massachusetts General Hospital, Boston, MA 02114, USA.,Harvard Medical School, Boston, MA 02115, USA.,Broad Institute of Harvard and Massachusetts Institute of Technology, Cambridge, MA 02142, USA
| | - Robert C Green
- Harvard Medical School, Boston, MA 02115, USA. .,Broad Institute of Harvard and Massachusetts Institute of Technology, Cambridge, MA 02142, USA.,Partners HealthCare Personalized Medicine, Boston, MA 02115, USA.,Department of Medicine, Brigham and Women's Hospital, Boston, MA 02115, USA
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Pinheiro M, Pinto C, Peixoto A, Veiga I, Mesquita B, Henrique R, Lopes P, Sousa O, Fragoso M, Dias LM, Baptista M, Marinho C, Mangold E, Vaccaro C, Evans DG, Farrington S, Dunlop MG, Teixeira MR. The MSH2 c.388_389del mutation shows a founder effect in Portuguese Lynch syndrome families. Clin Genet 2012; 84:244-50. [PMID: 23170986 DOI: 10.1111/cge.12062] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/21/2012] [Revised: 11/14/2012] [Accepted: 11/14/2012] [Indexed: 01/13/2023]
Abstract
The MSH2 c.388_389del mutation has occasionally been described in Lynch families worldwide. At the Portuguese Oncology Institute in Porto, Portugal, we have identified 16 seemingly unrelated families with this germline mutation. To evaluate if this alteration is a founder or a recurrent mutation we performed haplotype analysis in the 16 Portuguese index cases and 55 relatives, as well as in four index cases and 13 relatives reported from Germany, Scotland, England, and Argentina. In the Portuguese families we observed a shared haplotype of approximately 10 Mb and all were originated from the north of Portugal. These results suggest that this alteration is a founder mutation in Portugal with a relatively recent origin. In the reported families outside Portugal with this mutation different haplotype backgrounds were observed, supporting the hypothesis that it occurred de novo on multiple occasions. We also conclude that the high proportion of families with the MSH2 c.388_389del mutation indicates that screening for this alteration as a first step may be cost-effective in the genetic testing of Lynch syndrome suspects of Portuguese ancestry, especially those originating from the north of Portugal.
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Affiliation(s)
- M Pinheiro
- Department of Genetics, Portuguese Oncology Institute, Porto, Portugal
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Valentin MD, da Silva FC, dos Santos EMM, Lisboa BG, de Oliveira LP, Ferreira FDO, Gomy I, Nakagawa WT, Aguiar Junior S, Redal M, Vaccaro C, Valle AD, Sarroca C, Carraro DM, Rossi BM. Characterization of germline mutations of MLH1 and MSH2 in unrelated south American suspected Lynch syndrome individuals. Fam Cancer 2012; 10:641-7. [PMID: 21681552 DOI: 10.1007/s10689-011-9461-y] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
Lynch syndrome (LS) is an autosomal dominant syndrome that predisposes individuals to development of cancers early in life. These cancers are mainly the following: colorectal, endometrial, ovarian, small intestine, stomach and urinary tract cancers. LS is caused by germline mutations in DNA mismatch repair genes (MMR), mostly MLH1 and MSH2, which are responsible for more than 85% of known germline mutations. To search for germline mutations in MLH1 and MSH2 genes in 123 unrelated South American suspected LS patients (Bethesda or Amsterdam Criteria) DNA was obtained from peripheral blood, and PCR was performed followed by direct sequencing in both directions of all exons and intron-exon junctions regions of the MLH1 and MSH2 genes. MLH1 or MSH2 pathogenic mutations were found in 28.45% (34/123) of the individuals, where 25/57 (43.85%) fulfilled Amsterdam I, II and 9/66 (13.63%) the Bethesda criteria. The mutations found in both genes were as follows: nonsense (35.3%), frameshift (26.47%), splicing (23.52%), and missense (9%). Thirteen alterations (35.14%) were described for the first time. The data reported in this study add new information about MLH1 and MSH2 gene mutations and contribute to better characterize LS in Brazil, Uruguay and Argentina. The high rate of novel mutations demonstrates the importance of defining MLH1 and MSH2 mutations in distinct LS populations.
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Affiliation(s)
- Mev Dominguez Valentin
- Laboratory of Genomics and Molecular Biology, Centro Internacional de Pesquisa e Ensino, A.C.Camargo Hospital, São Paulo, Brazil.
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