1
|
Bouras A, Lefol C, Ruano E, Grand-Masson C, Auclair-Perrossier J, Wang Q. Splicing analysis of 24 potential spliceogenic variants in MMR genes and clinical interpretation based on refined ACMG/AMP criteria. Hum Mol Genet 2024; 33:850-859. [PMID: 38311346 DOI: 10.1093/hmg/ddae016] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/10/2023] [Revised: 12/18/2023] [Accepted: 01/19/2024] [Indexed: 02/10/2024] Open
Abstract
Lynch syndrome (LS) is a common hereditary cancer syndrome caused by heterozygous germline pathogenic variants in DNA mismatch repair (MMR) genes. Splicing defect constitutes one of the major mechanisms for MMR gene inactivation. Using RT-PCR based RNA analysis, we investigated 24 potential spliceogenic variants in MMR genes and determined their pathogenicity based on refined splicing-related American College of Medical Genetics and Genomics/Association for Molecular Pathology (ACMG/AMP) criteria. Aberrant transcripts were confirmed in 19 variants and 17 of which were classified as pathogenic including 11 located outside of canonical splice sites. Most of these variants were previously reported in LS patients without mRNA splicing assessment. Thus, our study provides crucial evidence for pathogenicity determination, allowing for appropriate clinical follow-up. We also found that computational predictions were globally well correlated with RNA analysis results and the use of both SPiP and SpliceAI software appeared more efficient for splicing defect prediction.
Collapse
Affiliation(s)
- Ahmed Bouras
- Centre Léon Bérard, Laboratory of Constitutional Genetics for Frequent Cancer HCL-CLB, 28 Laennec street, 69008 Lyon, France
- Inserm U1052, Lyon Cancer Research Center, 28 Laennec street, 69008 Lyon, France
| | - Cedrick Lefol
- Centre Léon Bérard, Laboratory of Constitutional Genetics for Frequent Cancer HCL-CLB, 28 Laennec street, 69008 Lyon, France
| | - Eric Ruano
- Centre Léon Bérard, Laboratory of Constitutional Genetics for Frequent Cancer HCL-CLB, 28 Laennec street, 69008 Lyon, France
| | - Chloé Grand-Masson
- Centre Léon Bérard, Laboratory of Constitutional Genetics for Frequent Cancer HCL-CLB, 28 Laennec street, 69008 Lyon, France
| | - Jessie Auclair-Perrossier
- Centre Léon Bérard, Lyon Cancer Research Center, Cancer Genomic Platform, 28 Laennec street, 69008 Lyon, France
| | - Qing Wang
- Centre Léon Bérard, Laboratory of Constitutional Genetics for Frequent Cancer HCL-CLB, 28 Laennec street, 69008 Lyon, France
- Centre Léon Bérard, Lyon Cancer Research Center, Cancer Genomic Platform, 28 Laennec street, 69008 Lyon, France
| |
Collapse
|
2
|
Meulemans L, Baert Desurmont S, Waill MC, Castelain G, Killian A, Hauchard J, Frebourg T, Coulet F, Martins A, Muleris M, Gaildrat P. Comprehensive RNA and protein functional assessments contribute to the clinical interpretation of MSH2 variants causing in-frame splicing alterations. J Med Genet 2022; 60:450-459. [PMID: 36113988 DOI: 10.1136/jmg-2022-108576] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/14/2022] [Accepted: 08/26/2022] [Indexed: 11/04/2022]
Abstract
BackgroundSpliceogenic variants in disease-causing genes are often presumed pathogenic since most induce frameshifts resulting in loss of function. However, it was recently shown in cancer predisposition genes that some may trigger in-frame anomalies that preserve function. Here, we addressed this question by using MSH2, a DNA mismatch repair gene implicated in Lynch syndrome, as a model system.MethodsEighteen MSH2 variants, mostly localised within canonical splice sites, were analysed by using minigene splicing assays. The impact of the resulting protein alterations was assessed in a methylation tolerance-based assay. Clinicopathological characteristics of variant carriers were collected.ResultsThree in-frame RNA biotypes were identified based on variant-induced spliceogenic outcomes: exon skipping (E3, E4, E5 and E12), segmental exonic deletions (E7 and E15) and intronic retentions (I3, I6, I12 and I13). The 10 corresponding protein isoforms exhibit either large deletions (49–93 amino acids (aa)), small deletions (12 or 16 aa) or insertions (3–10 aa) within different functional domains. We showed that all these modifications abrogate MSH2 function, in agreement with the clinicopathological features of variant carriers.ConclusionAltogether, these data demonstrate that MSH2 function is intolerant to in-frame indels caused by the spliceogenic variants analysed in this study, supporting their pathogenic nature. This work stresses the importance of combining complementary RNA and protein approaches to ensure accurate clinical interpretation of in-frame spliceogenic variants.
Collapse
Affiliation(s)
- Laëtitia Meulemans
- Normandie Univ, UNIROUEN, Inserm U1245, Normandy Centre for Genomic and Personalized Medicine, F-76000 Rouen, France
| | - Stéphanie Baert Desurmont
- Normandie Univ, UNIROUEN, Inserm U1245, Normandy Centre for Genomic and Personalized Medicine, and CHU Rouen, Department of Genetics, F-76000 Rouen, France
| | - Marie-Christine Waill
- Department of Genetics, AP-HP.Sorbonne Université, Hôpital Pitié-Salpêtrière, Paris, France
| | - Gaia Castelain
- Normandie Univ, UNIROUEN, Inserm U1245, Normandy Centre for Genomic and Personalized Medicine, F-76000 Rouen, France
| | - Audrey Killian
- Normandie Univ, UNIROUEN, Inserm U1245, Normandy Centre for Genomic and Personalized Medicine, F-76000 Rouen, France
| | - Julie Hauchard
- Normandie Univ, UNIROUEN, Inserm U1245, Normandy Centre for Genomic and Personalized Medicine, F-76000 Rouen, France
| | - Thierry Frebourg
- Normandie Univ, UNIROUEN, Inserm U1245, Normandy Centre for Genomic and Personalized Medicine, and CHU Rouen, Department of Genetics, F-76000 Rouen, France
| | - Florence Coulet
- Department of Genetics, AP-HP.Sorbonne Université, Hôpital Pitié-Salpêtrière, Paris, France
- Inserm UMR-S 938, Centre de Recherche Saint-Antoine, CRSA, Paris, France
| | - Alexandra Martins
- Normandie Univ, UNIROUEN, Inserm U1245, Normandy Centre for Genomic and Personalized Medicine, F-76000 Rouen, France
| | - Martine Muleris
- Department of Genetics, AP-HP.Sorbonne Université, Hôpital Pitié-Salpêtrière, Paris, France
- Inserm UMR-S 938, Centre de Recherche Saint-Antoine, CRSA, Paris, France
| | - Pascaline Gaildrat
- Normandie Univ, UNIROUEN, Inserm U1245, Normandy Centre for Genomic and Personalized Medicine, F-76000 Rouen, France
| |
Collapse
|
3
|
Pourtavakoli A, Ghafouri-Fard S. Calcium signaling in neurodevelopment and pathophysiology of autism spectrum disorders. Mol Biol Rep 2022; 49:10811-10823. [PMID: 35857176 DOI: 10.1007/s11033-022-07775-6] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/29/2022] [Accepted: 07/05/2022] [Indexed: 11/24/2022]
Abstract
BACKGROUND Autism spectrum disorder (ASD) covers a group of neurodevelopmental disorders with complex genetic background. Several genetic mutations, epigenetic alterations, copy number variations and single nucleotide polymorphisms have been reported that cause ASD or modify its phenotype. Among signaling pathways that influence pathogenesis of ASD, calcium signaling has a prominent effect. METHODS We searched PubMed and Google Scholar databases with key words "Calcium signaling" and "Autism spectrum disorder". CONCLUSION This type of signaling has essential roles in the cell physiology. Endoplasmic reticulum and mitochondria are the key organelles involved in this signaling. It is vastly accepted that organellar disorders intensely influence the central nervous system (CNS). Several lines of evidence indicate alterations in the function of calcium channels in polygenic disorders affecting CNS. In the current review, we describe the role of calcium signaling in normal function of CNS and pathophysiology of ASD.
Collapse
Affiliation(s)
- Ashkan Pourtavakoli
- Department of Medical Genetics, Shahid Beheshti University of Medical Sciences, Tehran, Iran
| | - Soudeh Ghafouri-Fard
- Department of Medical Genetics, Shahid Beheshti University of Medical Sciences, Tehran, Iran.
| |
Collapse
|
4
|
Morak M, Pineda M, Martins A, Gaildrat P, Tubeuf H, Drouet A, Gómez C, Dámaso E, Schaefer K, Steinke-Lange V, Koehler U, Laner A, Hauchard J, Chauris K, Holinski-Feder E, Capellá G. Splicing analyses for variants in MMR genes: best practice recommendations from the European Mismatch Repair Working Group. Eur J Hum Genet 2022; 30:1051-1059. [PMID: 35676339 PMCID: PMC9437034 DOI: 10.1038/s41431-022-01106-w] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/25/2021] [Revised: 03/20/2022] [Accepted: 04/11/2022] [Indexed: 11/09/2022] Open
Abstract
Over 20% of the DNA mismatch repair (MMR) germline variants in suspected Lynch syndrome patients are classified as variants of uncertain significance (VUS). Well-established functional assays are pivotal for assessing the biological impact of these variants and provide relevant evidence for clinical classification. In our collaborative European Mismatch Repair Working Group (EMMR-WG) we compared three different experimental approaches for evaluating the effect of seven variants on mRNA splicing in MMR genes: (i) RT-PCR of full-length transcripts (FLT), (ii) RT-PCR of targeted transcript sections (TTS), both from patient biological samples and (iii) minigene splicing assays. An overall good concordance was observed between splicing patterns in TTS, FLT and minigene analyses for all variants. The FLT analysis depicted a higher number of different isoforms and mitigated PCR-bias towards shorter isoforms. TTS analyses may miss aberrant isoforms and minigene assays may under/overestimate the severity of certain splicing defects. The interpretation of the experimental findings must be cautious to adequately discriminate abnormal events from physiological complex alternative splicing patterns. A consensus strategy for investigating the impact of MMR variants on splicing was defined. First, RNA should be obtained from patient's cell cultures (such as fresh lymphocyte cultures) incubated with/without a nonsense-mediated decay inhibitor. Second, FLT RT-PCR analysis is recommended to oversee all generated isoforms. Third, TTS analysis and minigene assays are useful independent approaches for verifying and clarifying FLT results. The use of several methodologies is likely to increase the strength of the experimental evidence which contributes to improve variant interpretation.
Collapse
Affiliation(s)
- Monika Morak
- Medizinische Klinik und Poliklinik IV, Campus Innenstadt, Klinikum der Universität München, Munich, Germany.,MGZ - Medizinisch Genetisches Zentrum, Munich, Germany
| | - Marta Pineda
- Hereditary Cancer Program, Catalan Institute of Oncology-IDIBELL, ONCOBELL Program, L'Hospitalet, Barcelona, Spain.,Centro de Investigación Biomédica en Red de Cáncer (CIBERONC), Madrid, Spain
| | | | | | - Hélène Tubeuf
- Inserm U1245, UNIROUEN, Normandie Univ, F-76000, Rouen, France.,Interactive Biosoftware, Rouen, France
| | - Aurélie Drouet
- Inserm U1245, UNIROUEN, Normandie Univ, F-76000, Rouen, France
| | - Carolina Gómez
- Hereditary Cancer Program, Catalan Institute of Oncology-IDIBELL, ONCOBELL Program, L'Hospitalet, Barcelona, Spain
| | - Estela Dámaso
- Hereditary Cancer Program, Catalan Institute of Oncology-IDIBELL, ONCOBELL Program, L'Hospitalet, Barcelona, Spain
| | - Kerstin Schaefer
- Medizinische Klinik und Poliklinik IV, Campus Innenstadt, Klinikum der Universität München, Munich, Germany
| | - Verena Steinke-Lange
- Medizinische Klinik und Poliklinik IV, Campus Innenstadt, Klinikum der Universität München, Munich, Germany.,MGZ - Medizinisch Genetisches Zentrum, Munich, Germany
| | - Udo Koehler
- MGZ - Medizinisch Genetisches Zentrum, Munich, Germany
| | - Andreas Laner
- MGZ - Medizinisch Genetisches Zentrum, Munich, Germany
| | - Julie Hauchard
- Inserm U1245, UNIROUEN, Normandie Univ, F-76000, Rouen, France
| | - Karine Chauris
- Inserm U1245, UNIROUEN, Normandie Univ, F-76000, Rouen, France
| | - Elke Holinski-Feder
- Medizinische Klinik und Poliklinik IV, Campus Innenstadt, Klinikum der Universität München, Munich, Germany. .,MGZ - Medizinisch Genetisches Zentrum, Munich, Germany.
| | - Gabriel Capellá
- Hereditary Cancer Program, Catalan Institute of Oncology-IDIBELL, ONCOBELL Program, L'Hospitalet, Barcelona, Spain. .,Centro de Investigación Biomédica en Red de Cáncer (CIBERONC), Madrid, Spain.
| |
Collapse
|
5
|
Kaissarian NM, Meyer D, Kimchi-Sarfaty C. Synonymous Variants: Necessary Nuance in our Understanding of Cancer Drivers and Treatment Outcomes. J Natl Cancer Inst 2022; 114:1072-1094. [PMID: 35477782 PMCID: PMC9360466 DOI: 10.1093/jnci/djac090] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/18/2022] [Revised: 03/24/2022] [Accepted: 04/18/2022] [Indexed: 11/13/2022] Open
Abstract
Once called "silent mutations" and assumed to have no effect on protein structure and function, synonymous variants are now recognized to be drivers for some cancers. There have been significant advances in our understanding of the numerous mechanisms by which synonymous single nucleotide variants (sSNVs) can affect protein structure and function by affecting pre-mRNA splicing, mRNA expression, stability, folding, miRNA binding, translation kinetics, and co-translational folding. This review highlights the need for considering sSNVs in cancer biology to gain a better understanding of the genetic determinants of human cancers and to improve their diagnosis and treatment. We surveyed the literature for reports of sSNVs in cancer and found numerous studies on the consequences of sSNVs on gene function with supporting in vitro evidence. We also found reports of sSNVs that have statistically significant associations with specific cancer types but for which in vitro studies are lacking to support the reported associations. Additionally, we found reports of germline and somatic sSNVs that were observed in numerous clinical studies and for which in silico analysis predicts possible effects on gene function. We provide a review of these investigations and discuss necessary future studies to elucidate the mechanisms by which sSNVs disrupt protein function and are play a role in tumorigeneses, cancer progression, and treatment efficacy. As splicing dysregulation is one of the most well recognized mechanisms by which sSNVs impact protein function, we also include our own in silico analysis for predicting which sSNVs may disrupt pre-mRNA splicing.
Collapse
Affiliation(s)
- Nayiri M Kaissarian
- Hemostasis Branch, Division of Plasma Protein Therapeutics, Office of Tissues and Advanced Therapies, Center for Biologics Evaluation & Research, US Food and Drug Administration, Silver Spring, MD, USA
| | - Douglas Meyer
- Hemostasis Branch, Division of Plasma Protein Therapeutics, Office of Tissues and Advanced Therapies, Center for Biologics Evaluation & Research, US Food and Drug Administration, Silver Spring, MD, USA
| | - Chava Kimchi-Sarfaty
- Hemostasis Branch, Division of Plasma Protein Therapeutics, Office of Tissues and Advanced Therapies, Center for Biologics Evaluation & Research, US Food and Drug Administration, Silver Spring, MD, USA
| |
Collapse
|
6
|
Kamburova Z, Popovska S, Kovacheva K, Petrov K, Nikolova S. Familial Lynch syndrome with early age of onset and confirmed splice site mutation in MSH2: A case report. Biomed Rep 2022; 16:39. [DOI: 10.3892/br.2022.1522] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/19/2021] [Accepted: 02/09/2022] [Indexed: 11/05/2022] Open
Affiliation(s)
- Zornitsa Kamburova
- Department of Medical Genetics, Medical University‑Pleven, Center of Medical Genetics in University Hospital ‘Dr. Georgi Stranski’, 5800 Pleven, Bulgaria
| | - Savelina Popovska
- Department of Pathoanatomy, Medical University‑Pleven, University Hospital ‘Dr. Georgi Stranski’, 5800 Pleven, Bulgaria
| | - Katya Kovacheva
- Department of Medical Genetics, Medical University‑Pleven, Center of Medical Genetics in University Hospital ‘Dr. Georgi Stranski’, 5800 Pleven, Bulgaria
| | - Krasimir Petrov
- Department of Pathoanatomy, Medical University‑Pleven, University Hospital ‘Dr. Georgi Stranski’, 5800 Pleven, Bulgaria
| | - Slavena Nikolova
- Department of Medical Genetics, Medical University‑Pleven, Center of Medical Genetics in University Hospital ‘Dr. Georgi Stranski’, 5800 Pleven, Bulgaria
| |
Collapse
|
7
|
Zhang R, Chen Z, Song Q, Wang S, Liu Z, Zhao X, Shi X, Guo W, Lang Y, Bottillo I, Shao L. Identification of seven exonic variants in the SLC4A1, ATP6V1B1, and ATP6V0A4 genes that alter RNA splicing by minigene assay. Hum Mutat 2021; 42:1153-1164. [PMID: 34157794 DOI: 10.1002/humu.24246] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/27/2021] [Revised: 06/02/2021] [Accepted: 06/19/2021] [Indexed: 12/25/2022]
Abstract
Primary distal renal tubular acidosis (dRTA) is a rare tubular disease associated with variants in SLC4A1, ATP6V0A4, ATP6V1B1, FOXⅠ1, or WDR72 genes. Currently, there is growing evidence that all types of exonic variants can alter splicing regulatory elements, affecting the precursor messenger RNA (pre-mRNA) splicing process. This study was to determine the consequences of variants associated with dRTA on pre-mRNA splicing combined with predictive bioinformatics tools and minigene assay. As a result, among the 15 candidate variants, 7 variants distributed in SLC4A1 (c.1765C>T, p.Arg589Cys), ATP6V1B1 (c.368G>T, p.Gly123Val; c.370C>T, p.Arg124Trp; c.484G>T, p.Glu162* and c.1102G>A, p.Glu368Lys) and ATP6V0A4 genes (c.322C>T, p.Gln108* and c.1572G>A, p.Pro524Pro) were identified to result in complete or incomplete exon skipping by either disruption of exonic splicing enhancers (ESEs) and generation of exonic splicing silencers, or interference with the recognition of the classic splicing site, or both. To our knowledge, this is the first study on pre-mRNA splicing of exonic variants in the dRTA-related genes. These results highlight the importance of assessing the effects of exonic variants at the mRNA level and suggest that minigene analysis is an effective tool for evaluating the effects of splicing on variants in vitro.
Collapse
Affiliation(s)
- Ruixiao Zhang
- Department of Nephrology, The Affiliated Qingdao Municipal Hospital of Qingdao University, Qingdao, China
| | - Zeqing Chen
- Academy for Engineering and Technology, Fudan University, Shanghai, China
| | - Qijing Song
- Emergency Center, People's Hospital of Jimo District, Qingdao, China
| | - Sai Wang
- Department of Nephrology, The Affiliated Qingdao Municipal Hospital of Qingdao University, Qingdao, China.,Department of Dermatology, Peking University First Hospital, Beijing, China
| | - Zhiying Liu
- Department of Nephrology, The Affiliated Qingdao Municipal Hospital of Qingdao University, Qingdao, China
| | - Xiangzhong Zhao
- Central Laboratory, The Affiliated Hospital of Qingdao University, Qingdao, China
| | - Xiaomeng Shi
- Department of Nephrology, The Affiliated Qingdao Municipal Hospital of Qingdao University, Qingdao, China
| | - Wencong Guo
- Department of Nephrology, The Affiliated Qingdao Municipal Hospital of Qingdao University, Qingdao, China
| | - Yanhua Lang
- Department of Nephrology, The Affiliated Qingdao Municipal Hospital of Qingdao University, Qingdao, China
| | - Irene Bottillo
- Division of Medical Genetics, Department of Molecular Medicine, San Camillo-Forlanini Hospital, Sapienza University, Rome, Italy
| | - Leping Shao
- Department of Nephrology, The Affiliated Qingdao Municipal Hospital of Qingdao University, Qingdao, China
| |
Collapse
|
8
|
Dominguez-Valentin M, Plazzer JP, Sampson JR, Engel C, Aretz S, Jenkins MA, Sunde L, Bernstein I, Capella G, Balaguer F, Macrae F, Winship IM, Thomas H, Evans DG, Burn J, Greenblatt M, de Vos tot Nederveen Cappel WH, Sijmons RH, Nielsen M, Bertario L, Bonanni B, Tibiletti MG, Cavestro GM, Lindblom A, Valle AD, Lopez-Kostner F, Alvarez K, Gluck N, Katz L, Heinimann K, Vaccaro CA, Nakken S, Hovig E, Green K, Lalloo F, Hill J, Vasen HFA, Perne C, Büttner R, Görgens H, Holinski-Feder E, Morak M, Holzapfel S, Hüneburg R, von Knebel Doeberitz M, Loeffler M, Rahner N, Weitz J, Steinke-Lange V, Schmiegel W, Vangala D, Crosbie EJ, Pineda M, Navarro M, Brunet J, Moreira L, Sánchez A, Serra-Burriel M, Mints M, Kariv R, Rosner G, Piñero TA, Pavicic WH, Kalfayan P, Broeke SWT, Mecklin JP, Pylvänäinen K, Renkonen-Sinisalo L, Lepistö A, Peltomäki P, Hopper JL, Win AK, Buchanan DD, Lindor NM, Gallinger S, Marchand LL, Newcomb PA, Figueiredo JC, Thibodeau SN, Therkildsen C, Hansen TVO, Lindberg L, Rødland EA, Neffa F, Esperon P, Tjandra D, Möslein G, Seppälä TT, Møller P. No Difference in Penetrance between Truncating and Missense/Aberrant Splicing Pathogenic Variants in MLH1 and MSH2: A Prospective Lynch Syndrome Database Study. J Clin Med 2021; 10:jcm10132856. [PMID: 34203177 PMCID: PMC8269121 DOI: 10.3390/jcm10132856] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/24/2021] [Revised: 06/15/2021] [Accepted: 06/16/2021] [Indexed: 12/31/2022] Open
Abstract
Background. Lynch syndrome is the most common genetic predisposition for hereditary cancer. Carriers of pathogenic changes in mismatch repair (MMR) genes have an increased risk of developing colorectal (CRC), endometrial, ovarian, urinary tract, prostate, and other cancers, depending on which gene is malfunctioning. In Lynch syndrome, differences in cancer incidence (penetrance) according to the gene involved have led to the stratification of cancer surveillance. By contrast, any differences in penetrance determined by the type of pathogenic variant remain unknown. Objective. To determine cumulative incidences of cancer in carriers of truncating and missense or aberrant splicing pathogenic variants of the MLH1 and MSH2 genes. Methods. Carriers of pathogenic variants of MLH1 (path_MLH1) and MSH2 (path_MSH2) genes filed in the Prospective Lynch Syndrome Database (PLSD) were categorized as truncating or missense/aberrant splicing according to the InSiGHT criteria for pathogenicity. Results. Among 5199 carriers, 1045 had missense or aberrant splicing variants, and 3930 had truncating variants. Prospective observation years for the two groups were 8205 and 34,141 years, respectively, after which there were no significant differences in incidences for cancer overall or for colorectal cancer or endometrial cancers separately. Conclusion. Truncating and missense or aberrant splicing pathogenic variants were associated with similar average cumulative incidences of cancer in carriers of path MLH1 and path_MSH2.
Collapse
Affiliation(s)
- Mev Dominguez-Valentin
- Department of Tumor Biology, Institute of Cancer Research, The Norwegian Radium Hospital, 0379 Oslo, Norway; (S.N.); (E.H.); (E.A.R.); (P.M.)
- European Hereditary Tumour Group (EHTG), c/o Lindsays, Caledonian Exchange 19A Canning Street, Edinburgh EH3 8HE, UK; (J.R.S.); (C.E.); (G.C.); (J.B.); (R.H.S.); (J.-P.M.); (G.M.); (T.T.S.)
- The International Society for Gastrointestinal Hereditary Tumours (InSiGHT), The Polyposis Registry, St Mark’s Hospital, Watford Road, Harrow, Middlesex HA1 3UJ, UK; (J.-P.P.); (F.M.); (E.H.-F.)
- Correspondence:
| | - John-Paul Plazzer
- The International Society for Gastrointestinal Hereditary Tumours (InSiGHT), The Polyposis Registry, St Mark’s Hospital, Watford Road, Harrow, Middlesex HA1 3UJ, UK; (J.-P.P.); (F.M.); (E.H.-F.)
- Department of Medicine, Colorectal Medicine and Genetics, The Royal Melbourne Hospital, Melbourne, VIC 3050, Australia;
| | - Julian R. Sampson
- European Hereditary Tumour Group (EHTG), c/o Lindsays, Caledonian Exchange 19A Canning Street, Edinburgh EH3 8HE, UK; (J.R.S.); (C.E.); (G.C.); (J.B.); (R.H.S.); (J.-P.M.); (G.M.); (T.T.S.)
- Institute of Medical Genetics, Division of Cancer and Genetics, Cardiff University School of Medicine, Heath Park, Cardiff CF14 4XN, UK
| | - Christoph Engel
- European Hereditary Tumour Group (EHTG), c/o Lindsays, Caledonian Exchange 19A Canning Street, Edinburgh EH3 8HE, UK; (J.R.S.); (C.E.); (G.C.); (J.B.); (R.H.S.); (J.-P.M.); (G.M.); (T.T.S.)
- Institute for Medical Informatics, Statistics and Epidemiology, University of Leipzig, 04107 Leipzig, Germany;
| | - Stefan Aretz
- Institute of Human Genetics, National Center for Hereditary Tumor Syndromes, Medical Faculty, University Hospital Bonn, University of Bonn, 53127 Bonn, Germany; (S.A.); (C.P.); (S.H.)
| | - Mark A. Jenkins
- Melbourne School of Population and Global Health, Centre for Epidemiology and Biostatistics, The University of Melbourne, Parkville, VIC 3010, Australia; (M.A.J.); (J.L.H.); (A.K.W.)
| | - Lone Sunde
- Department of Clinical Genetics, Aalborg University Hospital, 9000 Aalborg, Denmark;
- Department of Biomedicine, Aarhus University, DK-8000 Aarhus, Denmark
| | - Inge Bernstein
- Department of Surgical Gastroenterology, Aalborg University Hospital, Aalborg University, 9100 Aalborg, Denmark;
- Department of Clinical Medicine, Aalborg University Hospital, Aalborg University, 9100 Aalborg, Denmark
| | - Gabriel Capella
- European Hereditary Tumour Group (EHTG), c/o Lindsays, Caledonian Exchange 19A Canning Street, Edinburgh EH3 8HE, UK; (J.R.S.); (C.E.); (G.C.); (J.B.); (R.H.S.); (J.-P.M.); (G.M.); (T.T.S.)
- The International Society for Gastrointestinal Hereditary Tumours (InSiGHT), The Polyposis Registry, St Mark’s Hospital, Watford Road, Harrow, Middlesex HA1 3UJ, UK; (J.-P.P.); (F.M.); (E.H.-F.)
- Hereditary Cancer Program, Institut Català d’Oncologia-IDIBELL, L, Hospitalet de Llobregat, 08908 Barcelona, Spain; (M.P.); (M.N.); (J.B.)
| | - Francesc Balaguer
- Gastroenterology Department, Hospital Clínic de Barcelona, Centro de Investigación Biomédica en Red de Enfermedades Hepáticas y Digestivas (CIBERehd), Institut d’Investigacions Biomediques August Pi i Sunyer (IDIBAPS), Universitat de Barcelona, 08036 Barcelona, Spain; (F.B.); (L.M.); (A.S.)
| | - Finlay Macrae
- The International Society for Gastrointestinal Hereditary Tumours (InSiGHT), The Polyposis Registry, St Mark’s Hospital, Watford Road, Harrow, Middlesex HA1 3UJ, UK; (J.-P.P.); (F.M.); (E.H.-F.)
- Department of Medicine, Colorectal Medicine and Genetics, The Royal Melbourne Hospital, Melbourne, VIC 3050, Australia;
| | - Ingrid M. Winship
- Department of Genomic Medicine, Royal Melbourne Hospital, University of Melbourne, Melbourne, VIC 3052, Australia;
- Department of Medicine, Royal Melbourne Hospital, University of Melbourne, Melbourne, VIC 3052, Australia
| | - Huw Thomas
- Department of Surgery and Cancer, St Mark’s Hospital, Imperial College London, London HA1 3UJ, UK;
| | - Dafydd Gareth Evans
- Manchester Centre for Genomic Medicine, Manchester University NHS Foundation Trust, Manchester M13 9WL, UK; (D.G.E.); (K.G.); (F.L.)
| | - John Burn
- European Hereditary Tumour Group (EHTG), c/o Lindsays, Caledonian Exchange 19A Canning Street, Edinburgh EH3 8HE, UK; (J.R.S.); (C.E.); (G.C.); (J.B.); (R.H.S.); (J.-P.M.); (G.M.); (T.T.S.)
- The International Society for Gastrointestinal Hereditary Tumours (InSiGHT), The Polyposis Registry, St Mark’s Hospital, Watford Road, Harrow, Middlesex HA1 3UJ, UK; (J.-P.P.); (F.M.); (E.H.-F.)
- Faculty of Medical Sciences, Newcastle University, Newcastle upon Tyne NE1 7RU, UK
| | - Marc Greenblatt
- Larner College of Medicine, University of Vermont, Burlington, VT 05405, USA;
| | | | - Rolf H. Sijmons
- European Hereditary Tumour Group (EHTG), c/o Lindsays, Caledonian Exchange 19A Canning Street, Edinburgh EH3 8HE, UK; (J.R.S.); (C.E.); (G.C.); (J.B.); (R.H.S.); (J.-P.M.); (G.M.); (T.T.S.)
- The International Society for Gastrointestinal Hereditary Tumours (InSiGHT), The Polyposis Registry, St Mark’s Hospital, Watford Road, Harrow, Middlesex HA1 3UJ, UK; (J.-P.P.); (F.M.); (E.H.-F.)
- Department of Genetics, University Medical Center Groningen, University of Groningen, 9713GZ Groningen, The Netherlands
| | - Maartje Nielsen
- Department of Clinical Genetics, Leids Universitair Medisch Centrum, 2300RC Leiden, The Netherlands; (M.N.); (S.W.t.B.)
| | - Lucio Bertario
- Division of Cancer Prevention and Genetics, IEO, European Institute of Oncology, Fondazione IRCCS Istituto Nazionale dei Tumori, IRCCS, 20141 Milan, Italy;
| | - Bernardo Bonanni
- Division of Cancer Prevention and Genetics, IEO, European Institute of Oncology, IRCCS, 20141 Milan, Italy;
| | - Maria Grazia Tibiletti
- Ospedale di Circolo ASST Settelaghi, Centro di Ricerca Tumori Eredo-Familiari, Università dell’Insubria, 21100 Varese, Italy;
| | - Giulia Martina Cavestro
- Gastroenterology and Gastrointestinal Endoscopy Unit, San Raffaele Scientific Institute, Vita-Salute San Raffaele University, 20132 Milan, Italy;
| | - Annika Lindblom
- Department of Molecular Medicine and Surgery, Karolinska Institutet, 171 76 Stockholm, Sweden;
| | - Adriana Della Valle
- Grupo Colaborativo Uruguayo, Investigación de Afecciones Oncológicas Hereditarias (GCU), Hospital Fuerzas Armadas, Montevideo 11600, Uruguay; (A.D.V.); (F.N.); (P.E.)
| | - Francisco Lopez-Kostner
- Programa Cáncer Heredo Familiar, Clínica Universidad de los Andes, Santiago 7550000, Chile; (F.L.-K.); (K.A.)
| | - Karin Alvarez
- Programa Cáncer Heredo Familiar, Clínica Universidad de los Andes, Santiago 7550000, Chile; (F.L.-K.); (K.A.)
| | - Nathan Gluck
- Department of Gastroenterology, Sackler Faculty of Medicine, Tel-Aviv Sourasky Medical Center, Tel-Aviv University, Tel-Aviv 64259, Israel; (N.G.); (R.K.); (G.R.)
| | - Lior Katz
- The Department of Gastroenterology, Gastro-Oncology Unit, High Risk and GI Cancer Prevention Clinic, Sheba Medical Center, Sheba 91120, Israel;
| | - Karl Heinimann
- Medical Genetics, Institute for Medical Genetics and Pathology, University Hospital Basel, 4031 Basel, Switzerland;
| | - Carlos A. Vaccaro
- Hereditary Cancer Program (PROCANHE), Hospital Italiano de Buenos Aires, Buenos Aires C1199ABB, Argentina; (C.A.V.); (T.A.P.); (W.H.P.); (P.K.)
- Instituto de Medicina Traslacional e Ingenieria Biomedica (IMTIB), CONICET IU, Hospital Italiano de Buenos Aires, Buenos Aires C1199ABB, Argentina
| | - Sigve Nakken
- Department of Tumor Biology, Institute of Cancer Research, The Norwegian Radium Hospital, 0379 Oslo, Norway; (S.N.); (E.H.); (E.A.R.); (P.M.)
- Centre for Cancer Cell Reprogramming (CanCell), Institute of Clinical Medicine, Faculty of Medicine, University of Oslo, 4950 Oslo, Norway
| | - Eivind Hovig
- Department of Tumor Biology, Institute of Cancer Research, The Norwegian Radium Hospital, 0379 Oslo, Norway; (S.N.); (E.H.); (E.A.R.); (P.M.)
- Department of Informatics, Centre for Bioinformatics, University of Oslo, 0316 Oslo, Norway
| | - Kate Green
- Manchester Centre for Genomic Medicine, Manchester University NHS Foundation Trust, Manchester M13 9WL, UK; (D.G.E.); (K.G.); (F.L.)
| | - Fiona Lalloo
- Manchester Centre for Genomic Medicine, Manchester University NHS Foundation Trust, Manchester M13 9WL, UK; (D.G.E.); (K.G.); (F.L.)
| | - James Hill
- Department of Surgery, Central Manchester University Hospitals NHS, Foundation Trust, University of Manchester, London M13 9WL, UK;
| | - Hans F. A. Vasen
- Department of Gastroenterology and Hepatology, Leiden University Medical Centre, 2333 Leiden, The Netherlands;
| | - Claudia Perne
- Institute of Human Genetics, National Center for Hereditary Tumor Syndromes, Medical Faculty, University Hospital Bonn, University of Bonn, 53127 Bonn, Germany; (S.A.); (C.P.); (S.H.)
| | - Reinhard Büttner
- Institute of Pathology, University of Cologne, 50937 Cologne, Germany;
| | - Heike Görgens
- Department of Surgery, Technische Universität Dresden, 01062 Dresden, Germany; (H.G.); (J.W.)
| | - Elke Holinski-Feder
- The International Society for Gastrointestinal Hereditary Tumours (InSiGHT), The Polyposis Registry, St Mark’s Hospital, Watford Road, Harrow, Middlesex HA1 3UJ, UK; (J.-P.P.); (F.M.); (E.H.-F.)
- Campus Innenstadt, Medizinische Klinik und Poliklinik IV, Klinikum der Universität München, 80336 Munich, Germany; (M.M.); (V.S.-L.)
- Center of Medical Genetics, 80335 Munich, Germany
| | - Monika Morak
- Campus Innenstadt, Medizinische Klinik und Poliklinik IV, Klinikum der Universität München, 80336 Munich, Germany; (M.M.); (V.S.-L.)
- Center of Medical Genetics, 80335 Munich, Germany
| | - Stefanie Holzapfel
- Institute of Human Genetics, National Center for Hereditary Tumor Syndromes, Medical Faculty, University Hospital Bonn, University of Bonn, 53127 Bonn, Germany; (S.A.); (C.P.); (S.H.)
| | - Robert Hüneburg
- Department of Internal Medicine, University Hospital Bonn, 53127 Bonn, Germany;
| | - Magnus von Knebel Doeberitz
- Department of Applied Tumour Biology, Institute of Pathology, University Hospital Heidelberg, 69120 Heidelberg, Germany;
- Cooperation Unit Applied Tumour Biology, German Cancer Research Center (DKFZ), 69120 Heidelberg, Germany
| | - Markus Loeffler
- Institute for Medical Informatics, Statistics and Epidemiology, University of Leipzig, 04107 Leipzig, Germany;
| | - Nils Rahner
- Medical School, Institute of Human Genetics, Heinrich-Heine-University, 40225 Dusseldorf, Germany;
| | - Jürgen Weitz
- Department of Surgery, Technische Universität Dresden, 01062 Dresden, Germany; (H.G.); (J.W.)
| | - Verena Steinke-Lange
- Campus Innenstadt, Medizinische Klinik und Poliklinik IV, Klinikum der Universität München, 80336 Munich, Germany; (M.M.); (V.S.-L.)
- Center of Medical Genetics, 80335 Munich, Germany
| | - Wolff Schmiegel
- Department of Medicine, Knappschaftskrankenhaus, Ruhr-University Bochum, D-44789 Bochum, Germany; (W.S.); (D.V.)
| | - Deepak Vangala
- Department of Medicine, Knappschaftskrankenhaus, Ruhr-University Bochum, D-44789 Bochum, Germany; (W.S.); (D.V.)
| | - Emma J. Crosbie
- Gynaecological Oncology Research Group, Manchester University NHS Foundation Trust, Manchester, UK and Division of Cancer Sciences, University of Manchester, Manchester M20 4GJ, UK;
| | - Marta Pineda
- Hereditary Cancer Program, Institut Català d’Oncologia-IDIBELL, L, Hospitalet de Llobregat, 08908 Barcelona, Spain; (M.P.); (M.N.); (J.B.)
| | - Matilde Navarro
- Hereditary Cancer Program, Institut Català d’Oncologia-IDIBELL, L, Hospitalet de Llobregat, 08908 Barcelona, Spain; (M.P.); (M.N.); (J.B.)
| | - Joan Brunet
- Hereditary Cancer Program, Institut Català d’Oncologia-IDIBELL, L, Hospitalet de Llobregat, 08908 Barcelona, Spain; (M.P.); (M.N.); (J.B.)
| | - Leticia Moreira
- Gastroenterology Department, Hospital Clínic de Barcelona, Centro de Investigación Biomédica en Red de Enfermedades Hepáticas y Digestivas (CIBERehd), Institut d’Investigacions Biomediques August Pi i Sunyer (IDIBAPS), Universitat de Barcelona, 08036 Barcelona, Spain; (F.B.); (L.M.); (A.S.)
| | - Ariadna Sánchez
- Gastroenterology Department, Hospital Clínic de Barcelona, Centro de Investigación Biomédica en Red de Enfermedades Hepáticas y Digestivas (CIBERehd), Institut d’Investigacions Biomediques August Pi i Sunyer (IDIBAPS), Universitat de Barcelona, 08036 Barcelona, Spain; (F.B.); (L.M.); (A.S.)
| | - Miquel Serra-Burriel
- Centre de Recerca en Economia i Salut (CRES-UPF), Universitat de Barcelona, 08002 Barcelona, Spain;
| | - Miriam Mints
- Division of Obstetrics and Gyneacology, Department of Women’s and Children’s Health, Karolinska Institutet, Karolinska University Hospital, Solna, 171 77 Stockholm, Sweden;
| | - Revital Kariv
- Department of Gastroenterology, Sackler Faculty of Medicine, Tel-Aviv Sourasky Medical Center, Tel-Aviv University, Tel-Aviv 64259, Israel; (N.G.); (R.K.); (G.R.)
| | - Guy Rosner
- Department of Gastroenterology, Sackler Faculty of Medicine, Tel-Aviv Sourasky Medical Center, Tel-Aviv University, Tel-Aviv 64259, Israel; (N.G.); (R.K.); (G.R.)
| | - Tamara Alejandra Piñero
- Hereditary Cancer Program (PROCANHE), Hospital Italiano de Buenos Aires, Buenos Aires C1199ABB, Argentina; (C.A.V.); (T.A.P.); (W.H.P.); (P.K.)
- Instituto de Medicina Traslacional e Ingenieria Biomedica (IMTIB), CONICET IU, Hospital Italiano de Buenos Aires, Buenos Aires C1199ABB, Argentina
| | - Walter Hernán Pavicic
- Hereditary Cancer Program (PROCANHE), Hospital Italiano de Buenos Aires, Buenos Aires C1199ABB, Argentina; (C.A.V.); (T.A.P.); (W.H.P.); (P.K.)
- Instituto de Medicina Traslacional e Ingenieria Biomedica (IMTIB), CONICET IU, Hospital Italiano de Buenos Aires, Buenos Aires C1199ABB, Argentina
| | - Pablo Kalfayan
- Hereditary Cancer Program (PROCANHE), Hospital Italiano de Buenos Aires, Buenos Aires C1199ABB, Argentina; (C.A.V.); (T.A.P.); (W.H.P.); (P.K.)
| | - Sanne W. ten Broeke
- Department of Clinical Genetics, Leids Universitair Medisch Centrum, 2300RC Leiden, The Netherlands; (M.N.); (S.W.t.B.)
| | - Jukka-Pekka Mecklin
- European Hereditary Tumour Group (EHTG), c/o Lindsays, Caledonian Exchange 19A Canning Street, Edinburgh EH3 8HE, UK; (J.R.S.); (C.E.); (G.C.); (J.B.); (R.H.S.); (J.-P.M.); (G.M.); (T.T.S.)
- The International Society for Gastrointestinal Hereditary Tumours (InSiGHT), The Polyposis Registry, St Mark’s Hospital, Watford Road, Harrow, Middlesex HA1 3UJ, UK; (J.-P.P.); (F.M.); (E.H.-F.)
- Departments of Surgery, Central Finland Hospital Nova, University of Jyväskylä, 40620 Jyväskylä, Finland
| | - Kirsi Pylvänäinen
- Department of Education and Science, Sport and Health Sciences, Central Finland Hospital Nova, University of Jyväskylä, FI-40014 Jyväskylä, Finland;
| | - Laura Renkonen-Sinisalo
- Applied Tumour Genomics Research Program, University of Helsinki, 00014 Helsinki, Finland; (L.R.-S.); (A.L.)
- Department of Gastrointestinal Surgery, Helsinki University Central Hospital, University of Helsinki, 00280 Helsinki, Finland
| | - Anna Lepistö
- Applied Tumour Genomics Research Program, University of Helsinki, 00014 Helsinki, Finland; (L.R.-S.); (A.L.)
- Department of Gastrointestinal Surgery, Helsinki University Central Hospital, University of Helsinki, 00280 Helsinki, Finland
| | - Päivi Peltomäki
- Department of Medical and Clinical Genetics, University of Helsinki, 00014 Helsinki, Finland;
| | - John L. Hopper
- Melbourne School of Population and Global Health, Centre for Epidemiology and Biostatistics, The University of Melbourne, Parkville, VIC 3010, Australia; (M.A.J.); (J.L.H.); (A.K.W.)
| | - Aung Ko Win
- Melbourne School of Population and Global Health, Centre for Epidemiology and Biostatistics, The University of Melbourne, Parkville, VIC 3010, Australia; (M.A.J.); (J.L.H.); (A.K.W.)
| | - Daniel D. Buchanan
- Centre for Cancer Research, Faculty of Medicine, Dentistry and Health Sciences, University of Melbourne, Melbourne, VIC 3010, Australia;
- Colorectal Oncogenomics Group, Department of Clinical Pathology, The University of Melbourne, Parkville, VIC 3010, Australia
- Genomic Medicine and Family Cancer Clinic, Royal Melbourne Hospital, Parkville, VIC 3010, Australia
| | - Noralane M. Lindor
- Department of Health Science Research, Mayo Clinic Arizona, Phoenix, AZ 85054, USA;
| | - Steven Gallinger
- Lunenfeld-Tanenbaum Research Institute, Mount Sinai Hospital, University of Toronto, Toronto, ON M5G 1X5, Canada;
| | | | - Polly A. Newcomb
- Public Health Sciences Division, Fred Hutchinson Cancer Research Center, Seattle, WA 98109-1024, USA;
| | | | - Stephen N. Thibodeau
- Department of Laboratory Medicine and Pathology, Mayo Clinic, Rochester, MN 55905, USA;
| | - Christina Therkildsen
- The Danish HNPCC Register, Clinical Research Centre, Copenhagen University Hospital, 2560 Hvidovre, Denmark;
| | - Thomas V. O. Hansen
- Department of Clinical Genetics, Rigshospitalet, Copenhagen University Hospital, 2100 Copenhagen, Denmark;
| | - Lars Lindberg
- Gastro Unit, Copenhagen University Hospital, 2560 Hvidovre, Denmark;
| | - Einar Andreas Rødland
- Department of Tumor Biology, Institute of Cancer Research, The Norwegian Radium Hospital, 0379 Oslo, Norway; (S.N.); (E.H.); (E.A.R.); (P.M.)
| | - Florencia Neffa
- Grupo Colaborativo Uruguayo, Investigación de Afecciones Oncológicas Hereditarias (GCU), Hospital Fuerzas Armadas, Montevideo 11600, Uruguay; (A.D.V.); (F.N.); (P.E.)
| | - Patricia Esperon
- Grupo Colaborativo Uruguayo, Investigación de Afecciones Oncológicas Hereditarias (GCU), Hospital Fuerzas Armadas, Montevideo 11600, Uruguay; (A.D.V.); (F.N.); (P.E.)
| | - Douglas Tjandra
- Department of Medicine, Colorectal Medicine and Genetics, The Royal Melbourne Hospital, Melbourne, VIC 3050, Australia;
- Department of Medicine, Royal Melbourne Hospital, University of Melbourne, Melbourne, VIC 3052, Australia
| | - Gabriela Möslein
- European Hereditary Tumour Group (EHTG), c/o Lindsays, Caledonian Exchange 19A Canning Street, Edinburgh EH3 8HE, UK; (J.R.S.); (C.E.); (G.C.); (J.B.); (R.H.S.); (J.-P.M.); (G.M.); (T.T.S.)
- The International Society for Gastrointestinal Hereditary Tumours (InSiGHT), The Polyposis Registry, St Mark’s Hospital, Watford Road, Harrow, Middlesex HA1 3UJ, UK; (J.-P.P.); (F.M.); (E.H.-F.)
- Surgical Center for Hereditary Tumors, Ev. Bethesda Khs Duisburg, University Witten-Herdecke, 58448 Herdecke, Germany
| | - Toni T. Seppälä
- European Hereditary Tumour Group (EHTG), c/o Lindsays, Caledonian Exchange 19A Canning Street, Edinburgh EH3 8HE, UK; (J.R.S.); (C.E.); (G.C.); (J.B.); (R.H.S.); (J.-P.M.); (G.M.); (T.T.S.)
- The International Society for Gastrointestinal Hereditary Tumours (InSiGHT), The Polyposis Registry, St Mark’s Hospital, Watford Road, Harrow, Middlesex HA1 3UJ, UK; (J.-P.P.); (F.M.); (E.H.-F.)
- Department of Gastrointestinal Surgery, Helsinki University Central Hospital, University of Helsinki, 00280 Helsinki, Finland
- Department of Surgical Oncology, Johns Hopkins Hospital, Baltimore, MA 21287, USA
| | - Pål Møller
- Department of Tumor Biology, Institute of Cancer Research, The Norwegian Radium Hospital, 0379 Oslo, Norway; (S.N.); (E.H.); (E.A.R.); (P.M.)
- European Hereditary Tumour Group (EHTG), c/o Lindsays, Caledonian Exchange 19A Canning Street, Edinburgh EH3 8HE, UK; (J.R.S.); (C.E.); (G.C.); (J.B.); (R.H.S.); (J.-P.M.); (G.M.); (T.T.S.)
- The International Society for Gastrointestinal Hereditary Tumours (InSiGHT), The Polyposis Registry, St Mark’s Hospital, Watford Road, Harrow, Middlesex HA1 3UJ, UK; (J.-P.P.); (F.M.); (E.H.-F.)
| |
Collapse
|
9
|
Yang C, Sheehan M, Borras E, Cadoo K, Offit K, Zhang L. Characterization of a germline splice site variant MLH1 c.678-3T>A in a Lynch syndrome family. Fam Cancer 2021; 19:315-322. [PMID: 32356167 DOI: 10.1007/s10689-020-00180-7] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/13/2023]
Abstract
Germline mutations in the DNA mismatch repair (MMR) genes cause Lynch syndrome. Classification and interpretation of intronic variants, especially those outside the consensus ± 1 ~ 2 splice sites are challenging as it is uncertain whether such variants would affect splicing accuracy and efficiency. The assessment of the pathogenicity of splice site variants in MLH1 is further complicated by the various isoforms due to alternative splicing. In this report, we describe a 42-year-old female with Lynch syndrome who carries a germline variant, MLH1 c.678-3T>A, in the splice acceptor site of intron 8. Functional studies and semiquantitative analysis demonstrated that this variant causes a significant increase in the transcripts with exon 9 or exon 9 and 10 deletions, which presumably leads to premature protein truncation or abnormal protein. In addition, we also observed MSI-H and loss of MLH1 by IHC in patient's tumor tissue. This variant also segregated with Lynch Syndrome related cancers in three affected family members. Based on these evidence, the MLH1 c.678-3T>A variant is considered pathogenic.
Collapse
Affiliation(s)
- Ciyu Yang
- Departments of Pathology, Memorial Sloan Kettering Cancer Center, New York, NY, 10065, USA
| | - Margaret Sheehan
- Departments of Medicine, Memorial Sloan Kettering Cancer Center, New York, NY, 10065, USA
| | - Ester Borras
- Departments of Pathology, Memorial Sloan Kettering Cancer Center, New York, NY, 10065, USA
| | - Karen Cadoo
- Departments of Medicine, Memorial Sloan Kettering Cancer Center, New York, NY, 10065, USA
| | - Kenneth Offit
- Departments of Medicine, Memorial Sloan Kettering Cancer Center, New York, NY, 10065, USA
| | - Liying Zhang
- Department of Pathology and Laboratory Medicine, David Geffen School of Medicine, University of California at Los Angeles (UCLA), 10833 Le Conte Ave, Los Angeles, CA, 90095, USA.
| |
Collapse
|
10
|
Tubeuf H, Charbonnier C, Soukarieh O, Blavier A, Lefebvre A, Dauchel H, Frebourg T, Gaildrat P, Martins A. Large-scale comparative evaluation of user-friendly tools for predicting variant-induced alterations of splicing regulatory elements. Hum Mutat 2020; 41:1811-1829. [PMID: 32741062 DOI: 10.1002/humu.24091] [Citation(s) in RCA: 25] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/05/2020] [Revised: 07/11/2020] [Accepted: 07/26/2020] [Indexed: 12/20/2022]
Abstract
Discriminating which nucleotide variants cause disease or contribute to phenotypic traits remains a major challenge in human genetics. In theory, any intragenic variant can potentially affect RNA splicing by altering splicing regulatory elements (SREs). However, these alterations are often ignored mainly because pioneer SRE predictors have proved inefficient. Here, we report the first large-scale comparative evaluation of four user-friendly SRE-dedicated algorithms (QUEPASA, HEXplorer, SPANR, and HAL) tested both as standalone tools and in multiple combined ways based on two independent benchmark datasets adding up to >1,300 exonic variants studied at the messenger RNA level and mapping to 89 different disease-causing genes. These methods display good predictive power, based on decision thresholds derived from the receiver operating characteristics curve analyses, with QUEPASA and HAL having the best accuracies either as standalone or in combination. Still, overall there was a tight race between the four predictors, suggesting that all methods may be of use. Additionally, QUEPASA and HEXplorer may be beneficial as well for predicting variant-induced creation of pseudoexons deep within introns. Our study highlights the potential of SRE predictors as filtering tools for identifying disease-causing candidates among the plethora of variants detected by high-throughput DNA sequencing and provides guidance for their use in genomic medicine settings.
Collapse
Affiliation(s)
- Hélène Tubeuf
- Inserm U1245, UNIROUEN, Normandie University, Normandy Centre for Genomic and Personalized Medicine, Rouen, France.,Interactive Biosoftware, Rouen, France
| | - Camille Charbonnier
- Inserm U1245, UNIROUEN, Normandie University, Normandy Centre for Genomic and Personalized Medicine, Rouen, France
| | - Omar Soukarieh
- Inserm U1245, UNIROUEN, Normandie University, Normandy Centre for Genomic and Personalized Medicine, Rouen, France
| | | | - Arnaud Lefebvre
- Computer Science, Information Processing and Systems Laboratory, UNIROUEN, Normandie University, Mont-Saint-Aignan, France
| | - Hélène Dauchel
- Computer Science, Information Processing and Systems Laboratory, UNIROUEN, Normandie University, Mont-Saint-Aignan, France
| | - Thierry Frebourg
- Inserm U1245, UNIROUEN, Normandie University, Normandy Centre for Genomic and Personalized Medicine, Rouen, France.,Department of Genetics, University Hospital, Normandy Centre for Genomic and Personalized Medicine, Rouen, France
| | - Pascaline Gaildrat
- Inserm U1245, UNIROUEN, Normandie University, Normandy Centre for Genomic and Personalized Medicine, Rouen, France
| | - Alexandra Martins
- Inserm U1245, UNIROUEN, Normandie University, Normandy Centre for Genomic and Personalized Medicine, Rouen, France
| |
Collapse
|
11
|
Li F, Xia Y, Wang G, Tang C, Zhan T, Shen J, Zhang J. Identification of a novel pathogenic MLH1 mutation and recommended genetic screening strategy: An investigation of three Chinese Lynch syndrome pedigrees. Mol Genet Genomic Med 2020; 8:e1295. [PMID: 32490589 PMCID: PMC7434735 DOI: 10.1002/mgg3.1295] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/03/2019] [Revised: 02/07/2020] [Accepted: 04/14/2020] [Indexed: 12/17/2022] Open
Abstract
Background Lynch syndrome (LS) is an autosomal‐dominant disorder that increases the risk of many cancers. The genetic basis of LS is germline mutations in DNA mismatch repair genes. Methods We performed next‐generation sequencing on blood cells obtained from the members of three unrelated LS pedigrees. Immunohistochemistry staining was performed to analyze protein expression. Results Multigene panel screening revealed three mutL homolog 1 (MLH1) pathogenic mutations (c.199G>A, c.790 + 1G>A, and c.1557_1558 + 8delGGGTACGTAA, unreported) confirmed by Sanger sequencing. Immunohistochemistry showed a loss of MLH1 protein expression. We also confirmed that the unreported mutant allele was inherited for at least three generations. Conclusion These results provide new insights into the molecular mechanisms underlying the pathogenicity of MLH1 mutations and reaffirm the importance of genetic screening for the early diagnosis of LS.
Collapse
Affiliation(s)
- Fan Li
- Department of General Surgery, The Second Affiliated Hospital, Nanjing Medical University, Nanjing, China
| | - Yunwei Xia
- Department of General Surgery, The Second Affiliated Hospital, Nanjing Medical University, Nanjing, China
| | - Guoguang Wang
- Department of General Surgery, The Second Affiliated Hospital, Nanjing Medical University, Nanjing, China
| | - Chaoyang Tang
- Department of General Surgery, The Second Affiliated Hospital, Nanjing Medical University, Nanjing, China
| | - Tian Zhan
- Department of General Surgery, The Second Affiliated Hospital, Nanjing Medical University, Nanjing, China
| | - Jian Shen
- Department of General Surgery, The Second Affiliated Hospital, Nanjing Medical University, Nanjing, China
| | - Jianping Zhang
- Department of General Surgery, The Second Affiliated Hospital, Nanjing Medical University, Nanjing, China
| |
Collapse
|
12
|
Dominguez-Valentin M, Nakken S, Tubeuf H, Vodak D, Ekstrøm PO, Nissen AM, Morak M, Holinski-Feder E, Holth A, Capella G, Davidson B, Evans DG, Martins A, Møller P, Hovig E. Results of multigene panel testing in familial cancer cases without genetic cause demonstrated by single gene testing. Sci Rep 2019; 9:18555. [PMID: 31811167 PMCID: PMC6898579 DOI: 10.1038/s41598-019-54517-z] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/07/2019] [Accepted: 11/15/2019] [Indexed: 01/08/2023] Open
Abstract
We have surveyed 191 prospectively sampled familial cancer patients with no previously detected pathogenic variant in the BRCA1/2, PTEN, TP53 or DNA mismatch repair genes. In all, 138 breast cancer (BC) cases, 34 colorectal cancer (CRC) and 19 multiple early-onset cancers were included. A panel of 44 cancer-predisposing genes identified 5% (9/191) pathogenic or likely pathogenic variants and 87 variants of uncertain significance (VUS). Pathogenic or likely pathogenic variants were identified mostly in familial BC individuals (7/9) and were located in 5 genes: ATM (3), BRCA2 (1), CHEK2 (1), MSH6 (1) and MUTYH (1), followed by multiple early-onset (2/9) individuals, affecting the CHEK2 and ATM genes. Eleven of the 87 VUS were tested, and 4/11 were found to have an impact on splicing by using a minigene splicing assay. We here report for the first time the splicing anomalies using this assay for the variants ATM c.3806A > G and BUB1 c.677C > T, whereas CHEK1 c.61G > A did not result in any detectable splicing anomaly. Our study confirms the presence of pathogenic or likely pathogenic variants in genes that are not routinely tested in the context of the above-mentioned clinical phenotypes. Interestingly, more than half of the pathogenic germline variants were found in the moderately penetrant ATM and CHEK2 genes, where only truncating variants from these genes are recommended to be reported in clinical genetic testing practice.
Collapse
Affiliation(s)
- Mev Dominguez-Valentin
- Department of Tumor Biology, Institute for Cancer Research, Oslo University Hospital, Oslo, Norway.
| | - Sigve Nakken
- Department of Tumor Biology, Institute for Cancer Research, Oslo University Hospital, Oslo, Norway.,Centre for Cancer Cell Reprogramming, Institute of Clinical Medicine, Faculty of Medicine, University of Oslo, Oslo, Norway
| | - Hélène Tubeuf
- Inserm-U1245, UNIROUEN, Normandie Univ, Normandy Centre for Genomic and Personalized Medicine, Rouen, France.,Interactive Biosoftware, Rouen, France
| | - Daniel Vodak
- Department of Tumor Biology, Institute for Cancer Research, Oslo University Hospital, Oslo, Norway
| | - Per Olaf Ekstrøm
- Department of Tumor Biology, Institute for Cancer Research, Oslo University Hospital, Oslo, Norway
| | - Anke M Nissen
- Medizinische Klinik und Poliklinik IV, Campus Innenstadt, Klinikum der Universität München, Ziemssenstr. 1, Munich, Germany.,MGZ-Medizinisch Genetisches Zentrum, Munich, Germany
| | - Monika Morak
- Medizinische Klinik und Poliklinik IV, Campus Innenstadt, Klinikum der Universität München, Ziemssenstr. 1, Munich, Germany.,MGZ-Medizinisch Genetisches Zentrum, Munich, Germany
| | - Elke Holinski-Feder
- Medizinische Klinik und Poliklinik IV, Campus Innenstadt, Klinikum der Universität München, Ziemssenstr. 1, Munich, Germany.,MGZ-Medizinisch Genetisches Zentrum, Munich, Germany
| | - Arild Holth
- Department of Pathology, Oslo University Hospital, Norwegian Radium Hospital, Oslo, Norway
| | - Gabriel Capella
- Hereditary Cancer Program, Catalan Institute of Oncology, Insititut d'Investigació Biomèdica de Bellvitge (IDIBELL), ONCOBELL Program, L'Hospitalet de Llobregat, Barcelona, Spain, and Centro de Investigación Biomédica en Red de Cáncer (CIBERONC), Barcelona, Spain
| | - Ben Davidson
- Department of Pathology, Oslo University Hospital, Norwegian Radium Hospital, Oslo, Norway.,University of Oslo, Faculty of Medicine, Institute of Clinical Medicine, N-, 0316, Oslo, Norway
| | - D Gareth Evans
- Department of Genomic Medicine, Division of Evolution and Genomic Sciences, The University of Manchester, Manchester Academic Health Science Centre, St. Mary's Hospital, Manchester, United Kingdom.,Prevent Breast Cancer Centre, Wythenshawe Hospital, Southmoor Road, Manchester, United Kingdom
| | - Alexandra Martins
- Inserm-U1245, UNIROUEN, Normandie Univ, Normandy Centre for Genomic and Personalized Medicine, Rouen, France
| | - Pål Møller
- Department of Tumor Biology, Institute for Cancer Research, Oslo University Hospital, Oslo, Norway.,Department of Human Medicine, Universität Witten/Herdecke, Wuppertal, Germany
| | - Eivind Hovig
- Department of Tumor Biology, Institute for Cancer Research, Oslo University Hospital, Oslo, Norway.,Department of Informatics, University of Oslo, Oslo, Norway
| |
Collapse
|
13
|
Edmonson MN, Patel AN, Hedges DJ, Wang Z, Rampersaud E, Kesserwan CA, Zhou X, Liu Y, Newman S, Rusch MC, McLeod CL, Wilkinson MR, Rice SV, Soussi T, Taylor JP, Benatar M, Becksfort JB, Nichols KE, Robison LL, Downing JR, Zhang J. Pediatric Cancer Variant Pathogenicity Information Exchange (PeCanPIE): a cloud-based platform for curating and classifying germline variants. Genome Res 2019; 29:1555-1565. [PMID: 31439692 PMCID: PMC6724669 DOI: 10.1101/gr.250357.119] [Citation(s) in RCA: 24] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/13/2019] [Accepted: 07/23/2019] [Indexed: 01/06/2023]
Abstract
Variant interpretation in the era of massively parallel sequencing is challenging. Although many resources and guidelines are available to assist with this task, few integrated end-to-end tools exist. Here, we present the Pediatric Cancer Variant Pathogenicity Information Exchange (PeCanPIE), a web- and cloud-based platform for annotation, identification, and classification of variations in known or putative disease genes. Starting from a set of variants in variant call format (VCF), variants are annotated, ranked by putative pathogenicity, and presented for formal classification using a decision-support interface based on published guidelines from the American College of Medical Genetics and Genomics (ACMG). The system can accept files containing millions of variants and handle single-nucleotide variants (SNVs), simple insertions/deletions (indels), multiple-nucleotide variants (MNVs), and complex substitutions. PeCanPIE has been applied to classify variant pathogenicity in cancer predisposition genes in two large-scale investigations involving >4000 pediatric cancer patients and serves as a repository for the expert-reviewed results. PeCanPIE was originally developed for pediatric cancer but can be easily extended for use for nonpediatric cancers and noncancer genetic diseases. Although PeCanPIE's web-based interface was designed to be accessible to non-bioinformaticians, its back-end pipelines may also be run independently on the cloud, facilitating direct integration and broader adoption. PeCanPIE is publicly available and free for research use.
Collapse
Affiliation(s)
- Michael N Edmonson
- Department of Computational Biology, St. Jude Children's Research Hospital, Memphis, Tennessee 38105, USA
| | - Aman N Patel
- Department of Computational Biology, St. Jude Children's Research Hospital, Memphis, Tennessee 38105, USA
| | - Dale J Hedges
- Department of Computational Biology, St. Jude Children's Research Hospital, Memphis, Tennessee 38105, USA
| | - Zhaoming Wang
- Department of Computational Biology, St. Jude Children's Research Hospital, Memphis, Tennessee 38105, USA
| | - Evadnie Rampersaud
- Department of Computational Biology, St. Jude Children's Research Hospital, Memphis, Tennessee 38105, USA
| | - Chimene A Kesserwan
- Department of Oncology, St. Jude Children's Research Hospital, Memphis, Tennessee 38105, USA
| | - Xin Zhou
- Department of Computational Biology, St. Jude Children's Research Hospital, Memphis, Tennessee 38105, USA
| | - Yanling Liu
- Department of Computational Biology, St. Jude Children's Research Hospital, Memphis, Tennessee 38105, USA
| | - Scott Newman
- Department of Computational Biology, St. Jude Children's Research Hospital, Memphis, Tennessee 38105, USA
| | - Michael C Rusch
- Department of Computational Biology, St. Jude Children's Research Hospital, Memphis, Tennessee 38105, USA
| | - Clay L McLeod
- Department of Computational Biology, St. Jude Children's Research Hospital, Memphis, Tennessee 38105, USA
| | - Mark R Wilkinson
- Department of Computational Biology, St. Jude Children's Research Hospital, Memphis, Tennessee 38105, USA
| | - Stephen V Rice
- Department of Computational Biology, St. Jude Children's Research Hospital, Memphis, Tennessee 38105, USA
| | - Thierry Soussi
- Sorbonne Université, UPMC Univ Paris 06, F-75005 Paris, France.,Department of Oncology-Pathology, Cancer Center Karolinska (CCK), Karolinska Institutet, 171 64 Stockholm, Sweden.,INSERM, U1138, Équipe 11, Centre de Recherche des Cordeliers, 75006 Paris, France
| | - J Paul Taylor
- Howard Hughes Medical Institute, Chevy Chase, Maryland 20815, USA.,Department of Cell and Molecular Biology, St. Jude Children's Research Hospital, Memphis, Tennessee 38105, USA
| | - Michael Benatar
- Department of Neurology, University of Miami, Miami, Florida 33136, USA
| | - Jared B Becksfort
- Department of Computational Biology, St. Jude Children's Research Hospital, Memphis, Tennessee 38105, USA
| | - Kim E Nichols
- Department of Oncology, St. Jude Children's Research Hospital, Memphis, Tennessee 38105, USA
| | - Leslie L Robison
- Department of Epidemiology and Cancer Control, St. Jude Children's Research Hospital, Memphis, Tennessee 38105, USA
| | - James R Downing
- Department of Pathology, St. Jude Children's Research Hospital, Memphis, Tennessee 38105, USA
| | - Jinghui Zhang
- Department of Computational Biology, St. Jude Children's Research Hospital, Memphis, Tennessee 38105, USA
| |
Collapse
|
14
|
Morak M, Schaefer K, Steinke-Lange V, Koehler U, Keinath S, Massdorf T, Mauracher B, Rahner N, Bailey J, Kling C, Haeusser T, Laner A, Holinski-Feder E. Full-length transcript amplification and sequencing as universal method to test mRNA integrity and biallelic expression in mismatch repair genes. Eur J Hum Genet 2019; 27:1808-1820. [PMID: 31332305 DOI: 10.1038/s41431-019-0472-8] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/27/2019] [Revised: 05/13/2019] [Accepted: 07/02/2019] [Indexed: 12/13/2022] Open
Abstract
In pathogenicity assessment, RNA-based analyses are important for the correct classification of variants, and require gene-specific cut-offs for allelic representation and alternative/aberrant splicing. Beside this, the diagnostic yield of RNA-based techniques capable to detect aberrant splicing or allelic loss due to intronic/regulatory variants has to be elaborated. We established a cDNA analysis for full-length transcripts (FLT) of the four DNA mismatch repair (MMR) genes to investigate the splicing pattern and transcript integrity with active/inhibited nonsense-mediated mRNA-decay (NMD). Validation was based on results from normal controls, samples with premature termination codons (PTC), samples with splice-site defects (SSD), and samples with pathogenic putative missense variants. The method was applied to patients with variants of uncertain significance (VUS) or unexplained immunohistochemical MMR deficiency. We categorized the allelic representation into biallelic (50 ± 10%) or allelic loss (≤10%), and >10% and <40% as unclear. We defined isoforms up to 10% and exon-specific exceptions as alternative splicing, set the cut-off for SSD in cDNA + P to 30-50%, and regard >10% and <30% as unclear. FLT cDNA analyses designated 16% of all putative missense variants and 12% of VUS as SSD, detected MMR-defects in 19% of the unsolved patients, and re-classified >30% of VUS. Our method allows a standardized, systematic cDNA analysis of the MMR FLTs to assess the pathogenicity mechanism of VUS on RNA level, which will gain relevance for precision medicine and gene therapy. Diagnostic accuracy will be enhanced by detecting MMR defects in hitherto unsolved patients. The data generated will help to calibrate a high-throughput NGS-based mRNA-analysis and optimize prediction programs.
Collapse
Affiliation(s)
- Monika Morak
- Medizinische Klinik und Poliklinik IV, Campus Innenstadt, Klinikum der Universität München, Ziemssenstr. 1, 80336, Munich, Germany. .,MGZ - Medical Genetics Center, Bayerstr. 3-5, 80335, Munich, Germany.
| | - Kerstin Schaefer
- Medizinische Klinik und Poliklinik IV, Campus Innenstadt, Klinikum der Universität München, Ziemssenstr. 1, 80336, Munich, Germany
| | - Verena Steinke-Lange
- Medizinische Klinik und Poliklinik IV, Campus Innenstadt, Klinikum der Universität München, Ziemssenstr. 1, 80336, Munich, Germany.,MGZ - Medical Genetics Center, Bayerstr. 3-5, 80335, Munich, Germany
| | - Udo Koehler
- MGZ - Medical Genetics Center, Bayerstr. 3-5, 80335, Munich, Germany
| | - Susanne Keinath
- Medizinische Klinik und Poliklinik IV, Campus Innenstadt, Klinikum der Universität München, Ziemssenstr. 1, 80336, Munich, Germany
| | - Trisari Massdorf
- Medizinische Klinik und Poliklinik IV, Campus Innenstadt, Klinikum der Universität München, Ziemssenstr. 1, 80336, Munich, Germany.,MGZ - Medical Genetics Center, Bayerstr. 3-5, 80335, Munich, Germany
| | - Brigitte Mauracher
- Medizinische Klinik und Poliklinik IV, Campus Innenstadt, Klinikum der Universität München, Ziemssenstr. 1, 80336, Munich, Germany
| | - Nils Rahner
- Medical Faculty, Institute of Human Genetics, Heinrich-Heine University, Düsseldorf, Germany
| | - Jessica Bailey
- Clinical Genetics, St. George's University Hospital NHS Foundation Trust, London, UK
| | | | - Tanja Haeusser
- MGZ - Medical Genetics Center, Bayerstr. 3-5, 80335, Munich, Germany
| | - Andreas Laner
- MGZ - Medical Genetics Center, Bayerstr. 3-5, 80335, Munich, Germany
| | - Elke Holinski-Feder
- Medizinische Klinik und Poliklinik IV, Campus Innenstadt, Klinikum der Universität München, Ziemssenstr. 1, 80336, Munich, Germany. .,MGZ - Medical Genetics Center, Bayerstr. 3-5, 80335, Munich, Germany.
| |
Collapse
|
15
|
First description of mutational analysis of MLH1, MSH2 and MSH6 in Algerian families with suspected Lynch syndrome. Fam Cancer 2017; 16:57-66. [PMID: 27468915 DOI: 10.1007/s10689-016-9917-1] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Abstract
Hereditary non-polyposis colorectal cancer (HNPCC) is an autosomal dominant disorder characterized by the early onset of colorectal cancer (CRC) linked to germline defects in Mismatch Repair (MMR) genes. We present here, the first molecular study of the correlation between CRC and mutations occurring in these genes performed in twenty-one unrelated Algerian families. The presence of germline mutations in MMR genes, MLH1, MSH2 and MSH6 genes was tested by sequencing all exons plus adjacent intronic sequences and Multiplex ligand-dependent probe amplification (MLPA) for testing large genomic rearrangements. Pathogenic mutations were identified in 20 % of families with clinical suspicion on HNPCC. Two novel variants described for the first time in Algerian families were identified in MLH1, c.881_884delTCAGinsCATTCCT and a large deletion in MSH6 gene from a young onset of CRC. Moreover, the variants of MSH2 gene: c.942+3A>T, c.1030C>T, the most described ones, were also detected in Algerian families. Furthermore, the families HNPCC caused by MSH6 germline mutation may show an age of onset that is comparable to this of patients with MLH1 and MSH2 mutations. In this study, we confirmed that MSH2, MLH1, and MSH6 contribute to CRC susceptibility. This work represents the implementation of a diagnostic algorithm for the identification of Lynch syndrome patients in Algerian families.
Collapse
|
16
|
Systematic analysis of splicing defects in selected primary immunodeficiencies-related genes. Clin Immunol 2017; 180:33-44. [DOI: 10.1016/j.clim.2017.03.010] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/18/2016] [Revised: 02/03/2017] [Accepted: 03/23/2017] [Indexed: 12/15/2022]
|
17
|
RNA splicing in human disease and in the clinic. Clin Sci (Lond) 2017; 131:355-368. [PMID: 28202748 DOI: 10.1042/cs20160211] [Citation(s) in RCA: 67] [Impact Index Per Article: 9.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/06/2016] [Revised: 12/06/2016] [Accepted: 12/15/2016] [Indexed: 01/12/2023]
Abstract
Defects at the level of the pre-mRNA splicing process represent a major cause of human disease. Approximately 15-50% of all human disease mutations have been shown to alter functioning of basic and auxiliary splicing elements. These elements are required to ensure proper processing of pre-mRNA splicing molecules, with their disruption leading to misprocessing of the pre-mRNA molecule and disease. The splicing process is a complex process, with much still to be uncovered before we are able to accurately predict whether a reported genomic sequence variant (GV) represents a splicing-associated disease mutation or a harmless polymorphism. Furthermore, even when a mutation is correctly identified as affecting the splicing process, there still remains the difficulty of providing an exact evaluation of the potential impact on disease onset, severity and duration. In this review, we provide a brief overview of splicing diagnostic methodologies, from in silico bioinformatics approaches to wet lab in vitro and in vivo systems to evaluate splicing efficiencies. In particular, we provide an overview of how the latest developments in high-throughput sequencing can be applied to the clinic, and are already changing clinical approaches.
Collapse
|
18
|
Suppressors and activators of JAK-STAT signaling at diagnosis and relapse of acute lymphoblastic leukemia in Down syndrome. Proc Natl Acad Sci U S A 2017; 114:E4030-E4039. [PMID: 28461505 DOI: 10.1073/pnas.1702489114] [Citation(s) in RCA: 54] [Impact Index Per Article: 7.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/03/2023] Open
Abstract
Children with Down syndrome (DS) are prone to development of high-risk B-cell precursor ALL (DS-ALL), which differs genetically from most sporadic pediatric ALLs. Increased expression of cytokine receptor-like factor 2 (CRLF2), the receptor to thymic stromal lymphopoietin (TSLP), characterizes about half of DS-ALLs and also a subgroup of sporadic "Philadelphia-like" ALLs. To understand the pathogenesis of relapsed DS-ALL, we performed integrative genomic analysis of 25 matched diagnosis-remission and -relapse DS-ALLs. We found that the CRLF2 rearrangements are early events during DS-ALL evolution and generally stable between diagnoses and relapse. Secondary activating signaling events in the JAK-STAT/RAS pathway were ubiquitous but highly redundant between diagnosis and relapse, suggesting that signaling is essential but that no specific mutations are "relapse driving." We further found that activated JAK2 may be naturally suppressed in 25% of CRLF2pos DS-ALLs by loss-of-function aberrations in USP9X, a deubiquitinase previously shown to stabilize the activated phosphorylated JAK2. Interrogation of large ALL genomic databases extended our findings up to 25% of CRLF2pos, Philadelphia-like ALLs. Pharmacological or genetic inhibition of USP9X, as well as treatment with low-dose ruxolitinib, enhanced the survival of pre-B ALL cells overexpressing mutated JAK2. Thus, somehow counterintuitive, we found that suppression of JAK-STAT "hypersignaling" may be beneficial to leukemic B-cell precursors. This finding and the reduction of JAK mutated clones at relapse suggest that the therapeutic effect of JAK specific inhibitors may be limited. Rather, combined signaling inhibitors or direct targeting of the TSLP receptor may be a useful therapeutic strategy for DS-ALL.
Collapse
|
19
|
Sunga AY, Ricker C, Espenschied CR, Castillo D, Melas M, Herzog J, Bannon S, Cruz-Correa M, Lynch P, Solomon I, Gruber SB, Weitzel JN. Spectrum of mismatch repair gene mutations and clinical presentation of Hispanic individuals with Lynch syndrome. Cancer Genet 2017; 212-213:1-7. [PMID: 28449805 PMCID: PMC8800930 DOI: 10.1016/j.cancergen.2017.01.003] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/19/2016] [Revised: 01/13/2017] [Accepted: 01/15/2017] [Indexed: 12/21/2022]
Abstract
Lynch syndrome (LS), the most common hereditary colorectal cancer syndrome, is caused by mismatch repair (MMR) gene mutations. However, data about MMR mutations in Hispanics are limited. This study aims to describe the spectrum of MMR mutations in Hispanics with LS and explore ancestral origins. This case series involved an IRB-approved retrospective chart review of self-identified Hispanic patients (n = 397) seen for genetic cancer risk assessment at four collaborating academic institutions in California, Texas, and Puerto Rico who were evaluated by MMR genotyping and/or tumor analysis. A literature review was conducted for all mutations identified. Of those who underwent clinical genetic testing (n = 176), 71 had MMR gene mutations. Nine mutations were observed more than once. One third (3/9) of recurrent mutations and two additional mutations (seen only once) were previously reported in Spain, confirming the influence of Spanish ancestry on MMR mutations in Hispanic populations. The recurrent mutations identified (n = 9) included both previously reported mutations as well as unique mutations not in the literature. This is the largest report of Hispanic MMR mutations in North America; however, a larger sample and haplotype analyses are needed to better understand recurrent MMR mutations in Hispanic populations.
Collapse
Affiliation(s)
- Annette Y Sunga
- Clinical Cancer Genetics, City of Hope National Medical Center, Duarte, CA 91010, USA
| | - Charité Ricker
- USC Norris Comprehensive Cancer Center, University of Southern California, Los Angeles, CA 90089, USA
| | - Carin R Espenschied
- Clinical Cancer Genetics, City of Hope National Medical Center, Duarte, CA 91010, USA
| | - Danielle Castillo
- Clinical Cancer Genetics, City of Hope National Medical Center, Duarte, CA 91010, USA
| | - Marilena Melas
- USC Norris Comprehensive Cancer Center, University of Southern California, Los Angeles, CA 90089, USA
| | - Josef Herzog
- Clinical Cancer Genetics, City of Hope National Medical Center, Duarte, CA 91010, USA
| | - Sarah Bannon
- Clinical Cancer Genetics, MD Anderson Cancer Center, Houston, TX 77030, USA
| | - Marcia Cruz-Correa
- Clinical Cancer Genetics, University of Puerto Rico Comprehensive Cancer Center, Rio Piedras 00935, Puerto Rico
| | - Patrick Lynch
- Clinical Cancer Genetics, MD Anderson Cancer Center, Houston, TX 77030, USA
| | - Ilana Solomon
- Clinical Cancer Genetics, City of Hope National Medical Center, Duarte, CA 91010, USA
| | - Stephen B Gruber
- USC Norris Comprehensive Cancer Center, University of Southern California, Los Angeles, CA 90089, USA
| | - Jeffrey N Weitzel
- Clinical Cancer Genetics, City of Hope National Medical Center, Duarte, CA 91010, USA.
| |
Collapse
|
20
|
Tricarico R, Kasela M, Mareni C, Thompson BA, Drouet A, Staderini L, Gorelli G, Crucianelli F, Ingrosso V, Kantelinen J, Papi L, De Angioletti M, Berardi M, Gaildrat P, Soukarieh O, Turchetti D, Martins A, Spurdle AB, Nyström M, Genuardi M. Assessment of the InSiGHT Interpretation Criteria for the Clinical Classification of 24 MLH1 and MSH2 Gene Variants. Hum Mutat 2016; 38:64-77. [PMID: 27629256 DOI: 10.1002/humu.23117] [Citation(s) in RCA: 24] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/26/2016] [Revised: 09/04/2016] [Accepted: 09/09/2016] [Indexed: 01/15/2023]
Abstract
Pathogenicity assessment of DNA variants in disease genes to explain their clinical consequences is an integral component of diagnostic molecular testing. The International Society for Gastrointestinal Hereditary Tumors (InSiGHT) has developed specific criteria for the interpretation of mismatch repair (MMR) gene variants. Here, we performed a systematic investigation of 24 MLH1 and MSH2 variants. The assessments were done by analyzing population frequency, segregation, tumor molecular characteristics, RNA effects, protein expression levels, and in vitro MMR activity. Classifications were confirmed for 15 variants and changed for three, and for the first time determined for six novel variants. Overall, based on our results, we propose the introduction of some refinements to the InSiGHT classification rules. The proposed changes have the advantage of homogenizing the InSIGHT interpretation criteria with those set out by the Evidence-based Network for the Interpretation of Germline Mutant Alleles (ENIGMA) consortium for the BRCA1/BRCA2 genes. We also observed that the addition of only few clinical data was sufficient to obtain a more stable classification for variants considered as "likely pathogenic" or "likely nonpathogenic." This shows the importance of obtaining as many as possible points of evidence for variant interpretation, especially from the clinical setting.
Collapse
Affiliation(s)
- Rossella Tricarico
- Department of Biomedical, Experimental and Clinical Sciences, Medical Genetics Unit, University of Florence, Florence, Italy.,Cancer Epigenetics and Cancer Biology Programs, Fox Chase Cancer Center, Philadelphia, Pennsylvania
| | - Mariann Kasela
- Department of Biosciences, Division of Genetics, University of Helsinki, Helsinki, Finland
| | | | - Bryony A Thompson
- Department of Oncological Sciences, Huntsman Cancer Institute, University of Utah, Salt Lake City, Utah.,Centre for Epidemiology and Biostatistics, Melbourne School of Population and Global Health, University of Melbourne, Victoria, Australia
| | - Aurélie Drouet
- Inserm-U1079-IRIB, Normandy Centre for Genomic and Personalized Medicine, University of Rouen, Rouen, France
| | - Lucia Staderini
- Department of Biomedical, Experimental and Clinical Sciences, Medical Genetics Unit, University of Florence, Florence, Italy.,Microbiology and Virology Department, Fondazione IRCCS Policlinico San Matteo, Pavia, Italy
| | - Greta Gorelli
- Department of Biomedical, Experimental and Clinical Sciences, Medical Genetics Unit, University of Florence, Florence, Italy
| | - Francesca Crucianelli
- Department of Biomedical, Experimental and Clinical Sciences, Medical Genetics Unit, University of Florence, Florence, Italy
| | - Valentina Ingrosso
- Department of Biomedical, Experimental and Clinical Sciences, Medical Genetics Unit, University of Florence, Florence, Italy
| | - Jukka Kantelinen
- Department of Biosciences, Division of Genetics, University of Helsinki, Helsinki, Finland
| | - Laura Papi
- Department of Biomedical, Experimental and Clinical Sciences, Medical Genetics Unit, University of Florence, Florence, Italy
| | - Maria De Angioletti
- Cancer Genetics and Gene Transfer - Core Research Laboratory, Istituto Toscano Tumori, Florence, Italy.,ICCOM-CNR, Sesto Fiorentino, Italy
| | - Margherita Berardi
- Cancer Genetics and Gene Transfer - Core Research Laboratory, Istituto Toscano Tumori, Florence, Italy
| | - Pascaline Gaildrat
- Inserm-U1079-IRIB, Normandy Centre for Genomic and Personalized Medicine, University of Rouen, Rouen, France
| | - Omar Soukarieh
- Inserm-U1079-IRIB, Normandy Centre for Genomic and Personalized Medicine, University of Rouen, Rouen, France
| | - Daniela Turchetti
- Medical Genetics, Department of Medical and Surgical Sciences (DIMEC), University of Bologna, Bologna, Italy
| | - Alexandra Martins
- Inserm-U1079-IRIB, Normandy Centre for Genomic and Personalized Medicine, University of Rouen, Rouen, France
| | - Amanda B Spurdle
- Genetics and Computational Biology Department, QIMR Berghofer Medical Research Institute, Brisbane, Australia
| | - Minna Nyström
- Department of Biosciences, Division of Genetics, University of Helsinki, Helsinki, Finland
| | - Maurizio Genuardi
- Department of Biomedical, Experimental and Clinical Sciences, Medical Genetics Unit, University of Florence, Florence, Italy.,Institute of Genomic Medicine, A. Gemelli School of Medicine, Medical Genetics Unit, Catholic University of the Sacred Heart, Rome, Italy
| | | |
Collapse
|
21
|
Wang Q. Cancer predisposition genes: molecular mechanisms and clinical impact on personalized cancer care: examples of Lynch and HBOC syndromes. Acta Pharmacol Sin 2016; 37:143-9. [PMID: 26616728 PMCID: PMC4753377 DOI: 10.1038/aps.2015.89] [Citation(s) in RCA: 28] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/23/2015] [Accepted: 09/08/2015] [Indexed: 12/14/2022] Open
Abstract
Up to 10% of cancers occur through the inherited mutation of a group of genes called cancer predisposition genes. Individuals who carry a mutant allele of these genes have an increased susceptibility to cancer. A growing number of cancer susceptibility genes are being identified, and the physiopathology of germline mutation-based cancer development is also being elucidated with accumulating clinical and molecular data. More importantly, the identification of familial mutations has become routine practice, which is a perfect example of bench-to-bed translational medicine. Recently, other clinical applications of predisposition genes have been exploited, especially as efficient biomarkers predicting prognosis or response to treatment. Thus, it appears interesting to give an overview of the advances and impacts of predisposition genes in personalized cancer care by taking representative and common cancer syndromes as examples: Lynch syndrome for the first example, which is related to cancer susceptibility, and breast and ovary cancer syndrome for the second example, which involves BRCA deficiency-related targeted therapy.
Collapse
|
22
|
Exonic Splicing Mutations Are More Prevalent than Currently Estimated and Can Be Predicted by Using In Silico Tools. PLoS Genet 2016; 12:e1005756. [PMID: 26761715 PMCID: PMC4711968 DOI: 10.1371/journal.pgen.1005756] [Citation(s) in RCA: 116] [Impact Index Per Article: 14.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/26/2015] [Accepted: 12/01/2015] [Indexed: 01/01/2023] Open
Abstract
The identification of a causal mutation is essential for molecular diagnosis and clinical management of many genetic disorders. However, even if next-generation exome sequencing has greatly improved the detection of nucleotide changes, the biological interpretation of most exonic variants remains challenging. Moreover, particular attention is typically given to protein-coding changes often neglecting the potential impact of exonic variants on RNA splicing. Here, we used the exon 10 of MLH1, a gene implicated in hereditary cancer, as a model system to assess the prevalence of RNA splicing mutations among all single-nucleotide variants identified in a given exon. We performed comprehensive minigene assays and analyzed patient's RNA when available. Our study revealed a staggering number of splicing mutations in MLH1 exon 10 (77% of the 22 analyzed variants), including mutations directly affecting splice sites and, particularly, mutations altering potential splicing regulatory elements (ESRs). We then used this thoroughly characterized dataset, together with experimental data derived from previous studies on BRCA1, BRCA2, CFTR and NF1, to evaluate the predictive power of 3 in silico approaches recently described as promising tools for pinpointing ESR-mutations. Our results indicate that ΔtESRseq and ΔHZEI-based approaches not only discriminate which variants affect splicing, but also predict the direction and severity of the induced splicing defects. In contrast, the ΔΨ-based approach did not show a compelling predictive power. Our data indicates that exonic splicing mutations are more prevalent than currently appreciated and that they can now be predicted by using bioinformatics methods. These findings have implications for all genetically-caused diseases.
Collapse
|
23
|
Yurgelun MB, Allen B, Kaldate RR, Bowles KR, Judkins T, Kaushik P, Roa BB, Wenstrup RJ, Hartman AR, Syngal S. Identification of a Variety of Mutations in Cancer Predisposition Genes in Patients With Suspected Lynch Syndrome. Gastroenterology 2015; 149:604-13.e20. [PMID: 25980754 PMCID: PMC4550537 DOI: 10.1053/j.gastro.2015.05.006] [Citation(s) in RCA: 187] [Impact Index Per Article: 20.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/22/2015] [Revised: 05/06/2015] [Accepted: 05/09/2015] [Indexed: 12/20/2022]
Abstract
BACKGROUND & AIMS Multigene panels are commercially available tools for hereditary cancer risk assessment that allow for next-generation sequencing of numerous genes in parallel. However, it is not clear if these panels offer advantages over traditional genetic testing. We investigated the number of cancer predisposition gene mutations identified by parallel sequencing in individuals with suspected Lynch syndrome. METHODS We performed germline analysis with a 25-gene, next-generation sequencing panel using DNA from 1260 individuals who underwent clinical genetic testing for Lynch syndrome from 2012 through 2013. All patients had a history of Lynch syndrome-associated cancer and/or polyps. We classified all identified germline alterations for pathogenicity and calculated the frequencies of pathogenic mutations and variants of uncertain clinical significance (VUS). We also analyzed data on patients' personal and family history of cancer, including fulfillment of clinical guidelines for genetic testing. RESULTS Of the 1260 patients, 1112 met National Comprehensive Cancer Network (NCCN) criteria for Lynch syndrome testing (88%; 95% confidence interval [CI], 86%-90%). Multigene panel testing identified 114 probands with Lynch syndrome mutations (9.0%; 95% CI, 7.6%-10.8%) and 71 with mutations in other cancer predisposition genes (5.6%; 95% CI, 4.4%-7.1%). Fifteen individuals had mutations in BRCA1 or BRCA2; 93% of these met the NCCN criteria for Lynch syndrome testing and 33% met NCCN criteria for BRCA1 and BRCA2 analysis (P = .0017). An additional 9 individuals carried mutations in other genes linked to high lifetime risks of cancer (5 had mutations in APC, 3 had bi-allelic mutations in MUTYH, and 1 had a mutation in STK11); all of these patients met NCCN criteria for Lynch syndrome testing. A total of 479 individuals had 1 or more VUS (38%; 95% CI, 35%-41%). CONCLUSIONS In individuals with suspected Lynch syndrome, multigene panel testing identified high-penetrance mutations in cancer predisposition genes, many of which were unexpected based on patients' histories. Parallel sequencing also detected a high number of potentially uninformative germline findings, including VUS.
Collapse
Affiliation(s)
- Matthew B. Yurgelun
- Dana-Farber Cancer Institute, Boston, Massachusetts, USA,Harvard Medical School, Boston, Massachusetts, USA,Brigham and Women’s Hospital, Boston, Massachusetts, USA
| | - Brian Allen
- Myriad Genetic Laboratories, Salt Lake City, Utah, USA
| | | | | | | | | | | | | | | | - Sapna Syngal
- Dana-Farber Cancer Institute, Boston, Massachusetts, USA,Harvard Medical School, Boston, Massachusetts, USA,Brigham and Women’s Hospital, Boston, Massachusetts, USA
| |
Collapse
|
24
|
van der Klift HM, Jansen AML, van der Steenstraten N, Bik EC, Tops CMJ, Devilee P, Wijnen JT. Splicing analysis for exonic and intronic mismatch repair gene variants associated with Lynch syndrome confirms high concordance between minigene assays and patient RNA analyses. Mol Genet Genomic Med 2015; 3:327-45. [PMID: 26247049 PMCID: PMC4521968 DOI: 10.1002/mgg3.145] [Citation(s) in RCA: 55] [Impact Index Per Article: 6.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/08/2014] [Revised: 03/05/2015] [Accepted: 03/16/2015] [Indexed: 12/13/2022] Open
Abstract
A subset of DNA variants causes genetic disease through aberrant splicing. Experimental splicing assays, either RT-PCR analyses of patient RNA or functional splicing reporter minigene assays, are required to evaluate the molecular nature of the splice defect. Here, we present minigene assays performed for 17 variants in the consensus splice site regions, 14 exonic variants outside these regions, and two deep intronic variants, all in the DNA mismatch-repair (MMR) genes MLH1, MSH2, MSH6, and PMS2, associated with Lynch syndrome. We also included two deep intronic variants in APC and PKD2. For one variant (MLH1 c.122A>G), our minigene assay and patient RNA analysis could not confirm the previously reported aberrant splicing. The aim of our study was to further investigate the concordance between minigene splicing assays and patient RNA analyses. For 30 variants results from patient RNA analyses were available, either performed by our laboratory or presented in literature. Some variants were deliberately included in this study because they resulted in multiple aberrant transcripts in patient RNA analysis, or caused a splice effect other than the prevalent exon skip. While both methods were completely concordant in the assessment of splice effects, four variants exhibited major differences in aberrant splice patterns. Based on the present and earlier studies, together showing an almost 100% concordance of minigene assays with patient RNA analyses, we discuss the weight given to minigene splicing assays in the current criteria proposed by InSiGHT for clinical classification of MMR variants.
Collapse
Affiliation(s)
- Heleen M van der Klift
- Department of Human Genetics, Leiden University Medical Center Leiden, The Netherlands ; Department of Clinical Genetics, Leiden University Medical Center Leiden, The Netherlands
| | - Anne M L Jansen
- Department of Human Genetics, Leiden University Medical Center Leiden, The Netherlands
| | | | - Elsa C Bik
- Department of Clinical Genetics, Leiden University Medical Center Leiden, The Netherlands
| | - Carli M J Tops
- Department of Clinical Genetics, Leiden University Medical Center Leiden, The Netherlands
| | - Peter Devilee
- Department of Human Genetics, Leiden University Medical Center Leiden, The Netherlands ; Department of Pathology, Leiden University Medical Center Leiden, The Netherlands
| | - Juul T Wijnen
- Department of Human Genetics, Leiden University Medical Center Leiden, The Netherlands ; Department of Clinical Genetics, Leiden University Medical Center Leiden, The Netherlands
| |
Collapse
|
25
|
Hinrichsen I, Schäfer D, Langer D, Köger N, Wittmann M, Aretz S, Steinke V, Holzapfel S, Trojan J, König R, Zeuzem S, Brieger A, Plotz G. Functional testing strategy for coding genetic variants of unclear significance in MLH1 in Lynch syndrome diagnosis. Carcinogenesis 2014; 36:202-11. [PMID: 25477341 DOI: 10.1093/carcin/bgu239] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022] Open
Abstract
Lynch syndrome is caused by inactivating mutations in the MLH1 gene, but genetic variants of unclear significance frequently preclude diagnosis. Functional testing can reveal variant-conferred defects in gene or protein function. Based on functional defect frequencies and clinical applicability of test systems, we developed a functional testing strategy aimed at efficiently detecting pathogenic defects in coding MLH1 variants. In this strategy, tests of repair activity and expression are prioritized over analyses of subcellular protein localization and messenger RNA (mRNA) formation. This strategy was used for four unclear coding MLH1 variants (p.Asp41His, p.Leu507Phe, p.Gln689Arg, p.Glu605del + p.Val716Met). Expression was analyzed using a transfection system, mismatch repair (MMR) activity by complementation in vitro, mRNA formation by reverse transcriptase-PCR in carrier lymphocyte mRNA, and subcellular localization with dye-labeled fusion constructs. All tests included clinically meaningful controls. The strategy enabled efficient identification of defects in two unclear variants: the p.Asp41His variant showed loss of MMR activity, whereas the compound variant p.Glu605del + p.Val716Met had a defect of expression. This expression defect was significantly stronger than the pathogenic expression reference variant analyzed in parallel, therefore the defect of the compound variant is also pathogenic. Interestingly, the expression defect was caused additively by both of the compound variants, at least one of which is non-pathogenic when occurring by itself. Tests were neutral for p.Leu507Phe and p.Gln689Arg, and the results were consistent with available clinical data. We finally discuss the improved sensitivity and efficiency of the applied strategy and its limitations in analyzing unclear coding MLH1 variants.
Collapse
Affiliation(s)
- Inga Hinrichsen
- Biomedical Research Laboratory, Department of Internal Medicine 1 and Department of Human Genetics, Universitätsklinikum Frankfurt, Frankfurt D-60590, Germany, Institute of Human Genetics, University of Bonn, Bonn D-53127, Germany and Department of Internal Medicine 1, Universitätsklinikum Frankfurt D-60590, Frankfurt, Germany
| | - Dieter Schäfer
- Department of Human Genetics, Universitätsklinikum Frankfurt, Frankfurt D-60590, Germany
| | - Deborah Langer
- Biomedical Research Laboratory, Department of Internal Medicine 1 and Department of Human Genetics, Universitätsklinikum Frankfurt, Frankfurt D-60590, Germany, Institute of Human Genetics, University of Bonn, Bonn D-53127, Germany and Department of Internal Medicine 1, Universitätsklinikum Frankfurt D-60590, Frankfurt, Germany
| | - Nicole Köger
- Biomedical Research Laboratory, Department of Internal Medicine 1 and Department of Human Genetics, Universitätsklinikum Frankfurt, Frankfurt D-60590, Germany, Institute of Human Genetics, University of Bonn, Bonn D-53127, Germany and Department of Internal Medicine 1, Universitätsklinikum Frankfurt D-60590, Frankfurt, Germany
| | - Margarethe Wittmann
- Biomedical Research Laboratory, Department of Internal Medicine 1 and Department of Human Genetics, Universitätsklinikum Frankfurt, Frankfurt D-60590, Germany, Institute of Human Genetics, University of Bonn, Bonn D-53127, Germany and Department of Internal Medicine 1, Universitätsklinikum Frankfurt D-60590, Frankfurt, Germany
| | - Stefan Aretz
- Institute of Human Genetics, University of Bonn, Bonn D-53127, Germany and
| | - Verena Steinke
- Institute of Human Genetics, University of Bonn, Bonn D-53127, Germany and
| | - Stefanie Holzapfel
- Institute of Human Genetics, University of Bonn, Bonn D-53127, Germany and
| | - Jörg Trojan
- Department of Internal Medicine 1, Universitätsklinikum Frankfurt D-60590, Frankfurt, Germany
| | - Rainer König
- Department of Human Genetics, Universitätsklinikum Frankfurt, Frankfurt D-60590, Germany
| | - Stefan Zeuzem
- Department of Internal Medicine 1, Universitätsklinikum Frankfurt D-60590, Frankfurt, Germany
| | - Angela Brieger
- Biomedical Research Laboratory, Department of Internal Medicine 1 and Department of Human Genetics, Universitätsklinikum Frankfurt, Frankfurt D-60590, Germany, Institute of Human Genetics, University of Bonn, Bonn D-53127, Germany and Department of Internal Medicine 1, Universitätsklinikum Frankfurt D-60590, Frankfurt, Germany
| | - Guido Plotz
- Biomedical Research Laboratory, Department of Internal Medicine 1 and Department of Human Genetics, Universitätsklinikum Frankfurt, Frankfurt D-60590, Germany, Institute of Human Genetics, University of Bonn, Bonn D-53127, Germany and Department of Internal Medicine 1, Universitätsklinikum Frankfurt D-60590, Frankfurt, Germany
| |
Collapse
|
26
|
Thompson B, Martins A, Spurdle A. A review of mismatch repair gene transcripts: issues for interpretation of mRNA splicing assays. Clin Genet 2014; 87:100-8. [DOI: 10.1111/cge.12450] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/20/2014] [Revised: 06/17/2014] [Accepted: 06/24/2014] [Indexed: 12/21/2022]
Affiliation(s)
- B.A. Thompson
- Department of Genetics and Computational Biology; QIMR Berghofer Medical Research Institute; Brisbane Australia
- School of Medicine; University of Queensland; Brisbane Australia
| | - A. Martins
- Inserm U1079; University of Rouen, Institute for Research and Innovation in Biomedicine; Rouen France
| | - A.B. Spurdle
- Department of Genetics and Computational Biology; QIMR Berghofer Medical Research Institute; Brisbane Australia
| |
Collapse
|
27
|
Grodecká L, Lockerová P, Ravčuková B, Buratti E, Baralle FE, Dušek L, Freiberger T. Exon first nucleotide mutations in splicing: evaluation of in silico prediction tools. PLoS One 2014; 9:e89570. [PMID: 24586880 PMCID: PMC3931810 DOI: 10.1371/journal.pone.0089570] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/18/2013] [Accepted: 01/21/2014] [Indexed: 12/20/2022] Open
Abstract
Mutations in the first nucleotide of exons (E+1) mostly affect pre-mRNA splicing when found in AG-dependent 3′ splice sites, whereas AG-independent splice sites are more resistant. The AG-dependency, however, may be difficult to assess just from primary sequence data as it depends on the quality of the polypyrimidine tract. For this reason, in silico prediction tools are commonly used to score 3′ splice sites. In this study, we have assessed the ability of sequence features and in silico prediction tools to discriminate between the splicing-affecting and non-affecting E+1 variants. For this purpose, we newly tested 16 substitutions in vitro and derived other variants from literature. Surprisingly, we found that in the presence of the substituting nucleotide, the quality of the polypyrimidine tract alone was not conclusive about its splicing fate. Rather, it was the identity of the substituting nucleotide that markedly influenced it. Among the computational tools tested, the best performance was achieved using the Maximum Entropy Model and Position-Specific Scoring Matrix. As a result of this study, we have now established preliminary discriminative cut-off values showing sensitivity up to 95% and specificity up to 90%. This is expected to improve our ability to detect splicing-affecting variants in a clinical genetic setting.
Collapse
Affiliation(s)
- Lucie Grodecká
- Molecular Genetics Laboratory, Centre for Cardiovascular Surgery and Transplantation, Brno, Czech Republic
- Central European Institute of Technology, Masaryk University, Brno, Czech Republic
| | - Pavla Lockerová
- Molecular Genetics Laboratory, Centre for Cardiovascular Surgery and Transplantation, Brno, Czech Republic
| | - Barbora Ravčuková
- Molecular Genetics Laboratory, Centre for Cardiovascular Surgery and Transplantation, Brno, Czech Republic
| | - Emanuele Buratti
- International Centre for Genetic Engineering and Biotechnology, Trieste, Italy
| | | | - Ladislav Dušek
- Institute of Biostatistics and Analyses, Masaryk University, Brno, Czech Republic
| | - Tomáš Freiberger
- Molecular Genetics Laboratory, Centre for Cardiovascular Surgery and Transplantation, Brno, Czech Republic
- Central European Institute of Technology, Masaryk University, Brno, Czech Republic
- Institute of Clinical Immunology and Allergology, St. Anne’s University Hospital and Masaryk University, Brno, Czech Republic
- * E-mail:
| |
Collapse
|
28
|
De Lellis L, Aceto GM, Curia MC, Catalano T, Mammarella S, Veschi S, Fantini F, Battista P, Stigliano V, Messerini L, Mareni C, Sala P, Bertario L, Radice P, Cama A. Integrative analysis of hereditary nonpolyposis colorectal cancer: the contribution of allele-specific expression and other assays to diagnostic algorithms. PLoS One 2013; 8:e81194. [PMID: 24278394 PMCID: PMC3835792 DOI: 10.1371/journal.pone.0081194] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/27/2013] [Accepted: 10/09/2013] [Indexed: 01/27/2023] Open
Abstract
The identification of germline variants predisposing to hereditary nonpolyposis colorectal cancer (HNPCC) is crucial for clinical management of carriers, but several probands remain negative for such variants or bear variants of uncertain significance (VUS). Here we describe the results of integrative molecular analyses in 132 HNPCC patients providing evidences for improved genetic testing of HNPCC with traditional or next generation methods. Patients were screened for: germline allele-specific expression (ASE), nucleotide variants, rearrangements and promoter methylation of mismatch repair (MMR) genes; germline EPCAM rearrangements; tumor microsatellite instability (MSI) and immunohistochemical (IHC) MMR protein expression. Probands negative for pathogenic variants of MMR genes were screened for germline APC and MUTYH sequence variants. Most germline defects identified were sequence variants and rearrangements of MMR genes. Remarkably, altered germline ASE of MMR genes was detected in 8/22 (36.5%) probands analyzed, including 3 cases negative at other screenings. Moreover, ASE provided evidence for the pathogenic role and guided the characterization of a VUS shared by 2 additional probands. No germline MMR gene promoter methylation was observed and only one EPCAM rearrangement was detected. In several cases, tumor IHC and MSI diverged from germline screening results. Notably, APC or biallelic MUTYH germline defects were identified in 2/19 probands negative for pathogenic variants of MMR genes. Our results show that ASE complements gDNA-based analyses in the identification of MMR defects and in the characterization of VUS affecting gene expression, increasing the number of germline alterations detected. An appreciable fraction of probands negative for MMR gene variants harbors APC or MUTYH variants. These results indicate that germline ASE analysis and screening for APC and MUTYH defects should be included in HNPCC diagnostic algorithms.
Collapse
Affiliation(s)
- Laura De Lellis
- Department of Pharmacy, “G. d’Annunzio” University, Chieti, Italy
| | - Gitana Maria Aceto
- Department of Experimental and Clinical Sciences, “G. d’Annunzio” University, Chieti, Italy
- Unit of Molecular Pathology and Genomics, Aging Research Center, “G. d’Annunzio” University Foundation, Chieti, Italy
| | - Maria Cristina Curia
- Department of Medical, Oral and Biotechnological Sciences, “G. d’Annunzio” University, Chieti, Italy
- Unit of Molecular Pathology and Genomics, Aging Research Center, “G. d’Annunzio” University Foundation, Chieti, Italy
| | - Teresa Catalano
- Department of Clinical and Experimental Medicine, University of Messina, Messina, Italy
| | | | - Serena Veschi
- Unit of Molecular Pathology and Genomics, Aging Research Center, “G. d’Annunzio” University Foundation, Chieti, Italy
| | - Fabiana Fantini
- Department of Experimental and Clinical Sciences, “G. d’Annunzio” University, Chieti, Italy
| | - Pasquale Battista
- Department of Experimental and Clinical Sciences, “G. d’Annunzio” University, Chieti, Italy
| | - Vittoria Stigliano
- Department of Gastroenterology, Unit of Hereditary Colorectal Cancer, National Cancer Institute, Regina Elena (IRE), Rome, Italy
| | - Luca Messerini
- Section of Pathological Anatomy, Department of Medical and Surgical Critical Care, University of Florence, Florence, Italy
| | - Cristina Mareni
- Department of Internal Medicine, University of Genova, Genova, Italy
| | - Paola Sala
- Unit of Hereditary Digestive Tract Tumors, Department of Preventive and Predictive Medicine, Fondazione IRCCS Istituto Nazionale dei Tumori, Milan, Italy
| | - Lucio Bertario
- Unit of Hereditary Digestive Tract Tumors, Department of Preventive and Predictive Medicine, Fondazione IRCCS Istituto Nazionale dei Tumori, Milan, Italy
| | - Paolo Radice
- Unit of Molecular bases of genetic risk and genetic testing, Department of Preventive and Predictive Medicine, Fondazione IRCCS Istituto Nazionale dei Tumori, Milan, Italy
| | - Alessandro Cama
- Department of Pharmacy, “G. d’Annunzio” University, Chieti, Italy
- * E-mail:
| |
Collapse
|
29
|
Clinical correlation and molecular evaluation confirm that the MLH1 p.Arg182Gly (c.544A>G) mutation is pathogenic and causes Lynch syndrome. Fam Cancer 2013; 11:509-18. [PMID: 22773173 DOI: 10.1007/s10689-012-9544-4] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
Abstract
Approximately 25 % of mismatch repair (MMR) variants are exonic nucleotide substitutions. Some result in the substitution of one amino acid for another in the protein sequence, so-called missense variants, while others are silent. The interpretation of the effect of missense and silent variants as deleterious or neutral is challenging. Pre-symptomatic testing for clinical use is not recommended for relatives of individuals with variants classified as 'of uncertain significance'. These relatives, including non-carriers, are considered at high-risk as long as the contribution of the variant to disease causation cannot be determined. This results in continuing anxiety, and the application of potentially unnecessary screening and prophylactic interventions. We encountered a large Irish Lynch syndrome kindred that carries the c.544A>G (p.Arg182Gly) alteration in the MLH1 gene and we undertook to study the variant. The clinical significance of the variant remains unresolved in the literature. Data are presented on cancer incidence within five kindreds with the same germline missense variant in the MLH1 MMR gene. Extensive testing of relevant family members in one kindred, a review of the literature, review of online MMR mutation databases and use of in silico phenotype prediction tools were undertaken to study the significance of this variant. Clinical, histological, immunohistochemical and molecular evidence from these families and other independent clinical and scientific evidence indicates that the MLH1 p.Arg182Gly (c.544A>G) change causes Lynch syndrome and supports reclassification of the variant as pathogenic.
Collapse
|
30
|
Takahashi M, Furukawa Y, Shimodaira H, Sakayori M, Moriya T, Moriya Y, Nakamura Y, Ishioka C. Aberrant splicing caused by a MLH1 splice donor site mutation found in a young Japanese patient with Lynch syndrome. Fam Cancer 2013; 11:559-64. [PMID: 22766992 DOI: 10.1007/s10689-012-9547-1] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
Lynch syndrome, also known as hereditary non-polyposis colorectal cancer, characterized by predisposition to colorectal cancer and other associated cancers, is an autosomal-dominant disorder mainly caused by germline mutations in DNA mismatch repair (MMR) genes such as MLH1, MSH2, and MSH6. Some mutations that disrupt splice donor or acceptor sites cause aberrant mRNA splicing. These mutations are generally considered as pathogenic ones, however, it is sometimes uneasy to accurately predict their pathogenicity without functional assays, particularly when the mutation is a single nucleotide substitution. In this report, we describe a 25-year-old patient with Lynch syndrome who carries a germline variant in a splice donor site of the MLH1 gene (c.790 + 5 G > T), which was first detected among Asian populations. The immunohistochemical analysis revealed loss of MLH1 protein expression in the tumor. Our splicing assay confirmed that the intronic MLH1 variant actually caused aberrant splicing, supporting its pathogenic effect. Our data accumulate more information on the genotype-phenotype relationships in patients with Lynch syndrome.
Collapse
Affiliation(s)
- Masanobu Takahashi
- Department of Clinical Oncology, Institute of Development, Aging and Cancer, and Tohoku University Hospital, Tohoku University, 4-1 Seiryo-machi, Aoba-ku, Sendai, Japan
| | | | | | | | | | | | | | | |
Collapse
|
31
|
Pérez-Cabornero L, Infante M, Velasco E, Lastra E, Miner C, Durán M. Evaluating the effect of unclassified variants identified in MMR genes using phenotypic features, bioinformatics prediction, and RNA assays. J Mol Diagn 2013; 15:380-90. [PMID: 23523604 DOI: 10.1016/j.jmoldx.2013.02.003] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/02/2012] [Revised: 01/29/2013] [Accepted: 02/01/2013] [Indexed: 11/16/2022] Open
Abstract
Lynch syndrome is caused by mutations in one of the mismatch-repair system (MMR) genes. A major difficulty in diagnosis and management of Lynch syndrome is the existence of unclassified genetic variants (UVs) with unknown clinical significance, especially mutations with new descriptions and missense-type nucleotide substitutions. We evaluated the pathogenicity of 20 such mutations (6 in MLH1, 4 in MSH2, and 7 in MSH6) found in Spanish patients suspected of Lynch syndrome. The UVs were tested for evidence of MMR defect in tumor samples and were evaluated for co-occurrence with a pathogenic mutation, the cosegregation of the variant with the disease; where sufficient data were available, in silico resources at the protein level and mRNA analysis were used to assess the putative effect on the splicing mechanism. To evaluate the frequency of these UVs in the general population, a case--control study was also performed. Five variants were identified with similar frequencies in both cases and controls, suggesting a nonpathogenic effect in patients. In contrast, abnormal splicing mutations were detected in a high proportion of patients [3/20 (15%)]. In this study, we classified 15 of the 20 UVs: six variants with strong evidence of pathogenicity and nine variants that should be considered neutral variants. Clinical significance of the other five remains unknown.
Collapse
Affiliation(s)
- Lucia Pérez-Cabornero
- Cancer Genetics Laboratory, Institute of Biology and Molecular Genetics, University of Valladolid, Valladolid, Spain
| | | | | | | | | | | |
Collapse
|
32
|
Zhu M, Chen HM, Wang YP. Missense mutations of MLH1 and MSH2 genes detected in patients with gastrointestinal cancer are associated with exonic splicing enhancers and silencers. Oncol Lett 2013; 5:1710-1718. [PMID: 23760103 PMCID: PMC3678577 DOI: 10.3892/ol.2013.1243] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/23/2012] [Accepted: 02/18/2013] [Indexed: 01/11/2023] Open
Abstract
The MLH1 and MSH2 genes in DNA mismatch repair are important in the pathogenesis of gastrointestinal cancer. Recent studies of normal and alternative splicing suggest that the deleterious effects of missense mutations may in fact be splicing-related when they are located in exonic splicing enhancers (ESEs) or exonic splicing silencers (ESSs). In this study, we used ESE-finder and FAS-ESS software to analyze the potential ESE/ESS motifs of the 114 missense mutations detected in the two genes in East Asian gastrointestinal cancer patients. In addition, we used the SIFT tool to functionally analyze these mutations. The amount of the ESE losses (68) was 51.1% higher than the ESE gains (45) of all the mutations. However, the amount of the ESS gains (27) was 107.7% higher than the ESS losses (13). In total, 56 (49.1%) mutations possessed a potential exonic splicing regulator (ESR) error. Eighty-one mutations (71.1%) were predicted to be deleterious with a lower tolerance index as detected by the Sorting Intolerant from Tolerant (SIFT) tool. Among these, 38 (33.3%) mutations were predicted to be functionally deleterious and possess one potential ESR error, while 18 (15.8%) mutations were predicted to be functionally deleterious and exhibit two potential ESR errors. These may be more likely to affect exon splicing. Our results indicated that there is a strong correlation between missense mutations in MLH1 and MSH2 genes detected in East Asian gastrointestinal cancer patients and ESR motifs. In order to correctly understand the molecular nature of mutations, splicing patterns should be compared between wild-type and mutant samples.
Collapse
Affiliation(s)
- Ming Zhu
- Jiangsu Key Laboratory of Molecular Medicine, Nanjing University School of Medicine, Nanjing 210093; ; Department of Molecular Biology, Jiangsu Institute of Cancer Research, Nanjing 210009, P.R. China
| | | | | |
Collapse
|
33
|
Kriangkum J, Warkinton A, Belch AR, Pilarski LM. Alteration of introns in a hyaluronan synthase 1 (HAS1) minigene convert Pre-mRNA [corrected] splicing to the aberrant pattern in multiple myeloma (MM): MM patients harbor similar changes. PLoS One 2013; 8:e53469. [PMID: 23301075 PMCID: PMC3536762 DOI: 10.1371/journal.pone.0053469] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/07/2012] [Accepted: 11/30/2012] [Indexed: 11/26/2022] Open
Abstract
Aberrant pre-mRNA splice variants of hyaluronan synthase 1 (HAS1) have been identified in malignant cells from cancer patients. Bioinformatic analysis suggests that intronic sequence changes can underlie aberrant splicing. Deletions and mutations were introduced into HAS1 minigene constructs to identify regions that can influence aberrant intronic splicing, comparing the splicing pattern in transfectants with that in multiple myeloma (MM) patients. Introduced genetic variations in introns 3 and 4 of HAS1 as shown here can promote aberrant splicing of the type detected in malignant cells from MM patients. HAS1Vd is a novel intronic splice variant first identified here. HAS1Vb, an intronic splice variant previously identified in patients, skips exon 4 and utilizes the same intron 4 alternative 3′splice site as HAS1Vd. For transfected constructs with unaltered introns 3 and 4, HAS1Vd transcripts are readily detectable, frequently to the exclusion of HAS1Vb. In contrast, in MM patients, HAS1Vb is more frequent than HAS1Vd. In the HAS1 minigene, combining deletion in intron 4 with mutations in intron 3 leads to a shift from HAS1Vd expression to HAS1Vb expression. The upregulation of aberrant splicing, exemplified here by the expression of HAS1Vb, is shown here to be influenced by multiple genetic changes in intronic sequences. For HAS1Vb, this includes enhanced exon 4 skipping and increased usage of alternative 3′ splice sites. Thus, the combination of introduced mutations in HAS1 intron3 with introduced deletions in HAS1 intron 4 promoted a shift to an aberrant splicing pattern previously shown to be clinically significant. Most MM patients harbor genetic variations in intron 4, and as shown here, nearly half harbor recurrent mutations in HAS1 intron 3. Our work suggests that aberrant intronic HAS1 splicing in MM patients may rely on intronic HAS1 deletions and mutations that are frequent in MM patients but absent from healthy donors.
Collapse
Affiliation(s)
- Jitra Kriangkum
- Department of Oncology, Cross Cancer Institute, University of Alberta, Edmonton, Alberta, Canada
- * E-mail: (JK); (LMP)
| | - Amanda Warkinton
- Department of Oncology, Cross Cancer Institute, University of Alberta, Edmonton, Alberta, Canada
| | - Andrew R. Belch
- Department of Oncology, Cross Cancer Institute, University of Alberta, Edmonton, Alberta, Canada
| | - Linda M. Pilarski
- Department of Oncology, Cross Cancer Institute, University of Alberta, Edmonton, Alberta, Canada
- * E-mail: (JK); (LMP)
| |
Collapse
|
34
|
Heinen CD, Juel Rasmussen L. Determining the functional significance of mismatch repair gene missense variants using biochemical and cellular assays. Hered Cancer Clin Pract 2012; 10:9. [PMID: 22824075 PMCID: PMC3434035 DOI: 10.1186/1897-4287-10-9] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/19/2012] [Accepted: 06/28/2012] [Indexed: 12/15/2022] Open
Abstract
With the discovery that the hereditary cancer susceptibility disease Lynch syndrome (LS) is caused by deleterious germline mutations in the DNA mismatch repair (MMR) genes nearly 20 years ago, genetic testing can now be used to diagnose this disorder in patients. A definitive diagnosis of LS can direct how clinicians manage the disease as well as prevent future cancers for the patient and their families. A challenge emerges, however, when a germline missense variant is identified in a MMR gene in a suspected LS patient. The significance of a single amino acid change in these large repair proteins is not immediately obvious resulting in them being designated variants of uncertain significance (VUS). One important strategy for resolving this uncertainty is to determine whether the variant results in a non-functional protein. The ability to reconstitute the MMR reaction in vitro has provided an important experimental tool for studying the functional consequences of VUS. However, beyond this repair assay, a number of other experimental methods have been developed that allow us to test the effect of a VUS on discrete biochemical steps or other aspects of MMR function. Here, we describe some of these assays along with the challenges of using such assays to determine the functional consequences of MMR VUS which, in turn, can provide valuable insight into their clinical significance. With increased gene sequencing in patients, the number of identified VUS has expanded dramatically exacerbating this problem for clinicians. However, basic science research laboratories around the world continue to expand our knowledge of the overall MMR molecular mechanism providing new opportunities to understand the functional significance, and therefore pathogenic significance, of VUS.
Collapse
Affiliation(s)
- Christopher D Heinen
- Neag Comprehensive Cancer Center and Center for Molecular Medicine, University of Connecticut Health Center, 233 Farmington Avenue, ML3101 Farmington, CT, USA.
| | | |
Collapse
|
35
|
Borràs E, Pineda M, Brieger A, Hinrichsen I, Gómez C, Navarro M, Balmaña J, Ramón y Cajal T, Torres A, Brunet J, Blanco I, Plotz G, Lázaro C, Capellá G. Comprehensive functional assessment of MLH1 variants of unknown significance. Hum Mutat 2012; 33:1576-88. [PMID: 22736432 DOI: 10.1002/humu.22142] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/19/2012] [Accepted: 05/29/2012] [Indexed: 12/15/2022]
Abstract
Lynch syndrome is associated with germline mutations in DNA mismatch repair (MMR) genes. Up to 30% of DNA changes found are variants of unknown significance (VUS). Our aim was to assess the pathogenicity of eight MLH1 VUS identified in patients suspected of Lynch syndrome. All of them are novel or not previously characterized. For their classification, we followed a strategy that integrates family history, tumor pathology, and control frequency data with a variety of in silico and in vitro analyses at RNA and protein level, such as MMR assay, MLH1 and PMS2 expression, and subcellular localization. Five MLH1 VUS were classified as pathogenic: c.[248G>T(;)306G>C], c.[780C>G;788A>C], and c.791-7T>A affected mRNA processing, whereas c.218T>C (p.L73P) and c.244A>G [corrected] (p.T82A) impaired MMR activity. Two other VUS were considered likely neutral: the silent c.702G>A variant did not affect mRNA processing or stability, and c.974G>A (p.R325Q) did not influence MMR function. In contrast, variant c.25C>T (p.R9W) could not be classified, as it associated with intermediate levels of MMR activity. Comprehensive functional assessment of MLH1 variants was useful in their classification and became relevant in the diagnosis and genetic counseling of carrier families.
Collapse
Affiliation(s)
- Ester Borràs
- Hereditary Cancer Program, Catalan Institute of Oncology, ICO-IDIBELL, Hospitalet de Llobregat, Spain
| | | | | | | | | | | | | | | | | | | | | | | | | | | |
Collapse
|
36
|
Wang D, Zhou J, Wang T, Li X, Li S, Chen S, Ma G, Li J, Zhang X. Polymorphisms in MSH2 gene and risk of gastric cancer, and interactions with lifestyle factors in a Chinese population. Cancer Epidemiol 2012; 36:e171-6. [PMID: 22386861 DOI: 10.1016/j.canep.2012.02.003] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/14/2011] [Revised: 12/29/2011] [Accepted: 02/07/2012] [Indexed: 12/15/2022]
Abstract
BACKGROUND Although polymorphisms in DNA mismatch repair (MMR) gene MSH2 have been associated with risks of many cancers, little is known about their etiology role in gastric cancer (GC) and the potential interacting role with lifestyle factors known to damage DNA. METHODS A population-based study was conducted in 3 counties (Jintan, Taixing and Huaian) of Jiangsu Province, the high-risk areas of GC in China. We investigated the association of polymorphisms IVS12-6T>C and IVS10+12G>A in MSH2 gene with the risk of GC and the potential gene-lifestyle interaction. RESULTS The risk of GC was found to be associated with the IVS12-6C allele (CC vs TT, OR=2.34, 95% CI: 1.17-4.71) and IVS10+12A allele (GA or AA vs GG, OR=1.55, 95% CI: 1.14-2.21; and GA vs GG, OR=1.51, 95% CI: 1.04-2.17). Stratified analysis indicated that an increased risk of GC also was observed in: suspected familial subjects carrying the IVS12-6T>C (OR=1.68, 95% CI: 1.27-2.66) or IVS10+12G>A (OR=2.57, 95% CI: 1.53-4.10); or younger subjects carrying the IVS12-6T>C (OR=2.15, 95% CI: 1.24-3.91) or IVS10+12G>A (OR=2.23, 95% CI: 1.20-4.33); or male subjects carrying the IVS10+12G>A (OR=1.64; 95% CI: 1.10-2.54). Furthermore, the combined IVS12-6CC and IVS10+12AA genotypes also significantly increased the risk of GC (OR=2.12, 95% CI: 1.22-3.66). Statistically significant interactions were observed between: IVS10+12G>A and drinking, high pickled food or fried food intake (OR=2.32; 95% CI: 1.43-3.78, OR=2.55; 95% CI: 1.48-4.21 and OR=2.88; 95% CI: 1.70-4.94, respectively); and IVS12-6T>C and high pickled food intake or fried food intake (OR=2.65; 95% CI: 1.62-4.47 and OR=2.48; 95% CI: 1.42-4.13, respectively). CONCLUSION The IVS10+12G>A and IVS12-6T>C polymorphisms in MSH2 gene appear to be associated with risk of GC in this Chinese population. Risk for GC, stratified by related genotypes, was further modified by drinking, high pickled food or fried food intake. Larger prospective studies are needed to confirm these findings.
Collapse
Affiliation(s)
- Deqiang Wang
- Department of Chemotherapy, Institute of Cancer Research, Affiliated Hospital of Jiangsu University, Zhenjiang, China
| | | | | | | | | | | | | | | | | |
Collapse
|
37
|
Analysis and interpretation of RNA splicing alterations in genes involved in genetic disorders. Methods Mol Biol 2012; 867:49-63. [PMID: 22454054 DOI: 10.1007/978-1-61779-767-5_4] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/28/2023]
Abstract
Germ line mutations in genes involved in hereditary cancer syndromes, such as BRCA1 and BRCA2 in breast cancer and MSH2, MSH6, MLH1, and PSM2 in hereditary nonpolyposis colorectal cancer (HNPCC, more recently indicated as Lynch syndrome), confer a high risk to develop cancer. Mutation analysis in these genes has resulted in the identification of a large number of sequence variants, of which mutations causing frame shifts and nonsense codons are considered undoubtedly to be pathogenic. Many variants, however, cannot be classified as either disease-causing mutations or neutral variants and are therefore called unclassified variants (UVs). A subset of these variants may have an effect on RNA splicing. Appropriate RNA analysis will enable the characterization of the exact molecular nature of this effect and hence, is essential to determine the clinical relevance of the genomic variant. This chapter describes the design and implementation of RNA analysis as an indispensible tool in today's clinical diagnostic setting.
Collapse
|
38
|
Zhi W, Xue B, Wang L, Xiao N, He Q, Wang Y, Fan Y. The MLH1 2101C>A (Q701K) variant increases the risk of gastric cancer in Chinese males. BMC Gastroenterol 2011; 11:133. [PMID: 22136435 PMCID: PMC3275522 DOI: 10.1186/1471-230x-11-133] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/20/2010] [Accepted: 12/03/2011] [Indexed: 12/14/2022] Open
Abstract
Background Gastric cancer is one of the most common cancers affecting East Asians, and MLH1 could play a critical role during tumorigenesis in this condition. Methods Samples from 236 Chinese patients suffering from gastric cancer were screened for MLH1 germline mutations. Carrier frequencies of the mutations were compared between gastric cancer patients and 240 cancer-free controls. Bioinformatic analysis was used to predict the effect of these mutations on protein function and mRNA splicing. Results Six MLH1 sequence alterations were identified in gastric cancer patients including two promoter region substitutions, -93G>A and -28A>G, and four missense mutations 649C>T (R217C), 655A>G (I219V), 1151T>A (V384D) and 2101C>A (Q701K). Compared with the MLH1 2101CC genotype, the 2101CA genotype was associated with a risk of gastric cancer (OR = 8.42, 95% CI = 1.04-68.06) in males. Furthermore, the MLH1 2101C>A mutant was predicted by in silico analysis to affect exon splicing ability. Immunohistochemistry of one index patient carrying the MLH1 2101C>A mutation demonstrated a loss of MLH1 protein and normal expression of MSH2 and E-cadherin. No significant differences were demonstrated between cases and controls for the other five MLH1 variants but the data indicated an ethnic difference in the frequency of these variations between Eastern Asians and Western populations. Conclusions An ethnic-specific MLH1 mutation spectrum occurred in Chinese gastric cancer patients. The MLH1 2101C>A mutation could be a marker for susceptibility to gastric cancer, particularly in males.
Collapse
Affiliation(s)
- Wenxian Zhi
- Department of Medical Genetics, Medical School, Nanjing University, Nanjing, China
| | | | | | | | | | | | | |
Collapse
|
39
|
Identification and surveillance of 19 Lynch syndrome families in southern Italy: report of six novel germline mutations and a common founder mutation. Fam Cancer 2011; 10:285-95. [PMID: 21286823 DOI: 10.1007/s10689-011-9419-0] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/05/2023]
Abstract
Lynch syndrome (LS), or hereditary non-polyposis colorectal cancer (HNPCC), is an autosomal dominant condition responsible for early onset cancer mostly in the colonrectum and endometrium as well as in other organ sites. Lynch syndrome is caused by germline mutations in mismatch repair genes, prevalently in hMSH2, hMLH1, and less frequently in hMSH6 and hPMS2. Twenty-nine non-related index cases with colorectal cancer (CRC) were collected from a region in southeast Italy (Apulia). Among this set of patients, fifteen fulfilled the Amsterdam criteria II. The presence of tumor microsatellite instability (MSI) was assessed in all index cases and 19 (15 AC+/4 AC-) were classified as MSI-H. Mutation analysis performed on all patients, identified 15 pathogenic mutations in hMLH1 and 4 in hMSH2. 4/15 mutations in hMLH1 and 2/4 hMSH2 mutations have not been previously reported. Three previously reported mutations were further investigated for the possibility of a common founder effect. Genetic counseling was offered to all probands and extended to 183 relatives after molecular testing and 85 (46%) mutation carriers were identified. Eighty mutation carriers underwent an accurate clinical and instrumental surveillance protocol. Our results confirm that the identification of LS patients based exclusively on family history may miss patients carrying germline mutations in the MMR genes. Moreover, our results demonstrated that molecular screening and subsequent instrumental surveillance are very effective in identifying CRCs at earlier stages and reducing the number of deaths from secondary cancers in HNPCC patients.
Collapse
|
40
|
Robinson DO, Lin F, Lyon M, Raponi M, Cross E, White HE, Cox H, Clayton-Smith J, Baralle D. Systematic screening of FBN1 gene unclassified missense variants for splice abnormalities. Clin Genet 2011; 82:223-31. [PMID: 21895641 DOI: 10.1111/j.1399-0004.2011.01781.x] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
Abstract
Defects at the level of pre-mRNA splicing are a common source of genetic mutation but such mutations are not always easy to identify from DNA sequence data alone. Clinical practice has only recently begun to incorporate analysis for this type of abnormality. Some base changes at the DNA level currently viewed as unclassified variants or missense mutations may influence RNA splicing. To address this problem for fibrillin 1 (FBN1) gene missense mutations we have carried out RNA analysis and in silico analysis with splice site prediction programs on 40 cases with 36 different mutations. Direct analysis of RNA from blood was performed by cDNA preparation, PCR amplification of specific FBN1 fragments, gel electrophoresis and sequencing of the PCR products. Of the 36 missense base changes, direct RNA analysis identified 2 which caused an abnormality of splicing. In silico analysis using five splice site prediction programs did not always accurately predict the splicing seen by direct RNA analysis. In conclusion, some apparent missense mutations have an effect on splicing which can be identified by direct RNA analysis, however, in silico analysis of splice sites is not always accurate, should be carried out with more than one prediction program and results should be used with caution.
Collapse
Affiliation(s)
- D O Robinson
- Wessex Regional Genetics Laboratory, Salisbury District Hospital, Salisbury, Wiltshire SP2 8BJ, UK.
| | | | | | | | | | | | | | | | | |
Collapse
|
41
|
Betz B, Theiss S, Aktas M, Konermann C, Goecke TO, Möslein G, Schaal H, Royer-Pokora B. Comparative in silico analyses and experimental validation of novel splice site and missense mutations in the genes MLH1 and MSH2. J Cancer Res Clin Oncol 2011; 136:123-34. [PMID: 19669161 DOI: 10.1007/s00432-009-0643-z] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/26/2009] [Accepted: 07/17/2009] [Indexed: 12/24/2022]
Abstract
Hereditary non-polyposis colorectal cancer, an autosomal dominant predisposition to colorectal cancer and other malignancies, is caused by inactivating mutations of DNA mismatch repair genes, mainly MLH1 and MSH2. Missense mutations affect protein structure or function, but may also cause aberrant splicing, if located within splice sites (ss) or cis-acting sequences of splicing regulatory proteins, i.e., exonic splicing enhancers or exonic splicing silencers. Despite significant progress of ss scoring algorithms, the prediction for the impact of mutations on splicing is still unsatisfactory. For this study, we assessed ten ss and nine missense mutations outside ss in MLH1 and MSH2, including eleven newly identified mutations, and experimentally analyzed their effect at the RNA level. We additionally tested and compared the reliability of several web-based programs for the prediction of splicing outcome for these mutations.
Collapse
Affiliation(s)
- Beate Betz
- Institut fuer Humangenetik, Universitaetsklinikum Duesseldorf, Universitaetsstrasse 1, 40225 Duesseldorf, Germany
| | | | | | | | | | | | | | | |
Collapse
|
42
|
Abstract
PURPOSE Lynch syndrome is a genetic disease that predisposes to colorectal tumors, caused by mutation in mismatch repair genes. The use of genetic tests to identify mutation carriers does not always give perfectly clear results, as happens when an unclassified variant is found. This study aimed to define the pathogenic role of 35 variants present in MSH2, MLH1, MSH6, and PMS2 genes identified in our 15-year case study. METHODS We collected clinical and molecular data of all carriers, and then we analyzed the variants pathogenic role with web tools and molecular analyses. Using a Bayesian approach, we derived a posterior probability of pathogenicity and classified each variant according to a standardized five-class system. RESULTS The MSH2 p.Pro349Arg, p.Met688Arg, the MLH1 p.Gly67Arg, p.Thr82Ala, p.Lys618Ala, the MSH6 p.Ala1236Pro, and the PMS2 p.Arg20Gln were classified as pathogenic, and the MSH2 p.Cys697Arg and the PMS2 p.Ser46Ile were classified as likely pathogenic. Seven variants were likely nonpathogenic, 3 were nonpathogenic, and 16 remained uncertain. CONCLUSION Quantitative assessment of several parameters and their integration in a multifactorial likelihood model is the method of choice for classifying the variants. As such classifications can be associated with surveillance and testing recommendations, the results and the method developed in our study can be useful for helping laboratory geneticists in evaluation of genetic tests and clinicians in the management of carriers.
Collapse
|
43
|
Raponi M, Kralovicova J, Copson E, Divina P, Eccles D, Johnson P, Baralle D, Vorechovsky I. Prediction of single-nucleotide substitutions that result in exon skipping: identification of a splicing silencer in BRCA1 exon 6. Hum Mutat 2011; 32:436-44. [PMID: 21309043 DOI: 10.1002/humu.21458] [Citation(s) in RCA: 108] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/31/2010] [Accepted: 01/07/2011] [Indexed: 12/29/2022]
Abstract
Missense, nonsense, and translationally silent mutations can inactivate genes by altering the inclusion of mutant exons in mRNA, but their overall frequency among disease-causing exonic substitutions is unknown. Here, we have tested missense and silent mutations deposited in the BRCA1 mutation databases of unclassified variants for their effects on exon inclusion. Analysis of 21 BRCA1 variants using minigene assays revealed a single exon-skipping mutation c.231G>T. Comprehensive mutagenesis of an adjacent 12-nt segment showed that this silent mutation resulted in a higher level of exon skipping than the 35 other single-nucleotide substitutions. Exon inclusion levels of mutant constructs correlated significantly with predicted splicing enhancers/silencers, prompting the development of two online utilities freely available at http://www.dbass.org.uk. EX-SKIP quickly estimates which allele is more susceptible to exon skipping, whereas HOT-SKIP examines all possible mutations at each exon position and identifies candidate exon-skipping positions/substitutions. We demonstrate that the distribution of exon-skipping and disease-associated substitutions previously identified in coding regions was biased toward top-ranking HOT-SKIP mutations. Finally, we show that proteins 9G8, SC35, SF2/ASF, Tra2, and hnRNP A1 were associated with significant alterations of BRCA1 exon 6 inclusion in the mRNA. Together, these results facilitate prediction of exonic substitutions that reduce exon inclusion in mature transcripts.
Collapse
Affiliation(s)
- Michela Raponi
- University of Southampton School of Medicine, Southampton, United Kingdom
| | | | | | | | | | | | | | | |
Collapse
|
44
|
Auclair J, Vaissière T, Desseigne F, Lasset C, Bonadona V, Giraud S, Saurin JC, Joly MO, Leroux D, Faivre L, Audoynaud C, Montmain G, Ruano E, Herceg Z, Puisieux A, Wang Q. Intensity-dependent constitutional MLH1 promoter methylation leads to early onset of colorectal cancer by affecting both alleles. Genes Chromosomes Cancer 2010; 50:178-85. [PMID: 21213371 DOI: 10.1002/gcc.20842] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/23/2010] [Accepted: 10/25/2010] [Indexed: 12/27/2022] Open
Abstract
Constitutional epimutation is one of the causes for MLH1 gene inactivation associated with hereditary non-polyposis colon cancer (HNPCC) syndrome. Here we investigate MLH1 promoter hypermethylation in 110 sporadic early-onset colorectal cancer patients. Variable levels of hypermethylation were detected in 55 patients (50%). Importantly a reduced MLH1 gene expression was found in patients with high-level methylation, with the association of microsatellite instability (MSI) in their tumor cells. Such high-level methylation accounts for 7.4% of all patients included in this study. Furthermore, we found that in one case constitutional methylation affected both alleles, indicating a post-zygotic methylation dysregulation. Our findings suggest that constitutional epimutation is a mechanism underlying early-onset colorectal cancer, although it is involved in only a small proportion of patients, who require appropriate surveillance. Our findings provide further insight into the role of aberrant constitutional methylation in colon carcinogenesis and raise the question of whether prevalent low-level methylation constitutes a potential risk factor for cancer development.
Collapse
Affiliation(s)
- Jessie Auclair
- Centre Léon Bérard, Laboratoire de Recherche Translationnelle, Lyon, France
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | |
Collapse
|
45
|
Non-truncating hMLH1 variants identified in Slovenian gastric cancer patients are not associated with Lynch Syndrome: a functional analysis report. Fam Cancer 2010; 10:255-63. [DOI: 10.1007/s10689-010-9409-7] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
|
46
|
Ling IF, Gopalraj RK, Simpson JF, Estus S. Expression and regulation of a low-density lipoprotein receptor exon 12 splice variant. J Neurochem 2010; 115:614-24. [PMID: 20807319 DOI: 10.1111/j.1471-4159.2010.06972.x] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/21/2023]
Abstract
As low-density lipoprotein receptor (LDLR) contributes to cholesterol and amyloid beta homeostasis, insights into LDLR regulation may facilitate our understanding of cardiovascular disease and Alzheimer's disease. Previously, we identified LDLR isoforms that lacked exon 12 or exons 11-12 and that are predicted to encode soluble, dominant negative, LDLR. Moreover, these isoforms were associated with rs688, an exon 12 polymorphism that was associated with LDL-cholesterol and Alzheimer's disease risk. In this study, we present evidence that although the truncated LDLR isoforms are translated in vitro, they represent < 0.1% of CSF proteins. As these LDLR isoforms likely represent a loss of mRNA-encoding functional LDLR, we then focused upon identifying intron-exon boundary and exonic splicing enhancer elements critical to splicing. Exon 12 inclusion is enhanced by altering the 5' splice site in intron 12 towards a consensus splice donor sequence, consistent with its being a weak 5' splice site. Additionally, of the nine evolutionarily conserved putative splicing enhancer regions within exon 12, two regions that flank rs688 were critical to exon 12 inclusion. Overall, these results suggest that LDLR splice variants represent a loss of mRNA encoding functional LDLR and provide insights into the regulatory elements critical for LDLR exon 12 splicing.
Collapse
Affiliation(s)
- I-Fang Ling
- Department of Physiology, Sanders-Brown Center on Aging, University of Kentucky, Lexington, Kentucky 40536-0230, USA
| | | | | | | |
Collapse
|
47
|
Demokan S, Suoglu Y, Ulusan M, Dalay N. Analysis of the hMSH2 gene variants in head and neck cancer. DNA Cell Biol 2010; 29:449-57. [PMID: 20438357 DOI: 10.1089/dna.2009.1013] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022] Open
Abstract
The hMSH2 (human MutS homolog 2) gene plays a central role in DNA mismatch repair. Structural variations in the gene may lead to protein instability and deficient mismatch repair. However, the role of polymorphic variants of the hMSH2 gene have not been defined in head and neck cancer. In this study, the roles of three polymorphic variants in the functional domains of the gene were investigated in 166 patients with head and neck cancer by allele-specific PCR, electronical array addressing, and PCR/RFLP (restriction fragment length polymorphism). This is the first study to investigate the gIVS12-6T --> C polymorphism in head and neck cancer. A significant association between the CC genotype and reduced risk of disease suggests that the gIVS12-6T --> C substitution at the splice-acceptor site may affect the risk of head and neck cancer. We did not observe an association between the Asn127Ser and Gly322Asp polymorphisms and cancer risk. A possible role of the gIVS12-6T --> C substitution warrants further validation in larger cohorts because of low allele frequency.
Collapse
Affiliation(s)
- Semra Demokan
- Department of Basic Oncology, Oncology Institute, Istanbul Faculty of Medicine, Istanbul University, Capa, Istanbul, Turkey
| | | | | | | |
Collapse
|
48
|
Wang DQ, Zhou JN, Song L, Li SP, Ding JH, Li JT, Ma GJ, Chen SQ, Zhang XM. Genotype frequencies of the Val384Asp missense mutation in the hMLH1 gene in patients with familial gastric cancer. Shijie Huaren Xiaohua Zazhi 2010; 18:1669-1675. [DOI: 10.11569/wcjd.v18.i16.1669] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/06/2023] Open
Abstract
AIM: To investigate the etiological role of the missense mutation, Val384Asp, in the human mutL homolog 1 (hMLH1) gene in familial gastric cancer (FGC) based on a Chinese population in Jiangsu Province.
METHODS: A case-control study was conducted. One hundred newly diagnosed or suspected FGC patients and 180 healthy controls were included in the study. Peripheral white blood cells were obtained from all subjects for DNA extraction. The Val384Asp missense mutation was detected using PCR-based denaturing high-performance liquid chromatography (DHPLC) and verified by DNA sequencing. Bioinformatic software was then used to analyze the etiological mechanism of the Val384Asp missense mutation.
RESULTS: About 5% healthy individuals were Val384Asp carriers. Significant differences were noted for the following comparisons: patients with newly diagnosed or suspected FGC vs healthy controls (OR = 2.84, 95%CI: 1.07-7.81, P < 0.05), patients with an onset age ≥ 50 vs healthy controls (P < 0.05), patients with precancerous disease history vs healthy controls (P < 0.01), and patients having a high-risk family history of GC vs healthy controls (P < 0.05). Bioinformatic analysis showed that the Val384Asp missense mutation might destroy the structure of hMLH1 protein and impair its function. Besides, the conversion of T→A may disrupt pre-mRNA splicing.
CONCLUSION: The Val384Asp missense mutation may be associated with genetic susceptibility to FGC. Detection of the Val384Asp missense mutation may be able to help identify individuals with increased risk of FGC.
Collapse
|
49
|
Musante L, Kunde SA, Sulistio TO, Fischer U, Grimme A, Frints SG, Schwartz CE, MartÃnez F, Romano C, Ropers HH, Kalscheuer VM. Common pathological mutations inPQBP1induce nonsense-mediated mRNA decay and enhance exclusion of the mutant exon. Hum Mutat 2010; 31:90-8. [DOI: 10.1002/humu.21146] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/19/2023]
|
50
|
Functional characterization of rare missense mutations in MLH1 and MSH2 identified in Danish colorectal cancer patients. Fam Cancer 2009; 8:489-500. [PMID: 19697156 DOI: 10.1007/s10689-009-9274-4] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/17/2009] [Accepted: 07/20/2009] [Indexed: 12/21/2022]
Abstract
Recently, we have performed a population based study to analyse the frequency of colorectal cancer related MLH1 and MSH2 missense mutations in the Danish population. Half of the analyzed mutations were rare and most likely only present in the families where they were identified originally. Some of the missense mutations were located in conserved regions in the MLH1 and MSH2 proteins indicating a relation to disease development. In the present study, we functionally characterized 10 rare missense mutations in MLH1 and MSH2 identified in 13 Danish CRC families. To elucidate the pathogenicity of the missense mutations, we carried out in vitro functional analyses. The missense mutations were analyzed for their effect on protein expression and repair efficiency. The results of the functional analysis were correlated with clinical data on the families carrying these mutations. Eight missense mutations resulted in proteins with expression and repair efficiency similar to the wild type. One missense mutation (MSH2 p.Met688Val) caused reduced protein expression and one (MSH2 p.Leu187Arg) caused both reduced protein expression and repair deficiency. The MSH2 p.Leu187Arg mutation was found in an Amsterdam II family presenting with high microsatellite instability and loss of MSH2 and MSH6 proteins in tumours. In conclusion, only 1/10 missense mutations displayed repair deficiency and could be classified as pathogenic. No final conclusion can be drawn on the MSH2 p.Met688Val mutation, which caused reduced protein expression. Although, no deficiencies have been identified in the proteins harbouring the other missense mutations, pathogenicity of these variants cannot be unambiguously excluded.
Collapse
|