Jane Hübertz Frederiksen, Ulf Birkedal, Sarah Bachmann, Elisabeth Victoria Eliesen, Lene Juel Rasmussen, Katja Venborg Pedersen, Lana Al-Zehhawi, Susanne E Boonen, Lotte Krogh, Karina Rønlund, Lise Graversen, Jannie Assenholt, Kjeld Schmiegelow, Karin Wadt, Anne-Marie Gerdes, Thomas V O Hansen
{"title":"利用临床和功能数据对两个意义不明的 MLH1 变异进行重新分类。","authors":"Jane Hübertz Frederiksen, Ulf Birkedal, Sarah Bachmann, Elisabeth Victoria Eliesen, Lene Juel Rasmussen, Katja Venborg Pedersen, Lana Al-Zehhawi, Susanne E Boonen, Lotte Krogh, Karina Rønlund, Lise Graversen, Jannie Assenholt, Kjeld Schmiegelow, Karin Wadt, Anne-Marie Gerdes, Thomas V O Hansen","doi":"10.1002/mgg3.70026","DOIUrl":null,"url":null,"abstract":"<p><strong>Background: </strong>Pathogenic variants in the mismatch repair genes are associated with an elevated lifetime risk of colorectal cancer (CRC). We previously identified two variants of uncertain significance (VUS) in the MLH1 gene, c.696_698del, p.(Cys233del) and c.1919C > G, p.(Pro640Arg), in Danish families with numerous occurrences of CRC.</p><p><strong>Methods: </strong>To reclassify the variants we collected clinical data, initiated tumor and co-segregation analysis, and performed RNA splicing analysis, subcellular localization, and protein stability studies.</p><p><strong>Results: </strong>The functional analysis revealed that the c.696_698del, p.(Cys233del) variant had an effect at the RNA level, on subcellular localization, and on protein stability, while the c.1919C > G, p.(Pro640Arg) variant showed decreased expression in localization studies and decreased protein stability. These results suggest both variants disrupt DNA mismatch repair.</p><p><strong>Conclusion: </strong>By applying all collected data and functional results we propose to reclassify the c.696_698del, p.(Cys233del) and the c.1919C > G, p.(Pro640Arg) variants as likely pathogenic (class 4) using MMR gene-specific ACMG/AMP guidelines. Consequently, the two MLH1 variants can now be used for risk assessment of variant carriers, while family members without the variants can be excluded from intensified cancer surveillance and follow population recommendations.</p>","PeriodicalId":18852,"journal":{"name":"Molecular Genetics & Genomic Medicine","volume":"12 11","pages":"e70026"},"PeriodicalIF":1.5000,"publicationDate":"2024-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC11567815/pdf/","citationCount":"0","resultStr":"{\"title\":\"Reclassification of Two MLH1 Variants of Uncertain Significance Utilizing Clinical and Functional Data.\",\"authors\":\"Jane Hübertz Frederiksen, Ulf Birkedal, Sarah Bachmann, Elisabeth Victoria Eliesen, Lene Juel Rasmussen, Katja Venborg Pedersen, Lana Al-Zehhawi, Susanne E Boonen, Lotte Krogh, Karina Rønlund, Lise Graversen, Jannie Assenholt, Kjeld Schmiegelow, Karin Wadt, Anne-Marie Gerdes, Thomas V O Hansen\",\"doi\":\"10.1002/mgg3.70026\",\"DOIUrl\":null,\"url\":null,\"abstract\":\"<p><strong>Background: </strong>Pathogenic variants in the mismatch repair genes are associated with an elevated lifetime risk of colorectal cancer (CRC). We previously identified two variants of uncertain significance (VUS) in the MLH1 gene, c.696_698del, p.(Cys233del) and c.1919C > G, p.(Pro640Arg), in Danish families with numerous occurrences of CRC.</p><p><strong>Methods: </strong>To reclassify the variants we collected clinical data, initiated tumor and co-segregation analysis, and performed RNA splicing analysis, subcellular localization, and protein stability studies.</p><p><strong>Results: </strong>The functional analysis revealed that the c.696_698del, p.(Cys233del) variant had an effect at the RNA level, on subcellular localization, and on protein stability, while the c.1919C > G, p.(Pro640Arg) variant showed decreased expression in localization studies and decreased protein stability. These results suggest both variants disrupt DNA mismatch repair.</p><p><strong>Conclusion: </strong>By applying all collected data and functional results we propose to reclassify the c.696_698del, p.(Cys233del) and the c.1919C > G, p.(Pro640Arg) variants as likely pathogenic (class 4) using MMR gene-specific ACMG/AMP guidelines. Consequently, the two MLH1 variants can now be used for risk assessment of variant carriers, while family members without the variants can be excluded from intensified cancer surveillance and follow population recommendations.</p>\",\"PeriodicalId\":18852,\"journal\":{\"name\":\"Molecular Genetics & Genomic Medicine\",\"volume\":\"12 11\",\"pages\":\"e70026\"},\"PeriodicalIF\":1.5000,\"publicationDate\":\"2024-11-01\",\"publicationTypes\":\"Journal Article\",\"fieldsOfStudy\":null,\"isOpenAccess\":false,\"openAccessPdf\":\"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC11567815/pdf/\",\"citationCount\":\"0\",\"resultStr\":null,\"platform\":\"Semanticscholar\",\"paperid\":null,\"PeriodicalName\":\"Molecular Genetics & Genomic Medicine\",\"FirstCategoryId\":\"3\",\"ListUrlMain\":\"https://doi.org/10.1002/mgg3.70026\",\"RegionNum\":4,\"RegionCategory\":\"医学\",\"ArticlePicture\":[],\"TitleCN\":null,\"AbstractTextCN\":null,\"PMCID\":null,\"EPubDate\":\"\",\"PubModel\":\"\",\"JCR\":\"Q4\",\"JCRName\":\"GENETICS & HEREDITY\",\"Score\":null,\"Total\":0}","platform":"Semanticscholar","paperid":null,"PeriodicalName":"Molecular Genetics & Genomic Medicine","FirstCategoryId":"3","ListUrlMain":"https://doi.org/10.1002/mgg3.70026","RegionNum":4,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"Q4","JCRName":"GENETICS & HEREDITY","Score":null,"Total":0}
Reclassification of Two MLH1 Variants of Uncertain Significance Utilizing Clinical and Functional Data.
Background: Pathogenic variants in the mismatch repair genes are associated with an elevated lifetime risk of colorectal cancer (CRC). We previously identified two variants of uncertain significance (VUS) in the MLH1 gene, c.696_698del, p.(Cys233del) and c.1919C > G, p.(Pro640Arg), in Danish families with numerous occurrences of CRC.
Methods: To reclassify the variants we collected clinical data, initiated tumor and co-segregation analysis, and performed RNA splicing analysis, subcellular localization, and protein stability studies.
Results: The functional analysis revealed that the c.696_698del, p.(Cys233del) variant had an effect at the RNA level, on subcellular localization, and on protein stability, while the c.1919C > G, p.(Pro640Arg) variant showed decreased expression in localization studies and decreased protein stability. These results suggest both variants disrupt DNA mismatch repair.
Conclusion: By applying all collected data and functional results we propose to reclassify the c.696_698del, p.(Cys233del) and the c.1919C > G, p.(Pro640Arg) variants as likely pathogenic (class 4) using MMR gene-specific ACMG/AMP guidelines. Consequently, the two MLH1 variants can now be used for risk assessment of variant carriers, while family members without the variants can be excluded from intensified cancer surveillance and follow population recommendations.
期刊介绍：
Molecular Genetics & Genomic Medicine is a peer-reviewed journal for rapid dissemination of quality research related to the dynamically developing areas of human, molecular and medical genetics. The journal publishes original research articles covering findings in phenotypic, molecular, biological, and genomic aspects of genomic variation, inherited disorders and birth defects. The broad publishing spectrum of Molecular Genetics & Genomic Medicine includes rare and common disorders from diagnosis to treatment. Examples of appropriate articles include reports of novel disease genes, functional studies of genetic variants, in-depth genotype-phenotype studies, genomic analysis of inherited disorders, molecular diagnostic methods, medical bioinformatics, ethical, legal, and social implications (ELSI), and approaches to clinical diagnosis. Molecular Genetics & Genomic Medicine provides a scientific home for next generation sequencing studies of rare and common disorders, which will make research in this fascinating area easily and rapidly accessible to the scientific community. This will serve as the basis for translating next generation sequencing studies into individualized diagnostics and therapeutics, for day-to-day medical care.
Molecular Genetics & Genomic Medicine publishes original research articles, reviews, and research methods papers, along with invited editorials and commentaries. Original research papers must report well-conducted research with conclusions supported by the data presented.
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