A Novel Germline <i>MLH1</i> In-Frame Deletion in a Slovenian Lynch Syndrome Family Associated with Uncommon Isolated PMS2 Loss in Tumor Tissue
The diagnostics of Lynch syndrome (LS) is focused on the detection of DNA mismatch repair (MMR) system deficiency. MMR deficiency can be detected on tumor tissue by microsatellite instability (MSI) using molecular genetic test or by loss of expression of one of the four proteins (MLH1, MSH2, MSH6, a...
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doaj-6258bc1109004bf69ae44f5c7a095d312020-11-25T03:15:26ZengMDPI AGGenes2073-44252020-03-0111332510.3390/genes11030325genes11030325A Novel Germline <i>MLH1</i> In-Frame Deletion in a Slovenian Lynch Syndrome Family Associated with Uncommon Isolated PMS2 Loss in Tumor TissueGašper Klančar0Ana Blatnik1Vita Šetrajčič Dragoš2Vesna Vogrič3Vida Stegel4Olga Blatnik5Primož Drev6Barbara Gazič7Mateja Krajc8Srdjan Novaković9Department of Molecular Diagnostics, Institute of Oncology Ljubljana, SI-1000 Ljubljana, SloveniaCancer Genetics Clinic, Institute of Oncology Ljubljana, SI-1000 Ljubljana, SloveniaDepartment of Molecular Diagnostics, Institute of Oncology Ljubljana, SI-1000 Ljubljana, SloveniaDepartment of Molecular Diagnostics, Institute of Oncology Ljubljana, SI-1000 Ljubljana, SloveniaDepartment of Molecular Diagnostics, Institute of Oncology Ljubljana, SI-1000 Ljubljana, SloveniaDepartment of Pathology, Institute of Oncology Ljubljana, SI-1000 Ljubljana, SloveniaDepartment of Pathology, Institute of Oncology Ljubljana, SI-1000 Ljubljana, SloveniaDepartment of Pathology, Institute of Oncology Ljubljana, SI-1000 Ljubljana, SloveniaCancer Genetics Clinic, Institute of Oncology Ljubljana, SI-1000 Ljubljana, SloveniaDepartment of Molecular Diagnostics, Institute of Oncology Ljubljana, SI-1000 Ljubljana, SloveniaThe diagnostics of Lynch syndrome (LS) is focused on the detection of DNA mismatch repair (MMR) system deficiency. MMR deficiency can be detected on tumor tissue by microsatellite instability (MSI) using molecular genetic test or by loss of expression of one of the four proteins (MLH1, MSH2, MSH6, and PMS2) involved in the MMR system using immunohistochemistry (IHC) staining. According to the National Comprehensive Cancer Network (NCCN) guidelines, definitive diagnosis of LS requires the identification of the germline pathogenic variant in one of the MMR genes. In the report, we are presenting interesting novel <i>MLH1</i> in-frame deletion LRG_216t1:c.2236_2247delCTGCCTGATCTA p.(Leu746_Leu749del) associated with LS. The variant appears to be associated with uncommon isolated loss of PMS2 immunohistochemistry protein staining (expression) in tumor tissue instead of MLH1 and PMS2 protein loss, which is commonly seen with pathogenic variants in <i>MLH1</i>. The variant was classified as likely pathogenic, based on segregation analysis and molecular characterization of blood and tumor samples. According to the American College of Medical Genetics (ACMG) guidelines, the following evidence categories of PM1, PM2, PM4, and PP1 moderate have been used for classification of the novel variant. By detecting and classifying the novel <i>MLH1</i> variant as likely pathogenic, we confirmed the LS in this family.https://www.mdpi.com/2073-4425/11/3/325lynch syndromemmrnovel <i>mlh1</i> variantsegregation analysisisolated pms2 loss |
collection |
DOAJ |
language |
English |
format |
Article |
sources |
DOAJ |
author |
Gašper Klančar Ana Blatnik Vita Šetrajčič Dragoš Vesna Vogrič Vida Stegel Olga Blatnik Primož Drev Barbara Gazič Mateja Krajc Srdjan Novaković |
spellingShingle |
Gašper Klančar Ana Blatnik Vita Šetrajčič Dragoš Vesna Vogrič Vida Stegel Olga Blatnik Primož Drev Barbara Gazič Mateja Krajc Srdjan Novaković A Novel Germline <i>MLH1</i> In-Frame Deletion in a Slovenian Lynch Syndrome Family Associated with Uncommon Isolated PMS2 Loss in Tumor Tissue Genes lynch syndrome mmr novel <i>mlh1</i> variant segregation analysis isolated pms2 loss |
author_facet |
Gašper Klančar Ana Blatnik Vita Šetrajčič Dragoš Vesna Vogrič Vida Stegel Olga Blatnik Primož Drev Barbara Gazič Mateja Krajc Srdjan Novaković |
author_sort |
Gašper Klančar |
title |
A Novel Germline <i>MLH1</i> In-Frame Deletion in a Slovenian Lynch Syndrome Family Associated with Uncommon Isolated PMS2 Loss in Tumor Tissue |
title_short |
A Novel Germline <i>MLH1</i> In-Frame Deletion in a Slovenian Lynch Syndrome Family Associated with Uncommon Isolated PMS2 Loss in Tumor Tissue |
title_full |
A Novel Germline <i>MLH1</i> In-Frame Deletion in a Slovenian Lynch Syndrome Family Associated with Uncommon Isolated PMS2 Loss in Tumor Tissue |
title_fullStr |
A Novel Germline <i>MLH1</i> In-Frame Deletion in a Slovenian Lynch Syndrome Family Associated with Uncommon Isolated PMS2 Loss in Tumor Tissue |
title_full_unstemmed |
A Novel Germline <i>MLH1</i> In-Frame Deletion in a Slovenian Lynch Syndrome Family Associated with Uncommon Isolated PMS2 Loss in Tumor Tissue |
title_sort |
novel germline <i>mlh1</i> in-frame deletion in a slovenian lynch syndrome family associated with uncommon isolated pms2 loss in tumor tissue |
publisher |
MDPI AG |
series |
Genes |
issn |
2073-4425 |
publishDate |
2020-03-01 |
description |
The diagnostics of Lynch syndrome (LS) is focused on the detection of DNA mismatch repair (MMR) system deficiency. MMR deficiency can be detected on tumor tissue by microsatellite instability (MSI) using molecular genetic test or by loss of expression of one of the four proteins (MLH1, MSH2, MSH6, and PMS2) involved in the MMR system using immunohistochemistry (IHC) staining. According to the National Comprehensive Cancer Network (NCCN) guidelines, definitive diagnosis of LS requires the identification of the germline pathogenic variant in one of the MMR genes. In the report, we are presenting interesting novel <i>MLH1</i> in-frame deletion LRG_216t1:c.2236_2247delCTGCCTGATCTA p.(Leu746_Leu749del) associated with LS. The variant appears to be associated with uncommon isolated loss of PMS2 immunohistochemistry protein staining (expression) in tumor tissue instead of MLH1 and PMS2 protein loss, which is commonly seen with pathogenic variants in <i>MLH1</i>. The variant was classified as likely pathogenic, based on segregation analysis and molecular characterization of blood and tumor samples. According to the American College of Medical Genetics (ACMG) guidelines, the following evidence categories of PM1, PM2, PM4, and PP1 moderate have been used for classification of the novel variant. By detecting and classifying the novel <i>MLH1</i> variant as likely pathogenic, we confirmed the LS in this family. |
topic |
lynch syndrome mmr novel <i>mlh1</i> variant segregation analysis isolated pms2 loss |
url |
https://www.mdpi.com/2073-4425/11/3/325 |
work_keys_str_mv |
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