A germline missense mutation in exon 3 of the MSH2 gene in a Lynch syndrome family: correlation with phenotype and localization assay
Lynch syndrome is caused by germline mutations in any of the MisMatch Repair (MMR) genes. About 37% of MSH2 variants are missense variants causing single amino-acid substitutions. Whether missense variants affect the normal function of MMR proteins is crucial both to provide affected families a more accurate risk assessment and to offer predictive testing to family members. Here we report one family, fulfilling both Amsterdam I and II criteria and Bethesda guidelines, referred to our center for genetic counselling. The proband and some of her relatives have been investigated for microsatellite instability (MSI), immunohistochemical MMR protein staining, direct sequencing and Multiplex Ligation-dependent Probe Amplification (MLPA). Also Subcellular Localization Assay and Splice site predictions analyses were used. A germline missense variant of uncertain significance (exon 3, p.Val161Asp) was found in MSH2 gene in proband and in some relatives. The variant was associated with lack of expression of MSH2 protein (DMMR) and MSI-High status in tumour tissues. The localization assay of the MSH2 protein showed an abnormal subcellular localization pattern of the corresponding protein. Finally, splice-site prediction analysis ruled out a potential role of new splice sites as the cause behind the lack of expression of MSH2 protein and we suppose a potential correlation with other forms of post-transcriptional regulation (circular RNAs). The variant here reported shows a high correlation with phenotype and is located in an evolutionary conserved domain. The localization assay also suggest a potential pathogenic role, thus supporting further research on this matter.
KeywordsLynch syndrome Germline mutation Missense variant Genetic testing Pathogenic mutation
The authors have no funding sources to declare.
Compliance with ethical standards
Conflict of interest
The authors have no conflicts of interest to declare.
All procedures performed in studies involving human participants were in accordance with the ethical standards of the institutional and/or national research committee and with the 1964 Helsinki declaration and its later amendments or comparable ethical standards.
Informed consent was obtained from all individual participants included in the study.
- 5.Vasen HF, Blanco I, Aktan-Collan K, Gopie JP, Alonso A, Aretz S, Bernstein I, Bertario L, Burn J, Capella G, Colas C, Engel C, Frayling IM, Genuardi M, Heinimann K, Hes FJ, Hodgson SV, Karagiannis JA, Lalloo F, Lindblom A, Mecklin JP, Møller P, Myrhoj T, Nagengast FM, Parc Y, Ponz de Leon M, Renkonen-Sinisalo L, Sampson JR, Stormorken A, Sijmons RH, Tejpar S, Thomas HJ, Rahner N, Wijnen JT, Järvinen HJ, Möslein G, Mallorca Group (2013) Revised guidelines for the clinical management of Lynch syndrome (HNPCC): recommendations by a group of European experts. Gut 62:812–823. doi: 10.1136/gutjnl-2012-304356 CrossRefPubMedCentralPubMedGoogle Scholar
- 6.Boland CR, Thibodeau SN, Hamilton SR, Sidransky D, Eshleman JR, Burt RW, Meltzer SJ, Rodriguez-Bigas MA, Fodde R, Ranzani GN, Srivastava S (1998) A National Cancer Institute Workshop on microsatellite instability for cancer detection and familial predisposition: development on international criteria for the determination of microsatellite instability in colorectal cancer. Cancer Res 58:5248–5257PubMedGoogle Scholar
- 8.Maccaroni E, Bracci R, Giampieri R, Bianchi F, Belvederesi L, Brugiati C, Pagliaretta S, Del Prete M, Scartozzi M, Cascinu S (2015) Prognostic impact of mismatch repair genes germline defects in colorectal cancer patients: are all mutations equal? Oncotarget 6(36):33848–38737. doi: 10.18632/oncotarget.5395 CrossRefGoogle Scholar
- 12.Rodriguez-Bigas MA, Boland CR, Hamilton SR, Henson DE, Jass JR, Khan PM, Lynch H, Perucho M, Smyrk T, Sobin L, Srivastava S (1997) A National Cancer Institute Workshop on hereditary nonpolyposis colorectal Cancer syndrome: meeting highlights and Bethesda guidelines. J Natl Cancer Inst 89(23):1758–1762CrossRefPubMedGoogle Scholar
- 13.Umar A, Boland CR, Terdiman JP, Syngal S, de la Chapelle A, Rüschoff J, Fishel R, Lindor NM, Burgart LJ, Hamelin R, Hamilton SR, Hiatt RA, Jass J, Lindblom A, Lynch HT, Peltomaki P, Ramsey SD, Rodriguez-Bigas MA, Vasen HF, Hawk ET, Barrett JC, Freedman AN, Srivastava S (2004) Revised Bethesda Guidelines for hereditary nonpolyposis colorectal cancer (Lynch syndrome) and microsatellite instability. J Natl Cancer Inst 96(4):261–268CrossRefPubMedCentralPubMedGoogle Scholar
- 15.Bianchi F, Galizia E, Porfiri E, Belvederesi L, Catalani R, Loretelli C, Bracci R, Bearzi I, Turchi C, Viel A, Cellerino R (2007) A missense germline mutation in exon 7 of the MSH2 gene in a HNPCC family from center-Italy. Fam Cancer 6(1):97–102. doi: 10.1007/s10689-006-9110-z CrossRefPubMedGoogle Scholar
- 16.Plon SE, Eccles DM, Easton D, Foulkes WD, Genuardi M, Greenblatt MS, Hogervorst FB, Hoogerbrugge N, Spurdle AB, Tavtigian SV; IARC Unclassified Genetic Variants Working Group (2008) Sequence variant classification and reporting: recommendations for improving the interpretation of cancer susceptibility genetic test results. Hum Mutat 29:1282–1291. doi: 10.1002/humu.20880.CrossRefPubMedCentralPubMedGoogle Scholar
- 21.Scartozzi M, Bianchi F, Rosati S, Galizia E, Antolini A, Loretelli C, Piga A, Bearzi I, Cellerino R, Porfiri E (2002) Mutations of hMLH1 and hMSH2 in patients with suspected hereditary nonpolyposis colorectal cancer: correlation with microsatellite instability and abnormalities of mismatch repair protein expression. J Clin Oncol 20:1203–1208. doi: 10.1200/JCO.2002.20.5.1203 CrossRefPubMedGoogle Scholar
- 25.Drost M, Lützen A, van Hees S, Ferreira D, Calléja F, Zonneveld JB, Nielsen FC, Rasmussen LJ, de Wind N (2013) Genetic screens to identify pathogenic gene variants in the common cancer predisposition Lynch syndrome. Proc Natl Acad Sci USA 110(23):9403–9408. doi: 10.1073/pnas.1220537110 CrossRefPubMedCentralPubMedGoogle Scholar
- 32.Ollila S, Sarantaus L, Kariola R, Chan P, Hampel H, Holinski-Feder E, Macrae F, Kohonen-Corish M, Gerdes AM, Peltomäki P, Mangold E, de la Chapelle A, Greenblatt M, Nyström M (2006) Pathogenicity of MSH2 missense mutations is typically associated with impaired repair capability of the mutated protein. Gastroenterology 131(5):1408–1417. doi: 10.1053/j.gastro.2006.08.044 CrossRefPubMedGoogle Scholar
- 33.Piñol V, Castells A, Andreu M, Castellví-Bel S, Alenda C, Llor X, Xicola RM, Rodríguez-Moranta F, Payá A, Jover R, Bessa X; Gastrointestinal Oncology Group of the Spanish Gastroenterological Association (2005) Accuracy of revised Bethesda guidelines, microsatellite instability, and immunohistochemistry for the identification of patients with hereditary nonpolyposis colorectal cancer. JAMA 293(16):1986–1994. doi: 10.1001/jama.293.16.1986 CrossRefPubMedGoogle Scholar
- 44.Kumar L, Shamsuzzama, Haque R, Baghel T, Nazir A. Circular RNAs: the emerging class of non-coding RNAs and their potential role in human neurodegenerative diseases. Mol Neurobiol 1–11Google Scholar