rs63751455
Variant summary
Our verdict is Uncertain significance. Variant got 0 ACMG points: 1P and 1B. PP3BP6
The NM_000251.3(MSH2):c.728G>A(p.Arg243Gln) variant causes a missense change involving the alteration of a conserved nucleotide. The variant allele was found at a frequency of 0.0000199 in 1,611,374 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a pathogenic outcome for this variant. Variant has been reported in ClinVar as Conflicting classifications of pathogenicity (no stars).
Frequency
Consequence
NM_000251.3 missense
Scores
Clinical Significance
Conservation
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ACMG classification
Verdict is Uncertain_significance. Variant got 0 ACMG points.
Transcripts
RefSeq
Ensembl
Frequencies
GnomAD3 genomes AF: 0.0000132 AC: 2AN: 152030Hom.: 0 Cov.: 32
GnomAD3 exomes AF: 0.0000159 AC: 4AN: 251398Hom.: 0 AF XY: 0.0000147 AC XY: 2AN XY: 135868
GnomAD4 exome AF: 0.0000206 AC: 30AN: 1459344Hom.: 0 Cov.: 29 AF XY: 0.0000207 AC XY: 15AN XY: 726218
GnomAD4 genome AF: 0.0000132 AC: 2AN: 152030Hom.: 0 Cov.: 32 AF XY: 0.0000135 AC XY: 1AN XY: 74244
ClinVar
Submissions by phenotype
not provided Uncertain:5
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In silico analysis, which includes protein predictors and evolutionary conservation, supports a deleterious effect; Observed in individuals with a personal or family history including colorectal and other cancers (Auclair 2006, Moussa 2011, Ziada-Bouchaar 2016, Mandelker 2017); Published functional studies demonstrate lack of cell survival following MNNG-induced DNA damage, suggesting neutrality (Bouvet 2019); This variant is associated with the following publications: (PMID: 16395668, 21311894, 18383312, 26247049, 27468915, 26333163, 28873162, 26116798, 24953332, 31248416, 30998989) -
The MSH2 c.728G>A (p.Arg243Gln) variant has been reported in the published literature in individuals with colorectal cancer (PMID: 21311894 (2011)), Lynch syndrome (PMIDs: 27468915 (2017) and 16395668 (2006)), and constitutional mismatch repair deficiency syndrome (PMIDs: 26116798 (2015) and 16395668 (2006)). It has also been seen in breast cancer cases as well as in unaffected individuals in a large scale breast cancer association study (PMID: 33471991 (2021), see also LOVD (http://databases.lovd.nl/shared/genes/MSH2)). Functional studies demonstrated that the effect on protein function were inconclusive (PMIDs: 36011265 (2022), 33357406 (2021), 30998989 (2019), 26247049 (2015), and 16395668 (2006)). The frequency of this variant in the general population, 0.000016 (4/251398 chromosomes (Genome Aggregation Database, http://gnomad.broadinstitute.org)), is uninformative in the assessment of its pathogenicity. Analysis of this variant using bioinformatics tools for the prediction of the effect of amino acid changes on protein structure and function yielded conflicting predictions that this variant is benign or damaging. Based on the available information, we are unable to determine the clinical significance of this variant. -
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not specified Uncertain:2
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Variant summary: MSH2 c.728G>A (p.Arg243Gln) results in a conservative amino acid change located in the DNA mismatch repair protein MutS, connector domain of the encoded protein sequence. Four of five in-silico tools predict a damaging effect of the variant on protein function. The variant allele was found at a frequency of 1.6e-05 in 251398 control chromosomes. The available data on variant occurrences in the general population are insufficient to allow any conclusion about variant significance. c.728G>A has been reported in the literature in individuals affected with hereditary nonpolyposis colorectal cancer and colorectal cancer (Auclair_2006, Zaida-Bouchaar_2017, Castillejo_2014, Moussa_2011, Bodo_2015). These reports do not provide unequivocal conclusions about association of the variant with Hereditary Nonpolyposis Colorectal Cancer. Co-occurrences with other pathogenic variants were reported in 4 patients described in the literature, including the co-occurrence of homozygous PMS2 large deletions in a patient with CMMR (MSH2 c.1413dupA, p.Pro472ThrfsX4; MSH2 c.1030C>T, p.Gln344X ; PMS2 c.2275+210_2446-1356del, p.Ala759Glyfs*8), providing supporting evidence for a benign role. Two publications report splicing evidence showing no impact on splicing by the variant (Van der Klift_2015, Auclair_2006). Additionally, another functional study based on the proportion of cells that undergo death following exposure to methylating agents reported the variant to be neutral (Bouvet_2019). Five clinical diagnostic laboratories have submitted clinical-significance assessments for this variant to ClinVar after 2014 without evidence for independent evaluation. All laboratories classified the variant as uncertain significance. Based on the evidence outlined above, the variant was classified as a VUS - possibly benign variant. -
Lynch syndrome 1 Uncertain:1Benign:1
This variant is considered likely benign. This variant is strongly associated with less severe personal and family histories of cancer, typical for individuals without pathogenic variants in this gene [PMID: 27363726]. -
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Hereditary cancer-predisposing syndrome Benign:2
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This alteration is classified as likely benign based on a combination of the following: seen in unaffected individuals, population frequency, intact protein function, lack of segregation with disease, co-occurrence, RNA analysis, in silico models, amino acid conservation, lack of disease association in case-control studies, and/or the mechanism of disease or impacted region is inconsistent with a known cause of pathogenicity. -
Malignant tumor of breast Uncertain:1
The MSH2 p.Arg243Gln variant was identified in 3 of 224 proband chromosomes (frequency: 0.01) from Algerian, French and Tunisian individuals or families with Lynch syndrome or CRC (Ziada-Bouchaar 2017, Moussa 2011, Auclair 2006). In these studies, 2 of the probands had co-occurring pathogenic MSH2 variants (c.1030C>T/ p.Gln344X and c.1413dupA/p.Pro472ThrfsX4). The variant was also identified by our laboratory in 1 individual with breast cancer, co-occurring with a pathogenic BRCA2 variant (c.7234_7235insG, p.Thr2412Serfs*2) increasing the likelihood the MSH2 c.728G>A variant may not have clinical significance. In functional studies using patient RNA analysis and minigene splicing, both assays showed normal splicing (van der Klift 2015, Auclair 2006). A bioinformatics tool, multivariate analysis of protein polymorphisms-mismatch repair (MAPP-MMR), classified the variant as neutral (Chao 2008). The variant was also identified in dbSNP (ID: rs63751455) “With Uncertain significance allele”, ClinVar (classified uncertain significance, reviewed by an expert panel (2013); submitters: INSIGHT, Invitae, Ambry Genetics, GeneDx and 3 other laboratories), and UMD-LSDB (4x classified as UV). The variant was identified in control databases in 3 of 246198 chromosomes at a frequency of 0.00001 (Genome Aggregation Database Feb 27, 2017), observed in the following populations: Latino in 2 of 33578 chromosomes (freq: 0.00006) and European Non-Finnish in 1 of 111672 chromosomes (freq: 0.000009); it was not observed in the African, Other, Ashkenazi Jewish, East Asian, European Finnish and South Asian populations. The p.Arg243 residue is conserved across mammals and other organisms, and four out of five computational analyses (PolyPhen-2, SIFT, AlignGVGD, BLOSUM, MutationTaster) suggest that the Gln variant may impact the protein; however, this information is not predictive enough to assume pathogenicity. The variant occurs outside of the splicing consensus sequence and 2 of 4 in silico or computational prediction software programs (SpliceSiteFinder, MaxEntScan, NNSPLICE, GeneSplicer) predict a greater than 10% difference in splicing; this is not very predictive of pathogenicity. In summary, based on the above information the clinical significance of this variant cannot be determined with certainty at this time. This variant is classified as a variant of uncertain significance. -
Hereditary nonpolyposis colorectal neoplasms Benign:1
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Computational scores
Source:
Splicing
Find out detailed SpliceAI scores and Pangolin per-transcript scores at