2-47475198-C-G
Variant summary
Our verdict is Uncertain significance. Variant got 1 ACMG points: 2P and 1B. PM1BP6
The NM_000251.3(MSH2):āc.1933C>Gā(p.Gln645Glu) variant causes a missense change. The variant allele was found at a frequency of 0.0000118 in 1,613,098 control chromosomes in the GnomAD database, with no homozygous occurrence. 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 1 ACMG points.
Transcripts
RefSeq
Ensembl
Frequencies
GnomAD3 genomes AF: 0.00000660 AC: 1AN: 151492Hom.: 0 Cov.: 32
GnomAD3 exomes AF: 0.0000119 AC: 3AN: 251432Hom.: 0 AF XY: 0.0000147 AC XY: 2AN XY: 135884
GnomAD4 exome AF: 0.0000123 AC: 18AN: 1461606Hom.: 0 Cov.: 33 AF XY: 0.0000165 AC XY: 12AN XY: 727112
GnomAD4 genome AF: 0.00000660 AC: 1AN: 151492Hom.: 0 Cov.: 32 AF XY: 0.00 AC XY: 0AN XY: 73922
ClinVar
Submissions by phenotype
Lynch syndrome 1 Uncertain:2
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This variant is classified as a variant of uncertain significance as there is insufficient evidence to determine its impact on protein function and/or cancer risk. -
not provided Uncertain:2
Not observed at significant frequency in large population cohorts (gnomAD); In silico analysis indicates that this missense variant does not alter protein structure/function; Observed in an individual with a personal or family history suggestive of Lynch syndrome (Tournier 2008); Published functional studies demonstrate no damaging effect: mismatch repair function comparable to wild-type (PMID: 33357406); This variant is associated with the following publications: (PMID: 18561205, 26333163, 18822302, 21120944, 33357406) -
The MSH2 p.Gln645Glu variant was identified in the literature, although a frequency in an affected population was not provided. The variant was identified in dbSNP (ID: rs267607982) as "With Pathogenic, Uncertain significance allele", ClinVar (classified as uncertain significance by InSiGHT expert panel (2013), Invitae, Ambry Genetics, GeneDx, Color and Counsyl), and UMD-LSDB (1x as likely neutral). The variant was identified in control databases in 3 of 246212 chromosomes at a frequency of 0.00001 (Genome Aggregation Database Feb 27, 2017). The variant was observed in the following populations: Latino in 1 of 33582 chromosomes (freq: 0.00003) and European Non-Finnish in 2 of 111674 chromosomes (freq: 0.00002), while it was not observed in the African, Ashkenazi Jewish, East Asian, European Finnish, Other, or South Asian populations. The p.Gln645 residue is located in the ATPase domain of the MSH2 protein (Kansikas, 2011) and is conserved in mammals; however, computational analyses (PolyPhen-2, SIFT, AlignGVGD, BLOSUM, MutationTaster) provide inconsistent predictions regarding the impact to the protein; this information is not very predictive of pathogenicity. The variant occurs outside of the splicing consensus sequence and in silico or computational prediction software programs (SpliceSiteFinder, MaxEntScan, NNSPLICE, GeneSplicer) do not predict a difference in splicing. In addition, both an ex vivo splicing assay and RT-PCR analysis of patient RNA showed no effect on splicing (Tournier 2008). 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 cancer-predisposing syndrome Uncertain:1Benign:1
This missense variant replaces glutamine with glutamic acid at codon 645 of the MSH2 protein. Computational prediction is inconclusive regarding the impact of this variant on protein structure and function (internally defined REVEL score threshold 0.5 < inconclusive < 0.7, PMID: 27666373). This variant does not impact MSH2 function in a 6-thioguanine sensitivity assay in haploid human cells (internally defined LOF score threshold <= -1.32, PMID: 33357406). This variant has been reported in a family suspected of Lynch syndrome (PMID: 18561205). This variant has been identified in 3/251432 chromosomes in the general population by the Genome Aggregation Database (gnomAD). The available evidence is insufficient to determine the role of this variant in disease conclusively. Therefore, this variant is classified as a Variant of Uncertain Significance. -
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. -
Lynch syndrome Uncertain:1
This missense variant replaces glutamine with glutamic acid at codon 645 of the MSH2 protein. Computational prediction is inconclusive regarding the impact of this variant on protein structure and function (internally defined REVEL score threshold 0.5 < inconclusive < 0.7, PMID: 27666373). A functional study reported that this variant does not impact MSH2 function in a 6-thioguanine sensitivity assay in haploid human cells (PMID: 33357406). This variant has been reported in an individual with suspected Lynch syndrome, in which a tumor sample showed the loss of MLH1 and presence of MSH2 (PMID: 18561205 and Universal Mutation Database) and in at least two additional individuals associated with colorectal cancer (Leiden Open Variation Database). This variant has been identified in 3/251432 chromosomes in the general population by the Genome Aggregation Database (gnomAD). The available evidence is insufficient to determine the role of this variant in disease conclusively. Therefore, 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