rs879254203
Variant summary
Our verdict is Pathogenic. Variant got 10 ACMG points: 10P and 0B. PM1PM2PM5PP3_Strong
The NM_000251.3(MSH2):c.2170A>G(p.Thr724Ala) variant causes a missense change involving the alteration of a conserved nucleotide. The variant allele was found at a frequency of 0.00000186 in 1,614,072 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 Uncertain significance (★★). Another variant affecting the same amino acid position, but resulting in a different missense (i.e. T724K) has been classified as Pathogenic.
Frequency
Consequence
NM_000251.3 missense
Scores
Clinical Significance
Conservation
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ACMG classification
Verdict is Pathogenic. Variant got 10 ACMG points.
Transcripts
RefSeq
Ensembl
Frequencies
GnomAD3 genomes AF: 0.00000657 AC: 1AN: 152200Hom.: 0 Cov.: 32
GnomAD4 exome AF: 0.00000137 AC: 2AN: 1461872Hom.: 0 Cov.: 32 AF XY: 0.00000275 AC XY: 2AN XY: 727240
GnomAD4 genome AF: 0.00000657 AC: 1AN: 152200Hom.: 0 Cov.: 32 AF XY: 0.0000134 AC XY: 1AN XY: 74362
ClinVar
Submissions by phenotype
not provided Uncertain:2
In the published literature, a functional study showed inconclusive results regarding the variant's impact on protein function (PMID: 33357406 (2021)). The frequency of this variant in the general population, 0.0000066 (1/152200 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 predictions that this variant is damaging. Based on the available information, we are unable to determine the clinical significance of this variant. -
This variant is denoted MSH2 c.2170A>G at the cDNA level, p.Thr724Ala (T724A) at the protein level, and results in the change of a Threonine to an Alanine (ACG>GCG). This variant has not, to our knowledge, been published in the literature as a pathogenic or benign germline variant. MSH2 Thr724Ala was not observed in large population cohorts (Lek 2016). This variant is located in the ATPase domain (L?tzen 2008, Kansikas 2011). In silico analysis, which includes protein predictors and evolutionary conservation, supports a deleterious effect. Based on currently available evidence, it is unclear whether MSH2 Thr724Ala is a pathogenic or benign variant. We consider it to be a variant of uncertain significance. -
Hereditary cancer-predisposing syndrome Uncertain:2
The p.T724A variant (also known as c.2170A>G), located in coding exon 13 of the MSH2 gene, results from an A to G substitution at nucleotide position 2170. The threonine at codon 724 is replaced by alanine, an amino acid with similar properties. In a massively parallel cell-based functional assay testing susceptibility to a DNA damaging agent, 6-thioguanine (6-TG), this variant was reported to be functionally neutral (Jia X et al. Am J Hum Genet, 2021 01;108:163-175). This amino acid position is highly conserved in available vertebrate species. In addition, this alteration is predicted to be deleterious by in silico analysis. Since supporting evidence is limited at this time, the clinical significance of this alteration remains unclear. -
This missense variant replaces threonine with alanine at codon 724 of the MSH2 protein. Computational prediction suggests that this variant may have deleterious impact on protein structure and function (internally defined REVEL score threshold >= 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). To our knowledge, this variant has not been reported in individuals affected with MSH2-related disorders in the literature. This variant has not been identified 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. -
Lynch syndrome 1 Uncertain:1
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Lynch syndrome Uncertain:1
This missense variant replaces threonine with alanine at codon 724 of the MSH2 protein. Computational prediction suggests that this variant may have deleterious impact on protein structure and function (internally defined REVEL score threshold >= 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). To our knowledge, this variant has not been reported in individuals affected with MSH2-related disorders in the literature. This variant has not been identified 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 Uncertain:1
This sequence change replaces threonine, which is neutral and polar, with alanine, which is neutral and non-polar, at codon 724 of the MSH2 protein (p.Thr724Ala). This variant is not present in population databases (gnomAD no frequency). This variant has not been reported in the literature in individuals affected with MSH2-related conditions. ClinVar contains an entry for this variant (Variation ID: 246314). Invitae Evidence Modeling incorporating data from in vitro experimental studies (PMID: 33357406) indicates that this missense variant is not expected to disrupt MSH2 function with a negative predictive value of 95%. In summary, the available evidence is currently insufficient to determine the role of this variant in disease. Therefore, it has been classified as a Variant of Uncertain Significance. -
Computational scores
Source:
Splicing
Find out detailed SpliceAI scores and Pangolin per-transcript scores at