NM_000251.3:c.2417C>T
Variant summary
Our verdict is Uncertain significance. The variant received 3 ACMG points: 3P and 0B. PM1PP3
The NM_000251.3(MSH2):c.2417C>T(p.Thr806Ile) variant causes a missense change involving the alteration of a conserved nucleotide. The variant allele was found at a frequency of 0.00000743 in 1,614,076 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). Another variant affecting the same amino acid position, but resulting in a different missense (i.e. T806S) has been classified as Likely benign.
Frequency
Consequence
NM_000251.3 missense
Scores
Clinical Significance
Conservation
Publications
- Lynch syndromeInheritance: AD Classification: DEFINITIVE, SUPPORTIVE Submitted by: G2P, ClinGen, Orphanet
- Lynch syndrome 1Inheritance: AD Classification: DEFINITIVE, STRONG Submitted by: Labcorp Genetics (formerly Invitae), Genomics England PanelApp, Ambry Genetics
- Muir-Torre syndromeInheritance: AD Classification: DEFINITIVE, STRONG, SUPPORTIVE Submitted by: Genomics England PanelApp, Orphanet, G2P
- mismatch repair cancer syndrome 1Inheritance: AR Classification: DEFINITIVE, SUPPORTIVE Submitted by: ClinGen, Orphanet
- mismatch repair cancer syndrome 2Inheritance: AR Classification: DEFINITIVE, STRONG Submitted by: Labcorp Genetics (formerly Invitae), G2P
- ovarian cancerInheritance: AD Classification: STRONG Submitted by: Genomics England PanelApp
- malignant pancreatic neoplasmInheritance: AD Classification: MODERATE Submitted by: Genomics England PanelApp
- prostate cancerInheritance: AD Classification: MODERATE Submitted by: Ambry Genetics
- rhabdomyosarcomaInheritance: AR Classification: MODERATE Submitted by: Genomics England PanelApp
- breast cancerInheritance: AD Classification: NO_KNOWN Submitted by: Ambry Genetics
- hereditary breast carcinomaInheritance: AD Classification: NO_KNOWN Submitted by: ClinGen
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ACMG classification
Our verdict: Uncertain_significance. The variant received 3 ACMG points.
Transcripts
RefSeq
Ensembl
Frequencies
GnomAD3 genomes AF: 0.00000657 AC: 1AN: 152166Hom.: 0 Cov.: 31 show subpopulations
GnomAD2 exomes AF: 0.00000796 AC: 2AN: 251392 AF XY: 0.00000736 show subpopulations
GnomAD4 exome AF: 0.00000753 AC: 11AN: 1461792Hom.: 0 Cov.: 32 AF XY: 0.00000825 AC XY: 6AN XY: 727192 show subpopulations
Age Distribution
GnomAD4 genome AF: 0.00000657 AC: 1AN: 152284Hom.: 0 Cov.: 31 AF XY: 0.0000134 AC XY: 1AN XY: 74460 show subpopulations
ClinVar
Submissions by phenotype
Hereditary cancer-predisposing syndrome Uncertain:3
The p.T806I variant (also known as c.2417C>T), located in coding exon 14 of the MSH2 gene, results from a C to T substitution at nucleotide position 2417. The threonine at codon 806 is replaced by isoleucine, 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 isoleucine at codon 806 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). In a large breast cancer case-control study, this variant was observed in 1/60466 cases and 1/53461 unaffected controls (PMID: 33471991). This variant has been identified in 2/251392 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. -
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Lynch syndrome Uncertain:2
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This missense variant replaces threonine with isoleucine at codon 806 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). In a large breast cancer case-control study, this variant was observed in 1/60466 cases and 1/53461 unaffected controls (PMID: 33471991). This variant has been identified in 2/251392 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. -
not provided Uncertain:2
Not observed at a significant frequency in large population cohorts (Lek 2016); In silico analysis, which includes protein predictors and evolutionary conservation, supports a deleterious effect; Observed in an individual with colorectal cancer whose tumor demonstrated high microsatellite instability, lacked PMS2 expression, and harbored two somatic MLH1 variants (Pearlman 2019); This variant is associated with the following publications: (PMID: 30877237) -
The MSH2 c.2417C>T (p.Thr806Ile) variant has been reported in the published literature in an individual with colorectal cancer whose tumor lacked PM2 expression, had high microsatellite instability, and also had two somatic MLH1 variants (PMID: 30877237 (2019)). It has also been reported in an individual with breast cancer as well as in an unaffected control in a breast cancer association study (PMID: 33471991 (2021), see also LOVD (http://databases.lovd.nl/shared/genes/MSH2)). One functional analysis suggested that this variant has a neutral impact on cell function (PMID: 33357406 (2021)), but additional functional studies are needed to determine the global effect of this variant on gene or gene product. The frequency of this variant in the general population, 0.000008 (2/251392 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 deleterious or benign. Based on the available information, we are unable to determine the clinical significance of this variant. -
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