rs775464903
Variant summary
Our verdict is Uncertain significance. Variant got 4 ACMG points: 4P and 0B. PM2PP3PP5
The NM_000251.3(MSH2):c.2320A>G(p.Ile774Val) variant causes a missense change. The variant was absent in control chromosomes in GnomAD project. Variant has been reported in ClinVar as Conflicting classifications of pathogenicity (no stars).
Frequency
Consequence
NM_000251.3 missense
Scores
Clinical Significance
Conservation
Genome browser will be placed here
ACMG classification
Verdict is Uncertain_significance. Variant got 4 ACMG points.
Transcripts
RefSeq
Ensembl
Frequencies
GnomAD3 genomes Cov.: 31
GnomAD4 exome Cov.: 32
GnomAD4 genome Cov.: 31
ClinVar
Submissions by phenotype
not provided Pathogenic:2
- -
- -
Lynch syndrome 1 Pathogenic:1
- -
Gastric cancer Pathogenic:1
- -
Hereditary nonpolyposis colorectal neoplasms Pathogenic:1
This sequence change replaces isoleucine, which is neutral and non-polar, with valine, which is neutral and non-polar, at codon 774 of the MSH2 protein (p.Ile774Val). This variant is not present in population databases (gnomAD no frequency). This missense change has been observed in individuals with clinical features of Lynch syndrome (PMID: 28765196; external communication, internal data). Invitae Evidence Modeling of clinical and family history, age, sex, and reported ancestry of multiple individuals with this MSH2 variant has been performed. This variant is expected to be pathogenic with a positive predictive value of at least 99%. This is a validated machine learning model that incorporates the clinical features of 1,370,736 individuals referred to our laboratory for MSH2 testing. ClinVar contains an entry for this variant (Variation ID: 408475). 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 80%. Experimental studies have shown that this missense change does not substantially affect MSH2 function (PMID: 33357406). Algorithms developed to predict the effect of sequence changes on RNA splicing suggest that this variant may disrupt the consensus splice site. For these reasons, this variant has been classified as Pathogenic. -
Hereditary cancer-predisposing syndrome Pathogenic:1
The p.I774V pathogenic mutation (also known as c.2320A>G), located in coding exon 14 of the MSH2 gene, results from an A to G substitution at nucleotide position 2320. The isoleucine at codon 774 is replaced by valine, an amino acid with highly similar properties. This alteration has been reported in an individual who met Bethesda, but not Amsterdam criteria, and had osteosarcoma as well as early-onset, mismatch repair deficient rectal cancer displaying loss of MSH2 and MSH6 on immunohistochemistry (IHC) (de Rosa N et al. J. Clin. Oncol., 2016 Sep;34:3039-46; Borras E et al. Cancer Prev. Res. (Phila.), 2017 Oct;10:580-587). This alteration was also identified in several individuals whose family history met Amsterdam I/II criteria for Lynch syndrome and/or colorectal tumor showed loss of MSH2 protein expression by IHC and/or high microsatellite instability (MSI-H) (Ambry internal data). This variant is considered to be rare based on population cohorts in the Genome Aggregation Database (gnomAD). This nucleotide position is well conserved in available vertebrate species. In silico splice site analysis predicts that this alteration will result in the creation or strengthening of a novel splice donor site. RNA studies have demonstrated that this alteration results in abnormal splicing in the set of samples tested (Ambry internal data). This amino acid position is highly conserved in available vertebrate species. In addition, as a missense substitution this is predicted to be tolerated by in silico analysis. Based on the supporting evidence, this variant is interpreted as a disease-causing mutation. -
Lynch syndrome Uncertain:1
- -
Computational scores
Source:
Splicing
Find out detailed SpliceAI scores and Pangolin per-transcript scores at