2-47475129-C-G
Variant summary
Our verdict is Pathogenic. The variant received 10 ACMG points: 10P and 0B. PM1PM2PM5PP3_Strong
The NM_000251.3(MSH2):āc.1864C>Gā(p.Pro622Ala) variant causes a missense change involving the alteration of a conserved nucleotide. The variant allele was found at a frequency of 0.000000684 in 1,461,876 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. P622S) has been classified as Likely pathogenic.
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: Pathogenic. The variant received 10 ACMG points.
Transcripts
RefSeq
Ensembl
Frequencies
GnomAD3 genomes Cov.: 33
GnomAD4 exome AF: 6.84e-7 AC: 1AN: 1461876Hom.: 0 Cov.: 33 AF XY: 0.00000138 AC XY: 1AN XY: 727240 show subpopulations
GnomAD4 genome Cov.: 33
ClinVar
Submissions by phenotype
not provided Uncertain:2
Not observed at significant frequency in large population cohorts (gnomAD); In silico analysis supports that this missense variant has a deleterious effect on protein structure/function; Published functional studies demonstrate a significant increase in mutation rate compared to wild-type (Ollodart et al., 2021); Observed in an individual with premature ovarian insufficiency and primary amenorrhea (Luo et al., 2020); This variant is associated with the following publications: (PMID: 18822302, 21120944, 33848333, 32772095) -
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Hereditary cancer-predisposing syndrome Uncertain:2
This missense variant replaces proline with alanine at codon 622 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). To our knowledge, this variant has not been reported in individuals affected with hereditary cancer in the literature. However, a different missense variant at this codon, p.Pro622Leu, has been reported as disease-causing in ClinVar (variation ID: 1753) and to co-segregate with disease and exhibited functional defects in in vitro assays (InSiGHT; http://www.insight-database.org/classifications/index.html?gene=MSH2&variant=c.1865C%3ET). Moreover, other missense variants at this same codon, p.Pro622Arg, p.Pro622Thr and p.Pro622Glu, have also been reported as disease-causing in ClinVar and/or in individuals affected with Lynch syndrome-associated cancer (variation ID: 90805, 265573; InSiGHT/LOVD individual# 00199194). This variant has not been identified in the general population by the Genome Aggregation Database (gnomAD). Although there is a suspicion that this variant may be associated with disease, additional studies are necessary to determine the role of this variant in disease conclusively. Therefore, this variant is classified as a Variant of Uncertain Significance. -
The p.P622A variant (also known as c.1864C>G), located in coding exon 12 of the MSH2 gene, results from a C to G substitution at nucleotide position 1864. The proline at codon 622 is replaced by alanine, an amino acid with highly similar properties. Based on internal structural analysis, P622A is moderately destabilizing to the local structure (Ambry internal data). 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 Jan;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 conflicting at this time, the clinical significance of this alteration remains unclear. -
Hereditary nonpolyposis colorectal neoplasms Pathogenic:1
This sequence change replaces proline, which is neutral and non-polar, with alanine, which is neutral and non-polar, at codon 622 of the MSH2 protein (p.Pro622Ala). This variant is not present in population databases (gnomAD no frequency). This missense change has been observed in individual(s) with MSH2-related conditions (PMID: 35449176). ClinVar contains an entry for this variant (Variation ID: 186899). Advanced modeling performed at Invitae incorporating data from internal and/or published experimental studies (PMID: 33357406) indicates that this missense variant is not expected to disrupt MSH2 function with a negative predictive value of 80%. This variant disrupts the p.Pro622 amino acid residue in MSH2. Other variant(s) that disrupt this residue have been determined to be pathogenic (PMID: 8261515, 16116158, 16616355, 21309037, 22949379, 24362816). This suggests that this residue is clinically significant, and that variants that disrupt this residue are likely to be disease-causing. In summary, the currently available evidence indicates that the variant is pathogenic, but additional data are needed to prove that conclusively. Therefore, this variant has been classified as Likely Pathogenic. -
Computational scores
Source:
Splicing
Find out detailed SpliceAI scores and Pangolin per-transcript scores at