NM_000251.3:c.437G>T
Variant summary
Our verdict is Uncertain significance. The variant received 1 ACMG points: 2P and 1B. PM1BP6
The NM_000251.3(MSH2):c.437G>T(p.Gly146Val) variant causes a missense change involving the alteration of a conserved nucleotide. The variant allele was found at a frequency of 0.00000434 in 1,613,992 control chromosomes in the GnomAD database, with no homozygous occurrence. 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. G146R) has been classified as Uncertain significance.
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 1 ACMG points.
Transcripts
RefSeq
Ensembl
Frequencies
GnomAD3 genomes AF: 0.0000131 AC: 2AN: 152134Hom.: 0 Cov.: 31 show subpopulations
GnomAD2 exomes AF: 0.00000398 AC: 1AN: 251434 AF XY: 0.00 show subpopulations
GnomAD4 exome AF: 0.00000342 AC: 5AN: 1461858Hom.: 0 Cov.: 32 AF XY: 0.00000275 AC XY: 2AN XY: 727232 show subpopulations
Age Distribution
GnomAD4 genome AF: 0.0000131 AC: 2AN: 152134Hom.: 0 Cov.: 31 AF XY: 0.0000135 AC XY: 1AN XY: 74320 show subpopulations
ClinVar
Submissions by phenotype
Lynch syndrome 1 Uncertain:3
This submission and the accompanying classification are no longer maintained by the submitter. For more information on current observations and classification, please contact variantquestions@myriad.com. -
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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. -
Hereditary cancer-predisposing syndrome Uncertain:1Benign:2
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. -
This missense variant replaces glycine with valine at codon 146 of the MSH2 protein. Computational prediction suggests that this variant may not impact protein structure and function (internally defined REVEL score threshold <= 0.5, 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 an individual affected with endometrial cancer, who also carried a pathogenic variant in the MSH6 gene that could explain the observed phenotype (PMID: 28051113), as well as an individual affected with ovarian cancer (PMID: 31265121). This variant has been identified in 1/251434 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. -
PM2_Supporting, BS3, BP4, BP5 c.437G>T, located in exon 3 of the MSH2 gene, is predicted to result in the substitution of Gly by Val at codon 146, p.(Gly146Val).It is not present in the population database gnomAD v2.1.1, non cancer dataset (PM2_supporting). Computational tools for this variant suggest no significant impact on splicing and no significant impact on protein function (MAPP+PolyPhen-2 prior probability for pathogenicity: 0.0015 < 0.11 (BP4). A functional study based on cell viability assay in HEK293 or HAP1 cells using 6-TG treatment demonstrates normal function for this variant, with a LOF score -4,22 (PMID 33357406) (BS3). RT-PCR analysis of RNA with NMD-inhibition in carrier patients showed that this variant has no effect on splicing, also showing biallelic expression (r.437g>u; p.Gly146Val) (internal data). This variant has been identified in 3 patients from different families, coocurring with the germline variant MSH6 c.3955_3963del, which tumour immunohistochemistry (IHC) revealed: in the first case, a patient affected with colorectal cancer, the loss of only MSH6 protein expression; in the second case, a patient affected with endometrial cancer, the loss of MSH6 protein expression but no loss of MSH2 and tumour was MSI-H; and the third case, a patient affected with endometrial cancer, no loss of MSH2 protein expression (IHC of MSH6 was not evaluable) and tumour was MSI-H (internal data, PMID: 28051113) (BP5_Supporting). It was also identified in a patient affected with breast cancer and in a patient affected with endometrial cancer (no tumour information, internal data), and in another patient affected with ovarian cancer (PMID: 31265121). This variant has been reported in the ClinVar database (5x Uncertain Significance; 1x Likely benign), but not in Insight nor in LOVD databases. Based on currently available information, the variant c.437G>T should be considered a likely benign variant. -
Lynch syndrome Uncertain:1
This missense variant replaces glycine with valine at codon 146 of the MSH2 protein. Computational prediction suggests that this variant may not impact protein structure and function (internally defined REVEL score threshold <= 0.5, 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 an individual affected with endometrial cancer, who also carried a pathogenic variant in the MSH6 gene that could explain the observed phenotype (PMID: 28051113), as well as an individual affected with ovarian cancer (PMID: 31265121). This variant has been identified in 1/251434 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 Uncertain:1
This sequence change replaces glycine, which is neutral and non-polar, with valine, which is neutral and non-polar, at codon 146 of the MSH2 protein (p.Gly146Val). This variant is present in population databases (rs772052262, gnomAD 0.002%). This missense change has been observed in individual(s) with endometrial cancer (PMID: 28051113). ClinVar contains an entry for this variant (Variation ID: 186918). 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%. 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