2-47803672-C-T
Variant summary
Our verdict is Uncertain significance. The variant received 2 ACMG points: 2P and 0B. PM1
The NM_000179.3(MSH6):c.3425C>T(p.Thr1142Met) variant causes a missense change involving the alteration of a conserved nucleotide. The variant allele was found at a frequency of 0.0000366 in 1,614,044 control chromosomes in the GnomAD database, with no homozygous occurrence. 9/15 in silico tools predict a damaging outcome for this variant. Variant has been reported in ClinVar as Conflicting classifications of pathogenicity (no stars). Another nucleotide change resulting in the same amino acid substitution has been previously reported as Likely benign in ClinVar. Another variant affecting the same amino acid position, but resulting in a different missense (i.e. T1142A) has been classified as Uncertain significance.
Frequency
Consequence
NM_000179.3 missense
Scores
Clinical Significance
Conservation
Publications
- intellectual developmental disorder with dysmorphic facies and behavioral abnormalitiesInheritance: AD Classification: DEFINITIVE, STRONG Submitted by: Labcorp Genetics (formerly Invitae), Ambry Genetics, G2P
Genome browser will be placed here
ACMG classification
Our verdict: Uncertain_significance. The variant received 2 ACMG points.
Transcripts
RefSeq
Ensembl
Frequencies
GnomAD3 genomes AF: 0.0000460 AC: 7AN: 152162Hom.: 0 Cov.: 32 show subpopulations
GnomAD2 exomes AF: 0.0000239 AC: 6AN: 251338 AF XY: 0.0000368 show subpopulations
GnomAD4 exome AF: 0.0000356 AC: 52AN: 1461882Hom.: 0 Cov.: 33 AF XY: 0.0000426 AC XY: 31AN XY: 727242 show subpopulations
Age Distribution
GnomAD4 genome AF: 0.0000460 AC: 7AN: 152162Hom.: 0 Cov.: 32 AF XY: 0.0000135 AC XY: 1AN XY: 74336 show subpopulations
Age Distribution
ClinVar
Submissions by phenotype
not provided Uncertain:4
The frequency of this variant in the general population, 0.000031 (4/129104 chromosomes, http://gnomad.broadinstitute.org), is uninformative in assessment of its pathogenicity. In the published literature, the variant has been reported in an individual with personal or family history of breast/ovarian cancer, and in two family members affected with colon polyps (PMID: 24549055 (2014), 23523604 (2013)). In vitro functional study evaluating the function of the variant in response to a DNA-damaging agent indicated that this variant may not be pathogenic (PMID: 28531214 (2017)). Based on the available information, we are unable to determine the clinical significance of this variant. -
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 proficient mismatch repair activity (PMID: 28531214); Observed in individuals with polyps or history suggestive of hereditary breast and ovarian cancer syndrome (PMID: 23523604, 24549055); This variant is associated with the following publications: (PMID: 26333163, 27632392, 23621914, 23523604, 19250818, 23588873, 24549055, n/a, 33471991, 32885271, 28531214, 21120944, 12019211, 37937776) -
- -
- -
Hereditary cancer-predisposing syndrome Uncertain:3
- -
This missense variant replaces threonine with methionine at codon 1142 of the MSH6 protein. Computational prediction suggests that this variant may have deleterious impact on protein structure and function. A functional assay to detect DNA mismatch repair (MMR) deficiency in MSH6 deficient mouse embryonic stem cells found that the variant protein is likely MMR proficient (PMID: 28531214). This variant has been reported in individuals affected with Lynch syndrome (PMID: 19250818, 23523604), and in individuals affected with breast and/or ovarian cancer (PMID: 24549055, 32885271, 33471991). This variant has been identified in 7/282732 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. -
The p.T1142M variant (also known as c.3425C>T), located in coding exon 5 of the MSH6 gene, results from a C to T substitution at nucleotide position 3425. The threonine at codon 1142 is replaced by methionine, an amino acid with similar properties. This variant was reported in a Spanish family meeting Amsterdam criteria and segregated with disease in 2/2 affected relatives; however, tumor testing in this family demonstrated microsatellite stability and normal staining on IHC (Perez-Cabornero L et al. Eur. J. Cancer. 2009 May;45:1485-93; Perez-Cabornero L et al. J Mol Diagn. 2013 May;15:380-90). This alteration was reported in a cohort of suspected hereditary breast and ovarian cancer patients who underwent multi-gene panel testing (Castéra L et al. Eur. J. Hum. Genet., 2014 Nov;22:1305-13). This variant was also observed in 2/3251 individuals who met eligibility criteria for hereditary breast and ovarian cancer syndrome (Lerner-Ellis J et al. J Cancer Res Clin Oncol, 2021 Mar;147:871-879). In a functional study that utilized a genetic screening method to test mismatch repair activity in murine embryonic stem cells, p.T1142M did not demonstrate attenuated mismatch repair (Houlleberghs H et al. PLoS Genet., 2017 May;13:e1006765). This amino acid position is highly conserved in available vertebrate species. In addition, this alteration is predicted to be deleterious by in silico analysis. Based on the available evidence, the clinical significance of this variant remains unclear. -
not specified Uncertain:2
Variant summary: MSH6 c.3425C>T (p.Thr1142Met) results in a non-conservative amino acid change located in the DNA mismatch repair protein MutS, C-terminal domain (IPR000432) of the encoded protein sequence. Five of five in-silico tools predict a damaging effect of the variant on protein function. The variant allele was found at a frequency of 3.7e-05 in 1614044 control chromosomes, predominantly at a frequency of 7.8e-05 within the Non-Finnish European subpopulation in the gnomAD database. The available data on variant occurrences in the general population are insufficient to allow any conclusion about variant significance c.3425C>T has been reported in the literature in individuals affected with Lynch syndrome, hereditary breast and ovarian cancer or prostate cancer (example, Perez-Cabornero_2013, Castera_2014, Lerner-Ellis_2021, Yang_2024). These reports do not provide unequivocal conclusions about association of the variant with Lynch Syndrome. At least one publication reports experimental evidence evaluating an impact on protein function. These results showed no damaging effect of this variant on mismatch repair (MMR) activity (Houlleberghs_2017). The following publications have been ascertained in the context of this evaluation (PMID: 24549055, 23523604, 28531214, 32885271, 37937776, 38327772). ClinVar contains an entry for this variant (Variation ID: 89381). Based on the evidence outlined above, the variant was classified as VUS-possibly benign. -
Variant identified in a genome or exome case(s) and assessed due to predicted null impact of the variant or pathogenic assertions in the literature or databases. Disclaimer: This variant has not undergone full assessment. The following are preliminary notes: ClinVar: 4 VUS (including expert panel - no new evidence since expert classification) -
Lynch syndrome 5 Uncertain:1Benign:1
- -
This variant is considered likely benign. This variant is strongly associated with less severe personal and family histories of cancer, typical for individuals without pathogenic variants in this gene [PMID: 27363726]. -
Lynch syndrome Uncertain:1
This missense variant replaces threonine with methionine at codon 1142 of the MSH6 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). A functional assay to detect DNA mismatch repair (MMR) deficiency in MSH6 deficient mouse embryonic stem cells found that the variant protein is likely MMR proficient (PMID: 28531214). This variant has been reported in individuals affected with Lynch syndrome (PMID: 19250818, 23523604, Goverde 2018) and an individual suspected to be affected with hereditary breast and ovarian cancer (PMID: 24549055). This variant has been identified in 7/282732 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. -
Malignant tumor of breast Uncertain:1
The MSH6 p.Thr1142Met variant was identified in 3 of 1454 proband chromosomes (frequency: 0.002) from individuals or families with breast cancer/ovarian cancer, Lynch Syndrome, and polyps (Castera 2014, Perez-Cabornero 2009, Perez-Cabornero 2013). The variant was also identified in the following databases: dbSNP (ID: rs267608089) as "With Uncertain significance allele", ClinVar (5x, uncertain significance), Clinvitae (3x, uncertain significance), Cosmic (2x, confirmed somatic, in a carcinoma of the liver), Insight Colon Cancer Gene Variant Database (1x, uncertain significance), Mismatch Repair Genes Variant Database, and Insight Hereditary Tumors Database. The variant was not identified in MutDB, UMD-LSDB, or the Zhejiang Colon Cancer Database. The variant was identified in control databases in 7 of 277124 chromosomes at a frequency of 0.00003 (Genome Aggregation Database Feb 27, 2017). A functional study used an oligonucleotide directed mutagenesis screen in mouse embryonic stem cells to determine pathogenicity for MSH6 variants (Houlleberghs 2017). The c.3425C>T variant was classified as "not pathogenic" by this method. The p.Thr1142 residue is conserved across mammals and other organisms, and computational analyses (PolyPhen-2, SIFT, AlignGVGD, BLOSUM, MutationTaster) suggest that the variant may impact the protein; however, this information is not predictive enough to assume pathogenicity. The variant occurs outside of the splicing consensus sequence and 1 of 5 in silico or computational prediction software programs (SpliceSiteFinder, MaxEntScan, NNSPLICE, GeneSplicer, HumanSpliceFinder) predict a greater than 10% difference in splicing; this is also not very predictive of pathogenicity. In summary, based on the above information the clinical significance of this variant cannot be determined with certainty at this time. This variant is classified as a variant of uncertain significance. -
Endometrial carcinoma Uncertain:1
- -
Hereditary nonpolyposis colorectal neoplasms Benign:1
- -
Computational scores
Source:
Splicing
Find out detailed SpliceAI scores and Pangolin per-transcript scores at