rs374486449
Variant summary
Our verdict is Likely benign. The variant received -4 ACMG points: 0P and 4B. BP4_Strong
The NM_000179.3(MSH6):āc.831A>Cā(p.Glu277Asp) variant causes a missense change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.0000112 in 1,614,172 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a benign outcome for this variant. 15/22 in silico tools predict a benign 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. E277G) 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
 
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ACMG classification
Our verdict: Likely_benign. The variant received -4 ACMG points.
Transcripts
RefSeq
Ensembl
Frequencies
GnomAD3 genomes   AF:  0.0000526  AC: 8AN: 152170Hom.:  0  Cov.: 32 show subpopulations 
GnomAD2 exomes  AF:  0.0000199  AC: 5AN: 251120 AF XY:  0.0000147   show subpopulations 
GnomAD4 exome  AF:  0.00000616  AC: 9AN: 1461884Hom.:  0  Cov.: 34 AF XY:  0.00000550  AC XY: 4AN XY: 727242 show subpopulations 
Age Distribution
GnomAD4 genome   AF:  0.0000591  AC: 9AN: 152288Hom.:  0  Cov.: 32 AF XY:  0.0000537  AC XY: 4AN XY: 74462 show subpopulations 
Age Distribution
ClinVar
Submissions by phenotype
Lynch syndrome 5    Uncertain:2Benign:1 
This submission and the accompanying classification are no longer maintained by the submitter.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:2Benign:1 
This missense variant replaces glutamic acid with aspartic acid at codon 277 of the MSH6 protein. Computational prediction suggests that this variant may not impact protein structure and function (internally defined REVEL score threshold <= 0.5, PMID: 27666373). To our knowledge, functional studies have not been reported for this variant. This variant has been reported in individuals affected with breast cancer (PMID: 25186627, 29684080). This variant has been identified in 6/282520 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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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. -
not provided    Uncertain:2 
In silico analysis indicates that this missense variant does not alter protein structure/function; Observed in individuals with breast cancer (PMID: 25186627, 29684080, 34326862); This variant is associated with the following publications: (PMID: 23621914, 29684080, 21437237, 25186627, 34326862) -
The MSH6 c.831A>C (p.Glu277Asp) variant has been reported in the published literature in individuals affected with breast cancer (PMID: 25186627 (2015), 34326862 (2021)), as well as in a cohort of individuals with features of Cowden (CS) or Bannayan-Riley-Ruvalcaba (BRRS) syndrome (PMID: 29684080 (2018)). The frequency of this variant in the general population, 0.0002 (5/24952 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 predictions that this variant is benign. Based on the available information, we are unable to determine the clinical significance of this variant. -
not specified    Uncertain:1 
Variant summary: MSH6 c.831A>C (p.Glu277Asp) results in a conservative amino acid change in the encoded protein sequence. Four of five in-silico tools predict a benign effect of the variant and a study combining data from several in silico tools and structural analyses predicts the variant to have no effect on MSH6 function (Terui_2013). The variant allele was found at a frequency of 2.5e-05 (7/276832 control chromosomes) in all ethnicities, but was found predominantly in the African subpopulation (6/24016; frequency of 0.00025). This frequency is approximately 2 fold higher than expected for a pathogenic variant in MSH6 causing Lynch Syndrome (0.00025vs 0.00014), suggesting the variant may be a benign polymorphism in the African subpopulation. To our knowledge, no occurrence of c.831A>C in individuals affected with Lynch Syndrome and no experimental evidence demonstrating its impact on protein function have been reported. Four clinical diagnostic laboratories have submitted clinical-significance assessments for this variant to ClinVar after 2014 and all laboratories classified the variant as uncertain significance. Based on the evidence outlined above, the variant was classified as VUS-possibly benign until addtional information becomes available. -
Endometrial carcinoma;C1833477:Lynch syndrome 5;C5436807:Mismatch repair cancer syndrome 3    Uncertain:1 
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MSH6-related disorder    Uncertain:1 
The MSH6 c.831A>C variant is predicted to result in the amino acid substitution p.Glu277Asp. This variant has been reported in an individual with breast cancer (supporting info 002, Tung et al. 2015. PubMed ID: 25186627). It has also been reported in a breast cancer specimen from The Cancer Genome Atlas (Table S9, Yehia et al. 2018. PubMed ID: 29684080). This variant is reported in 0.020% of alleles in individuals of African descent in gnomAD (http://gnomad.broadinstitute.org/variant/2-48025953-A-C) and is interpreted as uncertain by the vast majority of submitters in ClinVar (https://www.ncbi.nlm.nih.gov/clinvar/variation/182612/?new_evidence=true). At this time, the clinical significance of this variant is uncertain due to the absence of conclusive functional and genetic evidence. -
Lynch syndrome    Uncertain:1 
This missense variant replaces glutamic acid with aspartic acid at codon 277 of the MSH6 protein. Computational prediction suggests that this variant may not impact protein structure and function (internally defined REVEL score threshold <= 0.5, PMID: 27666373). Splice site prediction tools suggest that this variant may not impact RNA splicing. To our knowledge, functional studies have not been performed for this variant. This variant has been reported in 1 individual affected with breast cancer (PMID:25186627). This variant has been identified in 6/282520 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. -
Endometrial carcinoma    Uncertain:1 
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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