2-47799827-G-T
Variant summary
Our verdict is Likely benign. The variant received -3 ACMG points: 0P and 3B. BP4_ModerateBP6
The NM_000179.3(MSH6):c.1844G>T(p.Cys615Phe) variant causes a missense change. The variant allele was found at a frequency of 0.0000062 in 1,614,058 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts 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. C615S) has been classified as Likely benign.
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 -3 ACMG points.
Transcripts
RefSeq
| Gene | Transcript | HGVSc | HGVSp | Effect | Exon rank | MANE | Protein | UniProt |
|---|---|---|---|---|---|---|---|---|
| MSH6 | NM_000179.3 | c.1844G>T | p.Cys615Phe | missense_variant | Exon 4 of 10 | ENST00000234420.11 | NP_000170.1 |
Ensembl
| Gene | Transcript | HGVSc | HGVSp | Effect | Exon rank | TSL | MANE | Protein | Appris | UniProt |
|---|---|---|---|---|---|---|---|---|---|---|
| MSH6 | ENST00000234420.11 | c.1844G>T | p.Cys615Phe | missense_variant | Exon 4 of 10 | 1 | NM_000179.3 | ENSP00000234420.5 |
Frequencies
GnomAD3 genomes AF: 0.0000263 AC: 4AN: 152190Hom.: 0 Cov.: 32 show subpopulations
GnomAD4 exome AF: 0.00000410 AC: 6AN: 1461868Hom.: 0 Cov.: 34 AF XY: 0.00000688 AC XY: 5AN XY: 727234 show subpopulations
Age Distribution
GnomAD4 genome AF: 0.0000263 AC: 4AN: 152190Hom.: 0 Cov.: 32 AF XY: 0.0000404 AC XY: 3AN XY: 74344 show subpopulations
Age Distribution
ClinVar
Submissions by phenotype
not provided Uncertain:3
In the published literature, this variant has been reported in an affected individual with colorectal cancer (PMID: 28135145 (2017)) and in a patient cohort with advanced cancer (PMID: 28873162 (2017)). The frequency of this variant in the general population, 0.000064 (2/31400 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.
In silico analysis supports that this missense variant does not alter protein structure/function; Observed in individuals with colorectal cancer or other advanced cancer (PMID: 28873162, 28135145); This variant is associated with the following publications: (PMID: 28873162, 28002797, 28135145, 17531815, 21120944)
Hereditary cancer-predisposing syndrome Uncertain:2Benign:1
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 cysteine with phenylalanine at codon 615 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 two individuals affected with colorectal cancer (PMID: 28135145) and in an individual affected with an unspecified advanced cancer (PMID: 28873162). This variant has been identified in 2/31400 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.
not specified Uncertain:2
DNA sequence analysis of the MSH6 gene demonstrated a sequence change, c.1844G>T, in exon 4 that results in an amino acid change, p.Cys615Phe. This sequence change has been identified in two individuals with colorectal cancer (PMID: 28135145). This sequence change has been described in the gnomAD database with a frequency of 0.0064% in the overall population (dbSNP rs730881793). The p.Cys615Phe change affects a poorly conserved amino acid residue located in a domain of the MSH6 protein that is known to be functional. The p.Cys615Phe substitution appears to be benign using several in-silico pathogenicity prediction tools (SIFT, PolyPhen2, Align GVGD, REVEL). Due to insufficient evidences and the lack of functional studies, the clinical significance of the p.Cys615Phe change remains unknown at this time. Heterozygous pathogenic variants in MSH6 are associated with Lynch syndrome [OMIM# 614350], which is associated with an increased risk of certain cancers, particularly colon and endometrial cancers. Hematological malignancies have been reported in some cases of Lynch syndrome however the exact risk is not well defined (PMID: 23730225). Homozygous or compound heterozygous pathogenic variants in MSH6 lead to a mismatch repair deficiency which is a rare childhood cancer predisposition syndrome with 4 main tumor types: hematologic malignancies, brain/central nervous system tumors, colorectal tumors and multiple intestinal polyps, and other malignancies including embryonic tumors and rhabdomyosarcoma [OMIM# 276300] (PMIDs: 19493351).
Variant summary: MSH6 c.1844G>T (p.Cys615Phe) results in a non-conservative amino acid change located in the DNA mismatch repair protein MutS, connector domain (IPR007860) of the encoded protein sequence. Four of five in-silico tools predict a benign effect of the variant on protein function. The variant was absent in 250636 control chromosomes. The available data on variant occurrences in the general population are insufficient to allow any conclusion about variant significance. c.1844G>T has been reported in the literature in individuals affected with Colorectal Cancer without strong evidence of causality (e.g., Yurgelun_2017). This report does not provide unequivocal conclusions about association of the variant with Lynch Syndrome. To our knowledge, no experimental evidence demonstrating an impact on protein function has been reported. The following publication was ascertained in the context of this evaluation (PMID: 28135145). Seven submitters have cited clinical-significance assessments for this variant to ClinVar after 2014. Multiple submitters reported the variant with conflicting assessments (VUS, n = 5; likely benign, n = 1; benign, n = 1). Based on the evidence outlined above, the variant was classified as uncertain significance.
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 cysteine with phenylalanine at codon 615 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 two individuals affected with colorectal cancer (PMID: 28135145) and in an individual affected with an unspecified advanced cancer (PMID: 28873162). This variant has been identified in 2/31400 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
Hereditary nonpolyposis colorectal neoplasms Benign:1
Computational scores
Source:
Splicing
Find out detailed SpliceAI scores and Pangolin per-transcript scores at