2-47799044-G-T
Variant summary
Our verdict is Likely benign. Variant got -3 ACMG points: 0P and 3B. BP4_ModerateBP6
The NM_000179.3(MSH6):c.1061G>T(p.Gly354Val) variant causes a missense change involving the alteration of a conserved nucleotide. The variant allele was found at a frequency of 0.000031 in 1,614,086 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).
Frequency
Consequence
NM_000179.3 missense
Scores
Clinical Significance
Conservation
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ACMG classification
Verdict is Likely_benign. Variant got -3 ACMG points.
Transcripts
RefSeq
Ensembl
Frequencies
GnomAD3 genomes AF: 0.00000657 AC: 1AN: 152204Hom.: 0 Cov.: 32
GnomAD3 exomes AF: 0.00000398 AC: 1AN: 251202Hom.: 0 AF XY: 0.00 AC XY: 0AN XY: 135762
GnomAD4 exome AF: 0.0000335 AC: 49AN: 1461882Hom.: 0 Cov.: 34 AF XY: 0.0000330 AC XY: 24AN XY: 727240
GnomAD4 genome AF: 0.00000657 AC: 1AN: 152204Hom.: 0 Cov.: 32 AF XY: 0.0000135 AC XY: 1AN XY: 74346
ClinVar
Submissions by phenotype
not provided Uncertain:3
The MSH6 c.1061G>T; p.Gly354Val variant (rs730881788), is reported in the literature in at least one individual with early-onset breast cancer (Maxwell 2015). This variant is reported as uncertain in ClinVar (Variation ID: 182618), and found in the general population with a low overall allele frequency of 0.003% (1/30980 alleles) in the Genome Aggregation Database. The glycine at codon 354 is not highly conserved, and computational programs that predict the effect of missense variants on the protein (SIFT, PolyPhen-2) suggest that this variant is tolerated. However, splicing algorithms (Alamut v.2.11) suggest this variant may have an impact on splicing by creating a cryptic donor site. Due to limited information, the clinical significance of the p.Gly354Val variant is uncertain at this time. REFERENCES Maxwell KN et al. Prevalence of mutations in a panel of breast cancer susceptibility genes in BRCA1/2-negative patients with early-onset breast cancer. Genet Med. 2015 Aug;17(8):630-8. -
The frequency of this variant in the general population, 0.000004 (1/251202 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 early-onset breast cancer (PMID: 25503501(2015)), pancreatic cancer (PMID: 29945567(2018)) and pediatric acute lymphoblastic leukemia (PMID: 26580448 (2015)). In a large-scale breast cancer association study, the variant was observed in breast cancer cases and in unaffected individuals (PMID: 33471991 (2021), see also LOVD (http://databases.lovd.nl/shared/genes/MSH6)). 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 observed at significant frequency in large population cohorts (gnomAD); In silico analysis supports that this missense variant does not alter protein structure/function; Observed in individuals with breast or other cancers (Maxwell et al., 2015; Zhang et al., 2015; Young et al., 2018); This variant is associated with the following publications: (PMID: 25503501, 26580448, 29945567) -
Lynch syndrome 5 Uncertain:2Benign:1
This variant is considered likely benign. This variant has been observed in conjunction with multiple pathogenic variants, reducing the likelihood this variant itself is pathogenic. -
The MSH6 c.1061G>T (p.Gly354Val) missense change has a maximum subpopulation frequency of 0.006% in gnomAD v2.1.1 (https://gnomad.broadinstitute.org/). The in silico tool REVEL is inconclusive about a pathogenic or benign effect of this variant on protein function, and functional studies have not been performed. This variant has been reported in an individual with pancreatic cancer (PMID: 29945567). This variant has not been reported in individuals with Lynch syndrome or constitutional mismatch repair deficiency. In summary, the evidence currently available is insufficient to determine the clinical significance of this variant. It has therefore been classified as of uncertain significance. -
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Hereditary cancer-predisposing syndrome Uncertain:2
The p.G354V variant (also known as c.1061G>T), located in coding exon 4 of the MSH6 gene, results from a G to T substitution at nucleotide position 1061. The glycine at codon 354 is replaced by valine, an amino acid with dissimilar properties. This alteration has been reported in one individual with early-onset breast cancer and in a pediatric patient diagnosed with acute lymphocytic leukemia (Maxwell KN et al. Genet. Med. 2015 Aug;17(8):630-8; Zhang J et al. N. Engl. J. Med. 2015 Dec;373(24):2336-2346). This alteration has also been reported in one individual with pancreatic cancer (Young E et al. BMC Cancer 2018 Jun;18(1):697). This amino acid position is not well conserved in available vertebrate species. In addition, the in silico prediction for this alteration is inconclusive. Since supporting evidence is limited at this time, the clinical significance of this alteration remains unclear. -
This missense variant replaces glycine with valine at codon 354 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 performed for this variant. This variant has been reported in an individual affected with breast cancer (PMID: 25503501) and an individual affected with childhood acute lymphoblastic leukemia (PMID: 26580448). This variant has been identified in 1/251202 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:1
Variant summary: MSH6 c.1061G>T (p.Gly354Val) results in a non-conservative amino acid change in the encoded protein sequence. Three of five in-silico tools predict a damaging effect of the variant on protein function. The variant allele was found at a frequency of 3.1e-05 in 1614086 control chromosomes (gnomAD v.4.0.0). This frequency is not significantly higher than estimated for a pathogenic variant in MSH6 causing Hereditary Nonpolyposis Colorectal Cancer (3.1e-05 vs 0.00014), allowing no conclusion about variant significance. c.1061G>T has been reported in the literature in at least one individual affected with early onset breast cancer (Maxwell_2015) and in individuals with other cancers without strong evidence for causality (e.g. Zhang_2015, Young_2018). These reports do not provide unequivocal conclusions about association of the variant with disease. To our knowledge, no experimental evidence demonstrating an impact on protein function has been reported. The following publications have been ascertained in the context of this evaluation (PMID: 25503501, 26580448, 29945567). ClinVar contains an entry for this variant (Variation ID: 182618). Based on the evidence outlined above, the variant was classified as uncertain significance. -
Breast and/or ovarian cancer Uncertain:1
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Lynch syndrome Uncertain:1
This missense variant replaces glycine with valine at codon 354 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 an individual affected with breast cancer (PMID: 25503501) and an individual affected with childhood acute lymphoblastic leukemia (PMID: 26580448). This variant has been identified in 1/251202 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. -
MSH6-related disorder Uncertain:1
The MSH6 c.1061G>T variant is predicted to result in the amino acid substitution p.Gly354Val. This variant has been reported in at least one individual with early-onset breast cancer (Maxwell et al. 2015. PubMed ID: 25503501) and an individual with acute lymphocytic leukemia (Zhang et al. 2015. PubMed ID: 26580448, Table S4a). This variant is reported in 0.0062% of alleles in individuals of African descent in gnomAD and is interpreted as uncertain significance by majority of the submitters in ClinVar (https://www.ncbi.nlm.nih.gov/clinvar/variation/182618/). At this time, the clinical significance of this variant is uncertain due to the absence of conclusive functional and genetic evidence. -
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