2-47806650-C-T
Variant summary
Our verdict is Uncertain significance. The variant received 2 ACMG points: 2P and 0B. PM5
The NM_000179.3(MSH6):c.4000C>T(p.Arg1334Trp) variant causes a missense, splice region change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.0000349 in 1,606,498 control chromosomes in the GnomAD database, with no homozygous occurrence. 3/3 splice prediction tools predict no significant impact on normal splicing. 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. R1334Q) has been classified as Pathogenic.
Frequency
Consequence
NM_000179.3 missense, splice_region
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: Uncertain_significance. The variant received 2 ACMG points.
Transcripts
RefSeq
Ensembl
Frequencies
GnomAD3 genomes AF: 0.0000528 AC: 8AN: 151444Hom.: 0 Cov.: 32 show subpopulations
GnomAD2 exomes AF: 0.0000368 AC: 9AN: 244568 AF XY: 0.0000302 show subpopulations
GnomAD4 exome AF: 0.0000330 AC: 48AN: 1455054Hom.: 0 Cov.: 35 AF XY: 0.0000207 AC XY: 15AN XY: 724122 show subpopulations
Age Distribution
GnomAD4 genome AF: 0.0000528 AC: 8AN: 151444Hom.: 0 Cov.: 32 AF XY: 0.0000812 AC XY: 6AN XY: 73892 show subpopulations
Age Distribution
ClinVar
Submissions by phenotype
Lynch syndrome 5 Uncertain:2
This submission and the accompanying classification are no longer maintained by the submitter.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. -
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. -
not provided Uncertain:2
The MSH6 c.4000C>T (p.Arg1334Trp) variant has been reported in the published literature in at least one individual with familial colon cancer (PMID: 25559809 (2015)) and one individual with pancreatic and breast cancer (PMID: 29360161 (2018)). Additionally, this variant was also identified in at least one reportedly healthy individual and affected individuals in large-scale breast cancer association study (PMID: 33471991 (2021), see also LOVD (http://databases.lovd.nl/shared/genes/ MSH6)). The frequency of this variant in the general population, 0.00012 (3/24502 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 damaging. Based on the available information, we are unable to determine the clinical significance of this variant. -
Observed in an individual with a personal and family history of colon cancer as well as in individuals with a personal history of breast and/or pancreatic cancer (PMID: 25559809, 29360161, 35449176, 33471991); In silico analysis supports that this missense variant has a deleterious effect on protein structure/function; This variant is associated with the following publications: (PMID: 25559809, 25275298, 29360161, 31391288, 23415222, 33471991, 25370038, 35449176, 17531815, 21120944, 12019211, 36243179) -
Hereditary cancer-predisposing syndrome Uncertain:1Benign:1
This missense variant replaces arginine with tryptophan at codon 1334 of the MSH6 protein. Computational prediction is inconclusive regarding the impact of this variant on protein structure and function (internally defined REVEL score threshold 0.5 < inconclusive < 0.7, PMID: 27666373). To our knowledge, functional studies have not been reported for this variant. This variant has been reported in an individual affected by early-onset, familial colorectal cancer (PMID: 25559809) and in an individual affected with an unspecified cancer (PMID: 31391288). In a large breast cancer case-control study, this variant was reported in 6/60466 cases and 2/53461 unaffected controls (PMID: 33471991). This variant has been identified in 11/275890 chromosomes in the general population by the Genome Aggregation Database (gnomAD). Different variants affecting the same codon, c.4001G>A (p.Arg1334Gln), c.4001G>C (p.Arg1334Pro), and c.4001G>T (p.Arg1334Leu, are considered to be disease-causing (ClinVar variation ID: 89506, 233214, 2673898), suggesting that this position is important for the protein function. 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. -
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 specified Uncertain:1
Variant summary: MSH6 c.4000C>T (p.Arg1334Trp) results in a non-conservative amino acid change in the encoded protein sequence. Five of five in-silico tools predict a damaging effect of the variant on protein function. 4/4 computational tools predict no significant impact on normal splicing. However, these predictions have yet to be confirmed by functional studies. The variant allele was found at a frequency of 3.7e-05 in 244568 control chromosomes (gnomAD). The available data on variant occurrences in the general population are insufficient to allow any conclusion about variant significance. c.4000C>T has been reported in the literature as somatic occurrence in individuals affected with chronic lymphocytic leukemia, HNSCC, polyposis and endometrial cancer (Landau_2013, Martin_2014, Elsayed_2015) and as germline occurrence in individuals affected with cancer including colorectal, pancreatic and breast cancer (Chubb_2015, Dudley_2018, Li_2020, Dorling_2021), but it was also reported in controls (Dorling_2021). These reports do 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. Six ClinVar submitters (evaluation after 2014) cite the variant as uncertain significance. Based on the evidence outlined above, the variant was classified as uncertain significance. -
Lynch syndrome Uncertain:1
This missense variant replaces arginine with tryptophan at codon 1334 of the MSH6 protein. Computational prediction is inconclusive regarding the impact of this variant on protein structure and function (internally defined REVEL score threshold 0.5 < inconclusive < 0.7, PMID: 27666373). To our knowledge, functional studies have not been reported for this variant. This variant has been reported in an individual affected by early-onset, familial colorectal cancer (PMID: 25559809) and in an individual affected with an unspecified cancer (PMID: 31391288). In a large breast cancer case-control study, this variant was reported in 6/60466 cases and 2/53461 unaffected controls (PMID: 33471991). This variant has been identified in 11/275890 chromosomes in the general population by the Genome Aggregation Database (gnomAD). Different variants affecting the same codon, c.4001G>A (p.Arg1334Gln), c.4001G>C (p.Arg1334Pro), and c.4001G>T (p.Arg1334Leu, are considered to be disease-causing (ClinVar variation ID: 89506, 233214, 2673898), suggesting that this position is important for the protein function. 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