rs200938360
Variant summary
Our verdict is Likely benign. The variant received -1 ACMG points: 2P and 3B. PM1BP4_ModerateBP6
The NM_000179.3(MSH6):c.1364A>C(p.Asn455Thr) variant causes a missense change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.0000304 in 1,613,910 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a benign outcome for this variant. 16/22 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. N455S) 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 -1 ACMG points.
Transcripts
RefSeq
| Gene | Transcript | HGVSc | HGVSp | Effect | Exon rank | MANE | Protein | UniProt |
|---|---|---|---|---|---|---|---|---|
| MSH6 | NM_000179.3 | c.1364A>C | p.Asn455Thr | 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.1364A>C | p.Asn455Thr | missense_variant | Exon 4 of 10 | 1 | NM_000179.3 | ENSP00000234420.5 |
Frequencies
GnomAD3 genomes AF: 0.0000394 AC: 6AN: 152150Hom.: 0 Cov.: 32 show subpopulations
GnomAD2 exomes AF: 0.0000597 AC: 15AN: 251056 AF XY: 0.0000590 show subpopulations
GnomAD4 exome AF: 0.0000294 AC: 43AN: 1461760Hom.: 0 Cov.: 34 AF XY: 0.0000358 AC XY: 26AN XY: 727186 show subpopulations
Age Distribution
GnomAD4 genome AF: 0.0000394 AC: 6AN: 152150Hom.: 0 Cov.: 32 AF XY: 0.0000404 AC XY: 3AN XY: 74330 show subpopulations
Age Distribution
ClinVar
Submissions by phenotype
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 asparagine with threonine at codon 455 of the MSH6 protein. Computational prediction suggests that this variant may not impact protein structure and function. To our knowledge, functional studies have not been reported for this variant. This variant has not been reported in individuals affected with MSH6-related disorders in the literature. This variant has been identified in 15/251056 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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not provided Uncertain:2
The MSH6 c.1364A>C (p.Asn455Thr) variant has been reported in individuals with head and neck squamous cell carcinoma (PMID: 26689913 (2015)), bladder cancer (PMID: 26845104 (2016)), pancreatic cancer (PMID: 30883245 (2019)), and thyroid cancer and melanoma (PMID: 32885271 (2021)). This variant has also been observed in reportedly healthy individuals (PMID: 22703879 (2012), 36243179 (2022)). The frequency of this variant in the general population, 0.00079 (8/10070 chromosomes in Ashkenazi Jewish subpopulation (Genome Aggregation Database, http://gnomad.broadinstitute.org)), is higher than would generally be expected for pathogenic variants in this gene. 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. -
Reported in individuals with various cancers such as pancreatic, bladder, thyroid, head/neck, and melanoma (PMID: 26689913, 26845104, 29684080, 30883245, 32885271); In silico analysis indicates that this missense variant does not alter protein structure/function; This variant is associated with the following publications: (PMID: 26689913, 23621914, 22703879, 26845104, 28873162, 29684080, 30883245, 21120944, 17531815, 30267214, 36243179, 32885271) -
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]. -
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. -
not specified Uncertain:1
Variant summary: MSH6 c.1364A>C (p.Asn455Thr) results in a non-conservative amino acid change located in the DNA mismatch repair protein MutS-like, N-terminal domain of the encoded protein sequence. Three of five in-silico tools predict a benign effect of the variant on protein function. The variant allele was found at a frequency of 6e-05 in 251056 control chromosomes (gnomAD). This frequency is not significantly higher than estimated for a pathogenic variant in MSH6 causing Hereditary Nonpolyposis Colorectal Cancer (6e-05 vs 0.00014), allowing no conclusion about variant significance. c.1364A>C has been reported in the literature in individuals affected with Hereditary Nonpolyposis Colorectal Cancer or other type of cancer (examples: Shirts_2015, Lu_2015, Abe_2019). These report(s) do not provide unequivocal conclusions about association of the variant with Hereditary Nonpolyposis Colorectal Cancer. 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: 30883245, 22703879, 26689913, 26845104, 23621914). Nine submitters have cited clinical-significance assessments for this variant to ClinVar after 2014 and classified the variant as VUS (n=6) or likely benign (n=3). Based on the evidence outlined above, the variant was classified as uncertain significance. -
Lynch syndrome Uncertain:1
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Malignant tumor of breast Uncertain:1
The MSH6 p.Asn455Thr variant was identified in 1 of 1142 control chromosomes (frequency: 0.001) in individuals with atherosclerosis phenotypes undergoing secondary (incidental) variant detection by exome sequencing (Johnston 2012_ 22703879). A bioinformatic tool, CoDP ((Combination of the Different Properties), that integrates 3 prediction models (MAPP, PolyPhen-2 and SIFT) and 2 structural properties, found that the variant had no impact on the MSH6 protein (Terui 2013 23621914). The variant was also identified in dbSNP (ID: rs200938360) “With Uncertain significance allele”, ClinVar (as uncertain significance by Ambry Genetics, Invitae, University of Washington, GeneDx, and Counsyl), Clinvitae (4x as uncertain significance), LOVD 3.0 (1x), and in control databases in 13 of 245818 chromosomes at a frequency of 0.00005 (Genome Aggregation Database Feb 27, 2017). Breakdown of the observations by population include African in 1 of 15302 chromosomes (freq: 0.00007), Latino in 4 of 33544 chromosomes (freq: 0.0001), European Non-Finnish in 1 of 111452 chromosomes (freq: 0.000009), Ashkenazi Jewish in 7 of 9842 chromosomes (freq: 0.0007), while not observed in the Other, East Asian, European Finnish and South Asian populations. The variant was not identified in Cosmic, MutDB, UMD-LSDB, Insight Colon Cancer Gene Variant Database, Zhejiang Colon Cancer Database, Mismatch Repair Genes Variant Database, and Insight Hereditary Tumors Database. The p.Asn455 residue is conserved in mammals but not in more distantly related organisms however four out of five computational analyses (PolyPhen-2, SIFT, AlignGVGD, BLOSUM, MutationTaster) do not suggest a high likelihood the variant Thr impacts the protein; this information is not predictive enough to rule out pathogenicity. The variant occurs outside of the splicing consensus sequence and in silico or computational prediction software programs (SpliceSiteFinder, MaxEntScan, NNSPLICE, GeneSplicer, HumanSpliceFinder) do not predict a difference in splicing. 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. -
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