2-47799877-A-G
Variant summary
Our verdict is Likely benign. The variant received -1 ACMG points: 0P and 1B. BP6
The NM_000179.3(MSH6):c.1894A>G(p.Lys632Glu) variant causes a missense change involving the alteration of a conserved nucleotide. The variant allele was found at a frequency of 0.0000112 in 1,614,086 control chromosomes in the GnomAD database, with no homozygous occurrence. 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. K632T) 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
Ensembl
Frequencies
GnomAD3 genomes AF: 0.0000131 AC: 2AN: 152228Hom.: 0 Cov.: 32 show subpopulations
GnomAD2 exomes AF: 0.0000160 AC: 4AN: 250718 AF XY: 0.0000295 show subpopulations
GnomAD4 exome AF: 0.0000109 AC: 16AN: 1461858Hom.: 0 Cov.: 34 AF XY: 0.0000151 AC XY: 11AN XY: 727234 show subpopulations
Age Distribution
GnomAD4 genome AF: 0.0000131 AC: 2AN: 152228Hom.: 0 Cov.: 32 AF XY: 0.0000269 AC XY: 2AN XY: 74370 show subpopulations
Age Distribution
ClinVar
Submissions by phenotype
Hereditary cancer-predisposing syndrome Uncertain:3
The p.K632E variant (also known as c.1894A>G), located in coding exon 4 of the MSH6 gene, results from an A to G substitution at nucleotide position 1894. The lysine at codon 632 is replaced by glutamic acid, an amino acid with similar properties. This variant was reported in a female proband with synchronous ovarian and endometrial cancers diagnosed at age 78 that showed absent MSH6 expression by immunohistochemistry while RNA studies demonstrated no impact on splicing when compared to controls (Morak M et al. Eur J Hum Genet, 2022 Sep;30:1051-1059). This amino acid position is highly conserved in available vertebrate species. In addition, this alteration is predicted to be deleterious by in silico analysis. Since supporting evidence is limited at this time, the clinical significance of this alteration remains unclear. -
This missense variant replaces lysine with glutamic acid at codon 632 of the MSH6 protein. Computational prediction suggests that this variant may have deleterious impact on protein structure and function (internally defined REVEL score threshold >= 0.7, PMID: 27666373). 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 5/282122 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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Lynch syndrome 5 Uncertain:1Benign: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. -
This variant is considered likely benign. Homozygosity for this variant has been confirmed in one or more individuals lacking clinical features consistent with gene-specific recessive disease, indicating that this variant is unlikely to be pathogenic. -
not specified Uncertain:1
Variant summary: MSH6 c.1894A>G (p.Lys632Glu) results in a 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 damaging effect of the variant on protein function. The variant allele was found at a frequency of 1.8e-05 in 276694 control chromosomes in gnomAD. This frequency is not significantly higher than expected for a pathogenic variant in MSH6 causing Lynch Syndrome (1.8e-05 vs 1.40E-04), allowing no conclusion about variant significance. To our knowledge, no occurrence of c.1894A>G in individuals affected with Lynch Syndrome and no experimental evidence demonstrating its impact on protein function have been reported. Three clinical diagnostic laboratories have submitted clinical-significance assessments for this variant to ClinVar after 2014 without evidence for independent evaluation. All laboratories classified 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 lysine with glutamic acid at codon 632 of the MSH6 protein. Computational prediction suggests that this variant may have deleterious impact on protein structure and function (internally defined REVEL score threshold >= 0.7, PMID: 27666373). 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 5/282122 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 provided Uncertain:1
Not observed at significant frequency in large population cohorts (gnomAD); In silico analysis supports that this missense variant has a deleterious effect on protein structure/function; Published functional studies suggest this variant does not cause a significant effect on splicing (Morak et al., 2022); Observed in an individual with ovarian and endometrial cancer with concordant tumor studies (Morak et al., 2022); This variant is associated with the following publications: (PMID: 24212087, 17531815, 21120944, 35676339) -
Malignant tumor of breast Uncertain:1
The MSH6 p.Lys632Glu variant was not identified in the literature nor was it identified in the UMD-LSDB or Mismatch Repair Genes Variant Database. The variant was identified in dbSNP (ID: rs755847154) as “With Uncertain significance allele”, and ClinVar (classified as uncertain significance by Invitae, Ambry Genetics, Counsyl and Institute for Biomarker Research). The variant was identified in control databases in 5 of 276694 chromosomes at a frequency of 0.00002 (Genome Aggregation Database Feb 27, 2017), observed in the following populations: Latino in 1 of 34406 chromosomes (freq: 0.00003) and European Non-Finnish in 4 of 126322 chromosomes (freq: 0.00003), while not observed in the African, Other, Ashkenazi Jewish, East Asian, Finnish, or South Asian populations. The p.Lys632 residue is conserved in mammals and computational analyses (PolyPhen-2, SIFT, AlignGVGD, BLOSUM, MutationTaster) provide inconsistent predictions regarding the impact to the protein; this information is not very predictive of pathogenicity. The variant occurs outside of the splicing consensus sequence and in silico or computational prediction software programs (SpliceSiteFinder, MaxEntScan, NNSPLICE, GeneSplicer,) 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