3-37011837-C-T
Variant summary
Our verdict is Likely benign. Variant got -2 ACMG points: 0P and 2B. BP4BP6
The NM_000249.4(MLH1):c.563C>T(p.Ala188Val) variant causes a missense change. The variant allele was found at a frequency of 0.00000496 in 1,613,416 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_000249.4 missense
Scores
Clinical Significance
Conservation
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ACMG classification
Verdict is Likely_benign. Variant got -2 ACMG points.
Transcripts
RefSeq
Ensembl
Frequencies
GnomAD3 genomes AF: 0.00000657 AC: 1AN: 152094Hom.: 0 Cov.: 32
GnomAD3 exomes AF: 0.0000279 AC: 7AN: 251302Hom.: 0 AF XY: 0.0000147 AC XY: 2AN XY: 135822
GnomAD4 exome AF: 0.00000479 AC: 7AN: 1461322Hom.: 0 Cov.: 30 AF XY: 0.00000275 AC XY: 2AN XY: 727008
GnomAD4 genome AF: 0.00000657 AC: 1AN: 152094Hom.: 0 Cov.: 32 AF XY: 0.00 AC XY: 0AN XY: 74284
ClinVar
Submissions by phenotype
Hereditary cancer-predisposing syndrome Uncertain:3
This missense variant replaces alanine with valine at codon 188 of the MLH1 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 not been reported in individuals affected with MLH1-related disorders in the literature. This variant has been reported in an individual affected with breast cancer (PMID: 33471991). This variant has been identified in 7/251302 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. -
BP4 c.563C>T, located in exon 7 of the MLH1 gene, is predicted to result in the substitution of alanine by valine at codon 188, p.(Ala188Val). This variant is found in 7/268097 alleles at a frequency of 0.002% in the gnomAD v2.1.1 database, non-cancer dataset. Computational tools for this variant suggest no significant impact on splicing and does not affect the protein function (MAPP+PolyPhen-2 prior probability for pathogenicity: 0.01) (BP4). To our knowledge, neither relevant clinical data nor well-established functional studies have been reported for this variant. This variant has been reported in the ClinVar database (6x uncertain significance, 1x likely benign), it has not been reported in LOVD, and it has not been classified by InSiGHT. Based on currently available information, the variant c.563C>T should be considered an uncertain significance variant, according to MMR-specific InSIGHT Guidelines, Draft v3.1. -
The p.A188V variant (also known as c.563C>T), located in coding exon 7 of the MLH1 gene, results from a C to T substitution at nucleotide position 563. The alanine at codon 188 is replaced by valine, an amino acid with similar properties. This amino acid position is poorly 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. -
Colorectal cancer, hereditary nonpolyposis, type 2 Uncertain:1Benign:1
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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]. -
not provided Uncertain:1Benign:1
The frequency of this variant in the general population, 0.00017 (6/34586 chromosomes, http://gnomad.broadinstitute.org), is uninformative in assessment of its pathogenicity. In the published literature, the variant has been reported in individuals with breast cancer (PMID: 33471991 (2021), LOVD https://databases.lovd.nl/shared/variants/MLH1). 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, which includes protein predictors and evolutionary conservation, supports that this variant does not alter protein structure/function; Has not been previously published as pathogenic or benign to our knowledge -
not specified Uncertain:1
Variant summary: MLH1 c.563C>T (p.Ala188Val) results in a non-conservative amino acid change in 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 2.8e-05 in 251302 control chromosomes. The available data on variant occurrences in the general population are insufficient to allow any conclusion about variant significance. c.563C>T has been reported in the literature as a VUS in at-least one individual with cancer within a cohort undergoing germline multigene panel testing (example, Li_2020). These report(s) 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. The following publication has been ascertained in the context of this evaluation (PMID: 31391288). ClinVar contains an entry for this variant (Variation ID: 419939). Based on the evidence outlined above, the variant was classified as uncertain significance. -
Muir-Torré syndrome;C1333991:Colorectal cancer, hereditary nonpolyposis, type 2;C5399763:Mismatch repair cancer syndrome 1 Uncertain:1
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Lynch syndrome Uncertain:1
This missense variant replaces alanine with valine at codon 188 of the MLH1 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 not been reported in individuals affected with hereditary cancer in the literature. This variant has been identified in 7/251302 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. -
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