rs786202458
Variant summary
Our verdict is Likely benign. Variant got -5 ACMG points: 0P and 5B. BP4_StrongBP6
The NM_001167617.3(MLH1):c.-508C>G variant causes a 5 prime UTR premature start codon gain change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.0000167 in 1,614,080 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_001167617.3 5_prime_UTR_premature_start_codon_gain
Scores
Clinical Significance
Conservation
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ACMG classification
Verdict is Likely_benign. Variant got -5 ACMG points.
Transcripts
RefSeq
Ensembl
Frequencies
GnomAD3 genomes AF: 0.0000328 AC: 5AN: 152218Hom.: 0 Cov.: 33
GnomAD3 exomes AF: 0.00000398 AC: 1AN: 251472Hom.: 0 AF XY: 0.00 AC XY: 0AN XY: 135922
GnomAD4 exome AF: 0.0000150 AC: 22AN: 1461862Hom.: 0 Cov.: 31 AF XY: 0.0000179 AC XY: 13AN XY: 727236
GnomAD4 genome AF: 0.0000328 AC: 5AN: 152218Hom.: 0 Cov.: 33 AF XY: 0.0000403 AC XY: 3AN XY: 74364
ClinVar
Submissions by phenotype
not specified Uncertain:2
DNA sequence analysis of the MLH1 gene demonstrated a sequence change, c.9C>G, in exon 1 that results in an amino acid change, p.Phe3Leu. This sequence change has been described in the gnomAD database with frequency of 0.0023% in the non-Finnish European subpopulation (dbSNP rs779759678). The p.Phe3Leu change affects a poorly conserved amino acid residue located in a domain of the MLH1 protein that is not known to be functional. The p.Phe3Leu substitution appears to be benign using several in-silico pathogenicity prediction tools (SIFT, PolyPhen2, Align GVGD, REVEL). This sequence change does not appear to have been previously described in individuals with MLH1-related disorders. Due to insufficient evidences and the lack of functional studies, the clinical significance of the p.Phe3Leu change remains unknown at this time. -
Variant summary: MLH1 c.9C>G (p.Phe3Leu) results in a non-conservative amino acid change in the encoded protein sequence. Four of five in-silico tools predict a benign effect of the variant on protein function. The variant allele was found at a frequency of 4e-06 in 251472 control chromosomes (gnomAD). The available data on variant occurrences in the general population are insufficient to allow any conclusion about variant significance. To our knowledge, no occurrence of c.9C>G in individuals affected with Hereditary Non-Polyposis Colon Cancer and no experimental evidence demonstrating its impact on protein function have been reported. Four ClinVar submitters (evaluation after 2014) cite the variant as likely benign (n=2) and as uncertain significance (n=2). Based on the evidence outlined above, the variant was classified as uncertain significance. -
not provided Uncertain:2
Not observed at significant frequency in large population cohorts (gnomAD); In silico analysis supports that this missense variant does not alter protein structure/function; In-silico analysis is inconclusive as to whether the variant alters gene splicing. In the absence of RNA/functional studies, the actual effect of this sequence change is unknown.; Not observed in any pancreatic cancer cases but was observed in an unaffected control (Mizukami 2020); This variant is associated with the following publications: (PMID: 22753075, 32980694) -
The MLH1 c.9C>G (p.Phe3Leu) variant has been reported in the published literature in reportedly healthy individuals in a large pancreatic cancer study (PMID: 32980694 (2020)) and a biliary tract cancer study (PMID: 36243179 (2022)). In a large scale breast cancer association study, this variant has been observed in one breast cancer case and in one reportedly healthy individual (PMID: 33471991 (2021), see also LOVD (http://databases.lovd.nl/shared)). The frequency of this variant in the general population, 0.000023 (3/129188 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 benign. Based on the available information, we are unable to determine the clinical significance of this variant. -
Colorectal cancer, hereditary nonpolyposis, type 2 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]. -
The MLH1 c.9C>G (p.Phe3Leu) missense change has a maximum subpopulation frequency of 0.0023% 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 to our knowledge functional studies have not been performed. To our knowledge, this variant has not been reported in individuals with Lynch syndrome or constitutional mismatch repair deficiency syndrome. 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. -
Hereditary cancer-predisposing syndrome Benign:2
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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. -
Lynch syndrome Benign: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