chr1-45332179-C-T
Variant summary
Our verdict is Uncertain significance. The variant received 2 ACMG points: 2P and 0B. PM1
The NM_001048174.2(MUTYH):c.836G>A(p.Arg279Gln) variant causes a missense change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.00012 in 1,614,188 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a benign outcome for this variant. 16/24 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. R279L) has been classified as Likely benign.
Frequency
Consequence
NM_001048174.2 missense
Scores
Clinical Significance
Conservation
Publications
- familial adenomatous polyposis 2Inheritance: AD, AR Classification: DEFINITIVE, STRONG, SUPPORTIVE Submitted by: Orphanet, Labcorp Genetics (formerly Invitae), Genomics England PanelApp, ClinGen, G2P
- colorectal cancerInheritance: AD Classification: NO_KNOWN Submitted by: ClinGen
- familial ovarian cancerInheritance: AD, AR Classification: NO_KNOWN Submitted by: ClinGen
- hereditary breast carcinomaInheritance: AD, AR Classification: NO_KNOWN Submitted by: ClinGen
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ACMG classification
Our verdict: Uncertain_significance. The variant received 2 ACMG points.
Transcripts
RefSeq
Ensembl
Gene | Transcript | HGVSc | HGVSp | Effect | Exon rank | TSL | MANE | Protein | Appris | UniProt |
---|---|---|---|---|---|---|---|---|---|---|
MUTYH | ENST00000456914.7 | c.836G>A | p.Arg279Gln | missense_variant | Exon 10 of 16 | 1 | NM_001048174.2 | ENSP00000407590.2 | ||
ENSG00000288208 | ENST00000671898.1 | n.1424G>A | non_coding_transcript_exon_variant | Exon 14 of 21 | ENSP00000499896.1 |
Frequencies
GnomAD3 genomes AF: 0.0000854 AC: 13AN: 152192Hom.: 0 Cov.: 33 show subpopulations
GnomAD2 exomes AF: 0.0000756 AC: 19AN: 251290 AF XY: 0.0000589 show subpopulations
GnomAD4 exome AF: 0.000124 AC: 181AN: 1461878Hom.: 0 Cov.: 36 AF XY: 0.000116 AC XY: 84AN XY: 727246 show subpopulations
Age Distribution
GnomAD4 genome AF: 0.0000854 AC: 13AN: 152310Hom.: 0 Cov.: 33 AF XY: 0.0000537 AC XY: 4AN XY: 74472 show subpopulations
Age Distribution
ClinVar
Submissions by phenotype
Familial adenomatous polyposis 2 Uncertain:3
This sequence change replaces arginine, which is basic and polar, with glutamine, which is neutral and polar, at codon 307 of the MUTYH protein (p.Arg307Gln). This variant is present in population databases (rs140156029, gnomAD 0.02%). This missense change has been observed in individual(s) with breast cancer or an unspecified cancer (PMID: 25186627, 28873162). ClinVar contains an entry for this variant (Variation ID: 141135). An algorithm developed to predict the effect of missense changes on protein structure and function outputs the following: PolyPhen-2: "Benign". The glutamine amino acid residue is found in multiple mammalian species, which suggests that this missense change does not adversely affect protein function. RNA analysis performed to evaluate the impact of this missense change on mRNA splicing indicates it does not significantly alter splicing (internal data). In summary, the available evidence is currently insufficient to determine the role of this variant in disease. Therefore, it has been classified as a Variant of Uncertain Significance. -
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The MUTYH c.920G>A (p.Arg307Gln) missense change has a maximum subpopulation frequency of 0.024% in gnomAD v2.1.1 (https://gnomad.broadinstitute.org). The in silico tool REVEL predicts a benign effect on protein function, but to our knowledge this prediction has not been confirmed by functional studies. To our knowledge, this variant has not been reported in individuals with MUTYH-associated polyposis. 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 Uncertain:1Benign: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. -
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not provided Uncertain:2
The MUTYH c.920G>A (p.Arg307Gln) variant has been reported in the published literature in individuals with breast cancer (PMID: 25186627 (2015), 33471991 (2021), see also LOVD (http://databases.lovd.nl/shared/genes/MUTYH)), colorectal cancer (PMID: 30267214 (2018), 28944238 (2017)) or an unspecified cancer (PMID: 28873162 (2017)). This variant has also been reported in unaffected individuals (PMID: 33471991 (2021), see also LOVD (http://databases.lovd.nl/shared/genes/MUTYH)). The frequency of this variant in the general population, 0.00024 (6/24920 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. -
In silico analysis, which includes protein predictors and evolutionary conservation, supports that this variant does not alter protein structure/function; In silico analysis, which includes splice predictors and evolutionary conservation, suggests this variant may impact gene splicing. In the absence of RNA/functional studies, the actual effect of this sequence change is unknown.; Observed in individuals with breast cancer and advanced cancer of unspecified type (Tung 2015, Mandelker 2017); This variant is associated with the following publications: (PMID: 28944238, 11092888, 11160897, 16879101, 20816984, 28873162, 25186627) -
not specified Uncertain:1
Variant summary: MUTYH c.920G>A (p.Arg307Gln) results in a 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 7.6e-05 in 251290 control chromosomes. This frequency is not significantly higher than estimated for a pathogenic variant in MUTYH causing MUTYH-Associated Polyposis (7.6e-05 vs 0.0046), allowing no conclusion about variant significance. c.920G>A has been reported in the literature as a VUS in settings of multigene panel testing in individuals affected with breast cancer/unspecified advanced cancer (e.g. Mandelker_2017, Tung_2015). These report(s) do not provide unequivocal conclusions about association of the variant with MUTYH-Associated Polyposis. A co-occurrence with a pathogenic variant has been observed at our laboratory (BRCA1 c.2457delC, p.Asp821fsX25; Internal testing). 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: 28944238, 28873162, 25186627). ClinVar contains an entry for this variant (Variation ID: 141135). Based on the evidence outlined above, the variant was classified as uncertain significance. -
Computational scores
Source:
Splicing
Find out detailed SpliceAI scores and Pangolin per-transcript scores at