1-45331488-C-T
Variant summary
Our verdict is Uncertain significance. The variant received 1 ACMG points: 2P and 1B. PM1BP4
The NM_001048174.2(MUTYH):c.1171G>A(p.Ala391Thr) variant causes a missense change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.0000874 in 1,614,058 control chromosomes in the GnomAD database, including 1 homozygotes. In-silico tool predicts 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. A391V) has been classified as Uncertain significance.
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 1 ACMG points.
Transcripts
RefSeq
Ensembl
| Gene | Transcript | HGVSc | HGVSp | Effect | Exon rank | TSL | MANE | Protein | Appris | UniProt |
|---|---|---|---|---|---|---|---|---|---|---|
| MUTYH | ENST00000456914.7 | c.1171G>A | p.Ala391Thr | missense_variant | Exon 13 of 16 | 1 | NM_001048174.2 | ENSP00000407590.2 | ||
| ENSG00000288208 | ENST00000671898.1 | n.1759G>A | non_coding_transcript_exon_variant | Exon 17 of 21 | ENSP00000499896.1 |
Frequencies
GnomAD3 genomes AF: 0.0000985 AC: 15AN: 152232Hom.: 1 Cov.: 33 show subpopulations
GnomAD2 exomes AF: 0.0000637 AC: 16AN: 251158 AF XY: 0.0000663 show subpopulations
GnomAD4 exome AF: 0.0000862 AC: 126AN: 1461826Hom.: 0 Cov.: 33 AF XY: 0.0000715 AC XY: 52AN XY: 727212 show subpopulations
Age Distribution
GnomAD4 genome AF: 0.0000985 AC: 15AN: 152232Hom.: 1 Cov.: 33 AF XY: 0.0000807 AC XY: 6AN XY: 74372 show subpopulations
Age Distribution
ClinVar
Submissions by phenotype
Familial adenomatous polyposis 2 Uncertain:4Benign:1
This missense variant replaces alanine with threonine at codon 419 of the MUTYH 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 been reported in individuals affected with MUTYH-associated polyposis, colorectal cancer, glioblastoma, and suspected Lynch syndrome (PMID: 17581577, 25980754, 26689913, Insight-database.org), This variant has been identified in 19/282560 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. -
This variant was observed in the ICSL laboratory as part of a predisposition screen in an ostensibly healthy population. It had not been previously curated by ICSL or reported in the Human Gene Mutation Database (HGMD: prior to June 1st, 2018), and was therefore a candidate for classification through an automated scoring system. Utilizing variant allele frequency, disease prevalence and penetrance estimates, and inheritance mode, an automated score was calculated to assess if this variant is too frequent to cause the disease. Based on the score, this variant could not be ruled out of causing disease and therefore its association with disease required further investigation. A literature search was performed for the gene, cDNA change, and amino acid change (if applicable). No publications were found based on this search. This variant was therefore classified as a variant of unknown significance for this disease. -
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. -
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Hereditary cancer-predisposing syndrome Uncertain:3Benign:1
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The missense variant NM_001128425.2(MUTYH):c.1255G>A (p.Ala419Thr) causes a change at the same amino acid residue as a previously established pathogenic variant. The p.Ala419Thr variant is observed in 16/113,578 (0.0141%) alleles from individuals of gnomAD Non Finnish European background in gnomAD. There is a small physicochemical difference between alanine and threonine, which is not likely to impact secondary protein structure as these residues share similar properties. For these reasons, this variant has been classified as Uncertain Significance. -
This alteration is classified as 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 alanine with threonine at codon 419 of the MUTYH 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 been reported in individuals affected with MUTYH-associated polyposis, colorectal cancer, glioblastoma, and suspected Lynch syndrome (PMID: 17581577, 25980754, 26689913, Insight-database.org), This variant has been identified in 19/282560 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:2
The MUTYH c.1255G>A (p.Ala419Thr) variant has been reported in the published literature in individuals with suspected Lynch syndrome (PMID: 25980754 (2015)) and glioblastoma (PMID: 26689913 (2015)). It has also been observed in several individuals with breast cancer and in reportedly healthy individuals in a case-control study (PMID: 33471991 (2021), see also LOVD (http://databases.lovd.nl/shared)). The frequency of this variant in the general population, 0.00013 (17/129004 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. -
Not observed at significant frequency in large population cohorts (gnomAD); In silico analysis supports that this missense variant does not alter protein structure/function; Observed in individuals with Lynch-associated cancers and/or polyps, breast cancer, or glioblastoma, and also observed in control groups (PMID: 26689913, 33471991, 25980754); This variant is associated with the following publications: (PMID: 25980754, 19725997, 17581577, 17161978, 26689913, 33122805, 33471991, 23108399) -
not specified Uncertain:1
Variant summary: MUTYH c.1255G>A (p.Ala419Thr) results in a non-conservative amino acid change located in the C-terminal domain (IPR029119) and NUDIX hydrolase domains (IPR000086) 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 6.4e-05 in 251158 control chromosomes (gnomAD). This frequency is not significantly higher than expected for a pathogenic variant in MUTYH causing MUTYH-associated Polyposis (6.4e-05 vs 0.0046), allowing no conclusion about variant significance. To our knowledge, there are no reports of c.1255G>A in individuals affected with MUTYH-associated Polyposis and no experimental evidence demonstrating an impact on protein function in the literature. c.1255G>A has been reported in an individual with Lynch syndrome (Yurgelun_2015) and in an individual with glioblastoma mulitforme (Lu_2015). These reports do not provide unequivocal conclusions about association of the variant with MUTYH-associated Polyposis. Eight other ClinVar submitters (evaluation after 2014) cite the variant as uncertain significance. Based on the evidence outlined above, the variant was classified as uncertain significance. -
Neoplasm of stomach;C0206711:Pilomatrixoma;C3272841:Familial adenomatous polyposis 2 Uncertain:1
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Computational scores
Source:
Splicing
Find out detailed SpliceAI scores and Pangolin per-transcript scores at