1-45334504-A-G
Variant summary
Our verdict is Pathogenic. Variant got 10 ACMG points: 10P and 0B. PVS1PM2
The NM_001048174.2(MUTYH):c.2T>C(p.Met1?) variant causes a start lost change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.00000124 in 1,613,998 control chromosomes in the GnomAD database, with no homozygous occurrence. Variant has been reported in ClinVar as Conflicting classifications of pathogenicity (no stars).
Frequency
Consequence
NM_001048174.2 start_lost
Scores
Clinical Significance
Conservation
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ACMG classification
Verdict is Pathogenic. Variant got 10 ACMG points.
Transcripts
RefSeq
Ensembl
Gene | Transcript | HGVSc | HGVSp | Effect | Exon rank | TSL | MANE | Protein | Appris | UniProt |
---|---|---|---|---|---|---|---|---|---|---|
MUTYH | ENST00000456914.7 | c.2T>C | p.Met1? | start_lost | Exon 2 of 16 | 1 | NM_001048174.2 | ENSP00000407590.2 | ||
ENSG00000288208 | ENST00000671898.1 | n.548T>C | non_coding_transcript_exon_variant | Exon 6 of 21 | ENSP00000499896.1 |
Frequencies
GnomAD3 genomes AF: 0.00000657 AC: 1AN: 152102Hom.: 0 Cov.: 32
GnomAD3 exomes AF: 0.00000795 AC: 2AN: 251474Hom.: 0 AF XY: 0.0000147 AC XY: 2AN XY: 135914
GnomAD4 exome AF: 6.84e-7 AC: 1AN: 1461778Hom.: 0 Cov.: 31 AF XY: 0.00000138 AC XY: 1AN XY: 727196
GnomAD4 genome AF: 0.00000657 AC: 1AN: 152220Hom.: 0 Cov.: 32 AF XY: 0.0000134 AC XY: 1AN XY: 74426
ClinVar
Submissions by phenotype
Familial adenomatous polyposis 2 Uncertain:3
This sequence change replaces methionine, which is neutral and non-polar, with threonine, which is neutral and polar, at codon 15 of the MUTYH protein (p.Met15Thr). This variant is present in population databases (rs201163858, gnomAD 0.006%). This variant has not been reported in the literature in individuals affected with MUTYH-related conditions. ClinVar contains an entry for this variant (Variation ID: 406849). An algorithm developed to predict the effect of missense changes on protein structure and function (PolyPhen-2) suggests that this variant is likely to be tolerated. This variant disrupts the p.Met15 amino acid residue in MUTYH. Other variant(s) that disrupt this residue have been determined to be pathogenic (PMID: 24691292). This suggests that this residue is clinically significant, and that variants that disrupt this residue are likely to be disease-causing. 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. -
This variant was determined to be of uncertain significance according to ACMG Guidelines, 2015 [PMID:25741868]. -
This missense variant replaces methionine with threonine at codon 15 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 an individual affected with breast cancer (PMID: 33471991). This variant has been identified in 2/251474 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 cancer-predisposing syndrome Pathogenic:1Uncertain:1
This missense variant replaces methionine with threonine at codon 15 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 an individual affected with breast cancer (PMID: 33471991). This variant has been identified in 2/251474 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. -
The p.M15T pathogenic mutation (also known as c.44T>C), located in coding exon 2 of the MUTYH gene, results from a T to C substitution at nucleotide position 44. The methionine at codon 15 is replaced by threonine, an amino acid with similar properties. This variant has been identified with a second MUTYH pathogenic variant in multiple individuals with clinical features of MUTYH-associated polyposis (Ambry internal data). Another alteration at the same codon, p.M15V, has been reported as co-occurring with a pathogenic MUTYH mutation in three siblings with colorectal cancer in their forties and a history of multiple adenomas in their fifties and sixties (Seguí N et al. Gut. 2015 Feb;64:355-6). This amino acid position is highly conserved in available vertebrate species. In addition, this alteration is predicted to be deleterious by in silico analysis. This variant is considered to be rare based on population cohorts in the Genome Aggregation Database (gnomAD). Based on the supporting evidence, this alteration is interpreted as a disease-causing mutation. -
not provided Uncertain:2
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This variant is denoted MUTYH c.44T>C at the cDNA level, p.Met15Thr (M15T) at the protein level, and results in the change of a Methionine to a Threonine (ATG>ACG). This variant has not, to our knowledge, been published in the literature as pathogenic or benign. MUTYH Met15Thr was not observed at a significant allele frequency in large population cohorts (Lek 2016). This variant is located within the RPA binding domain (Ruggieri 2013). In silico analysis, which includes protein predictors and evolutionary conservation, supports a deleterious effect. Based on currently available evidence, it is unclear whether MUTYH Met15Thr is a pathogenic or benign variant. We consider it to be a variant of uncertain significance. Of note, MUTYH-Associated Polyposis (MAP) is a recessive condition associated with two MUTYH pathogenic variants on opposite chromosomes. -
MUTYH-related disorder Uncertain:1
The MUTYH c.2T>C variant is predicted to disrupt the translation initiation site (Start loss). In an alternate transcript (NM_001128425.1), this variant is also known as c.44T>C (p.Met15Thr). This variant was reported in an individual with breast cancer (Breast Cancer Association Consortium et al 2021. PubMed ID: 33471991). This variant has also been identified with second MUTYH pathogenic variant in a family with colorectal cancer (Seguí N et al 2014. PubMed ID: 24691292). In vitro functional studies showed that this variant disrupts the start codon of the two transcripts that encode the nuclear MUTYH isoforms, but does not result in complete loss of mRNA expression (Seguí N et al 2014. PubMed ID: 24691292). This variant is reported in 0.0058% of alleles in individuals of Latino descent in gnomAD and has conflicting interpretations regarding its pathogenicity in ClinVar, ranging from uncertain to pathogenic (https://www.ncbi.nlm.nih.gov/clinvar/variation/406849/). Although we suspect that this variant may be pathogenic, at this time, the clinical significance of this variant is uncertain due to the absence of conclusive functional and genetic evidence. -
Computational scores
Source:
Splicing
Find out detailed SpliceAI scores and Pangolin per-transcript scores at