rs876658641
Variant summary
Our verdict is Uncertain significance. The variant received 4 ACMG points: 4P and 0B. PM2PP3PP5
The NM_001048174.2(MUTYH):c.420G>A(p.Glu140Glu) variant causes a splice region, synonymous change involving the alteration of a conserved nucleotide. The variant allele was found at a frequency of 0.00000205 in 1,461,856 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a benign outcome for this variant. 3/3 splice prediction tools predicting alterations to normal splicing. Variant has been reported in ClinVar as Conflicting classifications of pathogenicity (no stars).
Frequency
Consequence
NM_001048174.2 splice_region, synonymous
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 4 ACMG points.
Transcripts
RefSeq
Ensembl
| Gene | Transcript | HGVSc | HGVSp | Effect | Exon rank | TSL | MANE | Protein | Appris | UniProt |
|---|---|---|---|---|---|---|---|---|---|---|
| MUTYH | ENST00000456914.7 | c.420G>A | p.Glu140Glu | splice_region_variant, synonymous_variant | Exon 6 of 16 | 1 | NM_001048174.2 | ENSP00000407590.2 | ||
| ENSG00000288208 | ENST00000671898.1 | n.1008G>A | splice_region_variant, non_coding_transcript_exon_variant | Exon 10 of 21 | ENSP00000499896.1 |
Frequencies
GnomAD3 genomes Cov.: 32
GnomAD2 exomes AF: 0.00000399 AC: 1AN: 250620 AF XY: 0.00 show subpopulations
GnomAD4 exome AF: 0.00000205 AC: 3AN: 1461856Hom.: 0 Cov.: 35 AF XY: 0.00000275 AC XY: 2AN XY: 727234 show subpopulations
Age Distribution
GnomAD4 genome Cov.: 32
ClinVar
Submissions by phenotype
Familial adenomatous polyposis 2 Pathogenic:1Uncertain:2
This variant causes a G>A nucleotide substitution in the last nucleotide of exon 6 in the MUTYH gene. Splice site prediction tools suggest that this variant may impact RNA splicing, potentially disrupting the consensus donor splice site for this exon. This variant has been reported to impact RNA splicing by an external laboratory, however, detailed data are not available for review (ClinVar SCV000274164.6). This variant has been reported in an individual affected with early-onset colorectal cancer (PMID: 33359728). This variant has been identified in 1/250620 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 sequence change affects codon 168 of the MUTYH mRNA. It is a 'silent' change, meaning that it does not change the encoded amino acid sequence of the MUTYH protein. This variant also falls at the last nucleotide of exon 6, which is part of the consensus splice site for this exon. This variant is present in population databases (no rsID available, gnomAD 0.003%). This variant has been observed in individual(s) with MUTYH-related conditions (PMID: 33359728). ClinVar contains an entry for this variant (Variation ID: 230572). Variants that disrupt the consensus splice site are a relatively common cause of aberrant splicing (PMID: 17576681, 9536098). Algorithms developed to predict the effect of sequence changes on RNA splicing suggest that this variant may disrupt the consensus splice site. 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. -
Variant summary: MUTYH c.504G>A (p.Glu168Glu) alters a conserved nucleotide located close to a canonical splice site and therefore could affect mRNA splicing, leading to a significantly altered protein sequence. Several computational tools predict a significant impact on normal splicing: Three predict the variant weakens a 5' donor site. One predicts the variant abolishes a 5' splicing donor site. One predicts the variant creates a 3' acceptor site. Internal RNA splicing evidence suggests that this variant affects mRNA splicing, resulting primarily in skipping of exon 6, which is expected to be in frame (internal data). A variant within exon 6 (NM_001128425:c.470C>T, p.Pro157Leu) has been classified as pathogenic, suggesting that loss of this region of the protein is deleterious. The variant allele was found at a frequency of 4e-06 in 250620 control chromosomes. c.504G>A has been observed in the homozygous or unknown state in individual(s) affected with clinical features of MUTYH-Associated Polyposis but not meeting internal criteria for evidence application (Dharwadkar_2023, internal data). Further, a different laboratory has reported this variant in the presumed compound heterozygous state with a pathogenic 2nd variant in at least 1 individual with clinical features of MUTYH-associated polyposis (MAP) (Ambry Genetics, ClinVar), however these data could not be independently reviewed. These report(s) do not provide unequivocal conclusions about association of the variant with MUTYH-Associated Polyposis. The following publication has been ascertained in the context of this evaluation (PMID: 33359728). ClinVar contains an entry for this variant (Variation ID: 230572). Based on the evidence outlined above, the variant was classified as likely pathogenic. -
Hereditary cancer-predisposing syndrome Pathogenic:1Uncertain:1
This variant causes a G>A nucleotide substitution in the last nucleotide of exon 6 in the MUTYH gene. Splice site prediction tools suggest that this variant may impact RNA splicing, potentially disrupting the consensus donor splice site for this exon. This variant has been reported to impact RNA splicing by an external laboratory, however, detailed data are not available for review (ClinVar SCV000274164.6). This variant has been reported in an individual affected with early-onset colorectal cancer (PMID: 33359728). This variant has been identified in 1/250620 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 c.504G>A variant (also known as p.E168E), located in coding exon 6 of the MUTYH gene, results from a G to A substitution at nucleotide position 504. This nucleotide substitution does not change the amino acid at codon 168. However, this change occurs in the last base pair of coding exon 6, which makes it likely to have some effect on normal mRNA splicing. This variant has been detected in conjunction with a MUTYH pathogenic variant in an individual with clinical features of MUTYH-associated polyposis (MAP); however, the phase of the two variants is unknown (Ambry internal data). This variant is considered to be rare based on population cohorts in the Genome Aggregation Database (gnomAD). This nucleotide position is highly conserved in available vertebrate species. In silico splice site analysis predicts that this alteration will weaken the native splice donor site. RNA studies have demonstrated that this alteration results in abnormal splicing in the set of samples tested (Ambry internal data). The resulting transcript preserves the reading frame and is not expected to trigger nonsense-mediated mRNA decay; however, the impacted region is critical for protein function and a significant portion of the protein is affected (Ambry internal data). Based on the majority of available evidence to date, this variant is likely to be pathogenic. -
Computational scores
Source:
Splicing
Find out detailed SpliceAI scores and Pangolin per-transcript scores at