rs531178000
Variant summary
Our verdict is Uncertain significance. The variant received 0 ACMG points: 0P and 0B.
The NM_000038.6(APC):c.6977G>A(p.Arg2326Gln) variant causes a missense change. The variant allele was found at a frequency of 0.0000174 in 1,613,718 control chromosomes in the GnomAD database, with no homozygous occurrence. 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. R2326G) has been classified as Uncertain significance.
Frequency
Consequence
NM_000038.6 missense
Scores
Clinical Significance
Conservation
Publications
- classic or attenuated familial adenomatous polyposisInheritance: AD Classification: DEFINITIVE Submitted by: ClinGen
- desmoid tumorInheritance: AD Classification: DEFINITIVE, STRONG Submitted by: G2P, Genomics England PanelApp
- familial adenomatous polyposis 1Inheritance: AD Classification: DEFINITIVE, STRONG, MODERATE Submitted by: Genomics England PanelApp, Labcorp Genetics (formerly Invitae), Ambry Genetics
- gastric adenocarcinoma and proximal polyposis of the stomachInheritance: AD Classification: DEFINITIVE, STRONG, SUPPORTIVE Submitted by: Ambry Genetics, Labcorp Genetics (formerly Invitae), ClinGen, Orphanet
- sarcomaInheritance: AD Classification: MODERATE Submitted by: Genomics England PanelApp
- APC-related attenuated familial adenomatous polyposisInheritance: AD Classification: SUPPORTIVE Submitted by: Orphanet
- Turcot syndrome with polyposisInheritance: AD Classification: SUPPORTIVE Submitted by: Orphanet
- Cenani-Lenz syndactyly syndromeInheritance: AR Classification: SUPPORTIVE Submitted by: Orphanet
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ACMG classification
Our verdict: Uncertain_significance. The variant received 0 ACMG points.
Transcripts
RefSeq
| Gene | Transcript | HGVSc | HGVSp | Effect | Exon rank | MANE | Protein | UniProt |
|---|---|---|---|---|---|---|---|---|
| APC | NM_000038.6 | c.6977G>A | p.Arg2326Gln | missense_variant | Exon 16 of 16 | ENST00000257430.9 | NP_000029.2 |
Ensembl
Frequencies
GnomAD3 genomes AF: 0.0000460 AC: 7AN: 152120Hom.: 0 Cov.: 32 show subpopulations
GnomAD2 exomes AF: 0.00000399 AC: 1AN: 250628 AF XY: 0.00000738 show subpopulations
GnomAD4 exome AF: 0.0000144 AC: 21AN: 1461480Hom.: 0 Cov.: 34 AF XY: 0.0000124 AC XY: 9AN XY: 727068 show subpopulations
Age Distribution
GnomAD4 genome AF: 0.0000460 AC: 7AN: 152238Hom.: 0 Cov.: 32 AF XY: 0.0000403 AC XY: 3AN XY: 74438 show subpopulations
Age Distribution
ClinVar
Submissions by phenotype
not provided Uncertain:4
In silico analysis supports that this missense variant does not alter protein structure/function; Has not been previously published as pathogenic or benign to our knowledge -
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To the best of our knowledge, the variant has not been reported in the published literature. The frequency of this variant in the general population, 0.00012 (3/24850 chromosomes in African/African American subpopulation, http://gnomad.broadinstitute.org), is higher than would generally be expected for pathogenic variants in this gene. Analysis of this variant using bioinformatics tools for the prediction of the effect of amino acid changes on protein structure and function yielded conflicting predictions that this variant is benign or damaging. Based on the available information, we are unable to determine the clinical significance of this variant. -
Hereditary cancer-predisposing syndrome Uncertain:2Benign:1
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The p.R2326Q variant (also known as c.6977G>A), located in coding exon 15 of the APC gene, results from a G to A substitution at nucleotide position 6977. The arginine at codon 2326 is replaced by glutamine, an amino acid with highly similar properties. This amino acid position is highly conserved in available vertebrate species. In addition, in silico predictors for this gene do not accurately predict pathogenicity. Since supporting evidence is limited at this time, the clinical significance of this alteration remains unclear. -
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Familial adenomatous polyposis 1 Uncertain:2
This sequence change replaces arginine, which is basic and polar, with glutamine, which is neutral and polar, at codon 2326 of the APC protein (p.Arg2326Gln). This variant is present in population databases (rs531178000, gnomAD 0.01%). This missense change has been observed in individual(s) with colorectal cancer (PMID: 29596542). ClinVar contains an entry for this variant (Variation ID: 140854). Invitae Evidence Modeling of protein sequence and biophysical properties (such as structural, functional, and spatial information, amino acid conservation, physicochemical variation, residue mobility, and thermodynamic stability) indicates that this missense variant is not expected to disrupt APC protein function with a negative predictive value of 95%. 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. -
The APC c.6977G>A (p.Arg2326Gln) missense change has a maximum subpopulation frequency of 0.01% 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 the literature in individuals with APC-related disease. 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.? -
not specified Uncertain:1Benign:1
Classification criteria: BS1+BP1 -
Variant summary: APC c.6977G>A (p.Arg2326Gln) results in a conservative amino acid change located in the adenomatous polyposis coli protein basic domain of the encoded protein sequence. Three of five in-silico tools predict a damaging effect of the variant on protein function. The variant allele was found at a frequency of 4e-06 in 250628 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.6977G>A in individuals affected with APC-related cancer syndromes and no experimental evidence demonstrating its impact on protein function have been reported. Four clinical diagnostic laboratories have submitted clinical-significance assessments for this variant to ClinVar after 2014 and all classified the variant as uncertain significance. Based on the evidence outlined above, the variant was classified as uncertain significance. -
Classic or attenuated familial adenomatous polyposis Uncertain:1
This missense variant replaces arginine with glutamine at codon 2326 of the APC protein. Computational prediction suggests that this variant may not impact protein structure and function (internally defined REVEL score threshold <= 0.5, PMID: 27666373). Splice site prediction tools suggest that this variant may not impact RNA splicing. To our knowledge, functional studies have not been reported for this variant. This variant has not been reported in individuals affected with hereditary cancer in the literature. This variant has been identified in 3/282010 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. -
Familial adenomatous polyposis 1;C4749917:Gastric adenocarcinoma and proximal polyposis of the stomach;C5679615:APC-related attenuated familial adenomatous polyposis Other:1
Variant interpreted as Uncertain significance and reported on 02-04-2020 by Lab or GTR ID 500031. GenomeConnect assertions are reported exactly as they appear on the patient-provided report from the testing laboratory. GenomeConnect staff make no attempt to reinterpret the clinical significance of the variant. -
Computational scores
Source:
Splicing
Find out detailed SpliceAI scores and Pangolin per-transcript scores at