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

Genomes: 𝑓 0.000046 ( 0 hom., cov: 32)
Exomes 𝑓: 0.000014 ( 0 hom. )

Consequence

APC
NM_000038.6 missense

Scores

3
7
9

Clinical Significance

Conflicting classifications of pathogenicity criteria provided, conflicting classifications U:10B:2O:1

Conservation

PhyloP100: 5.92

Publications

3 publications found
Variant links:
Genes affected
APC (HGNC:583): (APC regulator of WNT signaling pathway) This gene encodes a tumor suppressor protein that acts as an antagonist of the Wnt signaling pathway. It is also involved in other processes including cell migration and adhesion, transcriptional activation, and apoptosis. Defects in this gene cause familial adenomatous polyposis (FAP), an autosomal dominant pre-malignant disease that usually progresses to malignancy. Mutations in the APC gene have been found to occur in most colorectal cancers, where disease-associated mutations tend to be clustered in a small region designated the mutation cluster region (MCR) and result in a truncated protein product. [provided by RefSeq, Jun 2022]
APC Gene-Disease associations (from GenCC):
  • classic or attenuated familial adenomatous polyposis
    Inheritance: AD Classification: DEFINITIVE Submitted by: ClinGen
  • desmoid tumor
    Inheritance: AD Classification: DEFINITIVE, STRONG Submitted by: G2P, Genomics England PanelApp
  • familial adenomatous polyposis 1
    Inheritance: AD Classification: DEFINITIVE, STRONG, MODERATE Submitted by: Genomics England PanelApp, Labcorp Genetics (formerly Invitae), Ambry Genetics
  • gastric adenocarcinoma and proximal polyposis of the stomach
    Inheritance: AD Classification: DEFINITIVE, STRONG, SUPPORTIVE Submitted by: Ambry Genetics, Labcorp Genetics (formerly Invitae), ClinGen, Orphanet
  • sarcoma
    Inheritance: AD Classification: MODERATE Submitted by: Genomics England PanelApp
  • APC-related attenuated familial adenomatous polyposis
    Inheritance: AD Classification: SUPPORTIVE Submitted by: Orphanet
  • Turcot syndrome with polyposis
    Inheritance: AD Classification: SUPPORTIVE Submitted by: Orphanet
  • Cenani-Lenz syndactyly syndrome
    Inheritance: AR Classification: SUPPORTIVE Submitted by: Orphanet

Genome browser will be placed here

ACMG classification

Classification was made for transcript

Our verdict: Uncertain_significance. The variant received 0 ACMG points.

Transcripts

RefSeq

Gene Transcript HGVSc HGVSp Effect Exon rank MANE Protein UniProt
APCNM_000038.6 linkc.6977G>A p.Arg2326Gln missense_variant Exon 16 of 16 ENST00000257430.9 NP_000029.2

Ensembl

Gene Transcript HGVSc HGVSp Effect Exon rank TSL MANE Protein Appris UniProt
APCENST00000257430.9 linkc.6977G>A p.Arg2326Gln missense_variant Exon 16 of 16 5 NM_000038.6 ENSP00000257430.4
ENSG00000258864ENST00000520401.1 linkn.228+13599G>A intron_variant Intron 3 of 7 3 ENSP00000454861.1

Frequencies

GnomAD3 genomes
AF:
0.0000460
AC:
7
AN:
152120
Hom.:
0
Cov.:
32
show subpopulations
Gnomad AFR
AF:
0.000121
Gnomad AMI
AF:
0.00
Gnomad AMR
AF:
0.00
Gnomad ASJ
AF:
0.00
Gnomad EAS
AF:
0.000193
Gnomad SAS
AF:
0.00
Gnomad FIN
AF:
0.00
Gnomad MID
AF:
0.00
Gnomad NFE
AF:
0.0000147
Gnomad OTH
AF:
0.00
GnomAD2 exomes
AF:
0.00000399
AC:
1
AN:
250628
AF XY:
0.00000738
show subpopulations
Gnomad AFR exome
AF:
0.0000619
Gnomad AMR exome
AF:
0.00
Gnomad ASJ exome
AF:
0.00
Gnomad EAS exome
AF:
0.00
Gnomad FIN exome
AF:
0.00
Gnomad NFE exome
AF:
0.00
Gnomad OTH exome
AF:
0.00
GnomAD4 exome
AF:
0.0000144
AC:
21
AN:
1461480
Hom.:
0
Cov.:
34
AF XY:
0.0000124
AC XY:
9
AN XY:
727068
show subpopulations
African (AFR)
AF:
0.0000299
AC:
1
AN:
33464
American (AMR)
AF:
0.00
AC:
0
AN:
44706
Ashkenazi Jewish (ASJ)
AF:
0.00
AC:
0
AN:
26126
East Asian (EAS)
AF:
0.00
AC:
0
AN:
39698
South Asian (SAS)
AF:
0.0000116
AC:
1
AN:
86248
European-Finnish (FIN)
AF:
0.00
AC:
0
AN:
53386
Middle Eastern (MID)
AF:
0.00
AC:
0
AN:
5768
European-Non Finnish (NFE)
AF:
0.0000153
AC:
17
AN:
1111698
Other (OTH)
AF:
0.0000331
AC:
2
AN:
60386
Allele Balance Distribution
Red line indicates average allele balance
Average allele balance: 0.494
Heterozygous variant carriers
0
2
4
7
9
11
0.00
0.20
0.40
0.60
0.80
0.95
Allele balance

Age Distribution

Exome Het
Variant carriers
0
2
4
6
8
10
<30
30-35
35-40
40-45
45-50
50-55
55-60
60-65
65-70
70-75
75-80
>80
Age
GnomAD4 genome
AF:
0.0000460
AC:
7
AN:
152238
Hom.:
0
Cov.:
32
AF XY:
0.0000403
AC XY:
3
AN XY:
74438
show subpopulations
African (AFR)
AF:
0.000120
AC:
5
AN:
41548
American (AMR)
AF:
0.00
AC:
0
AN:
15288
Ashkenazi Jewish (ASJ)
AF:
0.00
AC:
0
AN:
3468
East Asian (EAS)
AF:
0.000193
AC:
1
AN:
5180
South Asian (SAS)
AF:
0.00
AC:
0
AN:
4824
European-Finnish (FIN)
AF:
0.00
AC:
0
AN:
10610
Middle Eastern (MID)
AF:
0.00
AC:
0
AN:
294
European-Non Finnish (NFE)
AF:
0.0000147
AC:
1
AN:
68002
Other (OTH)
AF:
0.00
AC:
0
AN:
2112
Allele Balance Distribution
Red line indicates average allele balance
Average allele balance: 0.525
Heterozygous variant carriers
0
1
1
2
2
3
0.00
0.20
0.40
0.60
0.80
0.95
Allele balance

Age Distribution

Genome Het
Variant carriers
0
2
4
6
8
10
<30
30-35
35-40
40-45
45-50
50-55
55-60
60-65
65-70
70-75
75-80
>80
Age
Alfa
AF:
0.0000559
Hom.:
0
Bravo
AF:
0.0000378
ExAC
AF:
0.00000824
AC:
1
Asia WGS
AF:
0.000289
AC:
1
AN:
3478
EpiCase
AF:
0.0000545
EpiControl
AF:
0.00

ClinVar

Significance: Conflicting classifications of pathogenicity
Submissions summary: Uncertain:10Benign:2Other:1
Revision: criteria provided, conflicting classifications
LINK: link

Submissions by phenotype

not provided Uncertain:4
Feb 23, 2021
GeneDx
Significance:Uncertain significance
Review Status:criteria provided, single submitter
Collection Method:clinical testing

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 -

-
Joint Genome Diagnostic Labs from Nijmegen and Maastricht, Radboudumc and MUMC+
Significance:Uncertain significance
Review Status:no assertion criteria provided
Collection Method:clinical testing

- -

-
Laboratory of Diagnostic Genome Analysis, Leiden University Medical Center (LUMC)
Significance:Uncertain significance
Review Status:no assertion criteria provided
Collection Method:clinical testing

- -

Jan 05, 2023
Quest Diagnostics Nichols Institute San Juan Capistrano
Significance:Uncertain significance
Review Status:criteria provided, single submitter
Collection Method:clinical testing

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
Sep 23, 2024
Color Diagnostics, LLC DBA Color Health
Significance:Likely benign
Review Status:criteria provided, single submitter
Collection Method:clinical testing

- -

Mar 28, 2025
Ambry Genetics
Significance:Uncertain significance
Review Status:criteria provided, single submitter
Collection Method:clinical testing

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. -

Jun 03, 2021
Sema4, Sema4
Significance:Uncertain significance
Review Status:criteria provided, single submitter
Collection Method:curation

- -

Familial adenomatous polyposis 1 Uncertain:2
Nov 19, 2024
Labcorp Genetics (formerly Invitae), Labcorp
Significance:Uncertain significance
Review Status:criteria provided, single submitter
Collection Method:clinical testing

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. -

Aug 17, 2023
St. Jude Molecular Pathology, St. Jude Children's Research Hospital
Significance:Uncertain significance
Review Status:criteria provided, single submitter
Collection Method:clinical testing

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
Mar 04, 2025
Center for Genomic Medicine, Rigshospitalet, Copenhagen University Hospital
Significance:Likely benign
Review Status:criteria provided, single submitter
Collection Method:clinical testing

Classification criteria: BS1+BP1 -

Jun 06, 2022
Women's Health and Genetics/Laboratory Corporation of America, LabCorp
Significance:Uncertain significance
Review Status:criteria provided, single submitter
Collection Method:clinical testing

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
Apr 16, 2024
All of Us Research Program, National Institutes of Health
Significance:Uncertain significance
Review Status:criteria provided, single submitter
Collection Method:clinical testing

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
-
GenomeConnect, ClinGen
Significance:not provided
Review Status:no classification provided
Collection Method:phenotyping only

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: dbNSFP v4.3

Name
Calibrated prediction
Score
Prediction
AlphaMissense
Benign
0.12
BayesDel_addAF
Benign
-0.046
T
BayesDel_noAF
Benign
-0.12
CADD
Uncertain
25
DANN
Pathogenic
1.0
DEOGEN2
Uncertain
0.44
T;T
Eigen
Pathogenic
0.74
Eigen_PC
Pathogenic
0.74
FATHMM_MKL
Uncertain
0.94
D
LIST_S2
Uncertain
0.97
.;D
M_CAP
Benign
0.067
D
MetaRNN
Uncertain
0.46
T;T
MetaSVM
Uncertain
0.36
D
MutationAssessor
Benign
1.4
L;L
PhyloP100
5.9
PrimateAI
Uncertain
0.69
T
PROVEAN
Benign
-1.1
N;N
REVEL
Uncertain
0.46
Sift
Benign
0.069
T;T
Sift4G
Benign
0.25
T;T
Polyphen
1.0
D;D
Vest4
0.55
MVP
0.78
ClinPred
0.48
T
GERP RS
5.8
Varity_R
0.13
gMVP
0.48
Mutation Taster
=68/32
polymorphism

Splicing

Name
Calibrated prediction
Score
Prediction
SpliceAI score (max)
0.0
Details are displayed if max score is > 0.2

Find out detailed SpliceAI scores and Pangolin per-transcript scores at spliceailookup.broadinstitute.org

Publications

Other links and lift over

dbSNP: rs531178000; hg19: chr5-112178268; COSMIC: COSV99072959; API