rs1114167603

Variant summary

Our verdict is Uncertain significance. Variant got 3 ACMG points: 3P and 0B. PM5_SupportingPM2_SupportingPS4_Supporting

This summary comes from the ClinGen Evidence Repository: The c.3077A>C variant in APC is a missense variant predicted to cause the substitution of asparagine by threonine at amino acid position 1026 (p.Asn1026Thr). This variant has been reported in 3 probands with FAP worth 1.5 phenotype points (PS4_Supporting; Ambry Internal Data). This variant is absent from gnomAD v2.1.1 (PM2_Supporting). Another missense variant, c.3077A>G (p.Asn1026Ser) in the same codon has been classified as Likely Pathogenic for FAP by the ClinGen InSiGHT Hereditary Colorectal Cancer/Polyposis Variant Curation Expert Panel (HCCP VCEP) (PM5_Supporting; PMID 18166348). In summary, due to insufficient evidence, this variant is a Variant of Uncertain Significance for FAP based on the ACMG/AMP criteria applied, as specified by the HCCP VCEP: PS4_Supporting, PM2_Supporting, and PM5_Supporting (VCEP specifications version 1; date of approval: 12/12/2022). LINK:https://erepo.genome.network/evrepo/ui/classification/CA16028070/MONDO:0021056/089

Frequency

Genomes: not found (cov: 32)

Consequence

APC
NM_000038.6 missense

Scores

7
7
5

Clinical Significance

Uncertain significance reviewed by expert panel P:1U:4

Conservation

PhyloP100: 8.72
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]

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ACMG classification

Classification made for transcript

Verdict is Uncertain_significance. Variant got 3 ACMG points.

PS4
For more information check the summary or visit ClinGen Evidence Repository.
PM2
For more information check the summary or visit ClinGen Evidence Repository.
PM5
For more information check the summary or visit ClinGen Evidence Repository.

Transcripts

RefSeq

Gene Transcript HGVSc HGVSp Effect Exon rank MANE Protein UniProt
APCNM_000038.6 linkc.3077A>C p.Asn1026Thr missense_variant Exon 16 of 16 ENST00000257430.9 NP_000029.2 P25054-1Q4LE70

Ensembl

Gene Transcript HGVSc HGVSp Effect Exon rank TSL MANE Protein Appris UniProt
APCENST00000257430.9 linkc.3077A>C p.Asn1026Thr missense_variant Exon 16 of 16 5 NM_000038.6 ENSP00000257430.4 P25054-1
ENSG00000258864ENST00000520401.1 linkn.228+9699A>C intron_variant Intron 3 of 7 3 ENSP00000454861.1 H3BNH8

Frequencies

GnomAD3 genomes
Cov.:
32
GnomAD4 exome
Cov.:
33
GnomAD4 genome
Cov.:
32

ClinVar

Significance: Uncertain significance
Submissions summary: Pathogenic:1Uncertain:4
Revision: reviewed by expert panel
LINK: link

Submissions by phenotype

Familial adenomatous polyposis 1 Uncertain:2
Feb 25, 2023
ClinGen InSiGHT Hereditary Colorectal Cancer/Polyposis Variant Curation Expert Panel
Significance: Uncertain significance
Review Status: reviewed by expert panel
Collection Method: curation

The c.3077A>C variant in APC is a missense variant predicted to cause the substitution of asparagine by threonine at amino acid position 1026 (p.Asn1026Thr). This variant has been reported in 3 probands with FAP worth 1.5 phenotype points (PS4_Supporting; Ambry Internal Data). This variant is absent from gnomAD v2.1.1 (PM2_Supporting). Another missense variant, c.3077A>G (p.Asn1026Ser) in the same codon has been classified as Likely Pathogenic for FAP by the ClinGen InSiGHT Hereditary Colorectal Cancer/Polyposis Variant Curation Expert Panel (HCCP VCEP) (PM5_Supporting; PMID 18166348). In summary, due to insufficient evidence, this variant is a Variant of Uncertain Significance for FAP based on the ACMG/AMP criteria applied, as specified by the HCCP VCEP: PS4_Supporting, PM2_Supporting, and PM5_Supporting (VCEP specifications version 1; date of approval: 12/12/2022). -

Aug 31, 2024
Labcorp Genetics (formerly Invitae), Labcorp
Significance: Uncertain significance
Review Status: criteria provided, single submitter
Collection Method: clinical testing

This sequence change replaces asparagine, which is neutral and polar, with threonine, which is neutral and polar, at codon 1026 of the APC protein (p.Asn1026Thr). This variant is not present in population databases (gnomAD no frequency). This variant has not been reported in the literature in individuals affected with APC-related conditions. ClinVar contains an entry for this variant (Variation ID: 428167). 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%. This variant disrupts the p.Asn1026 amino acid residue in APC. Other variant(s) that disrupt this residue have been determined to be pathogenic (PMID: 18166348). 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. -

Hereditary cancer-predisposing syndrome Pathogenic:1
Jun 30, 2016
Ambry Genetics
Significance: Likely pathogenic
Review Status: criteria provided, single submitter
Collection Method: clinical testing

The p.N1026T variant (also known as c.3077A>C), located in coding exon 15 of the APC gene, results from an A to C substitution at nucleotide position 3077. The asparagine at codon 1026 is replaced by threonine, an amino acid with similar properties. While this exact alteration has not been reported in the literature to our knowledge, a similar alteration at this same location, p.N1026S (c.3077A>G), has been reported to segregate with disease in a large Spanish attenuated FAP family (Menéndez M et al. Gastroenterology 2008 Jan; 134(1):56-64). Menéndez M et al. further investigated the functional significance of the p.N1026S alteration using an in vitro beta-catenin binding assay and showed it resulted in a functionally altered protein. This variant is considered to be rare based on population cohorts in the Genome Aggregation Database (gnomAD). This amino acid position is highly conserved in available vertebrate species. In addition, in silico predictors for this gene do not accurately predict pathogenicity. Based on the majority of available evidence to date, this variant is likely to be pathogenic. -

not specified Uncertain:1
-
Mayo Clinic Laboratories, Mayo Clinic
Significance: Uncertain significance
Review Status: no assertion criteria provided
Collection Method: clinical testing

- -

Carcinoma of colon Uncertain:1
-
Department of Pathology and Laboratory Medicine, Sinai Health System
Significance: Uncertain significance
Review Status: no assertion criteria provided
Collection Method: clinical testing

The APC p.Asn1026Thr was not identified in the literature, dbSNP, 1000 Genomes Project, NHLBI GO Exome Sequencing Project (ESP, the Exome Aggregation Consortium (ExAC) database (released Jan 13, 2015), Clinvitae database, COSMIC, Zhejiang Colon Cancer Database (LOVD), ClinVar database, GeneInsight - COGR database, the InSiGHT Colon Cancer Gene Variant Database (LOVD) and UMD. A variant at the same loci, p.Asn1026Ser was identified in the literature and classified as pathogenic based on segregation data and in vivo studies (Menendez 2008). The p.Asn1026 residue is conserved across mammals and other organisms, and computational analyses (PolyPhen-2, SIFT, AlignGVGD, BLOSUM, MutationTaster) provide inconsistent predictions regarding the impact to the protein and this information is not very predictive of pathogenicity. The variant occurs outside of the splicing consensus sequence and in silico or computational prediction software programs (SpliceSiteFinder, MaxEntScan, NNSPLICE, GeneSplicer, HumanSpliceFinder) do not predict a difference in splicing. In summary, based on the above information, the clinical significance of this variant cannot be determined with certainty at this time. This variant is classified as a variant of uncertain significance. -

Computational scores

Source: dbNSFP v4.3

Name
Calibrated prediction
Score
Prediction
AlphaMissense
Pathogenic
0.99
BayesDel_addAF
Pathogenic
0.17
D
BayesDel_noAF
Uncertain
0.0
CADD
Uncertain
25
DANN
Uncertain
1.0
DEOGEN2
Uncertain
0.74
.;D;D;D
Eigen
Uncertain
0.58
Eigen_PC
Uncertain
0.66
FATHMM_MKL
Pathogenic
0.99
D
LIST_S2
Pathogenic
0.98
D;.;D;D
M_CAP
Benign
0.054
D
MetaRNN
Pathogenic
0.78
D;D;D;D
MetaSVM
Uncertain
0.50
D
MutationAssessor
Benign
0.55
.;N;N;.
PrimateAI
Pathogenic
0.87
D
PROVEAN
Benign
-1.3
N;N;N;N
REVEL
Pathogenic
0.65
Sift
Uncertain
0.0020
D;D;D;D
Sift4G
Benign
0.34
T;D;D;T
Polyphen
1.0
.;D;D;.
Vest4
0.88, 0.79
MutPred
0.72
.;Gain of sheet (P = 0.0149);Gain of sheet (P = 0.0149);Gain of sheet (P = 0.0149);
MVP
0.89
ClinPred
0.79
D
GERP RS
5.8
Varity_R
0.78
gMVP
0.59

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

LitVar

Below is the list of publications found by LitVar. It may be empty.

Other links and lift over

dbSNP: rs1114167603; hg19: chr5-112174368; API