5-112840329-A-G

Variant summary

Our verdict is Likely pathogenic. The variant received 6 ACMG points: 6P and 0B. PM1PM2PP3_Moderate

The NM_000038.6(APC):​c.4735A>G​(p.Ile1579Val) variant causes a missense change involving the alteration of a conserved nucleotide. The variant allele was found at a frequency of 0.000000684 in 1,461,880 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a pathogenic outcome for this variant. Variant has been reported in ClinVar as Uncertain significance (★★). Another variant affecting the same amino acid position, but resulting in a different missense (i.e. I1579F) has been classified as Uncertain significance.

Frequency

Genomes: not found (cov: 32)
Exomes 𝑓: 6.8e-7 ( 0 hom. )

Consequence

APC
NM_000038.6 missense

Scores

10
7
2

Clinical Significance

Uncertain significance criteria provided, multiple submitters, no conflicts U:2

Conservation

PhyloP100: 8.95

Publications

4 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: Likely_pathogenic. The variant received 6 ACMG points.

PM1
In a hotspot region, there are 2 aminoacids with missense pathogenic changes in the window of +-8 aminoacids around while only 1 benign, 34 uncertain in NM_000038.6
PM2
Very rare variant in population databases, with high coverage;
PP3
MetaRNN computational evidence supports a deleterious effect, 0.897

Transcripts

RefSeq

Gene Transcript HGVSc HGVSp Effect Exon rank MANE Protein UniProt
APCNM_000038.6 linkc.4735A>G p.Ile1579Val 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.4735A>G p.Ile1579Val missense_variant Exon 16 of 16 5 NM_000038.6 ENSP00000257430.4 P25054-1
ENSG00000258864ENST00000520401.1 linkn.228+11357A>G intron_variant Intron 3 of 7 3 ENSP00000454861.1 H3BNH8

Frequencies

GnomAD3 genomes
Cov.:
32
GnomAD4 exome
AF:
6.84e-7
AC:
1
AN:
1461880
Hom.:
0
Cov.:
66
AF XY:
0.00000138
AC XY:
1
AN XY:
727242
show subpopulations
African (AFR)
AF:
0.00
AC:
0
AN:
33480
American (AMR)
AF:
0.00
AC:
0
AN:
44724
Ashkenazi Jewish (ASJ)
AF:
0.00
AC:
0
AN:
26136
East Asian (EAS)
AF:
0.00
AC:
0
AN:
39700
South Asian (SAS)
AF:
0.00
AC:
0
AN:
86258
European-Finnish (FIN)
AF:
0.00
AC:
0
AN:
53414
Middle Eastern (MID)
AF:
0.00
AC:
0
AN:
5768
European-Non Finnish (NFE)
AF:
8.99e-7
AC:
1
AN:
1112004
Other (OTH)
AF:
0.00
AC:
0
AN:
60396
Allele Balance Distribution
Red line indicates average allele balance
Average allele balance: 0.475
Heterozygous variant carriers
0
0
1
1
2
2
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
Cov.:
32

ClinVar

Significance: Uncertain significance
Submissions summary: Uncertain:2
Revision: criteria provided, multiple submitters, no conflicts
LINK: link

Submissions by phenotype

Familial adenomatous polyposis 1 Uncertain:1
Jun 25, 2023
Labcorp Genetics (formerly Invitae), Labcorp
Significance:Uncertain significance
Review Status:criteria provided, single submitter
Collection Method:clinical testing

This variant is not present in population databases (gnomAD no frequency). This sequence change replaces isoleucine, which is neutral and non-polar, with valine, which is neutral and non-polar, at codon 1579 of the APC protein (p.Ile1579Val). This missense change has been observed in individual(s) with colorectal adenomas (PMID: 18199528). ClinVar contains an entry for this variant (Variation ID: 141684). Advanced modeling of protein sequence and biophysical properties (such as structural, functional, and spatial information, amino acid conservation, physicochemical variation, residue mobility, and thermodynamic stability) performed at Invitae indicates that this missense variant is not expected to disrupt APC protein function. 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 Uncertain:1
Aug 11, 2020
Ambry Genetics
Significance:Uncertain significance
Review Status:criteria provided, single submitter
Collection Method:clinical testing

The p.I1579V variant (also known as c.4735A>G), located in coding exon 15 of the APC gene, results from an A to G substitution at nucleotide position 4735. The isoleucine at codon 1579 is replaced by valine, an amino acid with highly similar properties. This alteration has been identified in patients whose clinical history is consistent with attenuated familial adenomatous polyposis (Ambry internal data). In one study, p.I1579V was detected in one individual with multiple colorectal adenomas (total number of adenomas unknown) and 0/969 unrelated healthy controls (Azzopardi D et al. Cancer Res. 2008 Jan 15;68(2):358-63). Overall, this study found a higher frequency of rare, non-synonymous changes in individuals with multiple adenomas. It has been suggested that this missense alteration within a SAMP-repeat region might disrupt APC secondary structure related to Axin binding (Minde DP et al. Mol Cancer. 2011 Aug 22;10:101). 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. -

Computational scores

Source: dbNSFP v4.3

Name
Calibrated prediction
Score
Prediction
AlphaMissense
Pathogenic
0.81
BayesDel_addAF
Pathogenic
0.45
D
BayesDel_noAF
Pathogenic
0.41
CADD
Uncertain
25
DANN
Pathogenic
1.0
DEOGEN2
Uncertain
0.61
D;D
Eigen
Pathogenic
0.78
Eigen_PC
Pathogenic
0.81
FATHMM_MKL
Pathogenic
0.97
D
LIST_S2
Uncertain
0.95
.;D
M_CAP
Uncertain
0.15
D
MetaRNN
Pathogenic
0.90
D;D
MetaSVM
Pathogenic
0.99
D
MutationAssessor
Uncertain
2.0
M;M
PhyloP100
8.9
PrimateAI
Uncertain
0.65
T
PROVEAN
Benign
-0.75
N;N
REVEL
Pathogenic
0.78
Sift
Uncertain
0.0030
D;D
Sift4G
Uncertain
0.015
D;D
Polyphen
0.99
D;D
Vest4
0.83
MutPred
0.84
Gain of catalytic residue at I1579 (P = 8e-04);Gain of catalytic residue at I1579 (P = 8e-04);
MVP
0.97
ClinPred
0.77
D
GERP RS
6.2
Varity_R
0.72
gMVP
0.62
Mutation Taster
=0/100
disease causing

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: rs587781935; hg19: chr5-112176026; API