5-112840621-G-A

Variant summary

Our verdict is Uncertain significance. The variant received 0 ACMG points: 2P and 2B. PM2BP4_Moderate

The NM_000038.6(APC):​c.5027G>A​(p.Arg1676Lys) variant causes a missense change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.000000684 in 1,461,728 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a benign outcome for this variant. 17/22 in silico tools predict a benign 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. R1676G) has been classified as Likely benign.

Frequency

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

Consequence

APC
NM_000038.6 missense

Scores

1
18

Clinical Significance

Uncertain significance criteria provided, multiple submitters, no conflicts U:4

Conservation

PhyloP100: 1.99

Publications

5 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.

PM2
Very rare variant in population databases, with high coverage;
BP4
Computational evidence support a benign effect (MetaRNN=0.1273841).

Transcripts

RefSeq

Gene Transcript HGVSc HGVSp Effect Exon rank MANE Protein UniProt
APCNM_000038.6 linkc.5027G>A p.Arg1676Lys 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.5027G>A p.Arg1676Lys missense_variant Exon 16 of 16 5 NM_000038.6 ENSP00000257430.4 P25054-1
ENSG00000258864ENST00000520401.1 linkn.228+11649G>A intron_variant Intron 3 of 7 3 ENSP00000454861.1 H3BNH8

Frequencies

GnomAD3 genomes
Cov.:
32
GnomAD4 exome
AF:
6.84e-7
AC:
1
AN:
1461728
Hom.:
0
Cov.:
66
AF XY:
0.00
AC XY:
0
AN XY:
727168
show subpopulations
⚠️ The allele balance in gnomAD version 4 Exomes is significantly skewed from the expected value of 0.5.
African (AFR)
AF:
0.00
AC:
0
AN:
33478
American (AMR)
AF:
0.00
AC:
0
AN:
44710
Ashkenazi Jewish (ASJ)
AF:
0.00
AC:
0
AN:
26132
East Asian (EAS)
AF:
0.00
AC:
0
AN:
39682
South Asian (SAS)
AF:
0.00
AC:
0
AN:
86232
European-Finnish (FIN)
AF:
0.00
AC:
0
AN:
53402
Middle Eastern (MID)
AF:
0.00
AC:
0
AN:
5768
European-Non Finnish (NFE)
AF:
0.00
AC:
0
AN:
1111938
Other (OTH)
AF:
0.0000166
AC:
1
AN:
60386
⚠️ The allele balance in gnomAD4 Exomes is highly skewed from 0.5 (p-value = 0.000000), which strongly suggests a high chance of mosaicism in these individuals.
Allele Balance Distribution
Red line indicates average allele balance
Average allele balance: 0.375
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:4
Revision: criteria provided, multiple submitters, no conflicts
LINK: link

Submissions by phenotype

Hereditary cancer-predisposing syndrome Uncertain:2
Jun 21, 2019
Color Diagnostics, LLC DBA Color Health
Significance:Uncertain significance
Review Status:criteria provided, single submitter
Collection Method:clinical testing

- -

Jul 18, 2022
Ambry Genetics
Significance:Uncertain significance
Review Status:criteria provided, single submitter
Collection Method:clinical testing

The p.R1676K variant (also known as c.5027G>A), located in coding exon 15 of the APC gene, results from a G to A substitution at nucleotide position 5027. The arginine at codon 1676 is replaced by lysine, an amino acid with highly similar properties. This amino acid position is not well 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. -

Familial adenomatous polyposis 1 Uncertain:1
May 28, 2019
Labcorp Genetics (formerly Invitae), Labcorp
Significance:Uncertain significance
Review Status:criteria provided, single submitter
Collection Method:clinical testing

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. Algorithms developed to predict the effect of missense changes on protein structure and function output the following: SIFT: "Tolerated"; PolyPhen-2: "Benign"; Align-GVGD: "Class C0". The lysine amino acid residue is found in multiple mammalian species, suggesting that this missense change does not adversely affect protein function. These predictions have not been confirmed by published functional studies and their clinical significance is uncertain. This variant has not been reported in the literature in individuals with APC-related conditions. ClinVar contains an entry for this variant (Variation ID: 489461). This variant is not present in population databases (ExAC no frequency). This sequence change replaces arginine with lysine at codon 1676 of the APC protein (p.Arg1676Lys). The arginine residue is moderately conserved and there is a small physicochemical difference between arginine and lysine. -

not provided Uncertain:1
Jan 07, 2021
Quest Diagnostics Nichols Institute San Juan Capistrano
Significance:Uncertain significance
Review Status:criteria provided, single submitter
Collection Method:clinical testing

- -

Computational scores

Source: dbNSFP v4.3

Name
Calibrated prediction
Score
Prediction
AlphaMissense
Benign
0.077
BayesDel_addAF
Benign
-0.029
T
BayesDel_noAF
Benign
-0.28
CADD
Benign
13
DANN
Benign
0.97
DEOGEN2
Benign
0.38
T;T
Eigen
Benign
-0.21
Eigen_PC
Benign
-0.013
FATHMM_MKL
Uncertain
0.80
D
LIST_S2
Benign
0.86
.;D
M_CAP
Benign
0.011
T
MetaRNN
Benign
0.13
T;T
MetaSVM
Benign
-0.68
T
MutationAssessor
Benign
1.1
L;L
PhyloP100
2.0
PrimateAI
Benign
0.42
T
PROVEAN
Benign
0.20
N;N
REVEL
Benign
0.24
Sift
Benign
0.57
T;T
Sift4G
Benign
0.97
T;T
Polyphen
0.0020
B;B
Vest4
0.077
MutPred
0.27
Gain of ubiquitination at R1676 (P = 0.0051);Gain of ubiquitination at R1676 (P = 0.0051);
MVP
0.74
ClinPred
0.14
T
GERP RS
6.2
Varity_R
0.091
gMVP
0.28
Mutation Taster
=86/14
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: rs143674116; hg19: chr5-112176318; API