5-112837560-C-G

Variant names:

Variant summary

Our verdict is Uncertain significance. The variant received 1 ACMG points: 2P and 1B. PM1BP4

The NM_000038.6(APC):c.1966C>G(p.Leu656Val) variant causes a missense change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.00000682 in 1,612,118 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a benign outcome for this variant. Variant has been reported in ClinVar as Conflicting classifications of pathogenicity (no stars). Synonymous variant affecting the same amino acid position (i.e. L656L) has been classified as Likely benign.

Frequency

Genomes: 𝑓 0.0000066 ( 0 hom., cov: 32)

Exomes 𝑓: 0.0000068 ( 0 hom. )

Consequence

APC
NM_000038.6 missense

Scores

Clinical Significance

Conflicting classifications of pathogenicity criteria provided, conflicting classifications U:9B:2

Conservation

PhyloP100: 1.34

Publications

7 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

APC links:

ENSG00000258864 (HGNC:):

ENSG00000258864 links:

Genome browser will be placed here

ACMG classification

Classification was made for transcript

Our verdict: Uncertain_significance. The variant received 1 ACMG points.

PM1

In a hotspot region, there are 4 aminoacids with missense pathogenic changes in the window of +-8 aminoacids around while only 2 benign, 32 uncertain in NM_000038.6

BP4

Computational evidence support a benign effect (MetaRNN=0.40262875).

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	MANE	Protein	UniProt
APC	NM_000038.6 link	c.1966C>G	p.Leu656Val	missense_variant	Exon 16 of 16	ENST00000257430.9	NP_000029.2

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	TSL	MANE	Protein	Appris	UniProt
APC	ENST00000257430.9 link	c.1966C>G	p.Leu656Val	missense_variant	Exon 16 of 16	5	NM_000038.6	ENSP00000257430.4
ENSG00000258864	ENST00000520401.1 link	n.228+8588C>G		intron_variant	Intron 3 of 7	3		ENSP00000454861.1

Frequencies

GnomAD3 genomes

AF:

0.00000658

AC:

AN:

152080

Hom.:

Cov.:

show subpopulations

Gnomad AFR

AF:

0.00

Gnomad AMI

AF:

0.00

Gnomad AMR

AF:

0.00

Gnomad ASJ

AF:

0.00

Gnomad EAS

AF:

0.00

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:

0.0000279

AC:

AN:

250602

AF XY:

0.0000221

show subpopulations

Gnomad AFR exome

AF:

0.00

Gnomad AMR exome

AF:

0.000174

Gnomad ASJ exome

AF:

0.00

Gnomad EAS exome

AF:

0.00

Gnomad FIN exome

AF:

0.00

Gnomad NFE exome

AF:

0.00000883

Gnomad OTH exome

AF:

0.00

GnomAD4 exome

AF:

0.00000685

AC:

AN:

1459920

Hom.:

Cov.:

AF XY:

0.00000551

AC XY:

AN XY:

726078

show subpopulations

African (AFR)

AF:

0.00

AC:

AN:

33464

American (AMR)

AF:

0.000134

AC:

AN:

44708

Ashkenazi Jewish (ASJ)

AF:

0.00

AC:

AN:

26124

East Asian (EAS)

AF:

0.00

AC:

AN:

39652

South Asian (SAS)

AF:

0.00

AC:

AN:

86146

European-Finnish (FIN)

AF:

0.00

AC:

AN:

53358

Middle Eastern (MID)

AF:

0.00

AC:

AN:

5764

European-Non Finnish (NFE)

AF:

0.00000360

AC:

AN:

1110380

Other (OTH)

AF:

0.00

AC:

AN:

60324

Allele Balance Distribution

Red line indicates average allele balance

Average allele balance: 0.435

Heterozygous variant carriers

0.00

0.20

0.40

0.60

0.80

0.95

Allele balance

Age Distribution

Exome Het

Variant carriers

<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:

0.00000657

AC:

AN:

152198

Hom.:

Cov.:

AF XY:

0.00

AC XY:

AN XY:

74412

show subpopulations

African (AFR)

AF:

0.00

AC:

AN:

41516

American (AMR)

AF:

0.00

AC:

AN:

15296

Ashkenazi Jewish (ASJ)

AF:

0.00

AC:

AN:

3470

East Asian (EAS)

AF:

0.00

AC:

AN:

5186

South Asian (SAS)

AF:

0.00

AC:

AN:

4824

European-Finnish (FIN)

AF:

0.00

AC:

AN:

10586

Middle Eastern (MID)

AF:

0.00

AC:

AN:

294

European-Non Finnish (NFE)

AF:

0.0000147

AC:

AN:

68008

Other (OTH)

AF:

0.00

AC:

AN:

2106

Allele Balance Distribution

Red line indicates average allele balance

Average allele balance: 0.575

Heterozygous variant carriers

0.00

0.20

0.40

0.60

0.80

0.95

Allele balance

Alfa

AF:

0.00

Hom.:

Bravo

AF:

0.0000113

ExAC

AF:

0.00000824

AC:

ClinVar

Significance: Conflicting classifications of pathogenicity

Submissions summary: Uncertain:9Benign:2

Revision: criteria provided, conflicting classifications

LINK: link

Submissions by phenotype

Familial adenomatous polyposis 1

Uncertain:3Benign:1

Dec 15, 2023

Baylor Genetics

Significance:Uncertain significance

Review Status:criteria provided, single submitter

Collection Method:clinical testing

- -

Jan 14, 2025

Labcorp Genetics (formerly Invitae), Labcorp

Significance:Uncertain significance

Review Status:criteria provided, single submitter

Collection Method:clinical testing

This sequence change replaces leucine, which is neutral and non-polar, with valine, which is neutral and non-polar, at codon 656 of the APC protein (p.Leu656Val). This variant is present in population databases (rs577466163, gnomAD 0.02%). This missense change has been observed in individual(s) with clinical features of attenuated adenomatous polyposis (PMID: 31285513). ClinVar contains an entry for this variant (Variation ID: 482253). 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%. RNA analysis performed to evaluate the impact of this missense change on mRNA splicing indicates it does not significantly alter splicing (internal data). 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. -

Jun 01, 2018

Molecular Oncology Laboratory, Hospital Clínico San Carlos

Significance:Uncertain significance

Review Status:no assertion criteria provided

Collection Method:clinical testing

- -

Apr 09, 2024

Mendelics

Significance:Likely benign

Review Status:criteria provided, single submitter

Collection Method:clinical testing

- -

Hereditary cancer-predisposing syndrome

Uncertain:2Benign:1

Jun 18, 2021

Ambry Genetics

Significance:Likely benign

Review Status:criteria provided, single submitter

Collection Method:clinical testing

This alteration is classified as likely benign based on a combination of the following: seen in unaffected individuals, population frequency, intact protein function, lack of segregation with disease, co-occurrence, RNA analysis, in silico models, amino acid conservation, lack of disease association in case-control studies, and/or the mechanism of disease or impacted region is inconsistent with a known cause of pathogenicity. -

Oct 12, 2023

Color Diagnostics, LLC DBA Color Health

Significance:Uncertain significance

Review Status:criteria provided, single submitter

Collection Method:clinical testing

This missense variant replaces leucine with valine at codon 656 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). To our knowledge, functional studies have not been reported for this variant. This variant has been reported in individuals affected with attenuated familial adenomatous polyposis (PMID: 31285513), breast cancer (DOI: 10.1101/2021.04.15.21255554), or colorectal cancer (PMID: 32635641). This variant has been identified in 7/250602 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. -

Jul 03, 2021

Sema4, Sema4

Significance:Uncertain significance

Review Status:criteria provided, single submitter

Collection Method:curation

- -

not provided

Uncertain:2

Nov 07, 2023

Quest Diagnostics Nichols Institute San Juan Capistrano

Significance:Uncertain significance

Review Status:criteria provided, single submitter

Collection Method:clinical testing

The APC c.1966C>G (p.Leu656Val) variant has been reported in the published literature in in individuals with adenomatous polyposis (PMID: 31285513 (2019)), Lynch-like syndrome (PMID: 32635641 (2020)), and breast cancer (PMID: 35534704 (2022)). The frequency of this variant in the general population, 0.00017 (6/34544 chromosomes in Latino/Admixed American subpopulation (Genome Aggregation Database, 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 predictions that this variant is damaging. Based on the available information, we are unable to determine the clinical significance of this variant. -

Nov 29, 2023

GeneDx

Significance:Uncertain significance

Review Status:criteria provided, single submitter

Collection Method:clinical testing

In silico analysis supports that this missense variant has a deleterious effect on protein structure/function; This variant is associated with the following publications: (PMID: 32635641, 31285513, 35534704, 18199528) -

not specified

Uncertain:1

Jan 24, 2025

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.1966C>G (p.Leu656Val) results in a conservative amino acid change in the encoded protein sequence. Four of five in-silico tools predict a benign effect of the variant on protein function. The variant allele was found at a frequency of 2.8e-05 in 250602 control chromosomes (gnomAD). The available data on variant occurrences in the general population are insufficient to allow any conclusion about variant significance. c.1966C>G has been reported in the literature in individuals affected with Attenuated adenomatous polyposis, Lynch-like syndrome or Breast cancer (Lorca_2019, Dmaso_2020, de Oliveira_2022). These reports do not provide unequivocal conclusions about association of the variant with Colorectal Cancer Risk. To our knowledge, no experimental evidence demonstrating an impact on protein function has been reported. The following publications have been ascertained in the context of this evaluation (PMID: 31285513, 32635641, 35534704). ClinVar contains an entry for this variant (Variation ID: 482253). Based on the evidence outlined above, the variant was classified as uncertain significance. -

Classic or attenuated familial adenomatous polyposis

Uncertain:1

Dec 15, 2023

All of Us Research Program, National Institutes of Health

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

Uncertain

0.47

BayesDel_addAF

Benign

-0.071

BayesDel_noAF

Uncertain

-0.070

CADD

Benign

(source)

DANN

Uncertain

0.99

DEOGEN2

Uncertain

0.58

.;D;D;T;T

Eigen

Uncertain

0.49

Eigen_PC

Uncertain

0.47

FATHMM_MKL

Uncertain

0.96

LIST_S2

Uncertain

0.93

D;.;D;D;D

M_CAP

Benign

0.054

MetaRNN

Benign

0.40

T;T;T;T;T

MetaSVM

Benign

-0.36

MutationAssessor

Benign

1.7

.;L;L;.;.

PhyloP100

1.3

PrimateAI

Pathogenic

0.81

PROVEAN

Uncertain

-2.9

D;N;N;D;.

REVEL

Uncertain

0.38

Sift

Benign

0.056

T;D;D;D;.

Sift4G

Uncertain

0.028

D;D;D;D;T

Polyphen

1.0

.;D;D;.;.

Vest4

0.74, 0.60

MutPred

0.51

.;Loss of helix (P = 0.1299);Loss of helix (P = 0.1299);Loss of helix (P = 0.1299);.;

MVP

0.77

ClinPred

0.74

GERP RS

3.8

Varity_R

0.80

gMVP

0.81

Mutation Taster

=43/57

disease causing

(source)

Splicing

Name

Calibrated prediction

Score

Prediction

SpliceAI score (max)

0.010

Details are displayed if max score is > 0.2

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

Publications

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Variant summary

Frequency

Consequence

Scores

Clinical Significance

Conservation

Publications

ACMG classification

Transcripts

RefSeq

Ensembl

Frequencies

Age Distribution

ClinVar

Submissions by phenotype

Computational scores

Splicing

Publications

Other links and lift over