rs752926571

Positions:

• chr5-112839558-G-A
• chr5-112839558-G-C

Variant summary

Our verdict is Likely benign. Variant got -4 ACMG points: 2P and 6B. PM1 BP4_Moderate BS2

The NM_000038.6(APC):​c.3964G>A​(p.Glu1322Lys) variant causes a missense change. The variant allele was found at a frequency of 0.000018 in 1,614,060 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a benign outcome for this variant. 12/21 in silico tools predict a benign outcome for this variant. 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. E1322Q) has been classified as Uncertain significance.

• Frequency:
  • Genomes: 𝑓 0.000013 (0 hom., cov: 32)
  • Exomes 𝑓: 0.000018 (0 hom.)
• Consequence: APC NM_000038.6 missense
• Clinical Significance: Conflicting classifications of pathogenicity criteria provided, conflicting classifications U:7 B:1
• Conservation: PhyloP100: 5.93

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]

ACMG classification

Verdict is Likely_benign. Variant got -4 ACMG points.

• PM1: In a hotspot region, there are 2 aminoacids with missense pathogenic changes in the window of +-8 aminoacids around while only 3 benign, 15 uncertain in NM_000038.6
• BP4: Computational evidence support a benign effect (MetaRNN=0.2466796).
• BS2: High AC in GnomAdExome4 at 27 AD gene.

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	UniProt
APC	NM_000038.6	c.3964G>A	p.Glu1322Lys	missense_variant	16/16	ENST00000257430.9

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Appris	UniProt
APC	ENST00000257430.9	c.3964G>A	p.Glu1322Lys	missense_variant	16/16	5	NM_000038.6	P1

Frequencies

GnomAD3 genomes AF: 0.0000131 AC: 2 AN: 152186 Hom.: 0 Cov.: 32

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: 0.0000294

Gnomad OTH AF: 0.00

GnomAD3 exomes AF: 0.0000239 AC: 6 AN: 251180 Hom.: 0 AF XY: 0.0000147 AC XY: 2 AN XY: 135742

Gnomad AFR exome AF: 0.00

Gnomad AMR exome AF: 0.0000868

Gnomad ASJ exome AF: 0.00

Gnomad EAS exome AF: 0.00

Gnomad SAS exome AF: 0.0000653

Gnomad FIN exome AF: 0.00

Gnomad NFE exome AF: 0.00000881

Gnomad OTH exome AF: 0.00

GnomAD4 exome AF: 0.0000185 AC: 27 AN: 1461874 Hom.: 0 Cov.: 33 AF XY: 0.0000165 AC XY: 12 AN XY: 727236

Gnomad4 AFR exome AF: 0.00

Gnomad4 AMR exome AF: 0.0000671

Gnomad4 ASJ exome AF: 0.00

Gnomad4 EAS exome AF: 0.00

Gnomad4 SAS exome AF: 0.0000464

Gnomad4 FIN exome AF: 0.00

Gnomad4 NFE exome AF: 0.0000162

Gnomad4 OTH exome AF: 0.0000331

GnomAD4 genome AF: 0.0000131 AC: 2 AN: 152186 Hom.: 0 Cov.: 32 AF XY: 0.0000135 AC XY: 1 AN XY: 74344

Gnomad4 AFR AF: 0.00

Gnomad4 AMR AF: 0.00

Gnomad4 ASJ AF: 0.00

Gnomad4 EAS AF: 0.00

Gnomad4 SAS AF: 0.00

Gnomad4 FIN AF: 0.00

Gnomad4 NFE AF: 0.0000294

Gnomad4 OTH AF: 0.00

Alfa AF: 0.0000712 Hom.: 0

Bravo AF: 0.00000756

ExAC AF: 0.0000165 AC: 2

ClinVar

Significance: Conflicting classifications of pathogenicity

Submissions summary: Uncertain:7 Benign:1

Revision: criteria provided, conflicting classifications

Submissions by phenotype

Familial adenomatous polyposis 1 Uncertain:2

Uncertain significance, criteria provided, single submitter	clinical testing	Invitae	Jan 27, 2024	This sequence change replaces glutamic acid, which is acidic and polar, with lysine, which is basic and polar, at codon 1322 of the APC protein (p.Glu1322Lys). The frequency data for this variant in the population databases is considered unreliable, as metrics indicate poor data quality at this position in the gnomAD database. 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: 232718). 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 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. -
Uncertain significance, criteria provided, single submitter	clinical testing	Baylor Genetics	Mar 06, 2024	- -

not provided Uncertain:2

Uncertain significance, criteria provided, single submitter	clinical testing	Quest Diagnostics Nichols Institute San Juan Capistrano	Nov 30, 2022	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, 0.000085 (3/35426 chromosomes in Latino/Admixed 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 predictions that this variant is benign. Based on the available information, we are unable to determine the clinical significance of this variant. -
Uncertain significance, criteria provided, single submitter	clinical testing	GeneDx	Jun 09, 2022	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; This variant is associated with the following publications: (PMID: 18199528) -

Hereditary cancer-predisposing syndrome Uncertain:1 Benign:1

Uncertain significance, criteria provided, single submitter	clinical testing	Color Diagnostics, LLC DBA Color Health	Nov 21, 2022	This missense variant replaces glutamic acid with lysine at codon 1322 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 an individual affected with advanced cancer (PMID: 28873162). This variant has been identified in 7/282580 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. -
Likely benign, criteria provided, single submitter	clinical testing	Ambry Genetics	Aug 18, 2022	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. -

not specified Uncertain:1

Uncertain significance, criteria provided, single submitter

clinical testing

Genetic Services Laboratory, University of Chicago

Jan 15, 2021

DNA sequence analysis of the APC gene demonstrated a sequence change, c.3964G>A, in exon 16 that results in an amino acid change, p.Glu1322Lys. This sequence change does not appear to have been previously described in patients with APC-related disorders and has been described in the gnomAD database in seven individuals with an overall population frequency of 0.003% (dbSNP rs752926571). The p.Glu1322Lys change affects a highly conserved amino acid residue located in a domain of the APC protein that is not known to be functional. In-silico pathogenicity prediction tools (SIFT, PolyPhen2, Align GVGD, REVEL) provide contradictory results for the p.Glu1322Lys substitution. Due to these contrasting evidences and the lack of functional studies, the clinical significance of the p.Glu1322Lys change remains unknown at this time. -

Classic or attenuated familial adenomatous polyposis Uncertain:1

Uncertain significance, criteria provided, single submitter

clinical testing

All of Us Research Program, National Institutes of Health

Oct 23, 2023

This missense variant replaces glutamic acid with lysine at codon 1322 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 an individual affected with advanced cancer (PMID: 28873162). This variant has been identified in 7/282580 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. -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Benign	0.11
BayesDel_addAF	Benign	-0.061	T
BayesDel_noAF	Benign	-0.13
CADD	Uncertain	24
DANN	Uncertain	0.99
DEOGEN2	Uncertain	0.46	T;T
Eigen	Benign	-0.052
Eigen_PC	Benign	0.098
FATHMM_MKL	Uncertain	0.90	D
M_CAP	Uncertain	0.091	D
MetaRNN	Benign	0.25	T;T
MetaSVM	Uncertain	-0.20	T
MutationAssessor	Benign	1.7	L;L
MutationTaster	Benign	1.0	D;D;D
PrimateAI	Benign	0.34	T
PROVEAN	Benign	0.030	N;N
REVEL	Benign	0.26
Sift	Benign	0.071	T;T
Sift4G	Benign	0.37	T;T
Polyphen		0.57	P;P
Vest4		0.27
MutPred		0.32		Gain of methylation at E1322 (P = 0.0022);Gain of methylation at E1322 (P = 0.0022);
MVP		0.79
ClinPred		0.32	T
GERP RS		5.2
Varity_R		0.090
gMVP		0.60

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

Other links and lift over

dbSNP: rs752926571; hg19: chr5-112175255; COSMIC: COSV99964740; COSMIC: COSV99964740;