rs768233232

Positions:

• chr5-112792473-G-A
• chr5-112792473-G-C

Variant summary

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

The NM_000038.6(APC):​c.673G>A​(p.Glu225Lys) variant causes a missense change. The variant allele was found at a frequency of 0.00000686 in 1,458,656 control chromosomes in the GnomAD database, with no homozygous occurrence. Variant has been reported in ClinVar as Uncertain significance (★★).

• Frequency:
  • Genomes: not found (cov: 32)
  • Exomes 𝑓: 0.0000069 (0 hom.)
• Consequence: APC NM_000038.6 missense
• Clinical Significance: Uncertain significance criteria provided, multiple submitters, no conflicts U:6
• Conservation: PhyloP100: 6.92

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 -2 ACMG points.

• PM1: In a coiled_coil_region (size 121) in uniprot entity APC_HUMAN there are 9 pathogenic changes around while only 3 benign (75%) in NM_000038.6
• BS2: High AC in GnomAdExome4 at 10 AD gene.

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	Protein	UniProt
APC	NM_000038.6	c.673G>A	p.Glu225Lys	missense_variant	7/16	ENST00000257430.9	NP_000029.2

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Protein	Appris	UniProt
APC	ENST00000257430.9	c.673G>A	p.Glu225Lys	missense_variant	7/16	5	NM_000038.6	ENSP00000257430	P1

Frequencies

GnomAD3 genomes Cov.: 32

GnomAD3 exomes AF: 0.00000398 AC: 1 AN: 251030 Hom.: 0 AF XY: 0.00000737 AC XY: 1 AN XY: 135654

Gnomad AFR exome AF: 0.00

Gnomad AMR exome AF: 0.0000289

Gnomad ASJ exome AF: 0.00

Gnomad EAS exome AF: 0.00

Gnomad SAS exome AF: 0.00

Gnomad FIN exome AF: 0.00

Gnomad NFE exome AF: 0.00

Gnomad OTH exome AF: 0.00

GnomAD4 exome AF: 0.00000686 AC: 10 AN: 1458656 Hom.: 0 Cov.: 29 AF XY: 0.00000827 AC XY: 6 AN XY: 725566

Gnomad4 AFR exome AF: 0.00

Gnomad4 AMR exome AF: 0.0000224

Gnomad4 ASJ exome AF: 0.00

Gnomad4 EAS exome AF: 0.00

Gnomad4 SAS exome AF: 0.0000233

Gnomad4 FIN exome AF: 0.00

Gnomad4 NFE exome AF: 0.00000630

Gnomad4 OTH exome AF: 0.00

GnomAD4 genome Cov.: 32

ExAC AF: 0.00000824 AC: 1

ClinVar

Significance: Uncertain significance

Submissions summary: Uncertain:6

Revision: criteria provided, multiple submitters, no conflicts

Submissions by phenotype

Familial adenomatous polyposis 1 Uncertain:3

Uncertain significance, criteria provided, single submitter	clinical testing	MGZ Medical Genetics Center	Jul 28, 2022	- -
Uncertain significance, criteria provided, single submitter	clinical testing	Labcorp Genetics (formerly Invitae), Labcorp	Nov 14, 2023	This sequence change replaces glutamic acid, which is acidic and polar, with lysine, which is basic and polar, at codon 225 of the APC protein (p.Glu225Lys). This variant is present in population databases (rs768233232, gnomAD 0.003%). 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: 490342). 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	Aug 24, 2023	- -

Hereditary cancer-predisposing syndrome Uncertain:2

Uncertain significance, criteria provided, single submitter	clinical testing	Color Diagnostics, LLC DBA Color Health	Nov 01, 2023	This missense variant replaces glutamic acid with lysine at codon 225 of the APC protein. Computational prediction is inconclusive regarding the impact of this variant on protein structure and function (internally defined REVEL score threshold 0.5 < inconclusive < 0.7, PMID: 27666373). To our knowledge, functional studies have not been reported for this variant. This variant has not been reported in individuals affected with APC-related disorders in the literature. This variant has been identified in 1/251030 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. -
Uncertain significance, criteria provided, single submitter	clinical testing	Ambry Genetics	May 24, 2023	The p.E225K variant (also known as c.673G>A), located in coding exon 6 of the APC gene, results from a G to A substitution at nucleotide position 673. The glutamic acid at codon 225 is replaced by lysine, an amino acid with similar properties. 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. -

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

Nov 20, 2023

This missense variant replaces glutamic acid with lysine at codon 225 of the APC protein. Computational prediction is inconclusive regarding the impact of this variant on protein structure and function (internally defined REVEL score threshold 0.5 < inconclusive < 0.7, PMID: 27666373). To our knowledge, functional studies have not been reported for this variant. This variant has not been reported in individuals affected with APC-related disorders in the literature. This variant has been identified in 1/251030 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	Pathogenic	0.73
BayesDel_addAF	Pathogenic	0.17	D
BayesDel_noAF	Uncertain	0.090
CADD	Pathogenic	30
DANN	Pathogenic	1.0
DEOGEN2	Pathogenic	0.83	D;D;T
Eigen	Pathogenic	0.75
Eigen_PC	Pathogenic	0.70
FATHMM_MKL	Pathogenic	0.98	D
LIST_S2	Uncertain	0.97	.;D;D
M_CAP	Uncertain	0.18	D
MetaRNN	Uncertain	0.71	D;D;D
MetaSVM	Pathogenic	0.83	D
MutationAssessor	Uncertain	2.3	M;M;.
MutationTaster	Benign	1.0	D;D;D
PrimateAI	Pathogenic	0.82	D
PROVEAN	Uncertain	-3.0	D;D;D
REVEL	Uncertain	0.61
Sift	Uncertain	0.0050	D;D;D
Sift4G	Uncertain	0.0080	D;D;D
Polyphen		1.0	D;D;.
Vest4		0.83
MutPred		0.25		Loss of helix (P = 0.0167);Loss of helix (P = 0.0167);Loss of helix (P = 0.0167);
MVP		0.90
ClinPred		0.93	D
GERP RS		5.2
Varity_R		0.64
gMVP		0.70

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: rs768233232; hg19: chr5-112128170; COSMIC: COSV99970911;