rs777219286

Positions:

• chr5-112827956-A-C
• chr5-112827956-A-G
• chr5-112827956-A-T

Variant summary

Our verdict is Uncertain significance. Variant got 4 ACMG points: 4P and 0B. PM1 PM2

The NM_000038.6(APC):​c.1576A>C​(p.Met526Leu) variant causes a missense change involving the alteration of a conserved nucleotide. The variant was absent in control chromosomes in GnomAD project. 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. M526V) has been classified as Likely benign.

• Frequency: Genomes: not found (cov: 32)
• Consequence: APC NM_000038.6 missense
• Clinical Significance: Uncertain significance criteria provided, single submitter U:1
• Conservation: PhyloP100: 8.95

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 Uncertain_significance. Variant got 4 ACMG points.

• PM1: In a repeat ARM 2 (size 42) in uniprot entity APC_HUMAN there are 7 pathogenic changes around while only 2 benign (78%) in NM_000038.6
• PM2: Very rare variant in population databases, with high coverage

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	Protein	UniProt
APC	NM_000038.6	c.1576A>C	p.Met526Leu	missense_variant	13/16	ENST00000257430.9	NP_000029.2

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Protein	Appris	UniProt
APC	ENST00000257430.9	c.1576A>C	p.Met526Leu	missense_variant	13/16	5	NM_000038.6	ENSP00000257430	P1

Frequencies

GnomAD3 genomes Cov.: 32

GnomAD4 exome Cov.: 30

GnomAD4 genome Cov.: 32

ClinVar

Significance: Uncertain significance

Submissions summary: Uncertain:1

Revision: criteria provided, single submitter

Submissions by phenotype

Hereditary cancer-predisposing syndrome Uncertain:1

Uncertain significance, criteria provided, single submitter

clinical testing

Color Diagnostics, LLC DBA Color Health

Aug 01, 2019

This missense variant replaces methionine with leucine at codon 526 of the APC protein. Computational prediction tools and conservation analyses are inconclusive regarding the impact of this variant on the protein function. Computational splicing tools suggest that this variant may not impact RNA splicing. To our knowledge, functional assays have not been performed for this variant nor has this variant been reported in individuals affected with hereditary cancer in the literature. This variant has not been identified in the general population by the Genome Aggregation Database (gnomAD). 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	Uncertain	0.47
BayesDel_addAF	Uncertain	0.16	D
BayesDel_noAF	Uncertain	-0.010
CADD	Uncertain	24
DANN	Benign	0.96
DEOGEN2	Uncertain	0.57	.;D;D;T;T
Eigen	Benign	0.17
Eigen_PC	Uncertain	0.35
FATHMM_MKL	Pathogenic	0.99	D
LIST_S2	Uncertain	0.91	D;.;D;D;D
M_CAP	Benign	0.032	D
MetaRNN	Uncertain	0.63	D;D;D;D;D
MetaSVM	Benign	-0.79	T
MutationAssessor	Benign	0.96	.;L;L;.;.
MutationTaster	Benign	1.0	D;D;D
PrimateAI	Pathogenic	0.81	D
PROVEAN	Uncertain	-2.4	N;N;N;N;.
REVEL	Uncertain	0.33
Sift	Benign	0.20	T;T;T;T;.
Sift4G	Benign	0.28	T;T;T;T;T
Polyphen		0.12	.;B;B;.;.
Vest4		0.77, 0.76
MutPred		0.63		.;Loss of MoRF binding (P = 0.0851);Loss of MoRF binding (P = 0.0851);Loss of MoRF binding (P = 0.0851);.;
MVP		0.89
ClinPred		0.85	D
GERP RS		5.4
Varity_R		0.61
gMVP		0.65

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: rs777219286; hg19: chr5-112163653;