5-112839366-A-G

Position:

• chr5-112839366-A-G

Variant summary

Our verdict is Likely benign. Variant got -2 ACMG points: 2P and 4B. PM2 BS2

The NM_000038.6(APC):​c.3772A>G​(p.Thr1258Ala) variant causes a missense change. The variant allele was found at a frequency of 0.00000342 in 1,461,304 control chromosomes in the GnomAD database, with no homozygous occurrence. Variant has been reported in ClinVar as Uncertain significance (★★). Synonymous variant affecting the same amino acid position (i.e. T1258T) has been classified as Likely benign.

• Frequency:
  • Genomes: not found (cov: 32)
  • Exomes 𝑓: 0.0000034 (0 hom.)
• Consequence: APC NM_000038.6 missense
• Clinical Significance: Uncertain significance criteria provided, multiple submitters, no conflicts U:2
• Conservation: PhyloP100: 5.68

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]

ENSG00000258864 (HGNC:):

ACMG classification

Verdict is Likely_benign. Variant got -2 ACMG points.

• PM2: Very rare variant in population databases, with high coverage
• BS2: High AC in GnomAdExome4 at 5 AD gene.

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	Protein	UniProt
APC	NM_000038.6	c.3772A>G	p.Thr1258Ala	missense_variant	16/16	ENST00000257430.9	NP_000029.2

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Protein	Appris	UniProt
APC	ENST00000257430.9	c.3772A>G	p.Thr1258Ala	missense_variant	16/16	5	NM_000038.6	ENSP00000257430.4
ENSG00000258864	ENST00000520401.1	n.228+10394A>G		intron_variant		3		ENSP00000454861.1

Frequencies

GnomAD3 genomes Cov.: 32

GnomAD4 exome AF: 0.00000342 AC: 5 AN: 1461304 Hom.: 0 Cov.: 33 AF XY: 0.00000275 AC XY: 2 AN XY: 726926

Gnomad4 AFR exome AF: 0.00

Gnomad4 AMR exome AF: 0.00

Gnomad4 ASJ exome AF: 0.00

Gnomad4 EAS exome AF: 0.0000252

Gnomad4 SAS exome AF: 0.0000116

Gnomad4 FIN exome AF: 0.00

Gnomad4 NFE exome AF: 0.00000270

Gnomad4 OTH exome AF: 0.00

GnomAD4 genome Cov.: 32

ClinVar

Significance: Uncertain significance

Submissions summary: Uncertain:2

Revision: criteria provided, multiple submitters, no conflicts

Submissions by phenotype

Familial adenomatous polyposis 1 Uncertain:1

Uncertain significance, criteria provided, single submitter

clinical testing

Labcorp Genetics (formerly Invitae), Labcorp

Dec 04, 2020

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 are either unavailable or do not agree on the potential impact of this missense change (SIFT: "Tolerated"; PolyPhen-2: "Probably Damaging"; Align-GVGD: "Class C0"). This variant has not been reported in the literature in individuals with APC-related disease. This variant is not present in population databases (ExAC no frequency). This sequence change replaces threonine with alanine at codon 1258 of the APC protein (p.Thr1258Ala). The threonine residue is highly conserved and there is a small physicochemical difference between threonine and alanine. -

Hereditary cancer-predisposing syndrome Uncertain:1

Uncertain significance, criteria provided, single submitter

clinical testing

Ambry Genetics

Jan 07, 2023

The p.T1258A variant (also known as c.3772A>G), located in coding exon 15 of the APC gene, results from an A to G substitution at nucleotide position 3772. The threonine at codon 1258 is replaced by alanine, an amino acid with similar properties. This amino acid position is conserved. 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. -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Benign	0.30
BayesDel_addAF	Uncertain	0.037	T
BayesDel_noAF	Benign	-0.18
CADD	Uncertain	25
DANN	Uncertain	1.0
DEOGEN2	Uncertain	0.51	D;D;T
Eigen	Benign	0.086
Eigen_PC	Uncertain	0.22
FATHMM_MKL	Uncertain	0.92	D
LIST_S2	Uncertain	0.94	.;D;D
M_CAP	Benign	0.044	D
MetaRNN	Uncertain	0.47	T;T;T
MetaSVM	Benign	-0.66	T
MutationAssessor	Benign	2.0	M;M;.
PrimateAI	Uncertain	0.65	T
PROVEAN	Benign	-0.79	N;N;N
REVEL	Uncertain	0.31
Sift	Uncertain	0.013	D;D;D
Sift4G	Benign	0.21	T;T;T
Polyphen		0.31	B;B;.
Vest4		0.68
MutPred		0.58		Loss of sheet (P = 0.0315);Loss of sheet (P = 0.0315);Loss of sheet (P = 0.0315);
MVP		0.80
ClinPred		0.88	D
GERP RS		4.8
Varity_R		0.16
gMVP		0.67

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: rs774968240; hg19: chr5-112175063;