5-112839376-C-T

Variant names:

• chr5-112839376-C-T
• rs1064794636
• NM_000038.6:c.3782C>T

Variant summary

Our verdict is Uncertain significance. Variant got 2 ACMG points: 2P and 0B. PM2

The NM_000038.6(APC):​c.3782C>T​(p.Thr1261Ile) variant causes a missense change. The variant allele was found at a frequency of 0.00000274 in 1,461,668 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: 0.0000027 (0 hom.)
• Consequence: APC NM_000038.6 missense
• Clinical Significance: Uncertain significance criteria provided, multiple submitters, no conflicts U:4
• Conservation: PhyloP100: 4.64

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 Uncertain_significance. Variant got 2 ACMG points.

• PM2: Very rare variant in population databases, with high coverage

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	MANE	Protein	UniProt
APC	NM_000038.6	c.3782C>T	p.Thr1261Ile	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	c.3782C>T	p.Thr1261Ile	missense_variant	Exon 16 of 16	5	NM_000038.6	ENSP00000257430.4
ENSG00000258864	ENST00000520401.1	n.228+10404C>T		intron_variant	Intron 3 of 7	3		ENSP00000454861.1

Frequencies

GnomAD3 genomes Cov.: 32

GnomAD4 exome AF: 0.00000274 AC: 4 AN: 1461668 Hom.: 0 Cov.: 33 AF XY: 0.00000413 AC XY: 3 AN XY: 727140

Gnomad4 AFR exome AF: 0.00

Gnomad4 AMR exome AF: 0.00

Gnomad4 ASJ exome AF: 0.00

Gnomad4 EAS exome AF: 0.00

Gnomad4 SAS exome AF: 0.00

Gnomad4 FIN exome AF: 0.00

Gnomad4 NFE exome AF: 8.99e-7

Gnomad4 OTH exome AF: 0.0000497

GnomAD4 genome Cov.: 32

ClinVar

Significance: Uncertain significance

Submissions summary: Uncertain:4

Revision: criteria provided, multiple submitters, no conflicts

Submissions by phenotype

Familial adenomatous polyposis 1 Uncertain:2

Aug 11, 2023

Baylor Genetics

Significance: Uncertain significance

Review Status: criteria provided, single submitter

Collection Method: clinical testing

- -

Dec 29, 2024

Labcorp Genetics (formerly Invitae), Labcorp

Significance: Uncertain significance

Review Status: criteria provided, single submitter

Collection Method: clinical testing

This sequence change replaces threonine, which is neutral and polar, with isoleucine, which is neutral and non-polar, at codon 1261 of the APC protein (p.Thr1261Ile). This variant is not present in population databases (gnomAD no frequency). 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: 420688). 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%. 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. -

not provided Uncertain:1

Jul 05, 2023

GeneDx

Significance: Uncertain significance

Review Status: criteria provided, single submitter

Collection Method: clinical testing

Not observed at significant frequency in large population cohorts (gnomAD); In silico analysis supports that this missense variant has a deleterious effect on protein structure/function; Has not been previously published as pathogenic or benign to our knowledge; This variant is associated with the following publications: (PMID: 25742471) -

Hereditary cancer-predisposing syndrome Uncertain:1

Apr 05, 2024

Ambry Genetics

Significance: Uncertain significance

Review Status: criteria provided, single submitter

Collection Method: clinical testing

The p.T1261I variant (also known as c.3782C>T), located in coding exon 15 of the APC gene, results from a C to T substitution at nucleotide position 3782. The threonine at codon 1261 is replaced by isoleucine, 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. -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Pathogenic	0.90
BayesDel_addAF	Pathogenic	0.17	D
BayesDel_noAF	Uncertain	0.010
CADD	Uncertain	25
DANN	Uncertain	1.0
DEOGEN2	Uncertain	0.77	D;D;T
Eigen	Uncertain	0.52
Eigen_PC	Uncertain	0.60
FATHMM_MKL	Uncertain	0.92	D
LIST_S2	Uncertain	0.97	.;D;D
M_CAP	Benign	0.039	D
MetaRNN	Uncertain	0.63	D;D;D
MetaSVM	Uncertain	-0.23	T
MutationAssessor	Uncertain	2.5	M;M;.
PrimateAI	Pathogenic	0.81	D
PROVEAN	Uncertain	-2.9	D;D;N
REVEL	Uncertain	0.44
Sift	Uncertain	0.0080	D;D;D
Sift4G	Uncertain	0.029	D;D;D
Polyphen		0.81	P;P;.
Vest4		0.78
MutPred		0.50		Gain of catalytic residue at T1261 (P = 0.0074);Gain of catalytic residue at T1261 (P = 0.0074);Gain of catalytic residue at T1261 (P = 0.0074);
MVP		0.80
ClinPred		0.97	D
GERP RS		6.0
Varity_R		0.49
gMVP		0.71

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: rs1064794636; hg19: chr5-112175073; COSMIC: COSV99971657; COSMIC: COSV99971657;