5-112843018-C-T

Variant summary

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

The NM_000038.6(APC):c.7424C>T(p.Thr2475Ile) variant causes a missense change involving the alteration of a non-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. T2475S) has been classified as Uncertain significance.

• Frequency: Genomes: not found (cov: 32)
• Consequence: APC NM_000038.6 missense
• Clinical Significance: Uncertain significance criteria provided, multiple submitters, no conflicts U:3
• Conservation: PhyloP100: 2.31

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 2 ACMG points.

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

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	UniProt
APC	NM_000038.6	c.7424C>T	p.Thr2475Ile	missense_variant	16/16	ENST00000257430.9

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Appris	UniProt
APC	ENST00000257430.9	c.7424C>T	p.Thr2475Ile	missense_variant	16/16	5	NM_000038.6	P1

Frequencies

GnomAD3 genomes Cov.: 32

GnomAD4 exome Cov.: 34

GnomAD4 genome Cov.: 32

ClinVar

Significance: Uncertain significance

Submissions summary: Uncertain:3

Revision: criteria provided, multiple submitters, no conflicts

Submissions by phenotype

Hereditary cancer-predisposing syndrome Uncertain:2

Uncertain significance, criteria provided, single submitter	clinical testing	Ambry Genetics	Dec 23, 2015	The p.T2475I variant (also known as c.7424C>T), located in coding exon 15 of the APC gene, results from a C to T substitution at nucleotide position 7424. The threonine at codon 2475 is replaced by isoleucine, an amino acid with similar properties. This variant was not reported in population based cohorts in the following databases: Database of Single Nucleotide Polymorphisms (dbSNP), NHLBI Exome Sequencing Project (ESP), and 1000 Genomes Project. In the ESP, this variant was not observed in 6501 samples (13002 alleles) with coverage at this position. To date, this alteration has been detected with an allele frequency of approximately 0.001% (greater than 70000 alleles tested) in our clinical cohort. This amino acid position is well 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 p.T2475I remains unclear. -
Uncertain significance, criteria provided, single submitter	clinical testing	Color Diagnostics, LLC DBA Color Health	Dec 04, 2023	This missense variant replaces threonine with isoleucine at codon 2475 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 not been reported in individuals affected with APC-related disorders in the literature. This variant has not been identified 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. -

Familial adenomatous polyposis 1 Uncertain:1

Uncertain significance, criteria provided, single submitter

clinical testing

Invitae

Jul 13, 2021

This sequence change replaces threonine with isoleucine at codon 2475 of the APC protein (p.Thr2475Ile). The threonine residue is highly conserved and there is a moderate physicochemical difference between threonine and isoleucine. This variant is not present in population databases (ExAC no frequency). This variant has not been reported in the literature in individuals with APC-related disease. Algorithms developed to predict the effect of missense changes on protein structure and function do not agree on the potential impact of this missense change (SIFT: "Deleterious"; PolyPhen-2: "Possibly Damaging"; Align-GVGD: "Class C0"). 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. -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Benign	0.21
BayesDel_addAF	Uncertain	0.066	T
BayesDel_noAF	Benign	-0.14
Cadd	Benign	20
Dann	Uncertain	1.0
DEOGEN2	Benign	0.38	T;T
Eigen	Uncertain	0.38
Eigen_PC	Uncertain	0.39
FATHMM_MKL	Uncertain	0.88	D
M_CAP	Uncertain	0.090	D
MetaRNN	Uncertain	0.49	T;T
MetaSVM	Uncertain	0.15	D
MutationAssessor	Benign	1.8	L;L
MutationTaster	Benign	1.0	D;D;D
PrimateAI	Uncertain	0.51	T
PROVEAN	Benign	-0.74	N;N
REVEL	Uncertain	0.34
Sift	Benign	0.045	D;D
Sift4G	Benign	0.23	T;T
Polyphen		0.95	P;P
Vest4		0.45
MutPred		0.33		Loss of phosphorylation at T2475 (P = 0.0116);Loss of phosphorylation at T2475 (P = 0.0116);
MVP		0.77
ClinPred		0.77	D
GERP RS		5.1
Varity_R		0.12
gMVP		0.43

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: rs1554088345; hg19: chr5-112178715;