5-112827139-A-T

Variant summary

Our verdict is Uncertain significance. Variant got 1 ACMG points: 2P and 1B. PM2 BP4

The NM_000038.6(APC):c.1440A>T(p.Gln480His) variant causes a missense change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.00000657 in 152,146 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a benign outcome for this variant. Variant has been reported in ClinVar as Uncertain significance (★★). Another nucleotide change resulting in same amino acid change has been previously reported as Uncertain significancein ClinVar. Another variant affecting the same amino acid position, but resulting in a different missense (i.e. Q480P) has been classified as Uncertain significance.

• Frequency: Genomes: 𝑓 0.0000066 (0 hom., cov: 32)
• Consequence: APC NM_000038.6 missense
• Clinical Significance: Uncertain significance criteria provided, multiple submitters, no conflicts U:3
• Conservation: PhyloP100: 1.42

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 1 ACMG points.

• PM2: Very rare variant in population databases, with high coverage
• BP4: Computational evidence support a benign effect (MetaRNN=0.30039674).

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	UniProt
APC	NM_000038.6	c.1440A>T	p.Gln480His	missense_variant	12/16	ENST00000257430.9

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Appris	UniProt
APC	ENST00000257430.9	c.1440A>T	p.Gln480His	missense_variant	12/16	5	NM_000038.6	P1

Frequencies

GnomAD3 genomes AF: 0.00000657 AC: 1 AN: 152146 Hom.: 0 Cov.: 32

Gnomad AFR AF: 0.0000241

Gnomad AMI AF: 0.00

Gnomad AMR AF: 0.00

Gnomad ASJ AF: 0.00

Gnomad EAS AF: 0.00

Gnomad SAS AF: 0.00

Gnomad FIN AF: 0.00

Gnomad MID AF: 0.00

Gnomad NFE AF: 0.00

Gnomad OTH AF: 0.00

GnomAD4 exome Cov.: 30

GnomAD4 genome AF: 0.00000657 AC: 1 AN: 152146 Hom.: 0 Cov.: 32 AF XY: 0.0000135 AC XY: 1 AN XY: 74326

Gnomad4 AFR AF: 0.0000241

Gnomad4 AMR AF: 0.00

Gnomad4 ASJ AF: 0.00

Gnomad4 EAS AF: 0.00

Gnomad4 SAS AF: 0.00

Gnomad4 FIN AF: 0.00

Gnomad4 NFE AF: 0.00

Gnomad4 OTH AF: 0.00

Bravo AF: 0.00000756

ClinVar

Significance: Uncertain significance

Submissions summary: Uncertain:3

Revision: criteria provided, multiple submitters, no conflicts

Submissions by phenotype

not specified Uncertain:1

Uncertain significance, criteria provided, single submitter

clinical testing

Women's Health and Genetics/Laboratory Corporation of America, LabCorp

Dec 11, 2017

Variant summary: The APC c.1440A>T (p.Gln480His) variant involves the alteration of a non-conserved nucleotide and is predicted to be benign by 3/4 in silico tools (SNPsandGO not captured due to low reliability index). This variant is absent in 245924 control chromosomes (gnomAD). One clinical laboratory in ClinVar and a reputable database (UMD) have classified this variant as uncertain significance. The variant of interest has not, to our knowledge, been reported in affected individuals via publications, nor has it been evaluated for functional impact by in vivo/vitro studies. Because of the absence of clinical information and the lack of functional studies, the variant is classified as a variant of uncertain significance (VUS) until additional information becomes available. -

Familial adenomatous polyposis 1 Uncertain:1

Uncertain significance, criteria provided, single submitter

clinical testing

Invitae

Dec 03, 2023

This sequence change replaces glutamine, which is neutral and polar, with histidine, which is basic and polar, at codon 480 of the APC protein (p.Gln480His). 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: 216150). 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. -

Hereditary cancer-predisposing syndrome Uncertain:1

Uncertain significance, criteria provided, single submitter

clinical testing

Ambry Genetics

Feb 16, 2022

The p.Q480H variant (also known as c.1440A>T), located in coding exon 11 of the APC gene, results from an A to T substitution at nucleotide position 1440. The glutamine at codon 480 is replaced by histidine, an amino acid with highly 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	Uncertain	0.54
BayesDel_addAF	Uncertain	0.11	D
BayesDel_noAF	Uncertain	-0.080
Cadd	Benign	18
Dann	Uncertain	0.98
Eigen	Benign	-0.34
Eigen_PC	Benign	-0.21
FATHMM_MKL	Uncertain	0.88	D
LIST_S2	Benign	0.82	T;.;D;T;T
M_CAP	Benign	0.018	T
MetaRNN	Benign	0.30	T;T;T;T;T
MetaSVM	Benign	-0.96	T
MutationTaster	Benign	1.0	D;D;D
PrimateAI	Pathogenic	0.79	T
PROVEAN	Uncertain	-3.8	D;D;D;D;.
REVEL	Uncertain	0.37
Sift	Benign	0.16	T;T;T;T;.
Sift4G	Benign	0.31	T;T;T;T;T
Polyphen		0.081	.;B;B;.;.
Vest4		0.75, 0.67
MutPred		0.51		.;Gain of catalytic residue at L479 (P = 0.2177);Gain of catalytic residue at L479 (P = 0.2177);Gain of catalytic residue at L479 (P = 0.2177);.;
MVP		0.89
ClinPred		0.31	T
GERP RS		0.81
Varity_R		0.70
gMVP		0.41

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: rs863224537; hg19: chr5-112162836;