5-112841977-C-G

Variant summary

Our verdict is Uncertain significance. Variant got 0 ACMG points: 2P and 2B. PM2 BP4_Moderate

The NM_000038.6(APC):c.6383C>G(p.Ala2128Gly) variant causes a missense change. The variant allele was found at a frequency of 0.00000274 in 1,461,070 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a benign outcome for this variant. 12/21 in silico tools predict a benign outcome for this variant. 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. A2128V) has been classified as Likely benign.

• 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:2
• Conservation: PhyloP100: 4.50

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 0 ACMG points.

• PM2: Very rare variant in population databases, with high coverage
• BP4: Computational evidence support a benign effect (MetaRNN=0.17586973).

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	UniProt
APC	NM_000038.6	c.6383C>G	p.Ala2128Gly	missense_variant	16/16	ENST00000257430.9

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Appris	UniProt
APC	ENST00000257430.9	c.6383C>G	p.Ala2128Gly	missense_variant	16/16	5	NM_000038.6	P1

Frequencies

GnomAD3 genomes Cov.: 32

GnomAD3 exomes AF: 0.00000399 AC: 1 AN: 250876 Hom.: 0 AF XY: 0.00000737 AC XY: 1 AN XY: 135598

Gnomad AFR exome AF: 0.00

Gnomad AMR exome AF: 0.00

Gnomad ASJ exome AF: 0.00

Gnomad EAS exome AF: 0.00

Gnomad SAS exome AF: 0.0000327

Gnomad FIN exome AF: 0.00

Gnomad NFE exome AF: 0.00

Gnomad OTH exome AF: 0.00

GnomAD4 exome AF: 0.00000274 AC: 4 AN: 1461070 Hom.: 0 Cov.: 34 AF XY: 0.00000275 AC XY: 2 AN XY: 726916

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: 0.0000232

Gnomad4 FIN exome AF: 0.00

Gnomad4 NFE exome AF: 0.00000180

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

Invitae

Nov 19, 2021

Algorithms developed to predict the effect of sequence changes on RNA splicing suggest that this variant may create or strengthen a splice site. 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 (SIFT, PolyPhen-2, Align-GVGD) all suggest that this variant is likely to be tolerated. This variant has not been reported in the literature in individuals affected with APC-related conditions. This variant is present in population databases (no rsID available, gnomAD 0.003%). This sequence change replaces alanine, which is neutral and non-polar, with glycine, which is neutral and non-polar, at codon 2128 of the APC protein (p.Ala2128Gly). -

Hereditary cancer-predisposing syndrome Uncertain:1

Uncertain significance, criteria provided, single submitter

clinical testing

Ambry Genetics

Jun 09, 2022

The p.A2128G variant (also known as c.6383C>G), located in coding exon 15 of the APC gene, results from a C to G substitution at nucleotide position 6383. The alanine at codon 2128 is replaced by glycine, 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	0.10
BayesDel_addAF	Uncertain	0.031	T
BayesDel_noAF	Benign	-0.10
Cadd	Benign	20
Dann	Uncertain	0.98
DEOGEN2	Uncertain	0.47	T;T
Eigen	Benign	-0.031
Eigen_PC	Benign	0.22
FATHMM_MKL	Uncertain	0.96	D
M_CAP	Benign	0.035	D
MetaRNN	Benign	0.18	T;T
MetaSVM	Uncertain	-0.13	T
MutationAssessor	Benign	0.14	N;N
MutationTaster	Benign	0.87	D;D;D
PrimateAI	Uncertain	0.57	T
PROVEAN	Benign	-0.62	N;N
REVEL	Benign	0.24
Sift	Benign	0.23	T;T
Sift4G	Benign	0.25	T;T
Polyphen		0.0050	B;B
Vest4		0.43
MutPred		0.35		Gain of loop (P = 0.0045);Gain of loop (P = 0.0045);
MVP		0.86
ClinPred		0.33	T
GERP RS		6.0
Varity_R		0.082
gMVP		0.24

Splicing

Name	Calibrated prediction	Score	Prediction
SpliceAI score (max)		0.010		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: rs753228011; hg19: chr5-112177674;