chr5-112818966-G-A

Position:

• chr5-112818966-G-A

Variant summary

Our verdict is Likely benign. Variant got -2 ACMG points: 2P and 4B. PP3_Moderate BS2

The NM_000038.6(APC):​c.934G>A​(p.Val312Met) variant causes a missense, splice region change involving the alteration of a conserved nucleotide. The variant allele was found at a frequency of 0.00000547 in 1,461,654 control chromosomes in the GnomAD database, with no homozygous occurrence. 2/3 splice prediction tools predicting alterations to normal splicing. Variant has been reported in ClinVar as Uncertain significance (★★).

• Frequency:
  • Genomes: not found (cov: 32)
  • Exomes 𝑓: 0.0000055 (0 hom.)
• Consequence: APC NM_000038.6 missense, splice_region
• Scores: Splicing: ADA: 0.9997
• Clinical Significance: Uncertain significance criteria provided, multiple submitters, no conflicts U:4
• Conservation: PhyloP100: 10.0

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 Likely_benign. Variant got -2 ACMG points.

• PP3: Splicing scoreres supports a deletorius effect: Scorers claiming Pathogenic: dbscSNV1_ADA, dbscSNV1_RF. No scorers claiming Uncertain. Scorers claiming Benign: max_spliceai.
• BS2: High AC in GnomAdExome4 at 8 AD gene.

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	Protein	UniProt
APC	NM_000038.6	c.934G>A	p.Val312Met	missense_variant, splice_region_variant	10/16	ENST00000257430.9	NP_000029.2

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Protein	Appris	UniProt
APC	ENST00000257430.9	c.934G>A	p.Val312Met	missense_variant, splice_region_variant	10/16	5	NM_000038.6	ENSP00000257430	P1

Frequencies

GnomAD3 genomes Cov.: 32

GnomAD4 exome AF: 0.00000547 AC: 8 AN: 1461654 Hom.: 0 Cov.: 33 AF XY: 0.00000275 AC XY: 2 AN XY: 727130

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: 0.00000630

Gnomad4 OTH exome AF: 0.0000166

GnomAD4 genome Cov.: 32

ClinVar

Significance: Uncertain significance

Submissions summary: Uncertain:4

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	May 16, 2023	The p.V312M variant (also known as c.934G>A) is located in coding exon 9 of the APC gene. The valine at codon 312 is replaced by methionine, an amino acid with highly similar properties. This change occurs in the first base pair of coding exon 9. 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. -
Uncertain significance, criteria provided, single submitter	clinical testing	Color Diagnostics, LLC DBA Color Health	Sep 25, 2023	This missense variant replaces valine with methionine at codon 312 of the APC protein. Computational prediction is inconclusive regarding the impact of this variant on protein structure and function (internally defined REVEL score threshold 0.5 < inconclusive < 0.7, 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

Labcorp Genetics (formerly Invitae), Labcorp

Sep 05, 2023

This sequence change replaces valine, which is neutral and non-polar, with methionine, which is neutral and non-polar, at codon 312 of the APC protein (p.Val312Met). 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: 411396). An algorithm developed to predict the effect of missense changes on protein structure and function (PolyPhen-2) suggests that this variant is likely to be disruptive. 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

Uncertain significance, criteria provided, single submitter

clinical testing

Mayo Clinic Laboratories, Mayo Clinic

Sep 11, 2020

- -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Pathogenic	0.97
BayesDel_addAF	Pathogenic	0.47	D
BayesDel_noAF	Pathogenic	0.44
CADD	Pathogenic	33
DANN	Uncertain	1.0
DEOGEN2	Pathogenic	0.84	.;D;D;T
Eigen	Pathogenic	0.80
Eigen_PC	Pathogenic	0.83
FATHMM_MKL	Pathogenic	1.0	D
LIST_S2	Uncertain	0.97	D;.;D;D
M_CAP	Pathogenic	0.30	D
MetaRNN	Uncertain	0.68	D;D;D;D
MetaSVM	Pathogenic	1.0	D
MutationAssessor	Uncertain	2.4	.;M;M;.
MutationTaster	Benign	1.0	D;D;D
PrimateAI	Pathogenic	0.88	D
PROVEAN	Uncertain	-2.9	D;D;D;D
REVEL	Pathogenic	0.70
Sift	Benign	0.085	T;D;D;T
Sift4G	Benign	0.073	T;D;D;T
Polyphen		0.88	.;P;P;.
Vest4		0.92, 0.84
MutPred		0.26		.;Loss of methylation at K311 (P = 0.0296);Loss of methylation at K311 (P = 0.0296);Loss of methylation at K311 (P = 0.0296);
MVP		0.98
ClinPred		0.95	D
GERP RS		5.7
RBP_binding_hub_radar		0.0
RBP_regulation_power_radar		1.7
Varity_R		0.46
gMVP		0.57

Splicing

Name	Calibrated prediction	Score	Prediction
dbscSNV1_ADA	Pathogenic	1.0
dbscSNV1_RF	Pathogenic	0.92
SpliceAI score (max)		0.13		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: rs1060503285; hg19: chr5-112154663; COSMIC: COSV57359333; COSMIC: COSV57359333;