rs878853416

chr5-112819237-G-Achr5-112819237-G-Cchr5-112819237-G-T

Variant summary

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

The NM_000038.6(APC):c.1205G>A(p.Arg402His) variant causes a missense change involving the alteration of a conserved nucleotide. The variant allele was found at a frequency of 0.00000205 in 1,461,626 control chromosomes in the GnomAD database, with no homozygous occurrence. 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. R402C) has been classified as Uncertain significance.

• Frequency:
  • Genomes: not found (cov: 32)
  • Exomes 𝑓: 0.0000021 (0 hom.)
• Consequence: APC NM_000038.6 missense
• Clinical Significance: Uncertain significance criteria provided, multiple submitters, no conflicts U:3
• Conservation: PhyloP100: 8.13

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.1205G>A	p.Arg402His	missense_variant	10/16	ENST00000257430.9

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Appris	UniProt
APC	ENST00000257430.9	c.1205G>A	p.Arg402His	missense_variant	10/16	5	NM_000038.6	P1

Frequencies

GnomAD3 genomes Cov.: 32

GnomAD4 exome AF: 0.00000205 AC: 3 AN: 1461626 Hom.: 0 Cov.: 33 AF XY: 0.00 AC XY: 0 AN XY: 727104

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: 0.00000270

Gnomad4 OTH exome AF: 0.00

GnomAD4 genome Cov.: 32

Bravo AF: 0.00000378

ClinVar

Significance: Uncertain significance

Submissions summary: Uncertain:3

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

Apr 28, 2022

This sequence change replaces arginine, which is basic and polar, with histidine, which is basic and polar, at codon 402 of the APC protein (p.Arg402His). 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: 236557). Algorithms developed to predict the effect of missense changes on protein structure and function are either unavailable or 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. -

not provided Uncertain:1

Uncertain significance, criteria provided, single submitter

clinical testing

GeneDx

Mar 15, 2018

This variant is denoted APC c.1205G>A at the cDNA level, p.Arg402His (R402H) at the protein level, and results in the change of an Arginine to a Histidine (CGT>CAT). This variant has not, to our knowledge, been published in the literature as pathogenic or benign. APC Arg402His was not observed in large population cohorts (Lek 2016). This variant is not located in a known functional domain. In silico analysis, which includes protein predictors and evolutionary conservation, supports a deleterious effect. Based on currently available evidence, it is unclear whether APC Arg402His is a pathogenic or benign variant. We consider it to be a variant of uncertain significance. -

Hereditary cancer-predisposing syndrome Uncertain:1

Uncertain significance, criteria provided, single submitter

clinical testing

Ambry Genetics

Mar 18, 2022

The p.R402H variant (also known as c.1205G>A), located in coding exon 9 of the APC gene, results from a G to A substitution at nucleotide position 1205. The arginine at codon 402 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	Pathogenic	0.86
BayesDel_addAF	Pathogenic	0.21	D
BayesDel_noAF	Uncertain	0.060
Cadd	Pathogenic	33
Dann	Pathogenic	1.0
Eigen	Pathogenic	0.78
Eigen_PC	Pathogenic	0.81
FATHMM_MKL	Pathogenic	0.99	D
LIST_S2	Uncertain	0.96	D;.;D;D
M_CAP	Benign	0.055	D
MetaRNN	Uncertain	0.68	D;D;D;D
MetaSVM	Benign	-0.30	T
MutationTaster	Benign	1.0	D;D;D
PrimateAI	Pathogenic	0.94	D
PROVEAN	Uncertain	-3.3	D;D;D;D
REVEL	Uncertain	0.46
Sift	Uncertain	0.0030	D;D;D;D
Sift4G	Uncertain	0.023	D;D;D;D
Polyphen		0.99	.;D;D;.
Vest4		0.69, 0.71
MutPred		0.42		.;Loss of MoRF binding (P = 0.0152);Loss of MoRF binding (P = 0.0152);Loss of MoRF binding (P = 0.0152);
MVP		0.80
ClinPred		1.0	D
GERP RS		5.9
Varity_R		0.64
gMVP		0.62

Splicing

Name	Calibrated prediction	Score	Prediction
SpliceAI score (max)		0.040		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: rs878853416; hg19: chr5-112154934;