rs200794097

chr5-112840986-A-Cchr5-112840986-A-Gchr5-112840986-A-T

Variant summary

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

The NM_000038.6(APC):c.5392A>C(p.Asn1798His) variant causes a missense change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.000000685 in 1,460,080 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a benign outcome for this variant. 14/21 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. N1798D) has been classified as Likely benign.

• Frequency:
  • Genomes: not found (cov: 33)
  • Exomes 𝑓: 6.8e-7 (0 hom.)
• Consequence: APC NM_000038.6 missense
• Clinical Significance: Uncertain significance criteria provided, multiple submitters, no conflicts U:3
• Conservation: PhyloP100: 3.37

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=0.22165394).

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	UniProt
APC	NM_000038.6	c.5392A>C	p.Asn1798His	missense_variant	16/16	ENST00000257430.9

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Appris	UniProt
APC	ENST00000257430.9	c.5392A>C	p.Asn1798His	missense_variant	16/16	5	NM_000038.6	P1

Frequencies

GnomAD3 genomes Cov.: 33

GnomAD4 exome AF: 6.85e-7 AC: 1 AN: 1460080 Hom.: 0 Cov.: 54 AF XY: 0.00 AC XY: 0 AN XY: 726470

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: 9.00e-7

Gnomad4 OTH exome AF: 0.00

GnomAD4 genome Cov.: 33

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

Quest Diagnostics Nichols Institute San Juan Capistrano

Apr 01, 2017

- -

Familial adenomatous polyposis 1 Uncertain:1

Uncertain significance, criteria provided, single submitter

clinical testing

Invitae

Aug 26, 2021

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 conditions. ClinVar contains an entry for this variant (Variation ID: 438881). 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, but these predictions have not been confirmed by published functional studies and their clinical significance is uncertain. 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. This sequence change replaces asparagine with histidine at codon 1798 of the APC protein (p.Asn1798His). The asparagine residue is highly conserved and there is a small physicochemical difference between asparagine and histidine. -

Hereditary cancer-predisposing syndrome Uncertain:1

Uncertain significance, criteria provided, single submitter

clinical testing

Ambry Genetics

Oct 31, 2022

The p.N1798H variant (also known as c.5392A>C), located in coding exon 15 of the APC gene, results from an A to C substitution at nucleotide position 5392. The asparagine at codon 1798 is replaced by histidine, an amino acid with similar properties. This alteration was detected in 1/224 unrelated Brazilian individuals with breast cancer (Sandoval RL et al. PLoS One, 2021 Feb;16:e0247363). 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 this alteration remains unclear. -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Benign	0.073
BayesDel_addAF	Uncertain	0.019	T
BayesDel_noAF	Benign	-0.21
Cadd	Benign	21
Dann	Uncertain	0.98
DEOGEN2	Benign	0.35	T;T
Eigen	Benign	0.089
Eigen_PC	Uncertain	0.26
FATHMM_MKL	Pathogenic	0.98	D
M_CAP	Benign	0.043	D
MetaRNN	Benign	0.22	T;T
MetaSVM	Benign	-0.39	T
MutationAssessor	Benign	0.90	L;L
MutationTaster	Benign	0.96	N;N;N
PrimateAI	Benign	0.38	T
PROVEAN	Benign	-1.0	N;N
REVEL	Benign	0.23
Sift	Uncertain	0.0050	D;D
Sift4G	Uncertain	0.043	D;D
Polyphen		0.14	B;B
Vest4		0.36
MutPred		0.17		Loss of stability (P = 0.0813);Loss of stability (P = 0.0813);
MVP		0.89
ClinPred		0.84	D
GERP RS		4.9
Varity_R		0.097
gMVP		0.53

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: rs200794097; hg19: chr5-112176683;