rs1350986347

Positions:

• chr5-112838260-A-C
• chr5-112838260-A-G
• chr5-112838260-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.2666A>C​(p.Lys889Thr) variant causes a missense change. The variant allele was found at a frequency of 0.00000137 in 1,461,884 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 (★★).

• Frequency:
  • Genomes: not found (cov: 32)
  • Exomes 𝑓: 0.0000014 (0 hom.)
• Consequence: APC NM_000038.6 missense
• Clinical Significance: Uncertain significance criteria provided, multiple submitters, no conflicts U:2
• Conservation: PhyloP100: 4.64

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]

ENSG00000258864 (HGNC:):

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=0.24574772).

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	Protein	UniProt
APC	NM_000038.6	c.2666A>C	p.Lys889Thr	missense_variant	16/16	ENST00000257430.9	NP_000029.2

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Protein	Appris	UniProt
APC	ENST00000257430.9	c.2666A>C	p.Lys889Thr	missense_variant	16/16	5	NM_000038.6	ENSP00000257430.4
ENSG00000258864	ENST00000520401.1	n.228+9288A>C		intron_variant		3		ENSP00000454861.1

Frequencies

GnomAD3 genomes Cov.: 32

GnomAD3 exomes AF: 0.00000399 AC: 1 AN: 250780 Hom.: 0 AF XY: 0.00 AC XY: 0 AN XY: 135490

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: 0.00000137 AC: 2 AN: 1461884 Hom.: 0 Cov.: 33 AF XY: 0.00000138 AC XY: 1 AN XY: 727240

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: 0.0000116

Gnomad4 FIN exome AF: 0.00

Gnomad4 NFE exome AF: 8.99e-7

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

Labcorp Genetics (formerly Invitae), Labcorp

Dec 05, 2021

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 lysine, which is basic and polar, with threonine, which is neutral and polar, at codon 889 of the APC protein (p.Lys889Thr). -

Hereditary cancer-predisposing syndrome Uncertain:1

Uncertain significance, criteria provided, single submitter

clinical testing

Ambry Genetics

May 06, 2021

The p.K889T variant (also known as c.2666A>C), located in coding exon 15 of the APC gene, results from an A to C substitution at nucleotide position 2666. The lysine at codon 889 is replaced by threonine, an amino acid with similar properties. This amino acid position is not 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	0.17
BayesDel_addAF	Uncertain	0.012	T
BayesDel_noAF	Benign	-0.12
CADD	Benign	22
DANN	Uncertain	0.99
DEOGEN2	Pathogenic	0.83	.;D;D;D
Eigen	Benign	-0.026
Eigen_PC	Benign	0.13
FATHMM_MKL	Uncertain	0.94	D
LIST_S2	Uncertain	0.86	D;.;D;D
M_CAP	Uncertain	0.11	D
MetaRNN	Benign	0.25	T;T;T;T
MetaSVM	Uncertain	0.56	D
MutationAssessor	Uncertain	2.5	.;M;M;.
PrimateAI	Uncertain	0.54	T
PROVEAN	Benign	-2.2	N;D;D;N
REVEL	Benign	0.28
Sift	Uncertain	0.025	D;D;D;D
Sift4G	Benign	0.14	T;D;D;T
Polyphen		0.0	.;B;B;.
Vest4		0.36, 0.31
MutPred		0.31		.;Loss of methylation at K889 (P = 0.0106);Loss of methylation at K889 (P = 0.0106);Loss of methylation at K889 (P = 0.0106);
MVP		0.91
ClinPred		0.54	D
GERP RS		4.8
Varity_R		0.22
gMVP		0.49

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: rs1350986347; hg19: chr5-112173957;