rs876658846

chr5-112767234-C-Achr5-112767234-C-Gchr5-112767234-C-T

Variant summary

Our verdict is Pathogenic. Variant got 18 ACMG points: 18P and 0B. PVS1 PM2 PP5_Very_Strong

The NM_000038.6(APC):c.266C>A(p.Ser89Ter) variant causes a stop gained change involving the alteration of a non-conserved nucleotide. The variant was absent in control chromosomes in GnomAD project. In-silico tool predicts a pathogenic outcome for this variant. Variant has been reported in ClinVar as Pathogenic (★★). Synonymous variant affecting the same amino acid position (i.e. S89S) has been classified as Likely benign. Variant results in nonsense mediated mRNA decay.

• Frequency: Genomes: not found (cov: 32)
• Consequence: APC NM_000038.6 stop_gained
• Clinical Significance: Pathogenic criteria provided, multiple submitters, no conflicts P:3
• Conservation: PhyloP100: 3.48

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 Pathogenic. Variant got 18 ACMG points.

• PVS1: Loss of function variant, product undergoes nonsense mediated mRNA decay. LoF is a known mechanism of disease.
• PM2: Very rare variant in population databases, with high coverage
• PP5: Variant 5-112767234-C-A is Pathogenic according to our data. Variant chr5-112767234-C-A is described in ClinVar as [Pathogenic]. Clinvar id is 566516.Status of the report is criteria_provided_multiple_submitters_no_conflicts, 2 stars. Variant chr5-112767234-C-A is described in Lovd as [Pathogenic].

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	UniProt
APC	NM_000038.6	c.266C>A	p.Ser89Ter	stop_gained	4/16	ENST00000257430.9

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Appris	UniProt
APC	ENST00000257430.9	c.266C>A	p.Ser89Ter	stop_gained	4/16	5	NM_000038.6	P1

Frequencies

GnomAD3 genomes Cov.: 32

GnomAD4 exome Cov.: 31

GnomAD4 genome Cov.: 32

ClinVar

Significance: Pathogenic

Submissions summary: Pathogenic:3

Revision: criteria provided, multiple submitters, no conflicts

Submissions by phenotype

Familial adenomatous polyposis 1 Pathogenic:2

Pathogenic, criteria provided, single submitter	clinical testing	Invitae	Oct 26, 2018	For these reasons, this variant has been classified as Pathogenic. Loss-of-function variants in APC are known to be pathogenic (PMID: 17963004, 20685668). This variant has not been reported in the literature in individuals with APC-related disease. This variant is not present in population databases (ExAC no frequency). This sequence change creates a premature translational stop signal (p.Ser89*) in the APC gene. It is expected to result in an absent or disrupted protein product. -
Pathogenic, criteria provided, single submitter	clinical testing	Myriad Genetics, Inc.	Apr 25, 2023	This variant is considered pathogenic. This variant creates a termination codon and is predicted to result in premature protein truncation. -

Hereditary cancer-predisposing syndrome Pathogenic:1

Pathogenic, criteria provided, single submitter

clinical testing

Ambry Genetics

Sep 01, 2021

The p.S89* pathogenic mutation (also known as c.266C>A), located in coding exon 3 of the APC gene, results from a C to A substitution at nucleotide position 266. This changes the amino acid from a serine to a stop codon within coding exon 3. This mutation has been detected in patients with colon polyposis (Urso ED et al. Surg Endosc, 2013 Jan;27:207-13; Ambry internal data). This variant is considered to be rare based on population cohorts in the Genome Aggregation Database (gnomAD). In addition to the clinical data presented in the literature, this alteration is expected to result in loss of function by premature protein truncation or nonsense-mediated mRNA decay. As such, this alteration is interpreted as a disease-causing mutation. -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
BayesDel_addAF	Pathogenic	0.63	D
BayesDel_noAF	Pathogenic	0.62
Cadd	Pathogenic	38
Dann	Uncertain	0.99
Eigen	Pathogenic	0.92
Eigen_PC	Pathogenic	0.79
FATHMM_MKL	Uncertain	0.93	D
MutationTaster	Benign	1.0	A;A;A
Vest4		0.91, 0.90
GERP RS		5.5

Splicing

Name	Calibrated prediction	Score	Prediction
SpliceAI score (max)		0.090		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: rs876658846; hg19: chr5-112102931;