rs1060503333

Positions:

• chr5-112821953-C-A
• chr5-112821953-C-G
• chr5-112821953-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.1370C>A​(p.Ser457*) variant causes a stop gained change involving the alteration of a 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 (★★). 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:7
• Conservation: PhyloP100: 7.91

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]

APC (HGNC:):

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 5-112821953-C-A is Pathogenic according to our data. Variant chr5-112821953-C-A is described in ClinVar as [Pathogenic]. Clinvar id is 433620.Status of the report is criteria_provided_multiple_submitters_no_conflicts, 2 stars. Variant chr5-112821953-C-A is described in Lovd as [Pathogenic].

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	Protein	UniProt
APC	NM_000038.6	c.1370C>A	p.Ser457*	stop_gained	11/16	ENST00000257430.9	NP_000029.2

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Protein	Appris	UniProt
APC	ENST00000257430.9	c.1370C>A	p.Ser457*	stop_gained	11/16	5	NM_000038.6	ENSP00000257430.4

Frequencies

GnomAD3 genomes Cov.: 32

GnomAD4 exome Cov.: 30

GnomAD4 genome Cov.: 32

ClinVar

Significance: Pathogenic

Submissions summary: Pathogenic:7

Revision: criteria provided, multiple submitters, no conflicts

Submissions by phenotype

Familial adenomatous polyposis 1 Pathogenic:2

Pathogenic, criteria provided, single submitter	clinical testing	Labcorp Genetics (formerly Invitae), Labcorp	Sep 26, 2021	For these reasons, this variant has been classified as Pathogenic. ClinVar contains an entry for this variant (Variation ID: 433620). This premature translational stop signal has been observed in individual(s) with familial adenomatous polyposis (FAP) and an individual with concomitant congenital hypertrophy of the retinal pigment epithelium (CHRPE) (PMID: 7959691, 20223039, 20685668). This variant is not present in population databases (ExAC no frequency). This sequence change creates a premature translational stop signal (p.Ser457*) in the APC gene. It is expected to result in an absent or disrupted protein product. Loss-of-function variants in APC are known to be pathogenic (PMID: 17963004, 20685668). -
Pathogenic, criteria provided, single submitter	clinical testing	Myriad Genetics, Inc.	May 01, 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:2

Pathogenic, criteria provided, single submitter	clinical testing	Ambry Genetics	Sep 14, 2023	The p.S457* pathogenic mutation (also known as c.1370C>A), located in coding exon 10 of the APC gene, results from a C to A substitution at nucleotide position 1370. This changes the amino acid from a serine to a stop codon within coding exon 10. This alteration has been reported in multiple patients with a clinical diagnosis of FAP or AFAP (Wallis YL et al. Hum. Genet., 1994 Nov;94:543-8; Friedl W et al. Hered Cancer Clin Pract, 2005 Sep;3:95-114; Lagarde A et al. J. Med. Genet., 2010 Oct;47:721-2). 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. -
Pathogenic, criteria provided, single submitter	clinical testing	Color Diagnostics, LLC DBA Color Health	Feb 11, 2020	This variant changes 1 nucleotide in exon 11 of the APC gene, creating a premature translation stop signal. This variant is expected to result in an absent or non-functional protein product. This variant has been reported in individuals affected with or suspected of having familial adenomatous polyposis (PMID: 20223039, 20685668). This variant has not been identified in the general population by the Genome Aggregation Database (gnomAD). Loss of APC function is a known mechanism of disease (clinicalgenome.org). Based on the available evidence, this variant is classified as Pathogenic. -

Carcinoma of colon Pathogenic:1

Pathogenic, no assertion criteria provided

clinical testing

Department of Pathology and Laboratory Medicine, Sinai Health System

-

The p.Ser457X variant results in a stop codon at postion Ser457 which is predicted to cause premature truncation of the protein product. This is a loss of function DNA variant and loss of function is an established disease mechanism for the APC gene. In addition, this variant has been previously reported in individuals with familial adenomatous polyposis (FAP) (Wallis_1994_7959691, Friedl_2005_20223039, Stekrova_2007_17411426). In summary, based on the above information this variant meets our criteria for being Pathogenic. -

Colonic neoplasm Pathogenic:1

Pathogenic, no assertion criteria provided

clinical testing

Medical Genetics Laboratory, Umraniye Training and Research Hospital, University of Health Sciences

Sep 12, 2021

- -

not provided Pathogenic:1

Pathogenic, criteria provided, single submitter

clinical testing

GeneDx

Mar 29, 2022

Nonsense variant predicted to result in protein truncation or nonsense mediated decay in a gene for which loss of function is a known mechanism of disease; Not observed at significant frequency in large population cohorts (gnomAD); This variant is associated with the following publications: (PMID: 25525159, 7959691, 34224960, 17411426, 27777639) -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
BayesDel_addAF	Pathogenic	0.63	D
BayesDel_noAF	Pathogenic	0.65
CADD	Pathogenic	39
DANN	Uncertain	0.99
Eigen	Uncertain	0.61
Eigen_PC	Uncertain	0.46
FATHMM_MKL	Pathogenic	0.99	D
Vest4		0.98, 0.98
GERP RS		5.2

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: rs1060503333; hg19: chr5-112157650; COSMIC: COSV57336845;