rs1554080070

Variant names:

• chr5-112819243-TC-T
• rs1554080070
• NM_000038.6:c.1213delC

Variant summary

Our verdict is Pathogenic. Variant got 12 ACMG points: 12P and 0B. PVS1 PM2 PP5_Moderate

The NM_000038.6(APC):​c.1213delC​(p.Arg405GlufsTer49) variant causes a frameshift change involving the alteration of a non-conserved nucleotide. The variant was absent in control chromosomes in GnomAD project. 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 frameshift
• Clinical Significance: Pathogenic criteria provided, single submitter P:2
• Conservation: PhyloP100: 1.55

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 12 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 5-112819243-TC-T is Pathogenic according to our data. Variant chr5-112819243-TC-T is described in ClinVar as [Pathogenic]. Clinvar id is 433617.Status of the report is criteria_provided_single_submitter, 1 stars.

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	MANE	Protein	UniProt
APC	NM_000038.6	c.1213delC	p.Arg405GlufsTer49	frameshift_variant	Exon 10 of 16	ENST00000257430.9	NP_000029.2

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	TSL	MANE	Protein	Appris	UniProt
APC	ENST00000257430.9	c.1213delC	p.Arg405GlufsTer49	frameshift_variant	Exon 10 of 16	5	NM_000038.6	ENSP00000257430.4

Frequencies

GnomAD3 genomes Cov.: 32

GnomAD4 exome Cov.: 33

GnomAD4 genome Cov.: 32

ClinVar

Significance: Pathogenic

Submissions summary: Pathogenic:2

Revision: criteria provided, single submitter

Submissions by phenotype

Familial adenomatous polyposis 1 Pathogenic:2

Apr 28, 2023

Myriad Genetics, Inc.

Significance: Pathogenic

Review Status: criteria provided, single submitter

Collection Method: clinical testing

This variant is considered pathogenic. This variant creates a frameshift predicted to result in premature protein truncation. -

-

Department of Pathology and Laboratory Medicine, Sinai Health System

Significance: Pathogenic

Review Status: no assertion criteria provided

Collection Method: clinical testing

The p.Arg405X variant has been previously reported in at least 4 of 2632 proband chromosomes in individuals with FAP (Selected publications: Nagase 1992, Friedl 2005). In addition, this variant has been identified as a frequent mutation in somatic colorectal cancer (Harismendy 2011, Powell 1992). The p.Arg405X variant leads to an amino acid change at position 405 of the polypeptide, and a premature stop codon 49 amino acids downstream. This variant is predicted to lead to a truncated or absent protein and loss of function. Loss of function variants of the APC gene are an established mechanism of disease causing mutations in FAP. In summary, based on the above information, this variant meets our criteria to be classified as pathogenic. -

Computational scores

Source: dbNSFP v4.3

Splicing

Name	Calibrated prediction	Score	Prediction
SpliceAI score (max)		0.060		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: rs1554080070; hg19: chr5-112154940;