rs1554086923

Positions:

• chr5-112841311-CA-C

Variant summary

Our verdict is Pathogenic. Variant got 14 ACMG points: 14P and 0B. PVS1_Strong PM2 PP5_Very_Strong

The NM_000038.6(APC):​c.5718del​(p.Ala1907LeufsTer12) 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 Likely pathogenic (★★).

• Frequency: Genomes: not found (cov: 32)
• Consequence: APC NM_000038.6 frameshift
• Clinical Significance: Likely pathogenic criteria provided, multiple submitters, no conflicts P:2
• Conservation: PhyloP100: 0.178

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 14 ACMG points.

• PVS1: Loss of function variant, product does not undergo nonsense mediated mRNA decay. Variant is located in the 3'-most exon, not predicted to undergo nonsense mediated mRNA decay. There are 10 pathogenic variants in the truncated region.
• PM2: Very rare variant in population databases, with high coverage
• PP5: Variant 5-112841311-CA-C is Pathogenic according to our data. Variant chr5-112841311-CA-C is described in ClinVar as [Likely_pathogenic]. Clinvar id is 504971.Status of the report is criteria_provided_multiple_submitters_no_conflicts, 2 stars.

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	Protein	UniProt
APC	NM_000038.6	c.5718del	p.Ala1907LeufsTer12	frameshift_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.5718del	p.Ala1907LeufsTer12	frameshift_variant	16/16	5	NM_000038.6	ENSP00000257430	P1

Frequencies

GnomAD3 genomes Cov.: 32

GnomAD4 exome Cov.: 65

GnomAD4 genome Cov.: 32

ClinVar

Significance: Likely pathogenic

Submissions summary: Pathogenic:2

Revision: criteria provided, multiple submitters, no conflicts

Submissions by phenotype

Familial multiple polyposis syndrome Pathogenic:1

Likely pathogenic, criteria provided, single submitter

clinical testing

Laboratory for Molecular Medicine, Mass General Brigham Personalized Medicine

Jul 26, 2016

The p.Ala1907fs variant in APC has not been previously reported in individuals w ith familial adenomatous polyposis (FAP) or in large population studies. This va riant is predicted to cause a frameshift, which alters the protein's amino acid sequence beginning at position 1907 and leads to a premature termination codon 1 2 amino acids downstream. This termination codon occurs in the last exon and may escape nonsense mediated decay resulting in a truncated protein (925 amino acid s shorter). Loss-of-function APC variants in this exon have been reported in ind ividuals with FAP. In summary, although additional studies are required to fully establish its clinical significance, the p.Ala1907Leufs variant is likely patho genic. -

not provided Pathogenic:1

Likely pathogenic, criteria provided, single submitter

clinical testing

GeneDx

Apr 20, 2022

Frameshift variant predicted to result in protein truncation in a gene for which loss-of-function is a known mechanism of disease; Not observed in large population cohorts (gnomAD); Has not been previously published as pathogenic or benign to our knowledge -

Computational scores

Source: dbNSFP v4.3

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: rs1554086923; hg19: chr5-112177008;