5-112842132-AAGAT-A

Position:

• chr5-112842132-AAGAT-A

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.6542_6545del​(p.Ile2181AsnfsTer17) variant causes a frameshift change. The variant allele was found at a frequency of 0.00000137 in 1,459,208 control chromosomes in the GnomAD database, with no homozygous occurrence. Variant has been reported in ClinVar as Likely pathogenic (★★).

• Frequency:
  • Genomes: not found (cov: 32)
  • Exomes 𝑓: 0.0000014 (0 hom.)
• Consequence: APC NM_000038.6 frameshift
• Clinical Significance: Likely pathogenic criteria provided, multiple submitters, no conflicts P:2
• Conservation: PhyloP100: 6.79

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 5 pathogenic variants in the truncated region.
• PM2: Very rare variant in population databases, with high coverage
• PP5: Variant 5-112842132-AAGAT-A is Pathogenic according to our data. Variant chr5-112842132-AAGAT-A is described in ClinVar as [Likely_pathogenic]. Clinvar id is 438885.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.6542_6545del	p.Ile2181AsnfsTer17	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.6542_6545del	p.Ile2181AsnfsTer17	frameshift_variant	16/16	5	NM_000038.6	ENSP00000257430	P1

Frequencies

GnomAD3 genomes Cov.: 32

GnomAD4 exome AF: 0.00000137 AC: 2 AN: 1459208 Hom.: 0 AF XY: 0.00000138 AC XY: 1 AN XY: 726022

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: 0.00

Gnomad4 FIN exome AF: 0.00

Gnomad4 NFE exome AF: 0.00000180

Gnomad4 OTH exome AF: 0.00

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

Apr 20, 2018

The p.Ile2181fs 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 2181 and leads to a premature termination codon 1 7 amino acids downstream. This termination codon occurs in the last exon and may escape nonsense mediated deca, therefore resulting in a truncated protein. Trun cating variants in the last exon of APC have been reported in individuals with F AP. In summary, although additional studies are required to fully establish its clinical significance, the p.Ile2181fs variant is likely pathogenic. ACMG/AMP Cr iteria applied: PVS1_Strong; PM2. -

not provided Pathogenic:1

Likely pathogenic, criteria provided, single submitter

clinical testing

Quest Diagnostics Nichols Institute San Juan Capistrano

Apr 03, 2017

- -

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: rs1554087515; hg19: chr5-112177829;