rs864622106

Positions:

• chr5-112839187-CAA-C
• chr5-112839187-CAA-CAAA

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.3595_3596del​(p.Lys1199GlufsTer8) variant causes a frameshift change. The variant allele was found at a frequency of 0.000000684 in 1,461,816 control chromosomes in the GnomAD database, with no homozygous occurrence. Variant has been reported in ClinVar as Pathogenic (★★).

• Frequency:
  • Genomes: not found (cov: 32)
  • Exomes 𝑓: 6.8e-7 (0 hom.)
• Consequence: APC NM_000038.6 frameshift
• Clinical Significance: Pathogenic criteria provided, multiple submitters, no conflicts P:5
• Conservation: PhyloP100: 6.62

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 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 137 pathogenic variants in the truncated region.
• PM2: Very rare variant in population databases, with high coverage
• PP5: Variant 5-112839187-CAA-C is Pathogenic according to our data. Variant chr5-112839187-CAA-C is described in ClinVar as [Pathogenic]. Clinvar id is 219466.Status of the report is criteria_provided_multiple_submitters_no_conflicts, 2 stars. Variant chr5-112839187-CAA-C is described in Lovd as [Pathogenic].

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	Protein	UniProt
APC	NM_000038.6	c.3595_3596del	p.Lys1199GlufsTer8	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.3595_3596del	p.Lys1199GlufsTer8	frameshift_variant	16/16	5	NM_000038.6	ENSP00000257430	P1

Frequencies

GnomAD3 genomes Cov.: 32

GnomAD4 exome AF: 6.84e-7 AC: 1 AN: 1461816 Hom.: 0 AF XY: 0.00 AC XY: 0 AN XY: 727212

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: 8.99e-7

Gnomad4 OTH exome AF: 0.00

GnomAD4 genome Cov.: 32

ClinVar

Significance: Pathogenic

Submissions summary: Pathogenic:5

Revision: criteria provided, multiple submitters, no conflicts

Submissions by phenotype

Familial adenomatous polyposis 1 Pathogenic:3

Pathogenic, criteria provided, single submitter	clinical testing	Labcorp Genetics (formerly Invitae), Labcorp	Mar 03, 2023	This sequence change creates a premature translational stop signal (p.Lys1199Glufs*8) in the APC gene. While this is not anticipated to result in nonsense mediated decay, it is expected to disrupt the last 1645 amino acid(s) of the APC protein. This variant is not present in population databases (gnomAD no frequency). This premature translational stop signal has been observed in individual(s) with familial adenomatous polyposis (PMID: 7951218, 8162022, 11933206, 21779980). ClinVar contains an entry for this variant (Variation ID: 219466). This variant is expected to disrupt the EB1 and HDLG binding sites, which mediate interactions with the cytoskeleton (PMID: 15311282, 17293347). While functional studies have not been performed to directly test the effect on APC protein function, this suggests that disruption of the C-terminal portion of the protein is functionally important. A different truncation (p.Tyr2645Lysfs*14) that lies downstream of this variant has been determined to be pathogenic (PMID: 9824584, 1316610, 27081525, 8381579, 22135120, Invitae). This suggests that deletion of this region of the APC protein is causative of disease. For these reasons, this variant has been classified as Pathogenic. -
Pathogenic, criteria provided, single submitter	clinical testing	Laboratorio de Genetica e Diagnostico Molecular, Hospital Israelita Albert Einstein	Nov 11, 2021	ACMG classification criteria: PVS1 strong, PS4 strong, PM2, PP1 supporting -
Pathogenic, criteria provided, single submitter	clinical testing	Myriad Genetics, Inc.	May 09, 2023	This variant is considered pathogenic. This variant creates a frameshift predicted to result in premature protein truncation. -

not provided Pathogenic:1

Pathogenic, criteria provided, single submitter

clinical testing

CeGaT Center for Human Genetics Tuebingen

Nov 01, 2022

APC: PVS1, PP1:Strong, PM2, PS4:Supporting -

Hereditary cancer-predisposing syndrome Pathogenic:1

Pathogenic, criteria provided, single submitter

clinical testing

Ambry Genetics

Aug 27, 2021

The c.3595_3596delAA pathogenic mutation, located in coding exon 15 of the APC gene, results from a deletion of two nucleotides at nucleotide positions 3595 to 3596, causing a translational frameshift with a predicted alternate stop codon (p.K1199Efs*8). This alteration occurs at the 3' terminus of theAPC gene, is not expected to trigger nonsense-mediated mRNA decay, and impacts the last 1645 amino acids of the protein. However, premature stop codons are typically deleterious in nature, the impacted region is critical for protein function, and a significant portion of the protein is affected (Ambry internal data). This mutation has been observed in multiple individuals with a personal and/or family history that is consistent with familial adenomatous polyposis or attenuated familial adenomatous polyposis (Mandl M et al. Hum Mol Genet, 1994 Jan;3:181-4; Kohoutová M et al. Hum Mutat, 2002 Apr;19:460-1; Vandrovcová J et al. Hum Mutat, 2004 Apr;23:397; Friedl W et al. Hered Cancer Clin Pract, 2005 Sep;3:95-114; Garzón-Benavides M et al. Rev Esp Enferm Dig, 2010 Nov;102:653-7; Jarry J et al. Fam Cancer, 2011 Dec;10:659-65; Jung SM et al. World J Gastroenterol, 2016 May;22:4380-8; Marabelli M et al. Genet Test Mol Biomarkers, 2016 12;20:777-785; Ambry internal data). This variant is considered to be rare based on population cohorts in the Genome Aggregation Database (gnomAD). Based on the supporting evidence, this alteration is interpreted as a disease-causing mutation. -

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: rs864622106; hg19: chr5-112174884;