rs397515735

Variant names:

Variant summary

Our verdict is Pathogenic. The variant received 18 ACMG points: 18P and 0B. PVS1PM2PP5_Very_Strong

The NM_000038.6(APC):c.896_897delCT(p.Ser299CysfsTer27) variant causes a frameshift change. The variant allele was found at a frequency of 0.000000685 in 1,460,126 control chromosomes in the GnomAD database, with no homozygous occurrence. Variant has been reported in ClinVar as Pathogenic (★★). Synonymous variant affecting the same amino acid position (i.e. S299S) has been classified as Benign. Variant results in nonsense mediated mRNA decay.

Frequency

Genomes: not found (cov: 32)

Exomes 𝑓: 6.8e-7 ( 0 hom. )

Consequence

APC
NM_000038.6 frameshift

Scores

Not classified

Clinical Significance

Pathogenic criteria provided, multiple submitters, no conflicts P:7

Conservation

PhyloP100: 4.96

Publications

2 publications found

Variant links:

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 Gene-Disease associations (from GenCC):

classic or attenuated familial adenomatous polyposis
Inheritance: AD Classification: DEFINITIVE Submitted by: ClinGen
desmoid tumor
Inheritance: AD Classification: DEFINITIVE, STRONG Submitted by: G2P, Genomics England PanelApp
familial adenomatous polyposis 1
Inheritance: AD Classification: DEFINITIVE, STRONG, MODERATE Submitted by: Genomics England PanelApp, Labcorp Genetics (formerly Invitae), Ambry Genetics
gastric adenocarcinoma and proximal polyposis of the stomach
Inheritance: AD Classification: DEFINITIVE, STRONG, SUPPORTIVE Submitted by: Ambry Genetics, Labcorp Genetics (formerly Invitae), ClinGen, Orphanet
sarcoma
Inheritance: AD Classification: MODERATE Submitted by: Genomics England PanelApp
APC-related attenuated familial adenomatous polyposis
Inheritance: AD Classification: SUPPORTIVE Submitted by: Orphanet
Turcot syndrome with polyposis
Inheritance: AD Classification: SUPPORTIVE Submitted by: Orphanet
Cenani-Lenz syndactyly syndrome
Inheritance: AR Classification: SUPPORTIVE Submitted by: Orphanet

APC links:

Genome browser will be placed here

ACMG classification

Classification was made for transcript

Our verdict: Pathogenic. The variant received 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 5-112815553-ACT-A is Pathogenic according to our data. Variant chr5-112815553-ACT-A is described in ClinVar as Pathogenic. ClinVar VariationId is 42251.Status of the report is criteria_provided_multiple_submitters_no_conflicts, 2 stars.

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	MANE	Protein	UniProt
APC	NM_000038.6 link	c.896_897delCT	p.Ser299CysfsTer27	frameshift_variant	Exon 9 of 16	ENST00000257430.9	NP_000029.2	P25054-1Q4LE70

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	TSL	MANE	Protein	Appris	UniProt
APC	ENST00000257430.9 link	c.896_897delCT	p.Ser299CysfsTer27	frameshift_variant	Exon 9 of 16	5	NM_000038.6	ENSP00000257430.4		P25054-1

Frequencies

GnomAD3 genomes

Cov.:

GnomAD4 exome

AF:

6.85e-7

AC:

AN:

1460126

Hom.:

AF XY:

0.00000138

AC XY:

AN XY:

726436

show subpopulations

African (AFR)

AF:

0.00

AC:

AN:

33418

American (AMR)

AF:

0.00

AC:

AN:

44662

Ashkenazi Jewish (ASJ)

AF:

0.00

AC:

AN:

26072

East Asian (EAS)

AF:

0.00

AC:

AN:

39616

South Asian (SAS)

AF:

0.00

AC:

AN:

86234

European-Finnish (FIN)

AF:

0.00

AC:

AN:

53270

Middle Eastern (MID)

AF:

0.00

AC:

AN:

5752

European-Non Finnish (NFE)

AF:

9.00e-7

AC:

AN:

1110852

Other (OTH)

AF:

0.00

AC:

AN:

60250

Allele Balance Distribution

Red line indicates average allele balance

Average allele balance: 0.425

Heterozygous variant carriers

0.00

0.20

0.40

0.60

0.80

0.95

Allele balance

GnomAD4 genome

Cov.:

ClinVar

Significance: Pathogenic

Submissions summary: Pathogenic:7

Revision: criteria provided, multiple submitters, no conflicts

LINK: link

Submissions by phenotype

Familial multiple polyposis syndrome

Pathogenic:2

Jan 06, 2025

Women's Health and Genetics/Laboratory Corporation of America, LabCorp

Significance:Pathogenic

Review Status:criteria provided, single submitter

Collection Method:clinical testing

Variant summary: APC c.896_897delCT (p.Ser299CysfsX27) results in a premature termination codon, predicted to cause a truncation of the encoded protein or absence of the protein due to nonsense mediated decay, which are commonly known mechanisms for disease. The variant was absent in 251118 control chromosomes. c.896_897delCT has been reported in the literature in multiple individuals affected with Familial Adenomatous Polyposis (example: Cao_2006). These data indicate that the variant is very likely to be associated with disease.The following publication has been ascertained in the context of this evaluation (PMID: 17026565). ClinVar contains an entry for this variant (Variation ID: 42251). Based on the evidence outlined above, the variant was classified as pathogenic. -

Apr 08, 2009

Laboratory for Molecular Medicine, Mass General Brigham Personalized Medicine

Significance:Pathogenic

Review Status:no assertion criteria provided

Collection Method:clinical testing

- -

Familial adenomatous polyposis 1

Pathogenic:2

Mar 04, 2024

Labcorp Genetics (formerly Invitae), Labcorp

Significance:Pathogenic

Review Status:criteria provided, single submitter

Collection Method:clinical testing

This sequence change creates a premature translational stop signal (p.Ser299Cysfs*27) 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). 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: 8118461, 17604324). It has also been observed to segregate with disease in related individuals. ClinVar contains an entry for this variant (Variation ID: 42251). For these reasons, this variant has been classified as Pathogenic. -

Apr 27, 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. -

not provided

Pathogenic:2

Jul 29, 2024

GeneDx

Significance:Pathogenic

Review Status:criteria provided, single submitter

Collection Method:clinical testing

Frameshift 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: 8118461, 8187091, 34454113, 17604324) -

Feb 21, 2018

Quest Diagnostics Nichols Institute San Juan Capistrano

Significance:Pathogenic

Review Status:criteria provided, single submitter

Collection Method:clinical testing

- -

Hereditary cancer-predisposing syndrome

Pathogenic:1

Jul 13, 2021

Ambry Genetics

Significance:Pathogenic

Review Status:criteria provided, single submitter

Collection Method:clinical testing

The c.896_897delCT pathogenic mutation, located in coding exon 8 of the APC gene, results from a deletion of two nucleotides at nucleotide positions 896 to 897, causing a translational frameshift with a predicted alternate stop codon (p.S299Cfs*27). This mutation has been reported in multiple familial adenomatous polyposis (FAP) families (Koorey DJ et al. Hum. Mutat., 1994;3:12-8; Hes FJ et al. Gut, 2008 Jan;57:71-6; Ambry internal data). 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. -

Computational scores

Source: dbNSFP v4.3

Name

Calibrated prediction

Score

Prediction

PhyloP100

5.0

Mutation Taster

=0/200

disease causing (ClinVar)

(source)

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

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Variant summary

Frequency

Consequence

Scores

Clinical Significance

Conservation

Publications

ACMG classification

Transcripts

RefSeq

Ensembl

Frequencies

ClinVar

Submissions by phenotype

Computational scores

Splicing

Publications

Other links and lift over