Genetic Variant APC:p.Gln1680* (chr5-112840632-C-T) – ACMG Classification: Pathogenic (14 pts)

Variant summary

Our verdict is Pathogenic. Variant got 14 ACMG points: 14P and 0B. PVS1_StrongPM2PP5_Very_Strong

The NM_000038.6(APC):c.5038C>T(p.Gln1680*) variant causes a stop gained change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.00000657 in 152,154 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a pathogenic outcome for this variant. Variant has been reported in ClinVar as Likely pathogenic (★★).

Frequency

Genomes: 𝑓 0.0000066 ( 0 hom., cov: 32)

Consequence

APC
NM_000038.6 stop_gained

Scores

Clinical Significance

Pathogenic/Likely pathogenic criteria provided, multiple submitters, no conflicts P:5

Conservation

PhyloP100: 0.865

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 links:

ENSG00000258864 (HGNC:):

ENSG00000258864 links:

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ACMG classification

Classification made for transcript

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 15 pathogenic variants in the truncated region.

PM2

Very rare variant in population databases, with high coverage;

PP5

Variant 5-112840632-C-T is Pathogenic according to our data. Variant chr5-112840632-C-T is described in ClinVar as [Likely_pathogenic]. Clinvar id is 230520.Status of the report is criteria_provided_multiple_submitters_no_conflicts, 2 stars. Variant chr5-112840632-C-T is described in Lovd as [Pathogenic].

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	MANE	Protein	UniProt
APC	NM_000038.6 link	c.5038C>T	p.Gln1680*	stop_gained	Exon 16 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.5038C>T	p.Gln1680*	stop_gained	Exon 16 of 16	5	NM_000038.6	ENSP00000257430.4		P25054-1
ENSG00000258864	ENST00000520401.1 link	n.228+11660C>T		intron_variant	Intron 3 of 7	3		ENSP00000454861.1		H3BNH8

Frequencies

GnomAD3 genomes

AF:

0.00000657

AC:

AN:

152154

Hom.:

Cov.:

show subpopulations

Gnomad AFR

AF:

0.00

Gnomad AMI

AF:

0.00

Gnomad AMR

AF:

0.00

Gnomad ASJ

AF:

0.00

Gnomad EAS

AF:

0.00

Gnomad SAS

AF:

0.00

Gnomad FIN

AF:

0.00

Gnomad MID

AF:

0.00

Gnomad NFE

AF:

0.0000147

Gnomad OTH

AF:

0.00

GnomAD4 exome

Cov.:

GnomAD4 genome

AF:

0.00000657

AC:

AN:

152154

Hom.:

Cov.:

AF XY:

0.00

AC XY:

AN XY:

74340

show subpopulations

Gnomad4 AFR

AF:

0.00

Gnomad4 AMR

AF:

0.00

Gnomad4 ASJ

AF:

0.00

Gnomad4 EAS

AF:

0.00

Gnomad4 SAS

AF:

0.00

Gnomad4 FIN

AF:

0.00

Gnomad4 NFE

AF:

0.0000147

Gnomad4 OTH

AF:

0.00

Bravo

AF:

0.00000378

ClinVar

Significance: Pathogenic/Likely pathogenic

Submissions summary: Pathogenic:5

Revision: criteria provided, multiple submitters, no conflicts

LINK: link

Submissions by phenotype

Familial adenomatous polyposis 1

Pathogenic:2

Feb 06, 2024

Baylor Genetics

Significance: Likely pathogenic

Review Status: criteria provided, single submitter

Collection Method: clinical testing

- -

May 12, 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 termination codon and is predicted to result in premature protein truncation. -

Familial multiple polyposis syndrome

Pathogenic:1

Sep 14, 2020

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

Significance: Likely pathogenic

Review Status: criteria provided, single submitter

Collection Method: clinical testing

Variant summary: APC c.5038C>T (p.Gln1680X) results in a premature termination codon, predicted to cause a truncation of the encoded protein. The variant was absent in 250054 control chromosomes (gnomAD). To our knowledge, no occurrence of c.5038C>T in individuals affected with Familial Adenomatous Polyposis has been reported. One publication reports experimental evidence evaluating an impact on protein function, however, does not allow convincing conclusions about the variant effect (Otsuka_2003). Two ClinVar submitters (evaluation after 2014) cite the variant as pathogenic. Based on the evidence outlined above, the variant was classified as likely pathogenic. -

not provided

Pathogenic:1

Aug 02, 2016

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

Mar 13, 2024

Ambry Genetics

Significance: Pathogenic

Review Status: criteria provided, single submitter

Collection Method: clinical testing

The p.Q1680* pathogenic mutation (also known as c.5038C>T), located in coding exon 15 of the APC gene, results from a C to T substitution at nucleotide position 5038. This changes the amino acid from a glutamine to a stop codon within coding exon 15. This variant has been observed in at least one individual with a personal and/or family history that is consistent with APC-associated polyposis conditions (Ambry internal data). This alteration is expected to result in loss of function by premature protein truncation or nonsense-mediated mRNA decay. This variant is considered to be rare based on population cohorts in the Genome Aggregation Database (gnomAD). As such, this alteration is interpreted as a disease-causing mutation. -

Computational scores

Source: dbNSFP v4.3

Name

Calibrated prediction

Score

Prediction

BayesDel_addAF

Pathogenic

0.63

BayesDel_noAF

Pathogenic

0.39

CADD

Pathogenic

DANN

Uncertain

1.0

Eigen

Uncertain

0.60

Eigen_PC

Uncertain

0.35

FATHMM_MKL

Benign

0.50

Vest4

0.96

GERP RS

5.0

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

Below is the list of publications found by LitVar. It may be empty.

Variant summary

Frequency

Consequence

Scores

Clinical Significance

Conservation

ACMG classification

Transcripts

RefSeq

Ensembl

Frequencies

ClinVar

Submissions by phenotype

Computational scores

Splicing

Publications

LitVar

Other links and lift over