rs864622376

Positions:

• chr5-112839610-G-GTTC

Variant summary

Our verdict is Likely benign. Variant got -3 ACMG points: 1P and 4B. PM4_Supporting BS2

The NM_000038.6(APC):​c.4018_4020dupTCT​(p.Ser1341dup) variant causes a conservative inframe insertion change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.00000743 in 1,614,008 control chromosomes in the GnomAD database, with no homozygous occurrence. Variant has been reported in ClinVar as Conflicting classifications of pathogenicity (no stars).

• Frequency:
  • Genomes: 𝑓 0.0000066 (0 hom., cov: 32)
  • Exomes 𝑓: 0.0000075 (0 hom.)
• Consequence: APC NM_000038.6 conservative_inframe_insertion
• Clinical Significance: Conflicting classifications of pathogenicity criteria provided, conflicting classifications U:5 B:1
• Conservation: PhyloP100: 1.12

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]

ENSG00000258864 (HGNC:):

ACMG classification

Verdict is Likely_benign. Variant got -3 ACMG points.

• PM4: Nonframeshift variant in NON repetitive region in NM_000038.6. Strenght limited to Supporting due to length of the change: 1aa.
• BS2: High AC in GnomAdExome4 at 11 AD gene.

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	Protein	UniProt
APC	NM_000038.6	c.4018_4020dupTCT	p.Ser1341dup	conservative_inframe_insertion	16/16	ENST00000257430.9	NP_000029.2

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Protein	Appris	UniProt
APC	ENST00000257430.9	c.4018_4020dupTCT	p.Ser1341dup	conservative_inframe_insertion	16/16	5	NM_000038.6	ENSP00000257430.4
ENSG00000258864	ENST00000520401.1	n.228+10640_228+10642dupTCT		intron_variant		3		ENSP00000454861.1

Frequencies

GnomAD3 genomes AF: 0.00000657 AC: 1 AN: 152126 Hom.: 0 Cov.: 32

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

GnomAD3 exomes AF: 0.00000797 AC: 2 AN: 251020 Hom.: 0 AF XY: 0.0000147 AC XY: 2 AN XY: 135668

Gnomad AFR exome AF: 0.00

Gnomad AMR exome AF: 0.00

Gnomad ASJ exome AF: 0.00

Gnomad EAS exome AF: 0.00

Gnomad SAS exome AF: 0.00

Gnomad FIN exome AF: 0.00

Gnomad NFE exome AF: 0.0000176

Gnomad OTH exome AF: 0.00

GnomAD4 exome AF: 0.00000752 AC: 11 AN: 1461882 Hom.: 0 Cov.: 33 AF XY: 0.00000825 AC XY: 6 AN XY: 727244

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: 0.00000899

Gnomad4 OTH exome AF: 0.0000166

GnomAD4 genome AF: 0.00000657 AC: 1 AN: 152126 Hom.: 0 Cov.: 32 AF XY: 0.0000135 AC XY: 1 AN XY: 74308

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: 0.0000227

ClinVar

Significance: Conflicting classifications of pathogenicity

Submissions summary: Uncertain:5 Benign:1

Revision: criteria provided, conflicting classifications

Submissions by phenotype

Familial adenomatous polyposis 1 Uncertain:2

Uncertain significance, criteria provided, single submitter	clinical testing	Labcorp Genetics (formerly Invitae), Labcorp	Jan 09, 2024	This variant, c.4018_4020dup, results in the insertion of 1 amino acid(s) of the APC protein (p.Ser1341dup), but otherwise preserves the integrity of the reading frame. This variant is present in population databases (no rsID available, gnomAD 0.002%). This variant has been observed in individual(s) with clinical features of APC-related conditions (PMID: 25980754). ClinVar contains an entry for this variant (Variation ID: 220089). Experimental studies and prediction algorithms are not available or were not evaluated, and the functional significance of this variant is currently unknown. In summary, the available evidence is currently insufficient to determine the role of this variant in disease. Therefore, it has been classified as a Variant of Uncertain Significance. -
Uncertain significance, criteria provided, single submitter	clinical testing	Baylor Genetics	Mar 19, 2024	- -

Hereditary cancer-predisposing syndrome Uncertain:1 Benign:1

Uncertain significance, criteria provided, single submitter	clinical testing	Color Diagnostics, LLC DBA Color Health	May 03, 2023	This variant causes an in-frame duplication of 1 amino acids of the APC protein. To our knowledge, functional studies have not been reported for this variant. This variant has not been reported in individuals affected with APC-related disorders in the literature. This variant has been identified in 2/251020 chromosomes in the general population by the Genome Aggregation Database (gnomAD). The available evidence is insufficient to determine the role of this variant in disease conclusively. Therefore, this variant is classified as a Variant of Uncertain Significance. -
Likely benign, criteria provided, single submitter	clinical testing	Ambry Genetics	May 16, 2023	This alteration is classified as likely benign based on a combination of the following: seen in unaffected individuals, population frequency, intact protein function, lack of segregation with disease, co-occurrence, RNA analysis, in silico models, amino acid conservation, lack of disease association in case-control studies, and/or the mechanism of disease or impacted region is inconsistent with a known cause of pathogenicity. -

Classic or attenuated familial adenomatous polyposis Uncertain:1

Uncertain significance, criteria provided, single submitter

clinical testing

All of Us Research Program, National Institutes of Health

May 30, 2024

This variant causes an in-frame duplication of 1 amino acids of the APC protein. To our knowledge, functional studies have not been reported for this variant. This variant has not been reported in individuals affected with APC-related disorders in the literature. This variant has been identified in 2/251020 chromosomes in the general population by the Genome Aggregation Database (gnomAD). The available evidence is insufficient to determine the role of this variant in disease conclusively. Therefore, this variant is classified as a Variant of Uncertain Significance. -

not provided Uncertain:1

Uncertain significance, criteria provided, single submitter

clinical testing

GeneDx

Dec 27, 2024

In-frame duplication of 1 amino acid in a non-repeat region; Observed in an individual undergoing multi-gene cancer panel testing due to a personal history of a Lynch syndrome-related cancer and/or polyps (PMID: 25980754); Not observed at significant frequency in large population cohorts (gnomAD); This variant is associated with the following publications: (PMID: 25980754, 18199528) -

Computational scores

Source: dbNSFP v4.3

Splicing

Find out detailed SpliceAI scores and Pangolin per-transcript scores at spliceailookup.broadinstitute.org

Publications

LitVar

Other links and lift over

dbSNP: rs864622376; hg19: chr5-112175307;