5-112707526-AT-TAGCAAGGG

Position:

• chr5-112707526-AT-TAGCAAGGG

Variant summary

Our verdict is Pathogenic. Variant got 10 ACMG points: 10P and 0B. PM2 PP5_Very_Strong

The NM_001407446.1(APC):​c.-192_-191delinsTAGCAAGGG variant causes a 5 prime UTR change involving the alteration of a non-conserved nucleotide. The variant was absent in control chromosomes in GnomAD project. Variant has been reported in ClinVar as Likely pathogenic (★★).

• Frequency: Genomes: not found (cov: 33)
• Consequence: APC NM_001407446.1 5_prime_UTR
• Clinical Significance: Likely pathogenic criteria provided, multiple submitters, no conflicts P:2
• Conservation: PhyloP100: 3.40

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 10 ACMG points.

• PM2: Very rare variant in population databases, with high coverage
• PP5: Variant 5-112707526-AT-TAGCAAGGG is Pathogenic according to our data. Variant chr5-112707526-AT-TAGCAAGGG is described in ClinVar as [Likely_pathogenic]. Clinvar id is 652807.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_001127511.3	c.-192_-191delinsTAGCAAGGG		5_prime_UTR_variant	1/14		NP_001120983.2
APC	NM_001354895.2	c.-375_-374delinsTAGCAAGGG		5_prime_UTR_variant	1/16		NP_001341824.1
APC	NM_001354897.2	c.-192_-191delinsTAGCAAGGG		5_prime_UTR_variant	1/15		NP_001341826.1

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Protein	Appris	UniProt
APC	ENST00000507379.6	c.-192_-191delinsTAGCAAGGG		5_prime_UTR_variant	1/14	2		ENSP00000423224
APC	ENST00000509732.6	c.-142_-141delinsTAGCAAGGG		5_prime_UTR_variant	1/16	4		ENSP00000426541	P1
APC	ENST00000505350.2	c.-192_-191delinsTAGCAAGGG		5_prime_UTR_variant, NMD_transcript_variant	1/16	3		ENSP00000481752

Frequencies

GnomAD3 genomes Cov.: 33

We have no GnomAD4 exomes data on this position. Probably position not covered by the project.

GnomAD4 genome Cov.: 33

ClinVar

Significance: Likely pathogenic

Submissions summary: Pathogenic:2

Revision: criteria provided, multiple submitters, no conflicts

Submissions by phenotype

Familial adenomatous polyposis 1 Pathogenic:1

Likely pathogenic, criteria provided, single submitter

clinical testing

Labcorp Genetics (formerly Invitae), Labcorp

Nov 20, 2018

This variant occurs in a non-coding region of the APC gene. It does not change the encoded amino acid sequence of the APC protein. The frequency data for this variant in the population databases is considered unreliable, as metrics indicate insufficient coverage at this position in the ExAC database. This variant has been observed in an individual with clinical features consistent with familial adenomatous polyposis (Invitae). While experimental studies and prediction algorithms are not available for this variant, it disrupts a region of the APC promoter that has been proposed to include the DNA binding site for the YY1 transcription factor. Other variants that affect this region of the APC promoter (c.-30416G>A, c.-30417T>C, c.-30418A>G, and c.-30418A>T) have been shown to disrupt YY1 binding to the APC promoter and result in reduced APC expression (PMID: 20685668, 21813476, 27087319). Other variants that disrupt the DNA sequence in this region of the APC promoter have been observed in affected individuals (PMID: 20685668, 21813476, 27087319, 27343414, Invitae), suggesting that integrity of this region is clinically significant. As a result, variants that disrupt this region of the APC promoter are likely to be causative of disease. In summary, the currently available evidence indicates that the variant is pathogenic, but additional data are needed to prove that conclusively. Therefore, this variant has been classified as Likely Pathogenic. -

Hereditary cancer-predisposing syndrome Pathogenic:1

Likely pathogenic, criteria provided, single submitter

clinical testing

Ambry Genetics

Sep 21, 2023

The c.-192_-191delATinsTAGCAAGGG variant, located in in the 5' untranslated region (5’UTR) of the APC gene, results from the deletion of two nucleotides and the insertion of nine nucleotides at nucleotide positions -192 to -191 upstream of the first translated codon. This alteration has been observed in at least one individual with a personal and/or family history that is consistent with gastric adenocarcinoma and proximal polyposis of the stomach (GAPPS) (Ambry internal data). Other alterations affecting these nucleotides (c.-192A>G, c.-191T>G, c.-191T>C) have been identified in GAPPS probands (Ambry internal data; Li J et al. Am. J. Hum. Genet. 2016 May;98:830-42; Roberts AG et al. JPGN Reports, 2021 Nov;2(4):e123). This region has been identified as a highly conserved transcription factor binding site for the APC 1B promoter region and point mutations have been shown to disrupt transcriptional activity (Li J et al. Am. J. Hum. Genet. 2016 May;98:830-42). This nucleotide position is highly conserved in available vertebrate species. Based on the majority of available evidence to date, this variant is likely to be pathogenic. -

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: rs1580995904; hg19: chr5-112043223;