rs1064792977

Positions:

• chr5-112834938-TGTTTCTTACTA-T

Variant summary

Our verdict is Pathogenic. Variant got 13 ACMG points: 13P and 0B. PVS1_Moderate PM2 PP3 PP5_Very_Strong

The NM_000038.6(APC):​c.1744-11_1744-1del variant causes a splice acceptor, splice polypyrimidine tract, intron change involving the alteration of a 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: 32)
• Consequence: APC NM_000038.6 splice_acceptor, splice_polypyrimidine_tract, intron
• Clinical Significance: Likely pathogenic criteria provided, multiple submitters, no conflicts P:2
• Conservation: PhyloP100: 8.95

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 13 ACMG points.

• PVS1: Splicing +-2 bp (donor or acceptor) variant, product NOT destroyed by NMD, known LOF gene, truncates exone, which is 0.025082044 fraction of the gene. Cryptic splice site detected, with MaxEntScore 4.1, offset of -15, new splice context is: caaattccaactctaattAGatg. Cryptic site results in inframe change. If cryptic site found is not functional and variant results in exon loss, it results in frameshift change.
• PM2: Very rare variant in population databases, with high coverage
• PP3: No computational evidence supports a deleterious effect, but strongly conserved according to phyloP
• PP5: Variant 5-112834938-TGTTTCTTACTA-T is Pathogenic according to our data. Variant chr5-112834938-TGTTTCTTACTA-T is described in ClinVar as [Likely_pathogenic]. Clinvar id is 411361.Status of the report is criteria_provided_multiple_submitters_no_conflicts, 2 stars.

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	UniProt
APC	NM_000038.6	c.1744-11_1744-1del		splice_acceptor_variant, splice_polypyrimidine_tract_variant, intron_variant		ENST00000257430.9

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Appris	UniProt
APC	ENST00000257430.9	c.1744-11_1744-1del		splice_acceptor_variant, splice_polypyrimidine_tract_variant, intron_variant		5	NM_000038.6	P1

Frequencies

GnomAD3 genomes Cov.: 32

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

GnomAD4 genome Cov.: 32

ClinVar

Significance: Likely pathogenic

Submissions summary: Pathogenic:2

Revision: criteria provided, multiple submitters, no conflicts

Submissions by phenotype

Familial adenomatous polyposis 1 Pathogenic:2

Likely pathogenic, criteria provided, single submitter	clinical testing	Labcorp Genetics (formerly Invitae), Labcorp	Jul 29, 2016	In summary, donor and acceptor splice site variants are typically truncating (PMID: 16199547), and truncating variants in APC are known to be pathogenic (PMID: 20685668, 17963004). However, without additional functional and/or genetic data, this variant has been classified as Likely Pathogenic. This sequence change affects an acceptor splice site in intron 14 of the APC gene. It is expected to disrupt mRNA splicing and likely results in an absent or disrupted protein product. This variant is not present in population databases (ExAC no frequency) and has not been reported in the literature in individuals with a APC-related disease. -
Likely pathogenic, criteria provided, single submitter	clinical testing	Myriad Genetics, Inc.	May 03, 2023	This variant is considered likely pathogenic. This variant occurs within a consensus splice junction and is predicted to result in abnormal mRNA splicing of either an out-of-frame exon or an in-frame exon necessary for protein stability and/or normal function. -

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: rs1064792977; hg19: chr5-112170635;