rs863225311

Variant summary

Our verdict is Likely pathogenic. The variant received 8 ACMG points: 8P and 0B. PP3PM2_SupportingPS1PS4_Moderate

This summary comes from the ClinGen Evidence Repository: The NM_000038.6(APC):c.1312+3A>C variant in APC is an intronic variant, which is located at the 3rd nucleotide in intron 10. This variant has been reported in 2 probands meeting phenotypic criteria, resulting in a total phenotype score of 2 points (PS4_Moderate, Ambry Genetics internal data, Tsukanov et al 2017; Russian Journal of Genetics, 2017, Vol. 53, No. 3, pp. 369–375). This variant is absent from gnomAD v2.1.1 (PM2_Supporting). The results from two in silico splicing predictors (SpliceAI and MaxEntScan) indicate that this variant may affect splicing by disrupting the donor splice site of intron 10 of APC (PP3). Moreover, this variant has similar in silico predictions compared to another noncanonical splicing variant at that same nucleotide position (c.1312+3A>G) (ClinVar ID: 217924), which is classified as pathogenic for FAP by the ClinGen InSiGHT Hereditary Colorectal Cancer/Polyposis VCEP (HCCP VCEP) (PS1). In summary, this variant meets the criteria to be classified as Likely Pathogenic for autosomal-dominant inherited FAP based on the ACMG/AMP criteria applied, as specified by the HCCP VCEP: criteria PS1, PM2_Supporting, PP3, and PS4_Moderate applied (VCEP specifications version v2.1.0; date of approval 11/24/2023). LINK:https://erepo.genome.network/evrepo/ui/classification/CA658655920/MONDO:0021056/089

Frequency

Genomes: not found (cov: 32)

Consequence

APC
NM_000038.6 splice_region, intron

Scores

2
Splicing: ADA: 0.9999
2

Clinical Significance

Likely pathogenic reviewed by expert panel P:2

Conservation

PhyloP100: 5.88

Publications

3 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

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ACMG classification

Classification was made for transcript

Our verdict: Likely_pathogenic. The variant received 8 ACMG points.

PS1
For more information check the summary or visit ClinGen Evidence Repository.
PS4
For more information check the summary or visit ClinGen Evidence Repository.
PM2
For more information check the summary or visit ClinGen Evidence Repository.
PP3
For more information check the summary or visit ClinGen Evidence Repository.

Transcripts

RefSeq

Gene Transcript HGVSc HGVSp Effect Exon rank MANE Protein UniProt
APCNM_000038.6 linkc.1312+3A>C splice_region_variant, intron_variant Intron 10 of 15 ENST00000257430.9 NP_000029.2 P25054-1Q4LE70

Ensembl

Gene Transcript HGVSc HGVSp Effect Exon rank TSL MANE Protein Appris UniProt
APCENST00000257430.9 linkc.1312+3A>C splice_region_variant, intron_variant Intron 10 of 15 5 NM_000038.6 ENSP00000257430.4 P25054-1

Frequencies

GnomAD3 genomes
Cov.:
32
GnomAD4 exome
Cov.:
33
GnomAD4 genome
Cov.:
32

ClinVar

Significance: Likely pathogenic
Submissions summary: Pathogenic:2
Revision: reviewed by expert panel
LINK: link

Submissions by phenotype

Familial adenomatous polyposis 1 Pathogenic:1
May 16, 2025
ClinGen InSiGHT Hereditary Colorectal Cancer/Polyposis Variant Curation Expert Panel
Significance:Likely pathogenic
Review Status:reviewed by expert panel
Collection Method:curation

The NM_000038.6(APC):c.1312+3A>C variant in APC is an intronic variant, which is located at the 3rd nucleotide in intron 10. This variant has been reported in 2 probands meeting phenotypic criteria, resulting in a total phenotype score of 2 points (PS4_Moderate, Ambry Genetics internal data, Tsukanov et al 2017; Russian Journal of Genetics, 2017, Vol. 53, No. 3, pp. 369–375). This variant is absent from gnomAD v2.1.1 (PM2_Supporting). The results from two in silico splicing predictors (SpliceAI and MaxEntScan) indicate that this variant may affect splicing by disrupting the donor splice site of intron 10 of APC (PP3). Moreover, this variant has similar in silico predictions compared to another noncanonical splicing variant at that same nucleotide position (c.1312+3A>G) (ClinVar ID: 217924), which is classified as pathogenic for FAP by the ClinGen InSiGHT Hereditary Colorectal Cancer/Polyposis VCEP (HCCP VCEP) (PS1). In summary, this variant meets the criteria to be classified as Likely Pathogenic for autosomal-dominant inherited FAP based on the ACMG/AMP criteria applied, as specified by the HCCP VCEP: criteria PS1, PM2_Supporting, PP3, and PS4_Moderate applied (VCEP specifications version v2.1.0; date of approval 11/24/2023). -

Hereditary cancer-predisposing syndrome Pathogenic:1
Jun 18, 2022
Ambry Genetics
Significance:Pathogenic
Review Status:criteria provided, single submitter
Collection Method:clinical testing

The c.1312+3A>C intronic pathogenic mutation results from an A to C substitution 3 nucleotides after coding exon 9 in the APC gene. This alteration has been detected in an individual diagnosed with >100 adenomatous polyps (Tsukanov AS et al. Russian J of Genet. 2017;53(3):369-375). Another alteration impacting the same donor site (c.1312+3A>G) has been detected in numerous familial adenomatous polyposis (FAP) families (Aretz S, et al. Hum. Mutat. 2004 Nov; 24(5):370-80; Lagarde A, et al. J. Med. Genet. 2010 Oct; 47(10):721-2; Nielsen M, et al. Clin. Genet. 2007 May; 71(5):427-33; Filipe B, et al. Clin. Genet. 2009 Sep; 76(3):242-55; Ambry internal data) and RNA analysis has shown that the c.1312+3A>G alteration leads to exon 9 skipping (Ambry internal data; Aretz S et al. Hum Mutat. 2004 Nov;24(5):370-80). This nucleotide position is well conserved in available vertebrate species. In silico splice site analysis predicts that this alteration will weaken the native splice donor site. This variant is considered to be rare based on population cohorts in the Genome Aggregation Database (gnomAD). Based on the supporting evidence, this alteration is interpreted as a disease-causing mutation. -

Computational scores

Source: dbNSFP v4.3

Name
Calibrated prediction
Score
Prediction
BayesDel_noAF
Benign
-0.32
CADD
Benign
18
DANN
Benign
0.97
PhyloP100
5.9
Mutation Taster
=0/100
disease causing (ClinVar)

Splicing

Name
Calibrated prediction
Score
Prediction
dbscSNV1_ADA
Pathogenic
1.0
dbscSNV1_RF
Pathogenic
0.97
SpliceAI score (max)
0.88
Details are displayed if max score is > 0.2
DS_DL_spliceai
0.88
Position offset: -3

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

Publications

Other links and lift over

dbSNP: rs863225311; hg19: chr5-112155044; COSMIC: COSV57382696; API