rs1060503261

Variant names:

• chr5-112801383-G-A
• rs1060503261
• NM_000038.6:c.834G>A

Your query was ambiguous. Multiple possible variants found:

• chr5-112801383-G-A
• chr5-112801383-G-C

Variant summary

Our verdict is Pathogenic. The variant received 12 ACMG points: 12P and 0B. PM2 PP3_Moderate PP5_Very_Strong

The NM_000038.6(APC):​c.834G>A​(p.Gln278Gln) variant causes a splice region, synonymous change. The variant was absent in control chromosomes in GnomAD project. In-silico tool predicts a benign outcome for this variant. 3/3 splice prediction tools predicting alterations to normal splicing. Variant has been reported in ClinVar as Likely pathogenic (★★).

• Frequency: Genomes: not found (cov: 32)
• Consequence: APC NM_000038.6 splice_region, synonymous
• Scores: Splicing: ADA: 0.9997
• Clinical Significance: Pathogenic/Likely pathogenic criteria provided, multiple submitters, no conflicts P:4
• Conservation: PhyloP100: 5.51
• Publications: 4 publications found

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

ACMG classification

Our verdict: Pathogenic. The variant received 12 ACMG points.

• PM2: Very rare variant in population databases, with high coverage
• PP3: Splicing predictors support a deleterious effect. Scorers claiming Pathogenic: dbscSNV1_ADA, dbscSNV1_RF, max_spliceai. No scorers claiming Uncertain. No scorers claiming Benign.
• PP5: Variant 5-112801383-G-A is Pathogenic according to our data. Variant chr5-112801383-G-A is described in ClinVar as Pathogenic/Likely_pathogenic. ClinVar VariationId is 411344.Status of the report is criteria_provided_multiple_submitters_no_conflicts, 2 stars.

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	MANE	Protein	UniProt
APC	NM_000038.6	c.834G>A	p.Gln278Gln	splice_region_variant, synonymous_variant	Exon 8 of 16	ENST00000257430.9	NP_000029.2

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	TSL	MANE	Protein	Appris	UniProt
APC	ENST00000257430.9	c.834G>A	p.Gln278Gln	splice_region_variant, synonymous_variant	Exon 8 of 16	5	NM_000038.6	ENSP00000257430.4

Frequencies

GnomAD3 genomes Cov.: 32

GnomAD4 exome Cov.: 25

GnomAD4 genome Cov.: 32

Alfa AF: 0.00 Hom.: 0

ClinVar

Significance: Pathogenic/Likely pathogenic

Submissions summary: Pathogenic:4

Revision: criteria provided, multiple submitters, no conflicts

Submissions by phenotype

Familial adenomatous polyposis 1 Pathogenic:2

May 12, 2019

Labcorp Genetics (formerly Invitae), Labcorp

Significance: Likely pathogenic

Review Status: criteria provided, single submitter

Collection Method: clinical testing

This variant is not present in population databases (ExAC no frequency). 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. A different variant affecting this nucleotide (c.834G>C) has been determined to be pathogenic (PMID: 18433509). This suggests that this nucleotide is important for normal RNA splicing, and that other variants at this position may also be pathogenic. Nucleotide substitutions within the consensus splice site are a relatively common cause of aberrant splicing (PMID: 17576681, 9536098). Algorithms developed to predict the effect of sequence changes on RNA splicing suggest that this variant may disrupt the consensus splice site, but this prediction has not been confirmed by published transcriptional studies. This variant has been observed in individuals and families affected with familial adenomatous polyposis (PMID: 20223039, 23159591, Invitae). ClinVar contains an entry for this variant (Variation ID: 411344). This sequence change affects codon 278 of the APC mRNA. It is a 'silent' change, meaning that it does not change the encoded amino acid sequence of the APC protein. This variant also falls at the last nucleotide of exon 8 of the APC coding sequence, which is part of the consensus splice site for this exon. -

Mar 22, 2024

Baylor Genetics

Significance: Likely pathogenic

Review Status: criteria provided, single submitter

Collection Method: clinical testing

- -

not provided Pathogenic:1

Oct 23, 2020

Institute of Medical Genetics and Applied Genomics, University Hospital Tübingen

Significance: Likely pathogenic

Review Status: criteria provided, single submitter

Collection Method: clinical testing

- -

Hereditary cancer-predisposing syndrome Pathogenic:1

Aug 17, 2022

Ambry Genetics

Significance: Pathogenic

Review Status: criteria provided, single submitter

Collection Method: clinical testing

The c.834G>A pathogenic mutation (also known as p.Q278Q), located in coding exon 7 of the APC gene, results from a G to A substitution at nucleotide position 834. This nucleotide substitution does not change the protein at codon 278. However, this change occurs in the last base pair of coding exon 7, which makes it likely to have some effect on normal mRNA splicing. This alteration has previously been reported in a family meeting diagnostic criteria for FAP or attenuated FAP (Friedl W et al. Hered Cancer Clin Pract 2005; 3(3):95-114; Kerr SE et al. J Mol Diagn 2013 Jan; 15(1):31-43). In addition, this alteration has been observed in multiple individuals with a personal and/or family history that is consistent with FAP/AFAP (Ambry internal data). A different alteration at the same position (c.834G>C) was previously reported in a family with FAP and was shown to create an alternative cryptic splice donor site 11 bp upstream, resulting in aberrant splicing of coding exon 7 (Kanter-Smoler G et al. BMC Med 2008; 6:10). This nucleotide position is highly conserved in available vertebrate species. In silico splice site analysis predicts that this alteration may weaken the native splice donor site and will result in the creation or strengthening of a novel splice donor site, however, direct evidence is insufficient at this time (Ambry internal data). 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	Uncertain	26
DANN	Benign	0.91
PhyloP100		5.5
RBP_binding_hub_radar		0.0
RBP_regulation_power_radar		1.7
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)		0.78		Details are displayed if max score is > 0.2
DS_DG_spliceai		0.78		Position offset: -11
DS_DL_spliceai		0.30		Position offset: 0

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

Other links and lift over

dbSNP: rs1060503261; hg19: chr5-112137080;