rs886039507

chr5-112819349-G-Achr5-112819349-G-C

Variant summary

Our verdict is Pathogenic. Variant got 14 ACMG points: 14P and 0B. PM2 PP3_Strong PP5_Very_Strong

The NM_000038.6(APC):c.1312+5G>A variant causes a splice donor 5th base, intron change involving the alteration of a conserved nucleotide. The variant was absent in control chromosomes in GnomAD project. In-silico tool predicts a benign outcome for this variant. 2/2 splice prediction tools predicting alterations to normal splicing. Variant has been reported in ClinVar as Pathogenic (★★).

• Frequency: Genomes: not found (cov: 32)
• Consequence: APC NM_000038.6 splice_donor_5th_base, intron
• Scores: Splicing: ADA: 1.000
• Clinical Significance: Pathogenic criteria provided, multiple submitters, no conflicts P:6
• Conservation: PhyloP100: 9.60

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 14 ACMG points.

• PM2: Very rare variant in population databases, with high coverage
• PP3: Splicing scoreres supports a deletorius effect: Scorers claiming Pathogenic: dbscSNV1_ADA, dbscSNV1_RF. No scorers claiming Uncertain. No scorers claiming Benign.
• PP5: Variant 5-112819349-G-A is Pathogenic according to our data. Variant chr5-112819349-G-A is described in ClinVar as [Pathogenic]. Clinvar id is 411416.Status of the report is criteria_provided_multiple_submitters_no_conflicts, 2 stars. Variant chr5-112819349-G-A is described in Lovd as [Likely_pathogenic]. Variant chr5-112819349-G-A is described in Lovd as [Pathogenic].

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	UniProt
APC	NM_000038.6	c.1312+5G>A		splice_donor_5th_base_variant, intron_variant		ENST00000257430.9

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Appris	UniProt
APC	ENST00000257430.9	c.1312+5G>A		splice_donor_5th_base_variant, intron_variant		5	NM_000038.6	P1

Frequencies

GnomAD3 genomes Cov.: 32

GnomAD4 exome Cov.: 33

GnomAD4 genome Cov.: 32

ClinVar

Significance: Pathogenic

Submissions summary: Pathogenic:6

Revision: criteria provided, multiple submitters, no conflicts

Submissions by phenotype

Familial adenomatous polyposis 1 Pathogenic:2

Pathogenic, criteria provided, single submitter	clinical testing	Invitae	Nov 25, 2021	For these reasons, this variant has been classified as Pathogenic. Variants that disrupt the consensus splice site are a relatively common cause of aberrant splicing (PMID: 17576681, 9536098). Studies have shown that this variant results in skipping of exon 10 (also referred to as exon 9) and introduces a premature termination codon (PMID: 15459959, 22987206). The resulting mRNA is expected to undergo nonsense-mediated decay. ClinVar contains an entry for this variant (Variation ID: 411416). This variant has been observed in individuals with familial adenomatous polyposis (PMID: 15459959, 20223039, 22987206). It has also been observed to segregate with disease in related individuals. This variant is not present in population databases (gnomAD no frequency). This sequence change falls in intron 10 of the APC gene. It does not directly change the encoded amino acid sequence of the APC protein. RNA analysis indicates that this variant induces altered splicing and may result in an absent or disrupted protein product. -
Pathogenic, criteria provided, single submitter	clinical testing	Baylor Genetics	Sep 16, 2021	- -

Hereditary cancer-predisposing syndrome Pathogenic:2

Pathogenic, criteria provided, single submitter	clinical testing	Color Diagnostics, LLC DBA Color Health	Jun 14, 2021	This variant causes a G to A nucleotide substitution at the +5 position of intron 10 of the APC gene. RNA studies show that this variants resulted in exon 10 skipping (PMID: 8125478, 15459959, 15833136, 19196998, 22987206). This variant has been reported in individuals affected with familial adenomatous polyposis or colonic polyposis (PMID: 8125478, 15459959, 15833136, 22987206, 29029407, 29406563). It has been shown that this variant segregates with disease (PMID: 8125478). This variant has not been identified in the general population by the Genome Aggregation Database (gnomAD). Loss of APC function is a known mechanism of disease (clinicalgenome.org). Based on the available evidence, this variant is classified as Pathogenic. -
Pathogenic, criteria provided, single submitter	clinical testing	Ambry Genetics	Dec 29, 2022	The c.1312+5G>A intronic pathogenic mutation results from a G to A substitution 5 nucleotides after coding exon 9 in the APC gene. This mutation has been detected in individuals with clinical diagnoses of familial adenomatous polyposis (FAP) and attenuated FAP (Ambry internal data; Aretz et al. Hum Mutat. 2004 Nov;24(5):370-80; Mihalatos M et al. BMC Cancer 2005 Apr;5:40; Schwarzova et al. Fam Cancer. 2013 Mar;12(1):35-42). This variant is considered to be rare based on population cohorts in the Genome Aggregation Database (gnomAD). RNA analysis reveals that this mutation leads to substantially increased exon 9 skipping relative to control RNA samples (Ambry internal data; Aretz et al. Hum Mutat. 2004 Nov;24(5):370-80; Mihalatos M et al. BMC Cancer 2005 Apr;5:40; Schwarzova et al. Fam Cancer. 2013 Mar;12(1):35-42). Based on the supporting evidence, this alteration is interpreted as a disease-causing mutation. -

Familial multiple polyposis syndrome Pathogenic:1

Pathogenic, criteria provided, single submitter

clinical testing

Women's Health and Genetics/Laboratory Corporation of America, LabCorp

Jul 10, 2019

Variant summary: APC c.1312+5G>A alters a conserved nucleotide located close to a canonical splice site and therefore could affect mRNA splicing, leading to a significantly altered protein sequence. Several computational tools predict a significant impact on normal splicing: Three predict the variant abolishes a 5' splicing donor site. Two predict the variant weakens a 5' donor site. Several publications report experimental evidence that this variant affects mRNA splicing, resulting in skipping of exon 9 and truncation of the protein (Aretz_2004, Mihalatos_2005, Schwarzova_2013). The variant was absent in 250464 control chromosomes. c.1312+5G>A has been reported in the literature in individuals affected with Familial Adenomatous Polyposis(FAP) or Attenuated Familial Adenomatous Polyposis(AFAP) (Aretz_2004, Mihalatos_2005, Schwarzova_2013, Yanus_2018). These data indicate that the variant is likely to be associated with disease. Two clinical diagnostic laboratories have submitted clinical-significance assessments of pathogenic for this variant to ClinVar after 2014. Based on the evidence outlined above, the variant was classified as pathogenic. -

not provided Pathogenic:1

Pathogenic, criteria provided, single submitter

clinical testing

Quest Diagnostics Nichols Institute San Juan Capistrano

Nov 19, 2018

A splicing study showed that this variant produced a shift of frame, and is therefore predicted to result in the loss of a functional protein. Not found in the gnomAD dataset, and the data is high quality (0/34534 chr). Statistically enriched in patients compared to ethnically matched controls. Found in at least one symptomatic patient. Predicted to negatively affect a known splice site. Nucleotide conservation is uninformative. -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
BayesDel_noAF	Benign	-0.25
Cadd	Benign	23
Dann	Uncertain	0.98

Splicing

Name	Calibrated prediction	Score	Prediction
dbscSNV1_ADA	Pathogenic	1.0
dbscSNV1_RF	Pathogenic	1.0
SpliceAI score (max)		0.52		Details are displayed if max score is > 0.2
DS_DL_spliceai		0.52		Position offset: -5

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

Publications

LitVar

Other links and lift over

dbSNP: rs886039507; hg19: chr5-112155046; COSMIC: COSV57358318; COSMIC: COSV57358318;