5-112841355-G-A
Variant summary
Our verdict is Uncertain significance. The variant received 0 ACMG points: 2P and 2B. BS2_SupportingPM2_SupportingBP1PS3_Supporting
This summary comes from the ClinGen Evidence Repository: The c.5761G>A variant in APC is a missense variant predicted to cause the substitution of glycine by serine at amino acid position 1921 (p.Gly1921Ser). APC is defined by the ClinGen InSiGHT Hereditary Colorectal Cancer/Polyposis Variant Curation Expert Panel (HCCP VCEP) as a gene for which primarily truncating variants are known to cause disease (BP1). This variant has been observed in more than 3 heterozygous individuals with no features of FAP, worth 3 healthy individual points (BS2_Supporting; Ambry Genetics internal data). A luciferase reporter plasmid transiently transfected into SW480 cells shows an inability to suppress beta-catenin-regulated transcription indicating that this variant impacts protein function (PS3_Supporting; PMID 18199528). This variant is absent from gnomAD v2.1.1 (PM2_Supporting). Due to conflicting evidence, this variant is classified as a Variant of Uncertain Significance (VUS) for FAP based on the ACMG/AMP criteria applied, as specified by the HCCP VCEP: BS2_supporting, BP1, PM2_supporting, and PS3_supporting (VCEP specifications version 1; date of approval: 12/12/2022). LINK:https://erepo.genome.network/evrepo/ui/classification/CV411472/MONDO:0021056/089
Frequency
Consequence
NM_000038.6 missense
Scores
Clinical Significance
Conservation
Publications
- classic or attenuated familial adenomatous polyposisInheritance: AD Classification: DEFINITIVE Submitted by: ClinGen
- desmoid tumorInheritance: AD Classification: DEFINITIVE, STRONG Submitted by: G2P, Genomics England PanelApp
- familial adenomatous polyposis 1Inheritance: AD Classification: DEFINITIVE, STRONG, MODERATE Submitted by: Genomics England PanelApp, Labcorp Genetics (formerly Invitae), Ambry Genetics
- gastric adenocarcinoma and proximal polyposis of the stomachInheritance: AD Classification: DEFINITIVE, STRONG, SUPPORTIVE Submitted by: Ambry Genetics, Labcorp Genetics (formerly Invitae), ClinGen, Orphanet
- sarcomaInheritance: AD Classification: MODERATE Submitted by: Genomics England PanelApp
- APC-related attenuated familial adenomatous polyposisInheritance: AD Classification: SUPPORTIVE Submitted by: Orphanet
- Turcot syndrome with polyposisInheritance: AD Classification: SUPPORTIVE Submitted by: Orphanet
- Cenani-Lenz syndactyly syndromeInheritance: AR Classification: SUPPORTIVE Submitted by: Orphanet
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ACMG classification
Our verdict: Uncertain_significance. The variant received 0 ACMG points.
Transcripts
RefSeq
Ensembl
| Gene | Transcript | HGVSc | HGVSp | Effect | Exon rank | TSL | MANE | Protein | Appris | UniProt |
|---|---|---|---|---|---|---|---|---|---|---|
| APC | ENST00000257430.9 | c.5761G>A | p.Gly1921Ser | missense_variant | Exon 16 of 16 | 5 | NM_000038.6 | ENSP00000257430.4 | ||
| ENSG00000258864 | ENST00000520401.1 | n.228+12383G>A | intron_variant | Intron 3 of 7 | 3 | ENSP00000454861.1 |
Frequencies
GnomAD3 genomes Cov.: 32
GnomAD4 exome Cov.: 65
GnomAD4 genome Cov.: 32
ClinVar
Submissions by phenotype
Familial adenomatous polyposis 1 Uncertain:3
This sequence change replaces glycine, which is neutral and non-polar, with serine, which is neutral and polar, at codon 1921 of the APC protein (p.Gly1921Ser). This variant is not present in population databases (gnomAD no frequency). This missense change has been observed in individual(s) with multiple colorectal adenomas (PMID: 18199528). ClinVar contains an entry for this variant (Variation ID: 411472). Invitae Evidence Modeling of protein sequence and biophysical properties (such as structural, functional, and spatial information, amino acid conservation, physicochemical variation, residue mobility, and thermodynamic stability) indicates that this missense variant is not expected to disrupt APC protein function with a negative predictive value of 95%. In summary, the available evidence is currently insufficient to determine the role of this variant in disease. Therefore, it has been classified as a Variant of Uncertain Significance. -
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The c.5761G>A variant in APC is a missense variant predicted to cause the substitution of glycine by serine at amino acid position 1921 (p.Gly1921Ser). APC is defined by the ClinGen InSiGHT Hereditary Colorectal Cancer/Polyposis Variant Curation Expert Panel (HCCP VCEP) as a gene for which primarily truncating variants are known to cause disease (BP1). This variant has been observed in more than 3 heterozygous individuals with no features of FAP, worth 3 healthy individual points (BS2_Supporting; Ambry Genetics internal data). A luciferase reporter plasmid transiently transfected into SW480 cells shows an inability to suppress beta-catenin-regulated transcription indicating that this variant impacts protein function (PS3_Supporting; PMID 18199528). This variant is absent from gnomAD v2.1.1 (PM2_Supporting). Due to conflicting evidence, this variant is classified as a Variant of Uncertain Significance (VUS) for FAP based on the ACMG/AMP criteria applied, as specified by the HCCP VCEP: BS2_supporting, BP1, PM2_supporting, and PS3_supporting (VCEP specifications version 1; date of approval: 12/12/2022). -
Hereditary cancer-predisposing syndrome Uncertain:2
This missense variant replaces glycine with serine at codon 1921 of the APC protein. Computational prediction suggests that this variant may not impact protein structure and function (internally defined REVEL score threshold <= 0.5, PMID: 27666373). To our knowledge, functional studies have not been reported for this variant. This variant has been reported in an individual affected with colorectal adenomas (PMID: 18199528). This variant has not been identified in the general population by the Genome Aggregation Database (gnomAD). The available evidence is insufficient to determine the role of this variant in disease conclusively. Therefore, this variant is classified as a Variant of Uncertain Significance. -
The p.G1921S variant (also known as c.5761G>A), located in coding exon 15 of the APC gene, results from a G to A substitution at nucleotide position 5761. The glycine at codon 1921 is replaced by serine, an amino acid with similar properties. This alteration was detected in one individual with 11-99 adenomatous colorectal polyps and was not detected in 969 matched healthy controls (Azzopardi D et al. Cancer Res., 2008 Jan;68:358-63). This amino acid position is not well conserved in available vertebrate species. In addition, in silico predictors for this gene do not accurately predict pathogenicity. Missense alterations in APC are not a common cause of disease (Spier I et al. Genet Med. 2024 Feb;26(2):100992). Based on the available evidence, the clinical significance of this variant remains unclear. -
Classic or attenuated familial adenomatous polyposis Uncertain:1
This missense variant replaces glycine with serine at codon 1921 of the APC protein. Computational prediction suggests that this variant may not impact protein structure and function (internally defined REVEL score threshold <= 0.5, PMID: 27666373). To our knowledge, functional studies have not been reported for this variant. This variant has been reported in an individual affected with colorectal adenomas (PMID: 18199528). This variant has not been identified in the general population by the Genome Aggregation Database (gnomAD). The available evidence is insufficient to determine the role of this variant in disease conclusively. Therefore, this variant is classified as a Variant of Uncertain Significance. -
Computational scores
Source:
Splicing
Find out detailed SpliceAI scores and Pangolin per-transcript scores at