rs1114167617
Variant summary
Our verdict is Likely pathogenic. The variant received 6 ACMG points: 6P and 0B. PM2_SupportingPS4_ModeratePM5_SupportingPP1_Moderate
This summary comes from the ClinGen Evidence Repository: The NM_000038.6:c.3083G>A variant in APC is a missense variant predicted to cause the substitution of serine to asparagine at amino acid position 1028 (p.Ser1028Asn). This variant has been reported in 4 probands/families meeting phenotypic criteria, resulting in a total phenotype score of 2 (PS4_Moderate; internal data Ambry Genetics; Labcorp Genetics (formerly Invitae); Peter MacCallum Cancer Centre, Victoria, Australia). The variant has been reported in 3 additional probands with a colorectal cancer/polyposis associated phenotype not meeting phenotypic criteria and one individual with colorectal cancer in the family history (internal data Ambry Genetics; Labcorp Genetics (formerly Invitae); Peter MacCallum Cancer Centre, Victoria, Australia). This variant has been reported to segregate with FAP in 5 meioses in 2 families (PP1_Moderate; internal data Ambry Genetics and Peter MacCallum Cancer Centre, Victoria, Australia). This variant is absent from gnomAD v2.1.1 (PM2_Supporting). Two other missense variants (c.3084T>A and c.3083G>T) in the same codon leading to a different amino acid change at this position (p.Ser1028Arg; p.Ser1028Ile) have been classified as Likely Pathogenic by the ClinGen InSiGHT Hereditary Colorectal Cancer/Polyposis Variant Curation Expert Panel (HCCP VCEP) (PM5_Supporting). 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 PS4_Moderate, PP1_Moderate, PM2_Supporting and PM5_Supporting (VCEP specifications version v2.1.0; date of approval 11/24/2023). LINK:https://erepo.genome.network/evrepo/ui/classification/CA16028084/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: Likely_pathogenic. The variant received 6 ACMG points.
Transcripts
RefSeq
Ensembl
Gene | Transcript | HGVSc | HGVSp | Effect | Exon rank | TSL | MANE | Protein | Appris | UniProt |
---|---|---|---|---|---|---|---|---|---|---|
APC | ENST00000257430.9 | c.3083G>A | p.Ser1028Asn | missense_variant | Exon 16 of 16 | 5 | NM_000038.6 | ENSP00000257430.4 | ||
ENSG00000258864 | ENST00000520401.1 | n.228+9705G>A | intron_variant | Intron 3 of 7 | 3 | ENSP00000454861.1 |
Frequencies
GnomAD3 genomes Cov.: 32
GnomAD4 exome Cov.: 33
GnomAD4 genome Cov.: 32
ClinVar
Submissions by phenotype
Familial adenomatous polyposis 1 Pathogenic:2Uncertain:1
The NM_000038.6:c.3083G>A variant in APC is a missense variant predicted to cause the substitution of serine to asparagine at amino acid position 1028 (p.Ser1028Asn). This variant has been reported in 4 probands/families meeting phenotypic criteria, resulting in a total phenotype score of 2 (PS4_Moderate; internal data Ambry Genetics; Labcorp Genetics (formerly Invitae); Peter MacCallum Cancer Centre, Victoria, Australia). The variant has been reported in 3 additional probands with a colorectal cancer/polyposis associated phenotype not meeting phenotypic criteria and one individual with colorectal cancer in the family history (internal data Ambry Genetics; Labcorp Genetics (formerly Invitae); Peter MacCallum Cancer Centre, Victoria, Australia). This variant has been reported to segregate with FAP in 5 meioses in 2 families (PP1_Moderate; internal data Ambry Genetics and Peter MacCallum Cancer Centre, Victoria, Australia). This variant is absent from gnomAD v2.1.1 (PM2_Supporting). Two other missense variants (c.3084T>A and c.3083G>T) in the same codon leading to a different amino acid change at this position (p.Ser1028Arg; p.Ser1028Ile) have been classified as Likely Pathogenic by the ClinGen InSiGHT Hereditary Colorectal Cancer/Polyposis Variant Curation Expert Panel (HCCP VCEP) (PM5_Supporting). 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 PS4_Moderate, PP1_Moderate, PM2_Supporting and PM5_Supporting (VCEP specifications version v2.1.0; date of approval 11/24/2023). -
This sequence change replaces serine, which is neutral and polar, with asparagine, which is neutral and polar, at codon 1028 of the APC protein (p.Ser1028Asn). This variant is not present in population databases (gnomAD no frequency). This variant has not been reported in the literature in individuals affected with APC-related conditions. ClinVar contains an entry for this variant (Variation ID: 428186). Advanced modeling of protein sequence and biophysical properties (such as structural, functional, and spatial information, amino acid conservation, physicochemical variation, residue mobility, and thermodynamic stability) performed at Invitae indicates that this missense variant is not expected to disrupt APC protein function. 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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Hereditary cancer-predisposing syndrome Pathogenic:1
The p.S1028N pathogenic mutation (also known as c.3083G>A), located in coding exon 15 of the APC gene, results from a G to A substitution at nucleotide position 3083. The serine at codon 1028 is replaced by asparagine, an amino acid with highly similar properties. This alteration has been observed in multiple individuals with a personal and/or family history that is consistent with APC-related disease (Ambry internal data; Personal communication). This alteration was shown to segregate with disease in one family (Ambry internal data). A nearby amino acid, APC p.N1026, likely interacts directly with APC p.S1028. A missense alteration at the nearby amino acid, APC p.N1026S, which was also shown to segregate with AFAP, is impaired in its ability to bind to β-Catenin and, thus, impaired in reducing β-Catenin signaling (Menéndez M et al. Gastroenterology. 2008 Jan;134:56-64; Kohler EM et al. Hum. Mol. Genet. 2008 Jul;17:1978-87). Internal structural analysis shows that this variant (p.S1028N) lies on the protein interface that is indicated to be important for β-Catenin binding (Ambry internal data). This variant is considered to be rare based on population cohorts in the Genome Aggregation Database (gnomAD). This amino acid position is highly conserved in available vertebrate species. In addition, in silico predictors for this gene do not accurately predict pathogenicity. Based on the supporting evidence, this alteration is interpreted as a disease-causing mutation. -
Computational scores
Source:
Splicing
Find out detailed SpliceAI scores and Pangolin per-transcript scores at