NM_000038.6:c.313A>G
Variant summary
Our verdict is Likely benign. The variant received -2 ACMG points: 0P and 2B. BP4_Moderate
The NM_000038.6(APC):c.313A>G(p.Ser105Gly) variant causes a missense change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.00000682 in 1,614,076 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a benign outcome for this variant. 15/22 in silico tools predict a benign outcome for this variant. Variant has been reported in ClinVar as Uncertain significance (★★). Another variant affecting the same amino acid position, but resulting in a different missense (i.e. S105N) has been classified as Uncertain significance.
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_benign. The variant received -2 ACMG points.
Transcripts
RefSeq
Ensembl
Frequencies
GnomAD3 genomes AF: 0.00000657 AC: 1AN: 152224Hom.: 0 Cov.: 32 show subpopulations
GnomAD4 exome AF: 0.00000684 AC: 10AN: 1461852Hom.: 0 Cov.: 31 AF XY: 0.00000688 AC XY: 5AN XY: 727232 show subpopulations
Age Distribution
GnomAD4 genome AF: 0.00000657 AC: 1AN: 152224Hom.: 0 Cov.: 32 AF XY: 0.0000134 AC XY: 1AN XY: 74374 show subpopulations ⚠️ The allele balance in gnomAD version 4 Genomes is significantly skewed from the expected value of 0.5.
Age Distribution
ClinVar
Submissions by phenotype
Familial adenomatous polyposis 1 Uncertain:2
This sequence change replaces serine, which is neutral and polar, with glycine, which is neutral and non-polar, at codon 105 of the APC protein (p.Ser105Gly). This variant is not present in population databases (gnomAD no frequency). This missense change has been observed in individual(s) with colon cancer (PMID: 37306523). ClinVar contains an entry for this variant (Variation ID: 482406). 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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not provided Uncertain:2
BP1, PM2 -
Not observed in large population cohorts (gnomAD); In silico analysis supports that this missense variant does not alter protein structure/function; Not observed in any cases, but was observed in unaffected controls from a biliary tract cancer study (Okawa et al., 2023); This variant is associated with the following publications: (PMID: 26900293, 36243179) -
Hereditary cancer-predisposing syndrome Uncertain:2
This missense variant replaces serine with glycine at codon 105 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 cancer (PMID: 26900293). 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.S105G variant (also known as c.313A>G), located in coding exon 3 of the APC gene, results from an A to G substitution at nucleotide position 313. The serine at codon 105 is replaced by glycine, an amino acid with similar properties. This alteration was identified in 1/103 individuals with colorectal cancer; however, clinical details were not provided for this individual (Chang YC et al. World J. Gastroenterol., 2016 Feb;22:2314-25). This amino acid position is highly 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). Since supporting evidence is limited at this time, the clinical significance of this alteration remains unclear. -
Classic or attenuated familial adenomatous polyposis Uncertain:1
This missense variant replaces serine with glycine at codon 105 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 cancer (PMID: 26900293). This variant has not been identified in the general population by the Genome Aggregation Database (gnomAD) but has been reported in a healthy control individual (PMID: 32980694). 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. -
APC-related disorder Uncertain:1
The APC c.313A>G variant is predicted to result in the amino acid substitution p.Ser105Gly. This variant has been reported in a patient with colorectal cancer and in patient with biliary tract cancer, although conclusive evidence of pathogenicity was not provided (Chang et al. 2016. PubMed ID: 26900293; Table S2, Okawa et al. 2023. PubMed ID: 36243179). This variant has not been reported in a large population database, indicating this variant is rare. This variant is interpreted as uncertain in ClinVar (https://www.ncbi.nlm.nih.gov/clinvar/variation/482406/). At this time, the clinical significance of this variant is uncertain due to the absence of conclusive functional and genetic evidence. -
Computational scores
Source:
Splicing
Find out detailed SpliceAI scores and Pangolin per-transcript scores at