5-112841721-A-G
Variant summary
Our verdict is Uncertain significance. The variant received 1 ACMG points: 1P and 0B. PP3
The NM_000038.6(APC):c.6127A>G(p.Ile2043Val) variant causes a missense change involving the alteration of a conserved nucleotide. The variant allele was found at a frequency of 0.00000434 in 1,613,700 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a pathogenic 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. I2043R) 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: Uncertain_significance. The variant received 1 ACMG points.
Transcripts
RefSeq
| Gene | Transcript | HGVSc | HGVSp | Effect | Exon rank | MANE | Protein | UniProt |
|---|---|---|---|---|---|---|---|---|
| APC | NM_000038.6 | c.6127A>G | p.Ile2043Val | missense_variant | Exon 16 of 16 | ENST00000257430.9 | NP_000029.2 |
Ensembl
Frequencies
GnomAD3 genomes AF: 0.00000657 AC: 1AN: 152202Hom.: 0 Cov.: 32 show subpopulations
GnomAD2 exomes AF: 0.00000399 AC: 1AN: 250880 AF XY: 0.00 show subpopulations
GnomAD4 exome AF: 0.00000411 AC: 6AN: 1461498Hom.: 0 Cov.: 34 AF XY: 0.00000413 AC XY: 3AN XY: 727074 show subpopulations
Age Distribution
GnomAD4 genome AF: 0.00000657 AC: 1AN: 152202Hom.: 0 Cov.: 32 AF XY: 0.0000134 AC XY: 1AN XY: 74356 show subpopulations
Age Distribution
ClinVar
Submissions by phenotype
Hereditary cancer-predisposing syndrome Uncertain:4
This missense variant replaces isoleucine with valine at codon 2043 of the APC protein. Computational prediction suggests that this variant may have deleterious impact on protein structure and function (internally defined REVEL score threshold >= 0.7, PMID: 27666373). To our knowledge, functional studies have not been reported for this variant. This variant has not been reported in individuals affected with APC-related disorders in the literature. This variant has been identified in 2/282286 chromosomes 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.
BP1 c.6127A>G, located in exon 16 of the APC gene, is predicted to result in the substitution of isoleucine by valine at codon 2043, p.(Ile2043Val) (BP1). This variant is found in 2/267754 alleles at a frequency of 0.0008% in the gnomAD v2.1.1 database, non-cancer dataset. The SpliceAI algorithm predicts no significant impact on splicing. APC c.6127A>G was identified in one patient diagnosed with attenuated familial adenomatous polyposis (22 colorectal adenomas at 53yr), but without family history, from our clinical cohort of patients. To our knowledge, no well-stablished functional studies have been reported for this variant. It has been reported in the ClinVar database (8x uncertain significance) and in the LOVD database (1x uncertain significance). Based on the currently available information, c.6127A>G is classified as an uncertain significance variant according to ClinGen-APC Guidelines version v1.
The p.I2043V variant (also known as c.6127A>G), located in coding exon 15 of the APC gene, results from an A to G substitution at nucleotide position 6127. The isoleucine at codon 2043 is replaced by valine, an amino acid with highly similar properties. This amino acid position is highly conserved in available vertebrate species. In addition, in silico predictors for this gene do not accurately predict pathogenicity. Since supporting evidence is limited at this time, the clinical significance of this alteration remains unclear.
Familial adenomatous polyposis 1 Uncertain:2
This sequence change replaces isoleucine, which is neutral and non-polar, with valine, which is neutral and non-polar, at codon 2043 of the APC protein (p.Ile2043Val). This variant is present in population databases (no rsID available, gnomAD 0.003%). 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: 233160). 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.
not provided Uncertain:2
Not observed at significant frequency in large population cohorts (gnomAD); In silico analysis indicates that this missense variant does not alter protein structure/function; Has not been previously published as pathogenic or benign to our knowledge; This variant is associated with the following publications: (PMID: 39125758, 18199528, 36901686)
The APC c.6127A>G (p.Ile2043Val) variant has not been reported in individuals with APC-related conditions in the published literature. The frequency of this variant in the general population, 0.0000071 (2/282286 chromosomes (Genome Aggregation Database, http://gnomad.broadinstitute.org)), is uninformative in the assessment of its pathogenicity. Analysis of this variant using bioinformatics tools for the prediction of the effect of amino acid changes on protein structure and function yielded predictions that this variant is damaging. Based on the available information, we are unable to determine the clinical significance of this variant.
not specified Uncertain:1
Variant summary: APC c.6127A>G (p.Ile2043Val) results in a conservative amino acid change located in the SAMP domain of the encoded protein sequence. Three of five in-silico tools predict a damaging effect of the variant on protein function. The variant allele was found at a frequency of 7.2e-06 in 276604 control chromosomes. This frequency is not higher than expected for a pathogenic variant in APC causing Familial Adenomatous Polyposis (7.2e-06 vs 7.1e-05), allowing no conclusion about variant significance. To our knowledge, no occurrence of c.6127A>G in individuals affected with Familial Adenomatous Polyposis and no experimental evidence demonstrating its impact on protein function have been reported. Two clinical diagnostic laboratories have submitted clinical-significance assessments for this variant to ClinVar after 2014, and both classified the variant as uncertain significance. Based on the evidence outlined above, the variant was classified as uncertain significance.
Classic or attenuated familial adenomatous polyposis Uncertain:1
This missense variant replaces isoleucine with valine at codon 2043 of the APC protein. Computational prediction is inconclusive regarding the impact of this variant on protein structure and function (internally defined REVEL score threshold 0.5 < inconclusive < 0.7, PMID: 27666373). To our knowledge, functional studies have not been reported for this variant. This variant has not been reported in individuals affected with hereditary cancer in the literature. This variant has been identified in 2/282286 chromosomes 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