rs748745776
Variant summary
Our verdict is Uncertain significance. The variant received 0 ACMG points: 0P and 0B.
The NM_000038.6(APC):c.6512G>A(p.Gly2171Glu) variant causes a missense change involving the alteration of a conserved nucleotide. The variant allele was found at a frequency of 0.0000422 in 1,610,952 control chromosomes in the GnomAD database, with no homozygous occurrence. Variant has been reported in ClinVar as Conflicting classifications of pathogenicity (no stars). Another variant affecting the same amino acid position, but resulting in a different missense (i.e. G2171R) 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 0 ACMG points.
Transcripts
RefSeq
| Gene | Transcript | HGVSc | HGVSp | Effect | Exon rank | MANE | Protein | UniProt |
|---|---|---|---|---|---|---|---|---|
| APC | NM_000038.6 | c.6512G>A | p.Gly2171Glu | missense_variant | Exon 16 of 16 | ENST00000257430.9 | NP_000029.2 |
Ensembl
Frequencies
GnomAD3 genomes AF: 0.0000197 AC: 3AN: 152034Hom.: 0 Cov.: 32 show subpopulations
GnomAD2 exomes AF: 0.0000521 AC: 13AN: 249444 AF XY: 0.0000739 show subpopulations
GnomAD4 exome AF: 0.0000446 AC: 65AN: 1458918Hom.: 0 Cov.: 34 AF XY: 0.0000455 AC XY: 33AN XY: 725944 show subpopulations
Age Distribution
GnomAD4 genome AF: 0.0000197 AC: 3AN: 152034Hom.: 0 Cov.: 32 AF XY: 0.0000135 AC XY: 1AN XY: 74260 show subpopulations
ClinVar
Submissions by phenotype
not specified Uncertain:2Benign:1
The p.Gly2171Glu variant in APC has not been previously reported in individuals with familial adenomatous polyposis or other APC-associated cancers but has been identified in 11/66074 of European chromosomes by the Exome Aggregation Consort ium (ExAC, http://exac.broadinstitute.org; dbSNP rs748745776). Computational pre diction tools and conservation analysis suggest that the p.Gly2171Glu variant ma y impact the protein, though this information is not predictive enough to determ ine pathogenicity. In summary, the clinical significance of the p.Gly2171Glu var iant is uncertain. -
Variant summary: APC c.6512G>A (p.Gly2171Glu) results in a non-conservative amino acid change in the encoded protein sequence. Four of five in-silico tools predict a damaging effect of the variant on protein function. The variant allele was found at a frequency of 5.2e-05 in 249444 control chromosomes, predominantly at a frequency of 0.00011 within the Non-Finnish European subpopulation in the gnomAD database. The observed variant frequency within Non-Finnish European control individuals in the gnomAD database is approximately 1.5 fold of the estimated maximal expected allele frequency for a pathogenic variant in APC causing Familial Adenomatous Polyposis phenotype (7.1e-05), strongly suggesting that the variant is a benign polymorphism found primarily in populations of Non-Finnish European origin. c.6512G>A has been reported in the literature in individuals undergoing multigene panel testing for Lynch syndrome (Yurgelun_2015), colorectal cancer/polyposis (Gordon_2019) and one case with B-ALL (Zhang_2015). These report(s) do not provide unequivocal conclusions about association of the variant with Familial Adenomatous Polyposis. To our knowledge, no experimental evidence demonstrating an impact on protein function has been reported. Four clinical diagnostic laboratories have submitted clinical-significance assessments for this variant to ClinVar after 2014 without evidence for independent evaluation. All laboratories classified the variant as uncertain significance, some citing overlapping evidence utilized in the context of this evaluation. Based on the evidence outlined above, the variant was classified as VUS-possibly benign. -
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Hereditary cancer-predisposing syndrome Uncertain:1Benign:1
This missense variant replaces glycine with glutamic acid at codon 2171 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 Lynch syndrome-associated cancer and/or polyps (PMID: 25980754, 31422818). This variant has been identified in 14/280842 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. -
This alteration is classified as likely benign based on a combination of the following: seen in unaffected individuals, population frequency, intact protein function, lack of segregation with disease, co-occurrence, RNA analysis, in silico models, amino acid conservation, lack of disease association in case-control studies, and/or the mechanism of disease or impacted region is inconsistent with a known cause of pathogenicity. -
Familial adenomatous polyposis 1 Uncertain:1
This sequence change replaces glycine, which is neutral and non-polar, with glutamic acid, which is acidic and polar, at codon 2171 of the APC protein (p.Gly2171Glu). This variant is present in population databases (rs748745776, gnomAD 0.01%). This missense change has been observed in individual(s) with colon polyps and/or colorectal cancer and acute lymphocytic leukemia (PMID: 26580448, 31422818). ClinVar contains an entry for this variant (Variation ID: 470051). 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. -
Classic or attenuated familial adenomatous polyposis Uncertain:1
This missense variant replaces glycine with glutamic acid at codon 2171 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). Splice site prediction tools suggest that this variant may not impact RNA splicing. 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 14/280842 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. -
not provided Uncertain:1
In silico analysis supports that this missense variant does not alter protein structure/function; This variant is associated with the following publications: (PMID: 25980754, 26580448, 31422818) -
Cancer or benign tumor Uncertain:1
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Computational scores
Source:
Splicing
Find out detailed SpliceAI scores and Pangolin per-transcript scores at