rs748940586
Variant summary
Our verdict is Uncertain significance. The variant received 0 ACMG points: 0P and 0B.
The NM_000038.6(APC):c.7018A>C(p.Asn2340His) variant causes a missense change. The variant allele was found at a frequency of 0.0000328 in 1,613,722 control chromosomes in the GnomAD database, with no homozygous occurrence. 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. N2340K) 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
Ensembl
Gene | Transcript | HGVSc | HGVSp | Effect | Exon rank | TSL | MANE | Protein | Appris | UniProt |
---|---|---|---|---|---|---|---|---|---|---|
APC | ENST00000257430.9 | c.7018A>C | p.Asn2340His | missense_variant | Exon 16 of 16 | 5 | NM_000038.6 | ENSP00000257430.4 | ||
ENSG00000258864 | ENST00000520401.1 | n.228+13640A>C | intron_variant | Intron 3 of 7 | 3 | ENSP00000454861.1 |
Frequencies
GnomAD3 genomes AF: 0.0000197 AC: 3AN: 152172Hom.: 0 Cov.: 32 show subpopulations
GnomAD2 exomes AF: 0.0000160 AC: 4AN: 250218 AF XY: 0.0000148 show subpopulations
GnomAD4 exome AF: 0.0000342 AC: 50AN: 1461550Hom.: 0 Cov.: 34 AF XY: 0.0000371 AC XY: 27AN XY: 727098 show subpopulations
GnomAD4 genome AF: 0.0000197 AC: 3AN: 152172Hom.: 0 Cov.: 32 AF XY: 0.00 AC XY: 0AN XY: 74344 show subpopulations
ClinVar
Submissions by phenotype
Familial adenomatous polyposis 1 Uncertain:2
This sequence change replaces asparagine, which is neutral and polar, with histidine, which is basic and polar, at codon 2340 of the APC protein (p.Asn2340His). This variant is present in population databases (rs748940586, gnomAD 0.004%). This missense change has been observed in individual(s) with colorectal cancer (PMID: 25559809). ClinVar contains an entry for this variant (Variation ID: 418637). 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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Hereditary cancer-predisposing syndrome Uncertain:2
This missense variant replaces asparagine with histidine at codon 2340 of the APC protein. Computational prediction tool 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 performed for this variant. This variant has been reported in an individual affected with colon cancer (PMID: 25559809). This variant has been identified in 4/250218 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. -
The p.N2340H variant (also known as c.7018A>C), located in coding exon 15 of the APC gene, results from an A to C substitution at nucleotide position 7018. The asparagine at codon 2340 is replaced by histidine, an amino acid with similar properties. This variant was observed in 1/626 individuals with early-onset familial colorectal cancer cases, who had germline genetic testing for colon cancer associated genes; this 55 year old female had proximal colon cancer and a maternal aunt with colorectal cancer at age 62 (Chubb D et al. J. Clin. Oncol. 2015 Feb; 33(5):426-32). This alteration was also reported in a cohort of elderly cancer-free individuals (Zheng G et al. Cancers (Basel), 2020 Sep;12:). This amino acid position is well 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. -
not provided Uncertain:1
Not observed at significant frequency in large population cohorts (gnomAD); In silico analysis indicates that this missense variant does not alter protein structure/function; This variant is associated with the following publications: (PMID: 32992489, 18199528, 25559809) -
Classic or attenuated familial adenomatous polyposis Uncertain:1
This missense variant replaces asparagine with histidine at codon 2340 of the APC protein. Computational prediction tool 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 performed for this variant. This variant has been reported in individuals affected with colon cancer (PMID: 25559809). This variant has been identified in 4/250218 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