rs749230730
Variant summary
Our verdict is Uncertain significance. The variant received 1 ACMG points: 1P and 0B. PP3
The NM_000038.6(APC):āc.6446A>Cā(p.His2149Pro) variant causes a missense change. The variant allele was found at a frequency of 0.0000174 in 1,613,294 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 Conflicting classifications of pathogenicity (no stars). Another variant affecting the same amino acid position, but resulting in a different missense (i.e. H2149R) 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
Ensembl
Gene | Transcript | HGVSc | HGVSp | Effect | Exon rank | TSL | MANE | Protein | Appris | UniProt |
---|---|---|---|---|---|---|---|---|---|---|
APC | ENST00000257430.9 | c.6446A>C | p.His2149Pro | missense_variant | Exon 16 of 16 | 5 | NM_000038.6 | ENSP00000257430.4 | ||
ENSG00000258864 | ENST00000520401.1 | n.228+13068A>C | intron_variant | Intron 3 of 7 | 3 | ENSP00000454861.1 |
Frequencies
GnomAD3 genomes AF: 0.0000131 AC: 2AN: 152176Hom.: 0 Cov.: 32 show subpopulations
GnomAD2 exomes AF: 0.0000160 AC: 4AN: 250380 AF XY: 0.0000147 show subpopulations
GnomAD4 exome AF: 0.0000178 AC: 26AN: 1461118Hom.: 0 Cov.: 34 AF XY: 0.0000138 AC XY: 10AN XY: 726912 show subpopulations
GnomAD4 genome AF: 0.0000131 AC: 2AN: 152176Hom.: 0 Cov.: 32 AF XY: 0.00 AC XY: 0AN XY: 74344 show subpopulations
ClinVar
Submissions by phenotype
Familial adenomatous polyposis 1 Uncertain:4
This variant is classified as a variant of uncertain significance as there is insufficient evidence to determine its impact on protein function and/or cancer risk. -
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This sequence change replaces histidine, which is basic and polar, with proline, which is neutral and non-polar, at codon 2149 of the APC protein (p.His2149Pro). This variant is present in population databases (rs749230730, gnomAD 0.003%). This missense change has been observed in individual(s) with familial adenomatous polyposis, colorectal cancer (PMID: 18199528, 28944238). ClinVar contains an entry for this variant (Variation ID: 185017). 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. -
This submission and the accompanying classification are no longer maintained by the submitter. For more information on current observations and classification, please contact variantquestions@myriad.com. -
not provided Uncertain:3
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Not observed at a significant frequency in large population cohorts (gnomAD); In silico analysis supports that this missense variant does not alter protein structure/function; Observed in individuals with adenomatous polyposis or early-onset colorectal cancer (Azzopardi et al., 2008; DeRycke et al., 2017); This variant is associated with the following publications: (PMID: 21859464, 18199528, 28944238) -
The APC c.6446A>C (p.His2149Pro) variant has been reported in the published literature in individuals with Familial Adenomatous Polyposis (FAP) (PMID:18199528 (2008)) and colorectal cancer (PMID: 28944238 (2017)). The frequency of this variant in the general population, 0.000039 (5/128728 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:1Benign:1
Variant summary: APC c.6446A>C (p.His2149Pro) 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 1.6e-05 in 252318 control chromosomes. The available data on variant occurrences in the general population are insufficient to allow any conclusion about variant significance. c.6446A>C has been reported in the literature in an individual affected with Familial Adenomatous Polyposis (Azzopardi 2008). These data do not allow any conclusion about variant significance. To our knowledge, no experimental evidence demonstrating an impact on protein function has been reported. The following publications have been ascertained in the context of this evaluation (PMID: 18199528, 21859464). Nine submitters have cited clinical-significance assessments for this variant to ClinVar after 2014 (VUS, n=8; Likely benign, n=1). Based on the evidence outlined above, the variant was classified as uncertain significance. -
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Hereditary cancer-predisposing syndrome Uncertain:1Benign:1
This missense variant replaces histidine with proline at codon 2149 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 been reported in individuals affected with familial adenomatous polyposis and colorectal cancer cancer in the literature (PMID: 21859464, 28944238). This variant has been identified in 5/281780 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. -
Classic or attenuated familial adenomatous polyposis Uncertain:1
This missense variant replaces histidine with proline at codon 2149 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 been reported in individuals affected with familial adenomatous polyposis and colorectal cancer cancer in the literature (PMID: 21859464, 28944238). This variant has been identified in 5/281780 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