rs1204161988
Variant summary
Our verdict is Uncertain significance. Variant got 2 ACMG points: 2P and 0B. PM2
The NM_000038.6(APC):c.5201A>C(p.Lys1734Thr) variant causes a missense change. The variant was absent in control chromosomes in GnomAD project. Variant has been reported in ClinVar as Uncertain significance (★★).
Frequency
Consequence
NM_000038.6 missense
Scores
Clinical Significance
Conservation
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ACMG classification
Verdict is Uncertain_significance. Variant got 2 ACMG points.
Transcripts
RefSeq
Ensembl
Gene | Transcript | HGVSc | HGVSp | Effect | Exon rank | TSL | MANE | Protein | Appris | UniProt |
---|---|---|---|---|---|---|---|---|---|---|
APC | ENST00000257430.9 | c.5201A>C | p.Lys1734Thr | missense_variant | Exon 16 of 16 | 5 | NM_000038.6 | ENSP00000257430.4 | ||
ENSG00000258864 | ENST00000520401.1 | n.228+11823A>C | intron_variant | Intron 3 of 7 | 3 | ENSP00000454861.1 |
Frequencies
GnomAD3 genomes Cov.: 32
GnomAD4 exome Cov.: 63
GnomAD4 genome Cov.: 32
ClinVar
Submissions by phenotype
not specified Uncertain:2
The p.Lys1734Thr variant in APC has not been previously reported in individuals with familial adenomatous polyposis or other APC-associated disorders and was ab sent from large population studies. Computational prediction tools and conservat ion analysis suggest that the p.Lys1734Thr variant may impact the protein, thoug h this information is not predictive enough to determine pathogenicity. In summa ry, the clinical significance of the p.Lys1734Thr variant is uncertain. -
Variant summary: APC c.5201A>C (p.Lys1734Thr) results in a non-conservative amino acid change located in the SAMP of the encoded protein sequence. Four of five in-silico tools predict a damaging effect of the variant on protein function. The variant was absent in 250518 control chromosomes. The available data on variant occurrences in the general population are insufficient to allow any conclusion about variant significance. To our knowledge, no occurrence of c.5201A>C in individuals affected with Familial Adenomatous Polyposis and no experimental evidence demonstrating its impact on protein function have been reported. One clinical diagnostic laboratory has submitted clinical-significance assessments for this variant to ClinVar after 2014 without evidence for independent evaluation. One laboratory classified the variant as uncertain significance. Based on the evidence outlined above, the variant was classified as uncertain significance. -
Familial adenomatous polyposis 1 Uncertain:1
This sequence change replaces lysine, which is basic and polar, with threonine, which is neutral and polar, at codon 1734 of the APC protein (p.Lys1734Thr). This variant is not present in population databases (gnomAD no frequency). 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: 517439). 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 lysine with threonine at codon 1734 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 been reported in a cohort of consisting of individuals affected with colorectal cancer or polyps, as well as healthy controls (PMID: 31422818). 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. -
Hereditary cancer-predisposing syndrome Uncertain:1
The p.K1734T variant (also known as c.5201A>C), located in coding exon 15 of the APC gene, results from an A to C substitution at nucleotide position 5201. The lysine at codon 1734 is replaced by threonine, an amino acid with similar properties. This alteration was detected in a study of 1,165 individuals with a history of colorectal cancer or colon polyps as well as 590 controls (Gordon AS et al. Am J Hum Genet, 2019 Sep;105:526-533). 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. -
Computational scores
Source:
Splicing
Find out detailed SpliceAI scores and Pangolin per-transcript scores at