5-112828871-T-G
Variant summary
Our verdict is Uncertain significance. The variant received 0 ACMG points: 0P and 0B.
The NM_000038.6(APC):āc.1642T>Gā(p.Leu548Val) variant causes a missense change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.00000744 in 1,612,718 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. L548F) 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.1642T>G | p.Leu548Val | missense_variant | Exon 14 of 16 | 5 | NM_000038.6 | ENSP00000257430.4 | ||
| ENSG00000258864 | ENST00000520401.1 | n.127T>G | non_coding_transcript_exon_variant | Exon 3 of 8 | 3 | ENSP00000454861.1 |
Frequencies
GnomAD3 genomes AF: 0.0000131 AC: 2AN: 152206Hom.: 0 Cov.: 33 show subpopulations
GnomAD2 exomes AF: 0.00000398 AC: 1AN: 251176 AF XY: 0.00 show subpopulations
GnomAD4 exome AF: 0.00000685 AC: 10AN: 1460512Hom.: 0 Cov.: 31 AF XY: 0.00000688 AC XY: 5AN XY: 726668 show subpopulations
Age Distribution
GnomAD4 genome AF: 0.0000131 AC: 2AN: 152206Hom.: 0 Cov.: 33 AF XY: 0.00 AC XY: 0AN XY: 74344 show subpopulations
ClinVar
Submissions by phenotype
Familial adenomatous polyposis 1 Uncertain:3Benign:1
The APC c.1642T>G (p.Leu548Val) missense change has a maximum subpopulation frequency of 0.0008% in gnomAD v2.1.1 (https://gnomad.broadinstitute.org/). The in silico tool REVEL is inconclusive about a pathogenic or benign effect of this variant on protein function, and functional studies have not been performed. This variant has not been reported in the literature in individuals with APC-related disease. In summary, the evidence currently available is insufficient to determine the clinical significance of this variant. It has therefore been classified as of uncertain significance.? -
This sequence change replaces leucine, which is neutral and non-polar, with valine, which is neutral and non-polar, at codon 548 of the APC protein (p.Leu548Val). This variant is present in population databases (no rsID available, gnomAD 0.0009%). 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: 411557). 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 variant is considered likely benign. This variant has been observed at a population frequency that is significantly greater than expected given the associated disease prevalence and penetrance. -
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Hereditary cancer-predisposing syndrome Uncertain:2
This missense variant replaces leucine with valine at codon 548 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 APC-related disorders in the literature. This variant has been identified in 1/251176 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.L548V variant (also known as c.1642T>G), located in coding exon 13 of the APC gene, results from a T to G substitution at nucleotide position 1642. The leucine at codon 548 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. -
not provided Uncertain:1
Not observed at significant frequency in large population cohorts (gnomAD); In silico analysis supports that this missense variant has a deleterious effect on protein structure/function; Identified in an individual with malignant mesothelioma and family history of colorectal cancer (PMID: 34008015); This variant is associated with the following publications: (PMID: 18199528, 34008015) -
Computational scores
Source:
Splicing
Find out detailed SpliceAI scores and Pangolin per-transcript scores at