rs761133356
Variant summary
Our verdict is Uncertain significance. The variant received 2 ACMG points: 2P and 0B. PM2
The NM_000038.6(APC):c.7667C>T(p.Ser2556Leu) variant causes a missense change involving the alteration of a conserved nucleotide. The variant allele was found at a frequency of 0.00000274 in 1,461,386 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. S2556A) 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 2 ACMG points.
Transcripts
RefSeq
Ensembl
| Gene | Transcript | HGVSc | HGVSp | Effect | Exon rank | TSL | MANE | Protein | Appris | UniProt |
|---|---|---|---|---|---|---|---|---|---|---|
| APC | ENST00000257430.9 | c.7667C>T | p.Ser2556Leu | missense_variant | Exon 16 of 16 | 5 | NM_000038.6 | ENSP00000257430.4 | ||
| ENSG00000258864 | ENST00000520401.1 | n.229-13388C>T | intron_variant | Intron 3 of 7 | 3 | ENSP00000454861.1 |
Frequencies
GnomAD3 genomes Cov.: 32
GnomAD2 exomes AF: 0.0000120 AC: 3AN: 250832 AF XY: 0.0000221 show subpopulations
GnomAD4 exome AF: 0.00000274 AC: 4AN: 1461386Hom.: 0 Cov.: 34 AF XY: 0.00000413 AC XY: 3AN XY: 727040 show subpopulations
Age Distribution
GnomAD4 genome Cov.: 32
ClinVar
Submissions by phenotype
Familial adenomatous polyposis 1 Uncertain:3
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. -
This sequence change replaces serine, which is neutral and polar, with leucine, which is neutral and non-polar, at codon 2556 of the APC protein (p.Ser2556Leu). This variant is present in population databases (rs761133356, gnomAD 0.002%). This missense change has been observed in individual(s) with colorectal cancer (PMID: 28135145). ClinVar contains an entry for this variant (Variation ID: 470103). 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. -
Hereditary cancer-predisposing syndrome Uncertain:2
The p.S2556L variant (also known as c.7667C>T), located in coding exon 15 of the APC gene, results from a C to T substitution at nucleotide position 7667. The serine at codon 2556 is replaced by leucine, an amino acid with dissimilar properties. This variant has been reported in an individual affected with colorectal cancer (Yurgelun MB et al. J Clin Oncol, 2017 Apr;35:1086-1095). This variant was also detected in 1/113 Italian non-BRCA patients with a personal and/or familial history of breast cancer, ovarian cancer, and/or pancreatic cancer (Germani A et al. J Clin Med, 2020 Sep;9). 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. -
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Classic or attenuated familial adenomatous polyposis Uncertain:1
This missense variant replaces serine with leucine at codon 2556 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 colorectal cancer and an individual affected with breast cancer (PMID: 28135145, 32957588). This variant has been identified in 3/250832 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. -
APC-related disorder Uncertain:1
The APC c.7667C>T variant is predicted to result in the amino acid substitution p.Ser2556Leu. This variant was reported in an individual with colorectal cancer, who also carried a rare variant in BRIP1 gene (see subject ID COLB5737-3 in Table A4, Yurgelun et al. 2017. PubMed ID: 28135145). This variant is reported in 0.0027% of alleles in individuals of European (Non-Finnish) descent in gnomAD. In ClinVar, this variant is interpreted as uncertain (https://www.ncbi.nlm.nih.gov/clinvar/variation/470103/). At this time, the clinical significance of this variant is uncertain due to the absence of conclusive functional and genetic evidence. -
Computational scores
Source:
Splicing
Find out detailed SpliceAI scores and Pangolin per-transcript scores at