rs751249843
Variant summary
Our verdict is Uncertain significance. The variant received 1 ACMG points: 1P and 0B. PP3
The NM_000038.6(APC):c.3535T>A(p.Tyr1179Asn) variant causes a missense change involving the alteration of a conserved nucleotide. The variant allele was found at a frequency of 0.0000137 in 1,461,780 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 Uncertain significance (★★). Another variant affecting the same amino acid position, but resulting in a different missense (i.e. Y1179D) 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
| Gene | Transcript | HGVSc | HGVSp | Effect | Exon rank | MANE | Protein | UniProt |
|---|---|---|---|---|---|---|---|---|
| APC | NM_000038.6 | c.3535T>A | p.Tyr1179Asn | missense_variant | Exon 16 of 16 | ENST00000257430.9 | NP_000029.2 |
Ensembl
Frequencies
GnomAD3 genomes Cov.: 32
GnomAD2 exomes AF: 0.00000400 AC: 1AN: 249950 AF XY: 0.00000738 show subpopulations
GnomAD4 exome AF: 0.0000137 AC: 20AN: 1461780Hom.: 0 Cov.: 33 AF XY: 0.0000110 AC XY: 8AN XY: 727188 show subpopulations
Age Distribution
GnomAD4 genome Cov.: 32
ClinVar
Submissions by phenotype
Familial adenomatous polyposis 1 Uncertain:2
This sequence change replaces tyrosine, which is neutral and polar, with asparagine, which is neutral and polar, at codon 1179 of the APC protein (p.Tyr1179Asn). This variant is present in population databases (rs751249843, gnomAD 0.0009%). This missense change has been observed in individual(s) with clinical features of Lynch syndrome (PMID: 25980754). ClinVar contains an entry for this variant (Variation ID: 411482). 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
The p.Y1179N variant (also known as c.3535T>A), located in coding exon 15 of the APC gene, results from a T to A substitution at nucleotide position 3535. The tyrosine at codon 1179 is replaced by asparagine, an amino acid with dissimilar properties. This alteration was identified in a cohort of 1260 individuals undergoing panel testing for Lynch syndrome due to having a diagnosis of a Lynch-associated cancer and/or polyps (Yurgelun MB et al. Gastroenterology. 2015 Sep;149(3):604-13.e20). This amino acid position is highly conserved in available vertebrate species. In addition, in silico predictors for this gene do not accurately predict pathogenicity. Missense alterations in APC are not a common cause of disease (Spier I et al. Genet Med. 2024 Feb;26(2):100992). Based on the available evidence, the clinical significance of this variant remains unclear. -
This missense variant replaces tyrosine with asparagine at codon 1179 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). 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 1 individual affected with a Lynch syndrome-associated tumor and/or polyps (PMID: 25980754). This variant has been identified in 1/249950 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. -
not provided Uncertain:1
This variant is denoted APC c.3535T>A at the cDNA level, p.Tyr1179Asn (Y1179N) at the protein level, and results in the change of a Tyrosine to an Asparagine (TAT>AAT). This variant has been observed in at least one individual with a Lynch syndrome-associated tumor and/or polyps (Yurgelun 2015). APC Tyr1179Asn was not observed at a significant allele frequency in large population cohorts (Lek 2016). Since Tyrosine and Asparagine differ in some properties, this is considered a semi-conservative amino acid substitution. APC Tyr1179Asn occurs at a position that is conserved across species and is not located in a known functional domain. In silico analyses are inconsistent regarding the effect this variant may have on protein structure and function. Based on currently available evidence, it is unclear whether APC Tyr1179Asn is a pathogenic or benign variant. We consider it to be a variant of uncertain significance. -
Computational scores
Source:
Splicing
Find out detailed SpliceAI scores and Pangolin per-transcript scores at