rs878853430
Variant summary
Our verdict is Likely benign. The variant received -4 ACMG points: 0P and 4B. BP4_Strong
The NM_000038.6(APC):c.2725A>G(p.Thr909Ala) variant causes a missense change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.00000479 in 1,461,880 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a benign outcome for this variant. 17/22 in silico tools predict a benign 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. T909S) 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: Likely_benign. The variant received -4 ACMG points.
Transcripts
RefSeq
| Gene | Transcript | HGVSc | HGVSp | Effect | Exon rank | MANE | Protein | UniProt |
|---|---|---|---|---|---|---|---|---|
| APC | NM_000038.6 | c.2725A>G | p.Thr909Ala | missense_variant | Exon 16 of 16 | ENST00000257430.9 | NP_000029.2 |
Ensembl
Frequencies
GnomAD3 genomes Cov.: 32
GnomAD4 exome AF: 0.00000479 AC: 7AN: 1461880Hom.: 0 Cov.: 33 AF XY: 0.00000413 AC XY: 3AN XY: 727240 show subpopulations
GnomAD4 genome Cov.: 32
ClinVar
Submissions by phenotype
Familial adenomatous polyposis 1 Uncertain:2
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This sequence change replaces threonine, which is neutral and polar, with alanine, which is neutral and non-polar, at codon 909 of the APC protein (p.Thr909Ala). This variant is not present in population databases (gnomAD no frequency). This missense change has been observed in individual(s) with breast cancer (PMID: 26976419). ClinVar contains an entry for this variant (Variation ID: 236578). 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. -
Hereditary cancer-predisposing syndrome Uncertain:2
This missense variant replaces threonine with alanine at codon 909 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 performed for this variant. This variant has been reported in an individual affected with breast cancer (PMID: 26976419). 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. -
The p.T909A variant (also known as c.2725A>G), located in coding exon 15 of the APC gene, results from an A to G substitution at nucleotide position 2725. The threonine at codon 909 is replaced by alanine, an amino acid with similar properties. This alteration has been reported as a variant of uncertain significance in an individual from a cohort of 488 patients with stages I to III breast cancer (Tung N et al. J. Clin. Oncol., 2016 May;34:1460-8). This amino acid position is not 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. -
not specified Uncertain:1
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not provided Uncertain:1
This variant is denoted APC c.2725A>G at the cDNA level, p.Thr909Ala (T909A) at the protein level, and results in the change of a Threonine to an Alanine (ACC>GCC). APC Thr909Ala was observed as a germline variant in at least one patient with breast cancer undergoing hereditary cancer panel testing and as a confirmed somatic variant in a sporadic colorectal tumor (Christie 2013, Tung 2016). APC Thr909Ala was not observed in approximately 6,500 individuals of European and African American ancestry in the NHLBI Exome Sequencing Project, suggesting it is not a common benign variant in these populations. Since Threonine and Alanine differ in polarity, charge, size or other properties, this is considered a non-conservative amino acid substitution. APC Thr909Ala occurs at a position that is not conserved and is not located in a known functional domain. In silico analyses predict that this variant is unlikely to alter protein structure or function. Based on currently available evidence, it is unclear whether APC Thr909Ala 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