rs878853441
Variant summary
Our verdict is Uncertain significance. The variant received 1 ACMG points: 2P and 1B. PM2BP4
The NM_000038.6(APC):c.3743C>T(p.Thr1248Ile) variant causes a missense change. The variant allele was found at a frequency of 0.00000248 in 1,613,054 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a benign outcome for this variant. 15/22 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. T1248A) 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
Ensembl
Gene | Transcript | HGVSc | HGVSp | Effect | Exon rank | TSL | MANE | Protein | Appris | UniProt |
---|---|---|---|---|---|---|---|---|---|---|
APC | ENST00000257430.9 | c.3743C>T | p.Thr1248Ile | missense_variant | Exon 16 of 16 | 5 | NM_000038.6 | ENSP00000257430.4 | ||
ENSG00000258864 | ENST00000520401.1 | n.228+10365C>T | intron_variant | Intron 3 of 7 | 3 | ENSP00000454861.1 |
Frequencies
GnomAD3 genomes AF: 0.00000657 AC: 1AN: 152174Hom.: 0 Cov.: 32 show subpopulations
GnomAD2 exomes AF: 0.00000401 AC: 1AN: 249570 AF XY: 0.00000741 show subpopulations
GnomAD4 exome AF: 0.00000205 AC: 3AN: 1460880Hom.: 0 Cov.: 33 AF XY: 0.00000138 AC XY: 1AN XY: 726676 show subpopulations
GnomAD4 genome AF: 0.00000657 AC: 1AN: 152174Hom.: 0 Cov.: 32 AF XY: 0.00 AC XY: 0AN XY: 74346 show subpopulations
ClinVar
Submissions by phenotype
Familial adenomatous polyposis 1 Uncertain:1
This sequence change replaces threonine, which is neutral and polar, with isoleucine, which is neutral and non-polar, at codon 1248 of the APC protein (p.Thr1248Ile). 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: 236594). 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. -
not provided Uncertain:1
This variant is denoted APC c.3743C>T at the cDNA level, p.Thr1248Ile (T1248I) at the protein level, and results in the change of a Threonine to an Isoleucine (ACT>ATT). This variant has not, to our knowledge, been published in the literature as pathogenic or benign. APC Thr1248Ile 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 Isoleucine differ in polarity, charge, size or other properties, this is considered a non-conservative amino acid substitution. APC Thr1248Ile occurs at a position that is not conserved and is located within the Ser-rich region responsible for down-regulation through a process mediated by direct ubiquitination (UniProt). 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 Thr1248Ile is a pathogenic or benign variant. We consider it to be a variant of uncertain significance. -
Hereditary cancer-predisposing syndrome Uncertain:1
The p.T1248I variant (also known as c.3743C>T), located in coding exon 15 of the APC gene, results from a C to T substitution at nucleotide position 3743. The threonine at codon 1248 is replaced by isoleucine, an amino acid with similar properties. Missense alterations in APC are not a common cause of disease (Spier I et al. Genet Med. 2024 Feb;26(2):100992). This amino acid position is poorly conserved in available vertebrate species. In addition, in silico predictors for this gene do not accurately predict pathogenicity. Based on the available evidence, the clinical significance of this variant remains unclear. -
Computational scores
Source:
Splicing
Find out detailed SpliceAI scores and Pangolin per-transcript scores at