rs773347338
Variant summary
Our verdict is Likely benign. The variant received -1 ACMG points: 2P and 3B. PM5BP4_ModerateBP6
The NM_000038.6(APC):āc.221A>Cā(p.Glu74Ala) variant causes a missense, splice region change involving the alteration of a conserved nucleotide. The variant allele was found at a frequency of 0.00000558 in 1,612,188 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a benign outcome for this variant. 3/3 splice prediction tools predict no significant impact on normal splicing. 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. E74G) has been classified as Uncertain significance.
Frequency
Consequence
NM_000038.6 missense, splice_region
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
Genome browser will be placed here
ACMG classification
Our verdict: Likely_benign. The variant received -1 ACMG points.
Transcripts
RefSeq
Ensembl
Frequencies
GnomAD3 genomes AF: 0.00000657 AC: 1AN: 152186Hom.: 0 Cov.: 32 show subpopulations
GnomAD2 exomes AF: 0.0000239 AC: 6AN: 251200 AF XY: 0.0000147 show subpopulations
GnomAD4 exome AF: 0.00000548 AC: 8AN: 1460002Hom.: 0 Cov.: 30 AF XY: 0.00000551 AC XY: 4AN XY: 726498 show subpopulations
GnomAD4 genome AF: 0.00000657 AC: 1AN: 152186Hom.: 0 Cov.: 32 AF XY: 0.00 AC XY: 0AN XY: 74344 show subpopulations
ClinVar
Submissions by phenotype
Hereditary cancer-predisposing syndrome Uncertain:2
The p.E74A variant (also known as c.221A>C) is located in coding exon 3 of the APC gene. The glutamic acid at codon 74 is replaced by alanine, an amino acid with dissimilar properties. This change occurs in the first base pair of coding exon 3. This amino acid position is highly conserved in available vertebrate species. Missense alterations in APC are not a common cause of disease (Spier I et al. Genet Med. 2024 Feb;26(2):100992). 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. -
This missense variant replaces glutamic acid with alanine at codon 74 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 not been reported in individuals affected with APC-related disorders in the literature. This variant has been identified in 6/251200 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:1Benign:1
- -
The APC c.221A>C (p.Glu74Ala) variant has not been reported in individuals with APC-related conditions in the published literature. The frequency of this variant in the general population, 0.000024 (6/251200 chromosomes (Genome Aggregation Database, http://gnomad.broadinstitute.org)), is uninformative in the assessment of its pathogenicity. Analysis of this variant using bioinformatics tools for the prediction of the effect of amino acid changes on protein structure and function yielded conflicting predictions that this variant is deleterious or benign. Based on the available information, we are unable to determine the clinical significance of this variant. -
Familial adenomatous polyposis 1 Benign:1
- -
Computational scores
Source:
Splicing
Find out detailed SpliceAI scores and Pangolin per-transcript scores at