rs76685252
Variant summary
Our verdict is Likely benign. The variant received -5 ACMG points: 0P and 5B. BP4_StrongBP6
The NM_000038.6(APC):c.647G>A(p.Arg216Gln) variant causes a missense, splice region change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.000028 in 1,606,644 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a benign outcome for this variant. 15/24 in silico tools predict 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. R216G) has been classified as Likely benign.
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
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ACMG classification
Our verdict: Likely_benign. The variant received -5 ACMG points.
Transcripts
RefSeq
Ensembl
Frequencies
GnomAD3 genomes AF: 0.0000527 AC: 8AN: 151884Hom.: 0 Cov.: 32 show subpopulations
GnomAD2 exomes AF: 0.0000400 AC: 10AN: 250290 AF XY: 0.0000296 show subpopulations
GnomAD4 exome AF: 0.0000261 AC: 38AN: 1454642Hom.: 0 Cov.: 29 AF XY: 0.0000235 AC XY: 17AN XY: 723576 show subpopulations
Age Distribution
GnomAD4 genome AF: 0.0000461 AC: 7AN: 152002Hom.: 0 Cov.: 32 AF XY: 0.0000673 AC XY: 5AN XY: 74290 show subpopulations
Age Distribution
ClinVar
Submissions by phenotype
Familial adenomatous polyposis 1 Uncertain:3Benign:1
This variant is considered likely benign. This variant has been observed at a population frequency that is significantly greater than expected given the associated disease prevalence and penetrance. -
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. -
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This sequence change replaces arginine, which is basic and polar, with glutamine, which is neutral and polar, at codon 216 of the APC protein (p.Arg216Gln). This variant is present in population databases (rs76685252, gnomAD 0.02%). This missense change has been observed in individual(s) with colorectal cancer, breast cancer (PMID: 18199528, 28135145, 35264596). ClinVar contains an entry for this variant (Variation ID: 188275). An algorithm developed to predict the effect of missense changes on protein structure and function (PolyPhen-2) suggests that this variant is likely to be tolerated. 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 specified Uncertain:1Benign:1
Variant summary: APC c.647G>A (p.Arg216Gln) results in a conservative amino acid change in the encoded protein sequence. Five of five in-silico tools predict a benign effect of the variant on protein function. Consensus agreement among computation tools predict no significant impact on normal splicing. However, these predictions have yet to be confirmed by functional studies. The variant allele was found at a frequency of 4e-05 in 250290 control chromosomes (gnomAD). This frequency is not significantly higher than estimated for a pathogenic variant in APC causing Familial Adenomatous Polyposis (4e-05 vs 7.1e-05), allowing no conclusion about variant significance. c.647G>A has been reported in the literature in individuals affected with colorectal cancer and breast cancer (examples:Azzopardi_2008, Yurgelun_2017, Guindalini_2022). These report(s) do not provide unequivocal conclusions about association of the variant with Familial Adenomatous Polyposis. To our knowledge, no experimental evidence demonstrating an impact on protein function has been reported. The following publications have been ascertained in the context of this evaluation (PMID: 18199528, 35264596, 21859464, 36243179, 26332594, 28135145). Nine submitters have cited clinical-significance assessments for this variant to ClinVar after 2014. Multiple submitters reported the variant with conflicting assessments (VUS n=7, likely benign n=2). Based on the evidence outlined above, the variant was classified as uncertain significance. -
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Hereditary cancer-predisposing syndrome Uncertain:1Benign:1
This alteration is classified as benign based on a combination of the following: seen in unaffected individuals, population frequency, intact protein function, lack of segregation with disease, co-occurrence, RNA analysis, in silico models, amino acid conservation, lack of disease association in case-control studies, and/or the mechanism of disease or impacted region is inconsistent with a known cause of pathogenicity. -
This missense variant replaces arginine with glutamine at codon 216 of the APC protein. Computational prediction is inconclusive regarding the impact of this variant on protein structure and function (internally defined REVEL score threshold 0.5 < inconclusive < 0.7, PMID: 27666373). To our knowledge, functional studies have not been reported for this variant. This variant has been reported in individuals affected with breast cancer, colorectal cancer, or colorectal adenomas (PMID: 18199528, 28135145, 35264596). This variant has been identified in 10/250290 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
In silico analysis indicates that this missense variant does not alter protein structure/function; Observed in individuals with colorectal cancer or adenomas, or breast cancer (PMID: 18199528, 21859464, 28135145, 35264596); This variant is associated with the following publications: (PMID: 21859464, 28748566, 28873162, 27329244, 18199528, 26332594, 28135145, 35264596, 36243179) -
APC-Associated Polyposis Disorders Benign:1
This variant was observed in the ICSL laboratory as part of a predisposition screen in an ostensibly healthy population. It had not been previously curated by ICSL or reported in the Human Gene Mutation Database (HGMD: prior to June 1st, 2018), and was therefore a candidate for classification through an automated scoring system. Utilizing variant allele frequency, disease prevalence and penetrance estimates, and inheritance mode, an automated score was calculated to assess if this variant is too frequent to cause the disease. Based on the score and internal cut-off values, a variant classified as likely benign is not then subjected to further curation. The score for this variant resulted in a classification of likely benign for this disease. -
Hereditary cancer Benign:1
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Computational scores
Source:
Splicing
Find out detailed SpliceAI scores and Pangolin per-transcript scores at