5-112839073-C-A
Variant summary
Our verdict is Likely benign. The variant received -2 ACMG points: 0P and 2B. BP4BP6
The NM_000038.6(APC):c.3479C>A(p.Thr1160Lys) variant causes a missense change. The variant allele was found at a frequency of 0.00027 in 1,613,950 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a benign outcome for this variant. 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. T1160A) has been classified as Likely benign.
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 -2 ACMG points.
Transcripts
RefSeq
Ensembl
| Gene | Transcript | HGVSc | HGVSp | Effect | Exon rank | TSL | MANE | Protein | Appris | UniProt |
|---|---|---|---|---|---|---|---|---|---|---|
| APC | ENST00000257430.9 | c.3479C>A | p.Thr1160Lys | missense_variant | Exon 16 of 16 | 5 | NM_000038.6 | ENSP00000257430.4 | ||
| ENSG00000258864 | ENST00000520401.1 | n.228+10101C>A | intron_variant | Intron 3 of 7 | 3 | ENSP00000454861.1 |
Frequencies
GnomAD3 genomes AF: 0.000151 AC: 23AN: 152176Hom.: 0 Cov.: 32 show subpopulations
GnomAD2 exomes AF: 0.0000957 AC: 24AN: 250788 AF XY: 0.0000811 show subpopulations
GnomAD4 exome AF: 0.000282 AC: 412AN: 1461774Hom.: 0 Cov.: 33 AF XY: 0.000278 AC XY: 202AN XY: 727192 show subpopulations
Age Distribution
GnomAD4 genome AF: 0.000151 AC: 23AN: 152176Hom.: 0 Cov.: 32 AF XY: 0.000135 AC XY: 10AN XY: 74344 show subpopulations
Age Distribution
ClinVar
Submissions by phenotype
not provided Uncertain:4Benign:1
In silico analysis supports that this missense variant does not alter protein structure/function; Observed in individuals with a personal history of colorectal adenomas or colorectal cancer (Azzopardi et al., 2008; Raskin et al., 2017); This variant is associated with the following publications: (PMID: 33918692, Biswas2021[abstract], 22703879, 25637381, 21859464, 18199528, 27150160, 27600092, 29212164, 28873162, 30709382, 35128723, 26580448, 35145771) -
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Familial adenomatous polyposis 1 Uncertain:1Benign:4
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 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. -
Hereditary cancer-predisposing syndrome Uncertain:2Benign:1
This missense variant replaces threonine with lysine at codon 1160 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). 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 one individual each affected with familial adenomatous polyposis (PMID: 18199528), colorectal cancer (PMID: 29212164), serrated polyposis syndrome (PMID: 35128723), breast cancer (PMID: 29684080) and in an individual(s) with an unspecified cancer (PMID: 28873162). This variant has also been observed in multiple individuals in the general population who were selected for phenotypes not directly related to cancer (PMID: 22703879, 25637381). This variant has been identified in 32/282180 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. -
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This alteration is classified as likely 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. -
Classic or attenuated familial adenomatous polyposis Uncertain:2
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This missense variant replaces threonine with lysine at codon 1160 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). 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 one individual each affected with familial adenomatous polyposis (PMID: 18199528), colorectal cancer (PMID: 29212164), serrated polyposis syndrome (PMID: 35128723), breast cancer (PMID: 29684080) and in an individual(s) with an unspecified cancer (PMID: 28873162). This variant has also been observed in multiple individuals in the general population who were selected for phenotypes not directly related to cancer (PMID: 22703879, 25637381). This variant has been identified in 32/282180 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 specified Uncertain:1Benign:1
Variant summary: APC c.3479C>A (p.Thr1160Lys) results in a non-conservative amino acid change located in the one of the 15 residue repeat domains (IPR009240) of the encoded protein sequence. Three of five in-silico tools predict a damaging effect of the variant on protein function. The variant allele was found at a frequency of 0.00027 in 1613950 control chromosomes, predominantly at a frequency of 0.00048 within the Non-Finnish European subpopulation in the gnomAD database. The observed variant frequency within Non-Finnish European control individuals in the gnomAD database is approximately 7 fold of the estimated maximal expected allele frequency for a pathogenic variant in APC causing Familial Adenomatous Polyposis phenotype (7.1e-05). c.3479C>A has been reported in the literature in individuals affected with non-FAP non-MAP colorectal adenomas (example, Azzopardi 2008), in a family with colorectal cancer without polyps (example, Raskin 2017) and as a VUS in settings of multigene panel testing performed in an individual with Serrated Polyposis Syndrome (SPS) (example, Murphy_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: 22703879, 18199528, 26580448, 29212164, 35128723). ClinVar contains an entry for this variant (Variation ID: 41503). Based on the evidence outlined above, the variant was classified as likely benign. -
Variant identified in a genome or exome case(s) and assessed due to predicted null impact of the variant or pathogenic assertions in the literature or databases. Disclaimer: This variant has not undergone full assessment. The following are preliminary notes: This variant is classified as DM in HGMD - it has been seen in one patient with colorectal adenoma and one unaffected patient. It has been classified with 1 star as VUS by 4 sumitters (GeneDx, Invitae, CSER_CC_NCGL, Biesecker lab) and Likely benign by 1 (Ambry). MaxMAF is 0.02% in ExAC (high for disease prevalence). -
APC-related disorder Uncertain:1
The APC c.3479C>A variant is predicted to result in the amino acid substitution p.Thr1160Lys. This variant was reported in multiple individuals with colorectal adenoma, but was also present in one unaffected 48 year old family member (Azzopardi et al. 2008. PubMed ID: 18199528; Table S1, Minde et al. 2011. PubMed ID: 21859464; Raskin et al. 2017. PubMed ID: 29212164). This variant is reported in 0.023% of alleles in individuals of European (Non-Finnish) descent in gnomAD (http://gnomad.broadinstitute.org/variant/5-112174770-C-A) and has conflicting interpretations regarding its pathogenicity in ClinVar, ranging from benign to uncertain (https://www.ncbi.nlm.nih.gov/clinvar/variation/41503/). At this time, the clinical significance of this variant is uncertain due to the absence of conclusive functional and genetic evidence. -
Colorectal adenoma Uncertain:1
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Computational scores
Source:
Splicing
Find out detailed SpliceAI scores and Pangolin per-transcript scores at