5-112838972-C-G
Variant summary
Our verdict is Likely benign. The variant received -3 ACMG points: 0P and 3B. BP4_ModerateBP6
The NM_000038.6(APC):āc.3378C>Gā(p.Ser1126Arg) variant causes a missense change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.0000254 in 1,613,926 control chromosomes in the GnomAD database, including 1 homozygotes. In-silico tool predicts a benign outcome for this variant. 13/22 in silico tools predict 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. S1126G) 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 -3 ACMG points.
Transcripts
RefSeq
Ensembl
| Gene | Transcript | HGVSc | HGVSp | Effect | Exon rank | TSL | MANE | Protein | Appris | UniProt |
|---|---|---|---|---|---|---|---|---|---|---|
| APC | ENST00000257430.9 | c.3378C>G | p.Ser1126Arg | missense_variant | Exon 16 of 16 | 5 | NM_000038.6 | ENSP00000257430.4 | ||
| ENSG00000258864 | ENST00000520401.1 | n.228+10000C>G | intron_variant | Intron 3 of 7 | 3 | ENSP00000454861.1 |
Frequencies
GnomAD3 genomes AF: 0.0000197 AC: 3AN: 151972Hom.: 0 Cov.: 32 show subpopulations
GnomAD2 exomes AF: 0.0000598 AC: 15AN: 250636 AF XY: 0.0000517 show subpopulations
GnomAD4 exome AF: 0.0000260 AC: 38AN: 1461836Hom.: 1 Cov.: 33 AF XY: 0.0000261 AC XY: 19AN XY: 727216 show subpopulations
Age Distribution
GnomAD4 genome AF: 0.0000197 AC: 3AN: 152090Hom.: 0 Cov.: 32 AF XY: 0.0000134 AC XY: 1AN XY: 74358 show subpopulations
ClinVar
Submissions by phenotype
not specified Benign:3Other:1
This variant is considered likely benign or benign based on one or more of the following criteria: it is a conservative change, it occurs at a poorly conserved position in the protein, it is predicted to be benign by multiple in silico algorithms, and/or has population frequency not consistent with disease. -
Variant summary: APC c.3378C>G (p.Ser1126Arg) results in a non-conservative amino acid change in the encoded protein sequence. Three of five in-silico tools predict a benign effect of the variant on protein function. The variant allele was found at a frequency of 2.5e-05 in 1613926 control chromosomes, predominantly at a frequency of 0.00051 within the East Asian subpopulation in the gnomAD database, including 1 homozygote. The observed variant frequency within East Asian 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), strongly suggesting that the variant is a benign polymorphism found primarily in populations of East Asian origin. c.3378C>G has been reported in the literature in individuals affected with Colorectal cancer as well as unaffected control study participants and the authors of this report classified the variant as likely benign (example: Fujita_2022). The following publication has been ascertained in the context of this evaluation (PMID: 33309985). ClinVar contains an entry for this variant (Variation ID: 127288). Based on the evidence outlined above, the variant was classified as likely benign. -
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Familial adenomatous polyposis 1 Uncertain:1Benign:2
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 Benign:3
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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. -
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Carcinoma of colon Uncertain:1Benign:1
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The APC, c.3378C>G, p.Ser1126Arg variant has been observed in the literature in 1 of 148 control chromosomes in individuals increasing the likelihood this variant does not have clinical significance. It was not, however, detected in any of the 160 proband chromosomes of individuals with sporadic colorectal carcinoma (Chen_2006_16569251). It was listed in dbSNP (ID: rs149353082) and reported from 1000 genomes with a frequency of 0.001, although only 1 chromosomes was found with this variant. It was not found in the UMD or LOVD databases. It was mentioned in Clinvar (1x by GeneDx with uncertain significance). This residue is not conserved in mammals and computational analyses (PolyPhen, SIFT, AlignGVGD) do not suggest a high likelihood of impact to the protein. Furthermore, this variant does not occur in any known important protein domain. However, this information is not predictive enough to rule out pathogenicity. In summary, based on the above information, and since there were fewer than 5 chromosomes identified with this variant in this analysis, the clinical significance of this variant cannot be determined with certainty although we would lean towards a more benign role, this variant is predicted benign. -
not provided Uncertain:1Benign:1
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APC-Associated Polyposis Disorders Benign:1
This variant was observed as part of a predisposition screen in an ostensibly healthy population. A literature search was performed for the gene, cDNA change, and amino acid change (where applicable). Publications were found based on this search. The evidence from the literature, in combination with allele frequency data from public databases where available, was sufficient to determine this variant is unlikely to cause disease. Therefore, this variant is classified as likely benign. -
Computational scores
Source:
Splicing
Find out detailed SpliceAI scores and Pangolin per-transcript scores at