rs148343173
Variant summary
Our verdict is Benign. The variant received -13 ACMG points: 0P and 13B. BP4_StrongBP6_Very_StrongBP7
The NM_000038.6(APC):c.993G>A(p.Ser331Ser) variant causes a synonymous change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.0000254 in 1,613,846 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 Likely benign (★★). Synonymous variant affecting the same amino acid position (i.e. S331S) has been classified as Likely benign.
Frequency
Consequence
NM_000038.6 synonymous
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: Benign. The variant received -13 ACMG points.
Transcripts
RefSeq
Ensembl
Frequencies
GnomAD3 genomes AF: 0.00000658 AC: 1AN: 152030Hom.: 0 Cov.: 32 show subpopulations
GnomAD2 exomes AF: 0.0000796 AC: 20AN: 251100 AF XY: 0.0000884 show subpopulations
GnomAD4 exome AF: 0.0000274 AC: 40AN: 1461816Hom.: 0 Cov.: 33 AF XY: 0.0000289 AC XY: 21AN XY: 727214 show subpopulations
Age Distribution
GnomAD4 genome AF: 0.00000658 AC: 1AN: 152030Hom.: 0 Cov.: 32 AF XY: 0.0000135 AC XY: 1AN XY: 74262 show subpopulations
ClinVar
Submissions by phenotype
Familial adenomatous polyposis 1 Benign:3
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This variant is considered benign. This variant is a silent/synonymous amino acid change and it is not expected to impact splicing. -
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. -
Hereditary cancer-predisposing syndrome Benign:2
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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. -
not specified Benign:1
Variant summary: APC c.993G>A alters a non-conserved nucleotide resulting in a synonymous change. 5/5 computational 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 8e-05 in 251100 control chromosomes. The observed variant frequency is approximately 1.12 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 benign. To our knowledge, no occurrence of c.993G>A in individuals affected with Familial Adenomatous Polyposis and no experimental evidence demonstrating its impact on protein function have been reported. Four clinical diagnostic laboratories have submitted clinical-significance assessments for this variant to ClinVar after 2014 without evidence for independent evaluation. All laboratories classified the variant as likely benign. Based on the evidence outlined above, the variant was classified as benign. -
not provided Benign:1
This variant is associated with the following publications: (PMID: 27693639) -
Malignant tumor of breast Benign:1
The APC p.Ser331= variant was not identified in the literature nor was it identified in the UMD-LSDB database. The variant was identified in dbSNP (rs148343173) as “with likely benign” allele, ClinVar (classified as likely benign by Invitae, Ambry Genetics, Color, GeneDx and Counsyl) and LOVD 3.0 (observed 1x). The variant was identified in control databases in 21 of 282,468 chromosomes at a frequency of 0.00007 (Genome Aggregation Database Feb 27, 2017). The variant was observed in the following populations: South Asian in 8 of 30,612 chromosomes (freq: 0.0003, increasing the likelihood this could be a low frequency benign variant), African in 6 of 24,956 chromosomes (freq: 0.0002), Latino in 3 of 35,418 chromosomes (freq: 0.00009), and European in 4 of 128,854 chromosomes (freq: 0.0003); it was not observed in the Ashkenazi Jewish, East Asian, Finnish or Other populations. The p.Ser331= variant is not expected to have clinical significance because it does not result in a change of amino acid and is not located in a known consensus splice site. The variant occurs at a non-highly conserved nucleotide outside of the splicing consensus sequence and in silico or computational prediction software programs (SpliceSiteFinder, MaxEntScan, NNSPLICE, GeneSplicer) do not predict a difference in splicing. In summary, based on the above information, the clinical significance of this variant cannot be determined with certainty at this time although we would lean towards a more benign role for this variant. This variant is classified as likely benign. -
APC-related disorder Benign:1
This variant is classified as likely benign based on ACMG/AMP sequence variant interpretation guidelines (Richards et al. 2015 PMID: 25741868, with internal and published modifications). -
Computational scores
Source:
Splicing
Find out detailed SpliceAI scores and Pangolin per-transcript scores at