chr5-112838968-T-C
Variant summary
Our verdict is Benign. The variant received -9 ACMG points: 0P and 9B. BP4_StrongBP6BS1
The NM_000038.6(APC):c.3374T>C(p.Val1125Ala) variant causes a missense change. The variant allele was found at a frequency of 0.000131 in 1,613,984 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. V1125L) has been classified as Uncertain significance.
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: Benign. The variant received -9 ACMG points.
Variant Effect in Transcripts
ACMG analysis was done for transcript: NM_000038.6. You can select a different transcript below to see updated ACMG assignments.
RefSeq Transcripts
| Selected | Gene | Transcript | Tags | HGVSc | HGVSp | Effect | Exon Rank | Protein | UniProt |
|---|---|---|---|---|---|---|---|---|---|
| APC | NM_000038.6 | MANE Select | c.3374T>C | p.Val1125Ala | missense | Exon 16 of 16 | NP_000029.2 | ||
| APC | NM_001407446.1 | c.3458T>C | p.Val1153Ala | missense | Exon 16 of 16 | NP_001394375.1 | |||
| APC | NM_001354896.2 | c.3428T>C | p.Val1143Ala | missense | Exon 17 of 17 | NP_001341825.1 |
Ensembl Transcripts
| Selected | Gene | Transcript | Tags | HGVSc | HGVSp | Effect | Exon Rank | Protein | UniProt |
|---|---|---|---|---|---|---|---|---|---|
| APC | ENST00000257430.9 | TSL:5 MANE Select | c.3374T>C | p.Val1125Ala | missense | Exon 16 of 16 | ENSP00000257430.4 | ||
| APC | ENST00000508376.6 | TSL:1 | c.3374T>C | p.Val1125Ala | missense | Exon 17 of 17 | ENSP00000427089.2 | ||
| APC | ENST00000502371.3 | TSL:1 | n.*1572T>C | non_coding_transcript_exon | Exon 12 of 12 | ENSP00000484935.2 |
Frequencies
GnomAD3 genomes AF: 0.000177 AC: 27AN: 152132Hom.: 0 Cov.: 32 show subpopulations
GnomAD2 exomes AF: 0.000607 AC: 152AN: 250618 AF XY: 0.000679 show subpopulations
GnomAD4 exome AF: 0.000126 AC: 184AN: 1461852Hom.: 0 Cov.: 33 AF XY: 0.000135 AC XY: 98AN XY: 727224 show subpopulations
Age Distribution
GnomAD4 genome AF: 0.000177 AC: 27AN: 152132Hom.: 0 Cov.: 32 AF XY: 0.000215 AC XY: 16AN XY: 74316 show subpopulations
Age Distribution
ClinVar
Submissions by phenotype
not specified Benign:4
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.3374T>C (p.Val1125Ala) 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 0.00061 in 251058 control chromosomes, predominantly at a frequency of 0.0081 within the East Asian subpopulation in the gnomAD database, including 1 homozygotes. The observed variant frequency within East Asian control individuals in the gnomAD database is approximately 113 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.3374T>C, has been reported in the literature in individuals affected with Familial Adenomatous Polyposis and other gastrointestinal polyposes/cancers, however without strong evidence for pathogenicity (example, Chang_2016, Kohda_2016, Li_2015, Grant_2015, Azzopard_2008, Tung_2016). In a Chinese family, this variant seemed to segregate with the disease in five affected members with FAP syndrome, however it cannot be ruled out that other undetected pathogenic variants could have actually explained the phenotype (Li_2015). Therefore these reports 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. Ten clinical diagnostic laboratories have submitted clinical-significance assessments for this variant to ClinVar after 2014 without evidence for independent evaluation (likely benign/benign, n=9; VUS, n=1). Based on the evidence outlined above reflecting the consensus among peers the variant was classified as benign.
Familial adenomatous polyposis 1 Benign:4
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.
Hereditary cancer-predisposing syndrome Benign:4
The missense variant NM_000038.6(APC):c.3374T>C (p.Val1125Ala) has not been reported previously as a pathogenic variant , to our knowledge. The p.Val1125Ala variant is observed in 148/18,364 (0.8059%) alleles from individuals of gnomAD East Asian background in gnomAD, which is greater than expected for the disorder. There is a small physicochemical difference between valine and alanine, which is not likely to impact secondary protein structure as these residues share similar properties. For these reasons, this variant has been classified as Likely Benign
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.
Neoplasm of the liver Uncertain:1
Carcinoma of colon Benign:1
The APC p.Val1125Ala variant was identified in 5 of 2666 proband chromosomes (frequency: 0.002) from individuals or families with colon and breast cancer (Chen 2006, Azzopardi 2008, Tung 2016). The variant was also identified in dbSNP (ID: rs377278397) as “With Uncertain significance allele”, ClinVar (as uncertain significance by GeneDx, likely benign by Ambry Genetics and Illumina, and benign by Invitae), Clinvitae (4x), and Zhejiang Colon Cancer Database. The variant was not identified in Cosmic, MutDB, LOVD 3.0, and UMD-LSDB databases. The variant was identified in control databases in 167 of 276336 chromosomes at a frequency of 0.0006 in the following populations: African in 1 of 23940 chromosomes (freq. 0.00004), East Asian in 160 (1 homozygous) of 18838 chromosomes (freq. 0.008), Other in 4 of 6452 chromosomes (freq. 0.0006), South Asian in 1 of 30754 chromosomes (freq. 0.00003), and Latino in 1 of 34390 chromosomes (freq. 0.00003), increasing the likelihood that this may be a low frequency benign variant in certain populations of origin (Genome Aggregation Consortium Feb 27, 2017). The p.Val1125Ala residue is conserved in in mammals but not in more distantly related organisms, with the variant amino acid Alanine (Ala) present in the African clawed frog, however computational analyses (PolyPhen-2, SIFT, AlignGVGD, BLOSUM, MutationTaster) do not suggest a high likelihood of impact to the protein; this information is not predictive enough to rule out pathogenicity. The variant occurs outside of the splicing consensus sequence and in silico or computational prediction software programs (SpliceSiteFinder, MaxEntScan, NNSPLICE, GeneSplicer, HumanSpliceFinder) 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-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.
not provided Benign:1
Computational scores
Source:
Splicing
Find out detailed SpliceAI scores and Pangolin per-transcript scores at