rs199775075
Variant summary
Our verdict is Likely benign. Variant got -4 ACMG points: 1P and 5B. PP3BP6BS2
The NM_000038.6(APC):c.5225G>A(p.Arg1742His) variant causes a missense change involving the alteration of a conserved nucleotide. The variant allele was found at a frequency of 0.0000372 in 1,614,076 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a pathogenic outcome for this variant. Variant has been reported in ClinVar as Conflicting classifications of pathogenicity (no stars).
Frequency
Consequence
NM_000038.6 missense
Scores
Clinical Significance
Conservation
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ACMG classification
Verdict is Likely_benign. Variant got -4 ACMG points.
Transcripts
RefSeq
Ensembl
Gene | Transcript | HGVSc | HGVSp | Effect | Exon rank | TSL | MANE | Protein | Appris | UniProt |
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APC | ENST00000257430.9 | c.5225G>A | p.Arg1742His | missense_variant | Exon 16 of 16 | 5 | NM_000038.6 | ENSP00000257430.4 | ||
ENSG00000258864 | ENST00000520401.1 | n.228+11847G>A | intron_variant | Intron 3 of 7 | 3 | ENSP00000454861.1 |
Frequencies
GnomAD3 genomes AF: 0.0000263 AC: 4AN: 152144Hom.: 0 Cov.: 32
GnomAD3 exomes AF: 0.0000399 AC: 10AN: 250600Hom.: 0 AF XY: 0.0000295 AC XY: 4AN XY: 135464
GnomAD4 exome AF: 0.0000383 AC: 56AN: 1461814Hom.: 0 Cov.: 63 AF XY: 0.0000413 AC XY: 30AN XY: 727202
GnomAD4 genome AF: 0.0000263 AC: 4AN: 152262Hom.: 0 Cov.: 32 AF XY: 0.0000537 AC XY: 4AN XY: 74442
ClinVar
Submissions by phenotype
not provided Uncertain:3Benign:1
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In silico analysis, which includes protein predictors and evolutionary conservation, supports that this variant does not alter protein structure/function; This variant is associated with the following publications: (PMID: 22703879) -
The APC p.Arg1742His variant was identified in the literature in 1 of 1144 chromosomes (frequency 0.001) in a cohort of participants with atherosclerosis phenotypes but no personal or family history of cancer, in an exome sequencing study looking at secondary variants that cause high penetrance cancer syndromes (Johnston 2012). The variant was also identified in dbSNP (ID: rs199775075) “With Uncertain significance” allele, ClinVar (classified as uncertain significance by Ambry Genetics, Invitae and Biesecker Lab (NIH)), Clinvitae (3X as uncertain significance) and in control databases in 9 of 245344 chromosomes at a frequency of 0.00004 increasing the likelihood that this may be a low frequency benign variant in certain populations of origin (Genome Aggregation Consortium Feb 27, 2017). The variant was not identified in the Cosmic, MutDB, UMD-LSDB, Insight Colon Cancer Gene Variant Database, and Zhejiang Colon Cancer Database. The p.Arg1742His residue is conserved in mammals and computational analyses (PolyPhen-2, SIFT, AlignGVGD, BLOSUM, MutationTaster) provide inconsistent predictions regarding the impact to the protein; this information is not very predictive of pathogenicity. The variant occurs outside of the splicing consensus sequence and 1 of 5 in silico or computational prediction software programs (SpliceSiteFinder, MaxEntScan, NNSPLICE, GeneSplicer, HumanSpliceFinder) predict a greater than 10% difference in splicing; this is not very predictive of pathogenicity. In summary, based on the above information the clinical significance of this variant cannot be determined with certainty at this time. This variant is classified as a variant of uncertain significance. -
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Familial adenomatous polyposis 1 Uncertain:3
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This sequence change replaces arginine, which is basic and polar, with histidine, which is basic and polar, at codon 1742 of the APC protein (p.Arg1742His). This variant is present in population databases (rs199775075, gnomAD 0.01%). This variant has not been reported in the literature in individuals affected with APC-related conditions. ClinVar contains an entry for this variant (Variation ID: 41508). Invitae Evidence Modeling of protein sequence and biophysical properties (such as structural, functional, and spatial information, amino acid conservation, physicochemical variation, residue mobility, and thermodynamic stability) indicates that this missense variant is not expected to disrupt APC protein function with a negative predictive value of 95%. 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. -
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Hereditary cancer-predisposing syndrome Uncertain:1Benign:1
This missense variant replaces arginine with histidine at codon 1742 of the APC protein. Computational prediction suggests that this variant may not impact protein structure and function (internally defined REVEL score threshold <= 0.5, PMID: 27666373). To our knowledge, functional studies have not been reported for this variant. This variant has not been reported in individuals affected with APC-related disorders in the literature. This variant has been identified in 10/250600 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. -
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:1
This missense variant replaces arginine with histidine at codon 1742 of the APC protein. Computational prediction suggests that this variant may not impact protein structure and function (internally defined REVEL score threshold <= 0.5, 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 not been reported in individuals affected with hereditary cancer in the literature. This variant has been identified in 10/250600 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. -
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. -
Computational scores
Source:
Splicing
Find out detailed SpliceAI scores and Pangolin per-transcript scores at