rs201764637
Variant summary
Our verdict is Likely benign. The variant received -3 ACMG points: 0P and 3B. BP4_ModerateBP6
The NM_000038.6(APC):c.317G>A(p.Arg106His) variant causes a missense change. The variant allele was found at a frequency of 0.0000527 in 1,614,148 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. R106L) 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
Genome browser will be placed here
ACMG classification
Our verdict: Likely_benign. The variant received -3 ACMG points.
Transcripts
RefSeq
Ensembl
Frequencies
GnomAD3 genomes  0.0000394  AC: 6AN: 152192Hom.:  0  Cov.: 32 show subpopulations 
GnomAD2 exomes  AF:  0.0000318  AC: 8AN: 251464 AF XY:  0.0000294   show subpopulations 
GnomAD4 exome  AF:  0.0000540  AC: 79AN: 1461838Hom.:  0  Cov.: 31 AF XY:  0.0000578  AC XY: 42AN XY: 727226 show subpopulations 
Age Distribution
GnomAD4 genome  0.0000394  AC: 6AN: 152310Hom.:  0  Cov.: 32 AF XY:  0.0000537  AC XY: 4AN XY: 74470 show subpopulations 
Age Distribution
ClinVar
Submissions by phenotype
Familial adenomatous polyposis 1    Uncertain:2Benign:2 
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 sequence change replaces arginine, which is basic and polar, with histidine, which is basic and polar, at codon 106 of the APC protein (p.Arg106His). This variant is present in population databases (rs201764637, gnomAD 0.02%). This missense change has been observed in individual(s) with familial adenomatous polyposis (PMID: 18199528). ClinVar contains an entry for this variant (Variation ID: 41524). 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. -
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. -
The APC p.Arg106His variant was not identified in the literature, nor was it identified in NHLBI GO Exome Sequencing Project, GeneInsight COGR, COSMIC, MutDB, UMD, InSiGHT Colon Cancer Gene Variant Database (LOVD), or the Zhejiang Colon Cancer Database (LOVD). The variant was identified in dbSNP (ID: rs201764637) as “With Uncertain significance allele”, the Clinvitae database and ClinVar database (classification uncertain significance, submitters Counsyl and Biesecker Lab/Human Development Section NIH), the 1000 Genomes Project, the NHLBI Exome Sequencing Project, the 1000 Genomes Project in 1 of 5000 chromosomes (frequency: 0.002), HAPMAP-SAS in 1 of 978 chromosomes (frequency: 0.001), the genome Aggregation Database (Feb 27, 2017) in 13 of 277212 chromosomes (freq. 0.00005) and the Exome Aggregation Consortium database (August 8th 2016) in 5 of 121334 chromosomes (freq. 0.00004) in the following population: South Asian in 5 of 16512 chromosomes (freq. 0.0003), but was not seen in African, East Asian, European, Latino and Other populations increasing the likelihood that this may be a low frequency benign variant in certain populations of origin. In addition the variant was identified in this case as co-occurring with a pathogenic APC variant (c.937_938delGA, p.Glu313AsnfsX13), increasing the likelihood that the variant may not have clinical significance. In addition the variant was identified by our laboratory in a patient with polyposis as co-occurring with a pathogenic APC variant (c.937_938delGA, p.Glu313AsnfsX13), increasing the likelihood that the variant may not have clinical significance . The p.Arg106 residue is conserved in mammals and the variant amino acid His is present in the African clawed frog suggesting that this amino acid substitution may be tolerated. Computational analyses (PolyPhen-2, SIFT, AlignGVGD, BLOSUM, MutationTaster) do not suggest a high likelihood of impact to the protein; however, 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. -
not specified    Uncertain:3 
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: Reported in 1 proband with cancer and a clinseq participant -
- -
Variant summary: APC c.317G>A (p.Arg106His) results in a non-conservative amino acid change in the encoded protein sequence. Four of five in-silico tools predict a benign effect of the variant on protein function. The variant allele was found at a frequency of 4.6e-05 in 284804 control chromosomes, predominantly at a frequency of 0.00023 within the South Asian subpopulation in the gnomAD database. The available data on variant occurrences in the general population are insufficient to allow any conclusion about variant significance. c.317G>A has been reported in the literature in at least an individual affected with familial adenomatous polyposis (Azzopard_2008). This report however, does 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. Nine other ClinVar submitters (evaluation after 2014) cite the variant as uncertain significance. Based on the evidence outlined above, the variant was classified as uncertain significance. -
not provided    Uncertain:3 
- -
In silico analysis supports that this missense variant does not alter protein structure/function; This variant is associated with the following publications: (PMID: 29422544, 21859464, 22703879, 29413759, 29245953, 18199528) -
- -
Hereditary cancer-predisposing syndrome    Uncertain:1Benign:2 
This alteration is classified as 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. -
- -
- -
Familial multiple polyposis syndrome    Uncertain:1 
- -
Classic or attenuated familial adenomatous polyposis    Uncertain:1 
This missense variant replaces arginine with histidine at codon 106 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 been reported in an individual affected with adenomatous polyposis (PMID: 18199528, 21859464). This variant has also been identified in 13/282866 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. -
Computational scores
Source: 
Splicing
 Find out detailed SpliceAI scores and Pangolin per-transcript scores at