NM_000038.6:c.2658G>T
Variant summary
Our verdict is Uncertain significance. The variant received 0 ACMG points: 2P and 2B. PM1BP4BP6
The NM_000038.6(APC):c.2658G>T(p.Gln886His) variant causes a missense change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.0000285 in 1,614,086 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. Q886R) 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: Uncertain_significance. The variant received 0 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.2658G>T | p.Gln886His | missense | Exon 16 of 16 | NP_000029.2 | ||
| APC | NM_001407446.1 | c.2742G>T | p.Gln914His | missense | Exon 16 of 16 | NP_001394375.1 | |||
| APC | NM_001354896.2 | c.2712G>T | p.Gln904His | 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.2658G>T | p.Gln886His | missense | Exon 16 of 16 | ENSP00000257430.4 | ||
| APC | ENST00000508376.6 | TSL:1 | c.2658G>T | p.Gln886His | missense | Exon 17 of 17 | ENSP00000427089.2 | ||
| APC | ENST00000502371.3 | TSL:1 | n.*856G>T | non_coding_transcript_exon | Exon 12 of 12 | ENSP00000484935.2 |
Frequencies
GnomAD3 genomes AF: 0.00000657 AC: 1AN: 152206Hom.: 0 Cov.: 32 show subpopulations
GnomAD2 exomes AF: 0.00000399 AC: 1AN: 250718 AF XY: 0.00000738 show subpopulations
GnomAD4 exome AF: 0.0000308 AC: 45AN: 1461880Hom.: 0 Cov.: 33 AF XY: 0.0000234 AC XY: 17AN XY: 727240 show subpopulations
Age Distribution
GnomAD4 genome AF: 0.00000657 AC: 1AN: 152206Hom.: 0 Cov.: 32 AF XY: 0.00 AC XY: 0AN XY: 74354 show subpopulations
ClinVar
Submissions by phenotype
Familial adenomatous polyposis 1 Uncertain:4
This sequence change replaces glutamine, which is neutral and polar, with histidine, which is basic and polar, at codon 886 of the APC protein (p.Gln886His). This variant is present in population databases (rs587780593, gnomAD 0.0009%). 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: 135694). 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.
This variant is classified as a variant of uncertain significance as there is insufficient evidence to determine its impact on protein function and/or cancer risk.
Classic or attenuated familial adenomatous polyposis Uncertain:2
This missense variant replaces glutamine with histidine at codon 886 of the APC protein. Computational prediction is inconclusive regarding the impact of this variant on protein structure and function (internally defined REVEL score threshold 0.5 < inconclusive < 0.7, 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 1/250718 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.
Hereditary cancer-predisposing syndrome Benign:2
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 Uncertain:1
This variant is denoted APC c.2658G>T at the cDNA level, p.Gln886His (Q886H) at the protein level, and results in the change of a Glutamine to a Histidine (CAG>CAT). This variant has not, to our knowledge, been published in the literature as pathogenic or benign. APC Gln886His was not observed in approximately 6,500 individuals of European and African American ancestry in the NHLBI Exome Sequencing Project, indicating it is not a common benign variant in these populations. Since Glutamine and Histidine differ in some properties, this is considered a semi-conservative amino acid substitution. APC Gln886His occurs at a position that is conserved through mammals and is not located in a known functional domain (UniProt). In silico analyses predict that this variant is probably damaging to protein structure and function. Based on currently available information, it is unclear whether APC Gln886His is pathogenic or benign. We consider it to be a variant of uncertain significance.
APC-Associated Polyposis Disorders Uncertain: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, this variant could not be ruled out of causing disease and therefore its association with disease required further investigation. A literature search was performed for the gene, cDNA change, and amino acid change (if applicable). No publications were found based on this search. This variant was therefore classified as a variant of unknown significance for this disease.
Gastric adenocarcinoma and proximal polyposis of the stomach Uncertain:1
The APC c.2658G>T (p.Gln886His) missense change has a maximum subpopulation frequency of 0.0008% in gnomAD v2.1.1 (https://gnomad.broadinstitute.org/). The in silico tool REVEL is inconclusive about a pathogenic or benign effect of this variant on protein function, and functional studies have not been performed. This variant has not been reported in the literature in individuals with APC-related disease. In summary, the evidence currently available is insufficient to determine the clinical significance of this variant. It has therefore been classified as of uncertain significance.?
Familial multiple polyposis syndrome Benign:1
The APC variant designated as NM_000038.5:c.2658G>T (p.Gln886His) is classified as likely benign. This variant was observed in an individual in one family who was documented not to have colon polyps on colonoscopy at over 70 years old. This observation is not consistent with either attenuated or classic familial adenomatous polyposis syndromes (Grover et al. 2012, PMID:22851115). Additional family members at risk of inheriting the variant have been documented to have no colon polyps. Bayesian analysis integrating all of this data (Tavtigian et al, 2018, PMID:29300386) gives a <1% probability of pathogenicity, which is consistent with a classification of likely benign. A modest (less than 2 fold) increase in cancer risk due to this variant cannot be entirely excluded. This analysis was performed in conjunction with the family studies project as part of the University of Washington Find My Variant Study.
Computational scores
Source:
Splicing
Find out detailed SpliceAI scores and Pangolin per-transcript scores at