Submissions for variant NM_000038.6(APC):c.669A>C (p.Gln223His)

gnomAD frequency: 0.00004  dbSNP: rs769482880

Total submissions: 10

Submitter	RCV	SCV	Clinical significance	Condition	Last evaluated	Review status	Method	Comment
Ambry Genetics	RCV000163884	SCV000214474	likely benign	Hereditary cancer-predisposing syndrome	2020-09-30	criteria provided, single submitter	clinical testing	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.
Counsyl	RCV000411931	SCV000489302	uncertain significance	Familial adenomatous polyposis 1	2016-09-19	criteria provided, single submitter	clinical testing
Labcorp Genetics (formerly Invitae), Labcorp	RCV000411931	SCV000552448	uncertain significance	Familial adenomatous polyposis 1	2025-01-22	criteria provided, single submitter	clinical testing	This sequence change replaces glutamine, which is neutral and polar, with histidine, which is basic and polar, at codon 223 of the APC protein (p.Gln223His). This variant is present in population databases (rs769482880, gnomAD 0.004%). This missense change has been observed in individual(s) with clinical features of APC-related conditions (PMID: 23159591). ClinVar contains an entry for this variant (Variation ID: 184601). 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) has been performed for this missense variant. However, the output from this modeling did not meet the statistical confidence thresholds required to predict the impact of this variant on APC protein function. 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.
Color Diagnostics, LLC DBA Color Health	RCV000163884	SCV000687091	uncertain significance	Hereditary cancer-predisposing syndrome	2023-04-03	criteria provided, single submitter	clinical testing	This missense variant replaces glutamine with histidine at codon 223 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 been reported in one individual being evaluated for familial adenomatous polyposis (PMID: 23159591). This variant has been identified in 4/251000 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.
Women's Health and Genetics/Laboratory Corporation of America, LabCorp	RCV001358755	SCV001554612	uncertain significance	not specified	2021-11-24	criteria provided, single submitter	clinical testing	Variant summary: APC c.669A>C (p.Gln223His) results in a non-conservative amino acid change in the encoded protein sequence. Five of five in-silico tools predict a damaging effect of the variant on protein function. The variant allele was found at a frequency of 1.6e-05 in 251000 control chromosomes. The available data on variant occurrences in the general population are insufficient to allow any conclusion about variant significance. c.669A>C has been reported in the literature as a VUS in one individual undergoing testing for APC gene analysis (example, Kerr_2013). This report 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. Four clinical diagnostic laboratories have submitted clinical-significance assessments for this variant to ClinVar after 2014 without evidence for independent evaluation (VUS, n=3; likely benign, n=1). Most submitters cite overlapping evidence utilized in the context of this evaluation. Based on the evidence outlined above, the variant was classified as uncertain significance.
GeneDx	RCV003126560	SCV003803535	uncertain significance	not provided	2024-05-20	criteria provided, single submitter	clinical testing	Not observed at significant frequency in large population cohorts (gnomAD); In silico analysis supports that this missense variant has a deleterious effect on protein structure/function; Observed in individuals undergoing APC genetic testing (PMID: 23159591); This variant is associated with the following publications: (PMID: 27882345, 23159591)
Myriad Genetics, Inc.	RCV000411931	SCV004018721	uncertain significance	Familial adenomatous polyposis 1	2023-02-17	criteria provided, single submitter	clinical testing	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.
St. Jude Molecular Pathology, St. Jude Children's Research Hospital	RCV000411931	SCV004031215	uncertain significance	Familial adenomatous polyposis 1	2023-06-27	criteria provided, single submitter	clinical testing	The APC c.669A>C (p.Gln223His) missense change has a maximum subpopulation frequency of 0.0029% in gnomAD non-cancer 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, however this prediction is not considered informative for missense variants affecting the APC gene. To our knowledge functional studies have not been performed and this variant has not been reported in individuals with APC-related familial adenomatous polyposis or attenuated familial adenomatous polyposis. 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.
All of Us Research Program, National Institutes of Health	RCV003995293	SCV004837302	uncertain significance	Classic or attenuated familial adenomatous polyposis	2023-06-26	criteria provided, single submitter	clinical testing	This missense variant replaces glutamine with histidine at codon 223 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 been reported in one individual being evaluated for familial adenomatous polyposis (PMID: 23159591). This variant has been identified in 4/251000 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.
Baylor Genetics	RCV000411931	SCV005056248	uncertain significance	Familial adenomatous polyposis 1	2024-03-08	criteria provided, single submitter	clinical testing