22-28725072-T-C
Variant summary
Our verdict is Likely pathogenic. Variant got 6 ACMG points: 6P and 0B. PM1PM2PP3_Moderate
The NM_007194.4(CHEK2):c.497A>G(p.Asn166Ser) variant causes a missense change. The variant allele was found at a frequency of 0.00000124 in 1,614,062 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 Uncertain significance (★★).
Frequency
Consequence
NM_007194.4 missense
Scores
Clinical Significance
Conservation
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ACMG classification
Verdict is Likely_pathogenic. Variant got 6 ACMG points.
Transcripts
RefSeq
Ensembl
Frequencies
GnomAD3 genomes AF: 0.00000657 AC: 1AN: 152234Hom.: 0 Cov.: 32
GnomAD4 exome AF: 6.84e-7 AC: 1AN: 1461828Hom.: 0 Cov.: 32 AF XY: 0.00 AC XY: 0AN XY: 727214
GnomAD4 genome AF: 0.00000657 AC: 1AN: 152234Hom.: 0 Cov.: 32 AF XY: 0.00 AC XY: 0AN XY: 74384
ClinVar
Submissions by phenotype
not provided Uncertain:3
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; Published functional studies demonstrate reduced DNA damage response in a yeast-based assay (Delimitsou et al., 2019); Identified in a pediatric patient with leukemia and in her mother with breast cancer (Gargallo et al., 2021); This variant is associated with the following publications: (PMID: 22419737, 19782031, 30851065, 34771502) -
In the published literature, this variant has been reported in an individuals with pediatric cancer (PMID: 34771502 (2021)), and breast cancer (PMID: 33471991 (2021),29522266 (2018), see also LOVD (http://databases.lovd.nl/shared/genes/CHEK2)). Additionally, a functional study suggests that the variant is not damaging to CHEK2 protein expression or function (PMID: 30851065 (2019)). The frequency of this variant in the general population, 0.0000066 (1/152234 chromosomes (Genome Aggregation Database, http://gnomad.broadinstitute.org)), is uninformative in the assessment of its pathogenicity. Analysis of this variant using bioinformatics tools for the prediction of the effect of amino acid changes on protein structure and function yielded predictions that this variant is damaging. Based on the available information, we are unable to determine the clinical significance of this variant. -
CHEK2: PM2, PS3:Supporting -
Hereditary cancer-predisposing syndrome Uncertain:2
The p.N166S variant (also known as c.497A>G), located in coding exon 3 of the CHEK2 gene, results from an A to G substitution at nucleotide position 497. The asparagine at codon 166 is replaced by serine, an amino acid with highly similar properties. In one study, this variant was detected in 1/5589 German BRCA1/2-negative probands with breast cancer (Hauke J et al. Cancer Med, 2018 Apr;7:1349-1358). In another study, this variant was reported in 4/60,466 breast cancer cases and in 0/53,461 controls (Dorling et al. N Engl J Med. 2021 02;384:428-439). This variant was also detected in a 1 month-old child with B-cell acute lymphoblastic leukemia whose mother was diagnosed with breast cancer at age 41 (Gargallo P et al. Cancers (Basel), 2021 Oct;13). This amino acid position is highly conserved in available vertebrate species. In addition, the in silico prediction for this alteration is inconclusive. Since supporting evidence is limited at this time, the clinical significance of this alteration remains unclear. -
This missense variant replaces asparagine with serine at codon 166 of the CHEK2 protein. Computational prediction suggests that this variant may have deleterious impact on protein structure and function (internally defined REVEL score threshold >= 0.7, PMID: 27666373). A functional study has shown this variant to damaging to the DNA damage repair activity of CHEK2 protein in a yeast assay (PMID: 30851065). This variant has been reported in an individual affected with breast cancer (Color internal data). This variant has not been identified 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 breast ovarian cancer syndrome Pathogenic:1
According to the ACMG SVI adaptation criteria we chose these criteria: PS3 (strong pathogenic): damaging by Storalova PMID: 37449874 & Delimitsou PMID: 30851065, PM2 (supporting pathogenic): 1x in GnomAD v3.1.2 non-cancer, 2x in GnomAD v4.1.0 , PP3 (supporting pathogenic): REVEL: 0.821 -
CHEK2-related disorder Uncertain:1
The CHEK2 c.497A>G variant is predicted to result in the amino acid substitution p.Asn166Ser. This variant has been reported in individuals with breast cancer (Table S2, Hauke et al. 2018. PubMed ID: 29522266; Supplemental Data, Breast Cancer Association Consortium et al. 2021. PubMed ID: 33471991) and pediatric cancer (Gargallo et al. 2021. PubMed ID: 34771502). Experimental studies have shown that this missense change affects CHEK2 function demonstrating reduced DNA damage response in a yeast-based assay (Tables S1-3 and Figure S2, Delimitsou et al. 2019. PubMed ID: 30851065). To our knowledge, this variant has not been reported in the literature or in a large population database, indicating this variant is rare. This variant is interpreted as a variant of uncertain significance in ClinVar (https://www.ncbi.nlm.nih.gov/clinvar/variation/142371/). At this time, the clinical significance of this variant is uncertain due to the absence of conclusive functional and genetic evidence. -
Familial cancer of breast Uncertain:1
This sequence change replaces asparagine, which is neutral and polar, with serine, which is neutral and polar, at codon 166 of the CHEK2 protein (p.Asn166Ser). This variant is not present in population databases (gnomAD no frequency). This missense change has been observed in individual(s) with breast cancer, acute lymphoblastic leukemia (PMID: 29522266, 34771502). ClinVar contains an entry for this variant (Variation ID: 142371). An algorithm developed to predict the effect of missense changes on protein structure and function (PolyPhen-2) suggests that this variant is likely to be disruptive. Experimental studies have shown that this missense change affects CHEK2 function (PMID: 30851065). 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. -
Computational scores
Source:
Splicing
Find out detailed SpliceAI scores and Pangolin per-transcript scores at