NM_007194.4:c.980A>G
Variant summary
Our verdict is Uncertain significance. The variant received 1 ACMG points: 2P and 1B. PP3_ModerateBS2_Supporting
The NM_007194.4(CHEK2):c.980A>G(p.Tyr327Cys) variant causes a missense change. The variant allele was found at a frequency of 0.000018 in 1,613,830 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 (★★). Another variant affecting the same amino acid position, but resulting in a different missense (i.e. Y327N) has been classified as Uncertain significance.
Frequency
Consequence
NM_007194.4 missense
Scores
Clinical Significance
Conservation
Publications
- CHEK2-related cancer predispositionInheritance: AD Classification: DEFINITIVE Submitted by: Ambry Genetics
- hereditary breast carcinomaInheritance: AD Classification: DEFINITIVE, STRONG Submitted by: Labcorp Genetics (formerly Invitae), ClinGen
- Li-Fraumeni syndrome 2Inheritance: AD Classification: DEFINITIVE Submitted by: G2P
- acute myeloid leukemiaInheritance: AD Classification: MODERATE Submitted by: Genomics England PanelApp
- hereditary nonpolyposis colon cancerInheritance: AD Classification: LIMITED Submitted by: ClinGen
- familial ovarian cancerInheritance: AD Classification: NO_KNOWN Submitted by: ClinGen
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ACMG classification
Our verdict: Uncertain_significance. The variant received 1 ACMG points.
Transcripts
RefSeq
Ensembl
Frequencies
GnomAD3 genomes  0.0000197  AC: 3AN: 152092Hom.:  0  Cov.: 31 show subpopulations 
GnomAD2 exomes  AF:  0.0000159  AC: 4AN: 251474 AF XY:  0.0000221   show subpopulations 
GnomAD4 exome  AF:  0.0000178  AC: 26AN: 1461738Hom.:  0  Cov.: 30 AF XY:  0.0000193  AC XY: 14AN XY: 727180 show subpopulations 
Age Distribution
GnomAD4 genome  0.0000197  AC: 3AN: 152092Hom.:  0  Cov.: 31 AF XY:  0.0000135  AC XY: 1AN XY: 74272 show subpopulations 
Age Distribution
ClinVar
Submissions by phenotype
not provided    Uncertain:6 
PM2 -
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In silico analysis supports that this missense variant has a deleterious effect on protein structure/function; Not observed at significant frequency in large population cohorts (gnomAD); Observed in individuals with breast, bilateral breast, or prostate cancer, but also in unaffected controls (PMID: 34326862, 32832836, 29522266, 12533788, 30287823, 31409080, 33471991); Published functional studies are conflicting: reduced kinase activity, but DNA damage response and cell growth comparable to wild type (PMID: 30851065, 31050813); This variant is associated with the following publications: (PMID: 28201779, 12533788, 30287823, 30851065, 31050813, 32295079, 33471991, 19782031, 22419737, 32885271, 34326862, 32832836, 29522266, 31409080, 36243179) -
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The frequency of this variant in the general population, 0.000026 (3/113756 chromosomes, http://gnomad.broadinstitute.org), is uninformative in assessment of its pathogenicity. In the published literature, the variant has been reported in individuals with breast cancer (PMID: 31050813 (2019), 33471991 (2021), https://databases.lovd.nl/shared/variants/CHEK2), in an individual with prostate cancer (PMID: 12533788 (2003)), and in an individual with breast and thyroid cancer (PMID: 31050813 (2019)). The variant is also found in unaffected individuals (PMID: 30287823 (2018), 33471991 (2021), https://databases.lovd.nl/shared/variants/CHEK2). A functional study in human cells demonstrated that this variant had a damaging effect on protein (PMID: 31050813 (2019)), while a study on yeast found no effect (PMID: 30851065 (2019)). 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. -
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Familial cancer of breast    Uncertain:6 
This sequence change replaces tyrosine, which is neutral and polar, with cysteine, which is neutral and slightly polar, at codon 327 of the CHEK2 protein (p.Tyr327Cys). This variant is present in population databases (rs587780194, gnomAD 0.003%). This missense change has been observed in individual(s) with prostate cancer or breast cancer (PMID: 12533788, 31050813, 34326862). ClinVar contains an entry for this variant (Variation ID: 128092). 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, 31050813). 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. -
The CHEK2 p.Tyr327Cys variant was identified in 1 of 800 proband chromosomes (frequency: 0.001) from an individual with sporadic prostate cancer and was not identified in 846 control chromosomes from healthy individuals or from 596 chromosomes from familial prostate cancer (Dong 2003). The variant was also identified in dbSNP (ID: rs587780194) as "With Uncertain significance allele", ClinVar (classified as uncertain significance by Gene Dx, Ambry Genetics, Counsyl, Invitae, Color and Fulgent Genetics). The variant was identified in control databases in 5 of 277198 chromosomes at a frequency of 0.00002 (Genome Aggregation Database Feb 27, 2017). The variant was observed in the following populations: Other in 1 of 6468 chromosomes (freq: 0.0002), European Non-Finnish in 3 of 126694 chromosomes (freq: 0.00002), and South Asian in 1 of 30782 chromosomes (freq: 0.00003), while the variant was not observed in the African, Latino, Ashkenazi Jewish, East Asian, or European Finnish populations. The p.Tyr327 residue is conserved in mammals but not in more distantly related organisms, and computational analyses (PolyPhen-2, SIFT, AlignGVGD, BLOSUM, MutationTaster) suggest that the variant may impact the protein; however, this information is not predictive enough to assume pathogenicity. The variant occurs outside of the splicing consensus sequence and in silico or computational prediction software programs (SpliceSiteFinder, MaxEntScan, NNSPLICE, GeneSplicer) 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. This variant is classified as a variant of uncertain significance. -
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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 sequence change replaces tyrosine with cysteine at codon 327 of the CHEK2 protein (p.Tyr327Cys). The tyrosine residue is highly conserved and there is a large physicochemical difference between tyrosine and cysteine. This variant is present in population databases (rs587780194, ExAC 0.006%). This variant has been observed in individuals affected with prostate cancer or breast cancer (PMID: 12533788, 31050813). ClinVar contains an entry for this variant (Variation ID: 128092) with 10 submitters all described it as of uncertain significance, two stars, no conflicts. In-silico predictions show pathogenic computational verdict based on 9 pathogenic predictions from BayesDel_addAF, DANN, EIGEN, FATHMM-MKL, LIST-S2, M-CAP, MutationTaster, PrimateAI and SIFT vs 3 benign predictions from DEOGEN2, MVP and MutationAssessor.. The clinical significance of these results is unknown. Therefore, it has been classified as a Variant of Uncertain -
Hereditary cancer-predisposing syndrome    Uncertain:3 
This missense variant replaces tyrosine with cysteine at codon 327 of the CHEK2 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). Functional impact of this variant on CHEK2 function is not clear, as one study in yeast has shown a neutral effect (PMID: 30851065), while another study in human cells reported a damaging effect (PMID: 31050813). This variant has been reported in an individual affected with breast cancer (PMID: 31050813) and in an individual affected with prostate cancer (PMID: 12533788). In a large case-control study, this variant has been observed in 5/60461 individuals affected with breast cancer and 5/53456 controls (OR=0.884, 95%CI 0.256 to 3.054; PMID: 33471991). This variant has been identified in 4/251474 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. -
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The p.Y327C variant (also known as c.980A>G), located in coding exon 8 of the CHEK2 gene, results from an A to G substitution at nucleotide position 980. The tyrosine at codon 327 is replaced by cysteine, an amino acid with highly dissimilar properties. This alteration has been identified in individuals diagnosed with prostate cancer (Dong X et al. Am. J. Hum. Genet. 2003 Feb;72:270-80; Matejcic M et al. JCO Precis Oncol, 2020 Jan;4:32-43). This alteration was also detected in 3/5589 German BRCA1/2-negative probands diagnosed with breast cancer (Hauke J et al. Cancer Med, 2018 Apr;7:1349-1358). This variant was also observed in 1/3251 individuals who met eligibility criteria for hereditary breast and ovarian cancer syndrome (Lerner-Ellis J et al. J Cancer Res Clin Oncol, 2021 Mar;147:871-879). Results from functional analyses of this variant are conflicting (Delimitsou A et al. Hum Mutat. 2019 May;40(5):631-648; Kleiblova P et al. Int J Cancer. 2019 Oct 1;145(7):1782-1797; Stolarova L et al. Clin Cancer Res, 2023 Aug;29:3037-3050). This amino acid position is highly conserved in available vertebrate species. In addition, this alteration is predicted to be deleterious by in silico analysis. Based on the available evidence, the clinical significance of this variant remains unclear. -
Breast and/or ovarian cancer    Pathogenic:1 
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CHEK2-related disorder    Uncertain:1 
The CHEK2 c.980A>G variant is predicted to result in the amino acid substitution p.Tyr327Cys. This variant has been reported in individuals with prostate cancer (Dong et al. 2003. PubMed ID: 12533788), breast cancer (Kleiblova et al. 2019. PubMed ID: 31050813; Table S4, Bhai et al. 2021. PubMed ID: 34326862), and in a control individual from a breast cancer study (Momozawa et al. 2018. PubMed ID: 30287823). This variant is reported in 0.0033% of alleles in individuals of South Asian descent in gnomAD. This variant is listed in ClinVar as uncertain by several diagnostic labs (https://www.ncbi.nlm.nih.gov/clinvar/variation/128092/). 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;C0376358:Prostate cancer;C0585442:Bone osteosarcoma;C5882668:CHEK2-related cancer predisposition    Uncertain:1 
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Bone osteosarcoma;C2931456:Familial prostate cancer;C5882668:CHEK2-related cancer predisposition    Uncertain:1 
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Computational scores
Source: 
Splicing
 Find out detailed SpliceAI scores and Pangolin per-transcript scores at