rs558321010
Variant summary
Our verdict is Likely benign. The variant received -3 ACMG points: 0P and 3B. BP4_ModerateBS2_Supporting
The NM_007194.4(CHEK2):c.134C>T(p.Thr45Met) variant causes a missense change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.0000167 in 1,613,930 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a benign outcome for this variant. 13/22 in silico tools predict a benign 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. T45A) 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: Likely_benign. The variant received -3 ACMG points.
Transcripts
RefSeq
Ensembl
Frequencies
GnomAD3 genomes   AF:  0.0000790  AC: 12AN: 151926Hom.:  0  Cov.: 31 show subpopulations 
GnomAD2 exomes  AF:  0.0000199  AC: 5AN: 251234 AF XY:  0.0000147   show subpopulations 
GnomAD4 exome  AF:  0.0000109  AC: 16AN: 1461886Hom.:  0  Cov.: 33 AF XY:  0.0000110  AC XY: 8AN XY: 727242 show subpopulations 
Age Distribution
GnomAD4 genome   AF:  0.0000723  AC: 11AN: 152044Hom.:  0  Cov.: 31 AF XY:  0.0000538  AC XY: 4AN XY: 74312 show subpopulations 
Age Distribution
ClinVar
Submissions by phenotype
Hereditary cancer-predisposing syndrome    Uncertain:3 
This missense variant replaces threonine with methionine at codon 45 of the CHEK2 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 individuals affected with sarcoma (PMID: 27498913), colorectal cancer (PMID 28944238) and unspecified pediatric cancer (PMID: 26580448). This variant has been identified in 8/282548 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. -
The p.T45M variant (also known as c.134C>T), located in coding exon 1 of the CHEK2 gene, results from a C to T substitution at nucleotide position 134. The threonine at codon 45 is replaced by methionine, an amino acid with similar properties. This alteration was detected in 1/6385 invasive epithelial ovarian cancer cases and 0/6115 controls of European ancestry (Song H et al. J Med Genet, 2021 May;58:305-313). This variant was also identified in a cohort of 3,579 African males diagnosed with prostate cancer who underwent multi-gene panel testing of 19 DNA repair and cancer predisposition genes (Matejcic M et al. JCO Precis Oncol, 2020 Jan;4:32-43). This alteration was reported as functional in a study assessing CHEK2-complementation through quantification of KAP1 phosphorylation and CHK2 autophosphorylation in human RPE1-CHEK2-knockout cells (Stolarova L et al. Clin Cancer Res, 2023 Aug;29:3037-3050). This amino acid position is well conserved in available vertebrate species. In addition, the in silico prediction for this alteration is inconclusive. Based on the available evidence, the clinical significance of this variant remains unclear. -
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not specified    Uncertain:2 
Variant summary: CHEK2 c.134C>T (p.Thr45Met) results in a non-conservative amino acid change in the encoded protein sequence. Four of five in-silico tools predict a damaging effect of the variant on protein function. The variant allele was found at a frequency of 2.5e-05 in 276880 control chromosomes (gnomAD). The available data on variant occurrences in the general population are insufficient to allow any conclusion about variant significance. c.134C>T has been reported in the literature in an individual diagnosed with Hypodiploid ALL. This report does not provide an unequivocal conclusion about association of the variant with Hereditary Breast and Ovarian Cancer. To our knowledge, no experimental evidence demonstrating an impact on protein function has been reported. Three ClinVar submission from other clinical diagnostic laboratories (evaluation after 2014) cites the variant as uncertain significance. Based on the evidence outlined above, the variant was classified as uncertain significance. -
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not provided    Uncertain:2 
Observed in individuals with breast, colorectal, prostate or other cancers and also in unaffected controls (PMID: 26580448, 27498913, 28944238, 32832836, 33471991, 32546565, 37449874); Published functional studies suggest a neutral effect: auto-phosphorylation and kinase activity comparable to wild type (PMID: 37449874); Not observed at significant frequency in large population cohorts (gnomAD); In silico analysis indicates that this missense variant does not alter protein structure/function; This variant is associated with the following publications: (PMID: 24448499, 27498913, 26580448, 28944238, 32832836, 33471991, 32546565, 37449874, 11733767, 22114986) -
The CHEK2 c.134C>T (p.Thr45Met) variant has been reported in the published literature in individuals with breast cancer (PMID: 37449874 (2023), 33471991 (2021), see LOVD (http://databases.lovd.nl/shared/)), colorectal cancer (PMID: 28944238 (2017)), and acute lymphoblastic leukemia (PMID: 26580448 (2015)). This variant has also been reported in unaffected individuals (PMID: 37449874 (2023), 33471991 (2021), see LOVD (http://databases.lovd.nl/shared/genes/CHEK2)). The frequency of this variant in the general population, 0.00012 (3/24932 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 conflicting predictions that this variant is benign or damaging. Based on the available information, we are unable to determine the clinical significance of this variant. -
Familial cancer of breast    Uncertain:2 
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This sequence change replaces threonine, which is neutral and polar, with methionine, which is neutral and non-polar, at codon 45 of the CHEK2 protein (p.Thr45Met). This variant is present in population databases (rs558321010, gnomAD 0.01%). This missense change has been observed in individual(s) with pediatric acute lymphoblastic leukemia (PMID: 26580448). ClinVar contains an entry for this variant (Variation ID: 230559). 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. 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. -
Hereditary nonpolyposis colon cancer    Uncertain:1 
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Familial cancer of breast;C0346629:Colorectal cancer;C0376358:Prostate cancer;C0585442:Bone osteosarcoma;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