rs864622613
Variant summary
Our verdict is Pathogenic. Variant got 18 ACMG points: 18P and 0B. PVS1PM2PP5_Very_Strong
The NM_007194.4(CHEK2):c.320-1G>T variant causes a splice acceptor, intron change. The variant was absent in control chromosomes in GnomAD project. In-silico tool predicts a pathogenic outcome for this variant. 3/3 splice prediction tools predicting alterations to normal splicing. Variant has been reported in ClinVar as Likely pathogenic (★★).
Frequency
Consequence
NM_007194.4 splice_acceptor, intron
Scores
Clinical Significance
Conservation
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ACMG classification
Verdict is Pathogenic. Variant got 18 ACMG points.
Transcripts
RefSeq
Ensembl
Frequencies
GnomAD3 genomes Cov.: 32
GnomAD4 exome Cov.: 32
GnomAD4 genome Cov.: 32
ClinVar
Submissions by phenotype
Familial cancer of breast Pathogenic:3
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This sequence change affects an acceptor splice site in intron 2 of the CHEK2 gene. It is expected to disrupt RNA splicing. Variants that disrupt the donor or acceptor splice site typically lead to a loss of protein function (PMID: 16199547), and loss-of-function variants in CHEK2 are known to be pathogenic (PMID: 21876083, 24713400). This variant is not present in population databases (gnomAD no frequency). Disruption of this splice site has been observed in individual(s) with CHEK2-related cancers (PMID: 32805687, 32885271). ClinVar contains an entry for this variant (Variation ID: 631377). Algorithms developed to predict the effect of sequence changes on RNA splicing suggest that this variant may disrupt the consensus splice site. In summary, the currently available evidence indicates that the variant is pathogenic, but additional data are needed to prove that conclusively. Therefore, this variant has been classified as Likely Pathogenic. -
This variant is considered likely pathogenic. This variant occurs within a consensus splice junction and is predicted to result in abnormal mRNA splicing of either an out-of-frame exon or an in-frame exon necessary for protein stability and/or normal function. -
Hereditary cancer-predisposing syndrome Pathogenic:2
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The c.320-1G>T intronic variant results from a G to T substitution one nucleotide upstream from coding exon 2 of the CHEK2 gene. A. This variant was 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(3):871-879). This variant was also identified in at least one individual in a cohort of patients undergoing multigene panel testing for hereditary cancer (Sutcliffe EG et al. Cancer Genet. 2020 Aug;246-247:12-17). This nucleotide position is highly conserved in available vertebrate species. In silico splice site analysis predicts that this alteration will weaken the native splice acceptor site; however, direct evidence is insufficient at this time (Ambry internal data). Alterations that disrupt the canonical splice site are expected to cause aberrant splicing, resulting in an abnormal protein or a transcript that is subject to nonsense-mediated mRNA decay. As such, this alteration is classified as likely pathogenic. -
Malignant tumor of breast Pathogenic:1
The CHEK2 c.320-1G>T variant was not identified in the literature nor was it identified in the dbSNP, Exome Aggregation Consortium (August 8th 2016), or the Genome Aggregation Database (Feb 27, 2017). The variant was identified in ClinVar (interpreted as "likely pathogenic" by Color). The c.320-1G>T variant is predicted to cause abnormal splicing because the nucleotide substitution occurs in the invariant region of the splice consensus sequence. 4 out of 4 in silico or computational prediction software programs (SpliceSiteFinder, MaxEntScan, NNSPLICE, GeneSplicer) predicted a greater than 10% difference in splicing. In summary, based on the above information the clinical significance of this variant cannot be determined with certainty at this time although we would lean towards a more pathogenic role for this variant. This variant is classified as likely pathogenic. -
Hereditary breast ovarian cancer syndrome Pathogenic:1
Variant summary: CHEK2 c.320-1G>T is located in a canonical splice-site and is predicted to affect mRNA splicing resulting in a significantly altered protein due to either exon skipping, shortening, or inclusion of intronic material. Several computational tools predict a significant impact on normal splicing: Four predict the variant abolishes the canonical 3' splicing acceptor site. However, these predictions have yet to be confirmed by functional studies. The variant was absent in 250870 control chromosomes. c.320-1G>T has been reported in the literature in individuals affected and/or undergoing multigene panel testing for hereditary cancer(s) (example, Sutcliffe_2020, Lerner-Ellis_2021). These data indicate that the variant may be associated with disease. To our knowledge, no experimental evidence demonstrating an impact on protein function has been reported. The following publications have been ascertained in the context of this evaluation (PMID: 32885271, 32805687). Four submitters have cited clinical-significance assessments for this variant to ClinVar after 2014. All submitters classified the variant as likely pathogenic. Based on the evidence outlined above, the variant was classified as likely pathogenic. -
Computational scores
Source:
Splicing
Find out detailed SpliceAI scores and Pangolin per-transcript scores at