rs1555926708
Variant summary
Our verdict is Likely pathogenic. Variant got 6 ACMG points: 6P and 0B. PM2PP3_Strong
The NM_007194.4(CHEK2):c.592G>C(p.Val198Leu) variant causes a missense, splice region change. The variant was absent in control chromosomes in GnomAD project. In-silico tool predicts a benign outcome for this variant. 3/3 splice prediction tools predicting alterations to normal splicing. Variant has been reported in ClinVar as Conflicting classifications of pathogenicity (no stars).
Frequency
Consequence
NM_007194.4 missense, splice_region
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 Cov.: 32
GnomAD4 exome Cov.: 32
GnomAD4 genome Cov.: 32
ClinVar
Submissions by phenotype
Hereditary cancer-predisposing syndrome Pathogenic:1Uncertain:1
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The c.592G>C variant (also known as p.V198L), located in coding exon 3 of the CHEK2 gene, results from a G to C substitution at nucleotide position 592. The amino acid change results in valine to leucine at codon 198, an amino acid with highly similar properties. However, this change occurs in the last base pair of coding exon 3, which makes it likely to have some effect on normal mRNA splicing. In silico splice site analysis predicts that this alteration will weaken the native splice donor site and RNA studies have demonstrated that this alteration results in abnormal splicing in the set of samples tested (Ambry internal data). Another alteration impacting the same donor site (c.592+1G>A) has been shown to have a similar impact on splicing (Ambry internal data). This variant is considered to be rare based on population cohorts in the Genome Aggregation Database (gnomAD). This nucleotide position is highly conserved in available vertebrate species. Based on the supporting evidence, this alteration is interpreted as a disease-causing mutation. -
CHEK2-related disorder Uncertain:1
The CHEK2 c.592G>C variant is predicted to result in the amino acid substitution p.Val198Leu. This variant is located at the last nucleotide of the exon and is predicted to abolish the canonical splice donor site (SpliceAI, Jaganathan et al. 2019. PubMed ID: 30661751). To our knowledge, this variant has not been reported in the literature or in a large population database (http://gnomad.broadinstitute.org), indicating this variant is rare. In ClinVar, this variant has conflicting interpretations of uncertain and pathogenic (https://www.ncbi.nlm.nih.gov/clinvar/variation/481730/). 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 valine, which is neutral and non-polar, with leucine, which is neutral and non-polar, at codon 198 of the CHEK2 protein (p.Val198Leu). This variant also falls at the last nucleotide of exon 4, which is part of the consensus splice site for this exon. This variant is not present in population databases (gnomAD no frequency). This variant has not been reported in the literature in individuals affected with CHEK2-related conditions. ClinVar contains an entry for this variant (Variation ID: 481730). 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 tolerated. Variants that disrupt the consensus splice site are a relatively common cause of aberrant splicing (PMID: 17576681, 9536098). Studies have shown this missense change is associated with multiple alternative transcripts involving intronic insertion, but one or more of the resulting mRNA isoform(s) may be naturally occurring (internal data). 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