22-28711907-A-G
Variant summary
Our verdict is Pathogenic. Variant got 11 ACMG points: 11P and 0B. PVS1PM2PP5
The NM_007194.4(CHEK2):c.792+2T>C variant causes a splice donor, intron change. The variant allele was found at a frequency of 0.0000131 in 152,310 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a pathogenic outcome for this variant. 2/3 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 splice_donor, intron
Scores
Clinical Significance
Conservation
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ACMG classification
Verdict is Pathogenic. Variant got 11 ACMG points.
Transcripts
RefSeq
Ensembl
Frequencies
GnomAD3 genomes AF: 0.0000131 AC: 2AN: 152192Hom.: 0 Cov.: 32
GnomAD3 exomes AF: 0.00000398 AC: 1AN: 251064Hom.: 0 AF XY: 0.00 AC XY: 0AN XY: 135732
GnomAD4 exome Data not reliable, filtered out with message: AC0 AF: 0.00 AC: 0AN: 1440640Hom.: 0 Cov.: 28 AF XY: 0.00 AC XY: 0AN XY: 718072
GnomAD4 genome AF: 0.0000131 AC: 2AN: 152310Hom.: 0 Cov.: 32 AF XY: 0.0000134 AC XY: 1AN XY: 74488
ClinVar
Submissions by phenotype
Familial cancer of breast Pathogenic:2Uncertain:2
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Disruption of this splice site has been observed in individual(s) with CHEK2-related conditions (PMID: 32885271, 32906215). This sequence change affects a donor splice site in intron 6 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 present in population databases (rs545982789, gnomAD 0.002%). This variant is also known as c.683+2T>C. ClinVar contains an entry for this variant (Variation ID: 220480). 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:1
The c.792+2T>C intronic variant results from a T to C substitution two nucleotides after coding exon 5 in the CHEK2 gene. In one study, this variant was reported in 1/60,466 breast cancer cases and in 0/53,461 controls (Dorling et al. N Engl J Med. 2021 02;384:428-439). This alteration was also reported as being found in at least one individual in a cohort of 516 patients being evaluated for suspected hereditary breast and ovarian cancer (Vargas-Parra G et al. Hum Mutat. 2020 12;41(12):2128-2142). This nucleotide position is highly conserved in available vertebrate species. In silico splice site analysis predicts that this alteration will weaken the native splice donor site and result in the creation or strengthening of a novel splice donor site. RNA studies have demonstrated that this alteration results in abnormal splicing in the set of samples tested (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. -
Hereditary breast ovarian cancer syndrome Pathogenic:1
According to the ACMG SVI adaptation criteria we chose these criteria: PVS1 (very strong pathogenic): as per Tayoun, 2018 (PMID: 30192042): GT-AG splice sites --> Exon skipping or use of a cryptic splice site disrupts reading frame and is predicted to undergo NMD --> Exon is present in biologically-relevant transcript(s) Feliubadaló 2017 (PMID: 28050010): Figure S6B (Supplementary): " Aberrant splicing caused by the CHEK2 c.792+2T>C variant, which shows the abolition of the wild-type donor site of exon 6. The RT-PCR analysis showed multiple bands (the 469-bp band corresponds to the predominant transcript) in the control samples. The 588-bp band belongs to an aberrant transcript showing a 119-bp insertion from intron 6. Sequencing of the aberrant cDNA showed the partial 119-bp insertion from intron 6. --> r.792_793ins792+1_792+119, p.(Asp265Alafs*12). RNA-Analysis (GC-HBOC) Intron retention intron 6 and skipping of exons 6-8 (NMD predicted) , PM2 (supporting pathogenic): gnomAD v4.1.0 Grpmax Filtering AF = 2.900e-7 (=0.00003% / 2x het in 1592950); absent from UK Biobank (468530 participants) -
Computational scores
Source:
Splicing
Find out detailed SpliceAI scores and Pangolin per-transcript scores at