22-28695250-T-C
Variant summary
Our verdict is Uncertain significance. Variant got 3 ACMG points: 3P and 0B. PP3_ModeratePP5
The NM_007194.4(CHEK2):c.1260-8A>G variant causes a splice region, intron change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.00000538 in 1,486,622 control chromosomes in the GnomAD database, with no homozygous occurrence. 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 splice_region, intron
Scores
Clinical Significance
Conservation
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ACMG classification
Verdict is Uncertain_significance. Variant got 3 ACMG points.
Transcripts
RefSeq
Ensembl
Frequencies
GnomAD3 genomes AF: 0.00000657 AC: 1AN: 152172Hom.: 0 Cov.: 32
GnomAD4 exome AF: 0.00000525 AC: 7AN: 1334450Hom.: 0 Cov.: 20 AF XY: 0.00000596 AC XY: 4AN XY: 670596
GnomAD4 genome AF: 0.00000657 AC: 1AN: 152172Hom.: 0 Cov.: 32 AF XY: 0.0000135 AC XY: 1AN XY: 74346
ClinVar
Submissions by phenotype
not provided Pathogenic:2Uncertain:3
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CHEK2: PVS1:Strong, PS3:Supporting -
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Not observed at significant frequency in large population cohorts (gnomAD); This variant is associated with the following publications: (PMID: 23054060, 31050813, 37725924) -
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Familial cancer of breast Pathogenic:2Uncertain:1
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This sequence change falls in intron 11 of the CHEK2 gene. It does not directly change the encoded amino acid sequence of the CHEK2 protein. RNA analysis indicates that this variant induces altered splicing and may result in an absent or altered protein product. This variant is not present in population databases (gnomAD no frequency). This variant has been observed in individual(s) with breast cancer (PMID: 31050813). ClinVar contains an entry for this variant (Variation ID: 216641). Studies have shown that this variant results in activation of a cryptic splice site, and produces a non-functional protein and/or introduces a premature termination codon (PMID: 31050813; internal data). For these reasons, this variant has been classified as Pathogenic. -
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Hereditary cancer-predisposing syndrome Pathogenic:2
This variant causes an A to G nucleotide substitution at the -8 position of intron 11 of the CHEK2 gene. RNA studies with multiple carrier individuals have shown that this variant creates a new splice acceptor site that results in the inclusion of 7 intronic nucleotides and, subsequently, frameshift and premature protein translation start signal (PMID: 31050813; ClinVar SCV002681983.1). This variant has been reported in an individual affected with familial breast cancer (PMID: 31050813) and in several unaffected individuals (PMID: 31050813). This variant has not been identified in the general population by the Genome Aggregation Database (gnomAD). Loss of CHEK2 function is a known mechanism of disease (clinicalgenome.org). Based on the available evidence, this variant is classified as Likely Pathogenic. -
The c.1260-8A>G intronic pathogenic mutation results from an A to G substitution 8 nucleotides upstream from coding exon 11 in the CHEK2 gene. This nucleotide position is well conserved in available vertebrate species. In silico splice site analysis predicts that this alteration will weaken the native splice acceptor site and will result in the creation or strengthening of a novel splice acceptor site. RNA studies have demonstrated that this alteration results in abnormal splicing in the set of samples tested (Ambry internal data; Kleiblova P et al. Int. J. Cancer, 2019 10;145:1782-1797). Based on the supporting evidence, this alteration is interpreted as a disease-causing mutation. -
Hereditary breast ovarian cancer syndrome Pathogenic:1
Splice Prediction positive, Splice effect experimentally proven by Kleiblova et al. 2019. According to the ACMG standard criteria we chose these criteria: PS3 (strong pathogenic): Splice effect experimentally proven by Kleiblova et al. 2019 and Ambry Genetics, PM2 (supporting pathogenic): Absent from gnomAD, PP3 (supporting pathogenic): SpliceAI Score 0.99 -
Computational scores
Source:
Splicing
Find out detailed SpliceAI scores and Pangolin per-transcript scores at