22-28694031-C-T

Position:

• chr22-28694031-C-T

Variant summary

Our verdict is Pathogenic. Variant got 22 ACMG points: 22P and 0B. PVS1 PM2 PP3_Strong PP5_Very_Strong

The NM_007194.4(CHEK2):​c.1461+1G>A variant causes a splice donor 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:
  • Genomes: not found (cov: 32)
  • Exomes 𝑓: 6.9e-7 (0 hom.)
  • Failed GnomAD Quality Control
• Consequence: CHEK2 NM_007194.4 splice_donor
• Scores: Splicing: ADA: 1.000
• Clinical Significance: Pathogenic/Likely pathogenic criteria provided, multiple submitters, no conflicts P:5
• Conservation: PhyloP100: 5.57

Genes affected

CHEK2 (HGNC:16627): (checkpoint kinase 2) In response to DNA damage and replication blocks, cell cycle progression is halted through the control of critical cell cycle regulators. The protein encoded by this gene is a cell cycle checkpoint regulator and putative tumor suppressor. It contains a forkhead-associated protein interaction domain essential for activation in response to DNA damage and is rapidly phosphorylated in response to replication blocks and DNA damage. When activated, the encoded protein is known to inhibit CDC25C phosphatase, preventing entry into mitosis, and has been shown to stabilize the tumor suppressor protein p53, leading to cell cycle arrest in G1. In addition, this protein interacts with and phosphorylates BRCA1, allowing BRCA1 to restore survival after DNA damage. Mutations in this gene have been linked with Li-Fraumeni syndrome, a highly penetrant familial cancer phenotype usually associated with inherited mutations in TP53. Also, mutations in this gene are thought to confer a predisposition to sarcomas, breast cancer, and brain tumors. This nuclear protein is a member of the CDS1 subfamily of serine/threonine protein kinases. Several transcript variants encoding different isoforms have been found for this gene. [provided by RefSeq, Apr 2012]

ACMG classification

Verdict is Pathogenic. Variant got 22 ACMG points.

• PVS1: Splicing variant, LoF is a know mechanism of disease, No cryptic splice site detected. Exon removal results in frameshift change.
• PM2: Very rare variant in population databases, with high coverage
• PP3: Splicing scoreres supports a deletorius effect: Scorers claiming Pathogenic: dbscSNV1_ADA, dbscSNV1_RF, max_spliceai. No scorers claiming Uncertain. No scorers claiming Benign.
• PP5: Variant 22-28694031-C-T is Pathogenic according to our data. Variant chr22-28694031-C-T is described in ClinVar as [Likely_pathogenic]. Clinvar id is 265565.Status of the report is criteria_provided_multiple_submitters_no_conflicts, 2 stars.

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	UniProt
CHEK2	NM_007194.4	c.1461+1G>A		splice_donor_variant		ENST00000404276.6

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Appris	UniProt
CHEK2	ENST00000404276.6	c.1461+1G>A		splice_donor_variant		1	NM_007194.4	P2

Frequencies

GnomAD3 genomes Cov.: 32

GnomAD4 exome Data not reliable, filtered out with message: AS_VQSR AF: 6.95e-7 AC: 1 AN: 1439664 Hom.: 0 Cov.: 29 AF XY: 0.00000139 AC XY: 1 AN XY: 716992

Gnomad4 AFR exome AF: 0.00

Gnomad4 AMR exome AF: 0.00

Gnomad4 ASJ exome AF: 0.00

Gnomad4 EAS exome AF: 0.00

Gnomad4 SAS exome AF: 0.00

Gnomad4 FIN exome AF: 0.00

Gnomad4 NFE exome AF: 9.03e-7

Gnomad4 OTH exome AF: 0.00

GnomAD4 genome Cov.: 32

ClinVar

Significance: Pathogenic/Likely pathogenic

Submissions summary: Pathogenic:5

Revision: criteria provided, multiple submitters, no conflicts

Submissions by phenotype

Familial cancer of breast Pathogenic:3

Pathogenic, criteria provided, single submitter	clinical testing	Human Genome Sequencing Center Clinical Lab, Baylor College of Medicine	Mar 07, 2017	This c.1461+1G>A variant has not been observed in our cohort database nor has been detected in the ExAC database. This variant was however reported in ClinVar but the clinical presentation of the patient was not available (SCV000322553.3). This variant affects the invariant donor splice site of intron 13 of the CHEK2 gene. Whole not validated for clinical use, computer-based algorithms predict this c.1461+1G>A change to disrupt this splicing site. A c.1461 +2T>C affecting the same invariant splice site was reported in a cohort of patients with breast and/or ovarian cancer [PMID 24549055]. This variant is classified as pathogenic. -
Likely pathogenic, criteria provided, single submitter	clinical testing	MGZ Medical Genetics Center	Feb 14, 2022	- -
Likely pathogenic, criteria provided, single submitter	clinical testing	Invitae	Oct 29, 2023	This sequence change affects a donor splice site in intron 13 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). 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: 265565). 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. -

not provided Pathogenic:1

Likely pathogenic, criteria provided, single submitter

clinical testing

GeneDx

Dec 17, 2021

Canonical splice site variant predicted to result in a null allele in a gene for which loss-of-function is a known mechanism of disease; Not observed at significant frequency in large population cohorts (Lek 2016); Identified in a cohort of predominantly healthy individuals undergoing clinical genetic testing (The eMERGE Consortium 2019); This variant is associated with the following publications: (PMID: 25839328, 31447099) -

Hereditary cancer-predisposing syndrome Pathogenic:1

Likely pathogenic, criteria provided, single submitter

clinical testing

Ambry Genetics

Dec 21, 2021

The c.1461+1G>A intronic variant results from a G to A substitution one nucleotide after coding exon 12 of the CHEK2 gene. 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. In silico splice site analysis predicts that this alteration will weaken the native splice donor 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. -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
BayesDel_addAF	Pathogenic	0.45	D
BayesDel_noAF	Pathogenic	0.40
CADD	Pathogenic	32
DANN	Uncertain	1.0
Eigen	Pathogenic	1.1
Eigen_PC	Pathogenic	0.96
FATHMM_MKL	Uncertain	0.95	D
MutationTaster	Benign	1.0	D;D;D;D;D;D;D;D;D;D;D
GERP RS		5.5
RBP_binding_hub_radar		0.0
RBP_regulation_power_radar		1.7

Splicing

Name	Calibrated prediction	Score	Prediction
dbscSNV1_ADA	Pathogenic	1.0
dbscSNV1_RF	Pathogenic	0.91
SpliceAI score (max)		0.99		Details are displayed if max score is > 0.2
DS_DL_spliceai		0.99		Position offset: 1

Find out detailed SpliceAI scores and Pangolin per-transcript scores at spliceailookup.broadinstitute.org

Publications

LitVar

Other links and lift over

dbSNP: rs886039629; hg19: chr22-29090019; COSMIC: COSV60416681; COSMIC: COSV60416681;