rs121908698

chr22-28725242-C-Achr22-28725242-C-Gchr22-28725242-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.444+1G>T variant causes a splice donor change. The variant was absent in control chromosomes in GnomAD project. 2/2 splice prediction tools predicting alterations to normal splicing. Variant has been reported in ClinVar as Likely pathogenic (★★).

• Frequency: Genomes: not found (cov: 32)
• Consequence: CHEK2 NM_007194.4 splice_donor
• Scores: Splicing: ADA: 1.000
• Clinical Significance: Pathogenic/Likely pathogenic criteria provided, multiple submitters, no conflicts P:6 O:1
• Conservation: PhyloP100: 6.03

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, Cryptic splice site detected, with MaxEntScore 6.3, offset of -1, new splice context is: cagGTtagg. Cryptic site results in frameshift change. If cryptic site found is not functional and variant results in exon loss, it 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. No scorers claiming Uncertain. No scorers claiming Benign.
• PP5: Variant 22-28725242-C-A is Pathogenic according to our data. Variant chr22-28725242-C-A is described in ClinVar as [Likely_pathogenic]. Clinvar id is 126914.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.444+1G>T		splice_donor_variant		ENST00000404276.6

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Appris	UniProt
CHEK2	ENST00000404276.6	c.444+1G>T		splice_donor_variant		1	NM_007194.4	P2

Frequencies

GnomAD3 genomes Cov.: 32

GnomAD3 exomes AF: 0.00000398 AC: 1 AN: 251274 Hom.: 0 AF XY: 0.00 AC XY: 0 AN XY: 135796

Gnomad AFR exome AF: 0.00

Gnomad AMR exome AF: 0.00

Gnomad ASJ exome AF: 0.00

Gnomad EAS exome AF: 0.00

Gnomad SAS exome AF: 0.00

Gnomad FIN exome AF: 0.00

Gnomad NFE exome AF: 0.00000880

Gnomad OTH exome AF: 0.00

GnomAD4 exome Cov.: 32

GnomAD4 genome Cov.: 32

ExAC AF: 0.00000824 AC: 1

ClinVar

Significance: Pathogenic/Likely pathogenic

Submissions summary: Pathogenic:6 Other:1

Revision: criteria provided, multiple submitters, no conflicts

Submissions by phenotype

Familial cancer of breast Pathogenic:4

Likely pathogenic, criteria provided, single submitter	clinical testing	Myriad Genetics, Inc.	Mar 09, 2023	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. -
Pathogenic, criteria provided, single submitter	clinical testing	MGZ Medical Genetics Center	Sep 08, 2021	- -
Pathogenic, criteria provided, single submitter	clinical testing	Invitae	Jan 10, 2024	This sequence change affects a donor splice site in intron 3 of the CHEK2 gene. RNA analysis indicates that disruption of this splice site induces altered splicing and may result in an absent or disrupted protein product. This variant is present in population databases (rs121908698, gnomAD 0.0009%). Disruption of this splice site has been observed in individual(s) with non-Hodgkin lymphoma or breast cancer (PMID: 18058223, 26506619). This variant is also known as IVS2+1G>T. ClinVar contains an entry for this variant (Variation ID: 126914). Studies have shown that disruption of this splice site results in activation of cryptic splice sites and introduces a premature termination codon (PMID: 26506619; Invitae). The resulting mRNA is expected to undergo nonsense-mediated decay. For these reasons, this variant has been classified as Pathogenic. -
Likely pathogenic, criteria provided, single submitter	clinical testing	Counsyl	Mar 15, 2017	- -

not provided Pathogenic:1 Other:1

not provided, no classification provided	literature only	Institute. of Biochemistry and Experimental Oncology, First Faculty of Medicine, Charles University in Prague	-	- -
Pathogenic, criteria provided, single submitter	clinical testing	GeneDx	Jan 06, 2016	This variant is denoted CHEK2 c.444+1G>T or IVS3+1G>T and consists of a G>T nucleotide substitution at the +1 position of intron 3 of the CHEK2 gene. This variant destroys a canonical splice donor site and is predicted to cause abnormal gene splicing, leading to either an abnormal message that is subject to nonsense-mediated mRNA decay or to an abnormal protein product. This variant, previously reported as IVS2+1G>T, has been observed in association with breast cancer (Kleibl 2008) and a different substitution at the same position, c.444+1G>A, is a Polish founder variant (Cybulski 2004). Based on the current evidence, we consider this variant to be pathogenic. -

Hereditary cancer-predisposing syndrome Pathogenic:1

Likely pathogenic, criteria provided, single submitter

clinical testing

Ambry Genetics

Feb 05, 2024

The c.444+1G>T intronic variant results from a G to T substitution one nucleotide after coding exon 2 of the CHEK2 gene. This alteration was reported in 1/673 unselected Czech breast cancer probands and was not identified in 683 matched controls (Kleibl Z et al. Breast Cancer Res. Treat. 2008 Nov;112(1):159-64). It has also been identified in a patient with non-Hodgkin lymphoma (Havranek O et al. PLoS ONE 2015 Oct;10(10):e0140819). 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 will result in the creation or strengthening of a novel splice donor site. RNA studies have shown that this alteration leads to a translational frameshift with a resultant premature stop codon (Ambry internal data; Havranek O et al. PLoS ONE 2015 Oct;10(10):e0140819). This variant is considered to be rare based on population cohorts in the Genome Aggregation Database (gnomAD). Of note, this alteration is also designated as IVS2+1G>T in published literature. 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. Based on the majority of available evidence to date, this variant is likely to be pathogenic. -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
BayesDel_addAF	Uncertain	0.11	D
BayesDel_noAF	Uncertain	-0.070
Cadd	Pathogenic	36
Dann	Benign	0.95
Eigen	Pathogenic	0.74
Eigen_PC	Uncertain	0.55
FATHMM_MKL	Uncertain	0.94	D
MutationTaster	Benign	1.0	D;D;D;D;D;D;D;D;D;D;D
GERP RS		4.9
RBP_binding_hub_radar		0.0
RBP_regulation_power_radar		1.1

Splicing

Name	Calibrated prediction	Score	Prediction
dbscSNV1_ADA	Pathogenic	1.0
dbscSNV1_RF	Pathogenic	0.74
SpliceAI score (max)		1.0		Details are displayed if max score is > 0.2
DS_DG_spliceai		0.98		Position offset: 2
DS_DL_spliceai		1.0		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: rs121908698; hg19: chr22-29121230; COSMIC: COSV105248021;