rs1555917041

Positions:

• chr22-28703567-CTAAGAAGAGGGGG-CCC

Variant summary

Our verdict is Pathogenic. Variant got 18 ACMG points: 18P and 0B. PVS1 PM2 PP5_Very_Strong

The NM_007194.4(CHEK2):​c.847-14_847-2delinsGG variant causes a splice acceptor, splice polypyrimidine tract, intron change. The variant was absent in control chromosomes in GnomAD project. Variant has been reported in ClinVar as Likely pathogenic (★★).

• Frequency: Genomes: not found (cov: 31)
• Consequence: CHEK2 NM_007194.4 splice_acceptor, splice_polypyrimidine_tract, intron
• Clinical Significance: Likely pathogenic criteria provided, multiple submitters, no conflicts P:6
• Conservation: PhyloP100: 5.55

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 18 ACMG points.

• PVS1: Splicing +-2 bp (donor or acceptor) variant, LoF is a know mechanism of disease, Cryptic splice site detected, with MaxEntScore 5.5, offset of 37, new splice context is: taaaaacttttttgatgcAGaag. 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
• PP5: Variant 22-28703568-TAAGAAGAGGGGG-CC is Pathogenic according to our data. Variant chr22-28703568-TAAGAAGAGGGGG-CC is described in ClinVar as [Likely_pathogenic]. Clinvar id is 439093.Status of the report is criteria_provided_multiple_submitters_no_conflicts, 2 stars.

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	Protein	UniProt
CHEK2	NM_007194.4	c.847-14_847-2delinsGG		splice_acceptor_variant, splice_polypyrimidine_tract_variant, intron_variant		ENST00000404276.6	NP_009125.1

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Protein	Appris	UniProt
CHEK2	ENST00000404276.6	c.847-14_847-2delinsGG		splice_acceptor_variant, splice_polypyrimidine_tract_variant, intron_variant		1	NM_007194.4	ENSP00000385747	P2

Frequencies

GnomAD3 genomes Cov.: 31

We have no GnomAD4 exomes data on this position. Probably position not covered by the project.

GnomAD4 genome Cov.: 31

ClinVar

Significance: Likely pathogenic

Submissions summary: Pathogenic:6

Revision: criteria provided, multiple submitters, no conflicts

Submissions by phenotype

Familial cancer of breast Pathogenic:3

Likely pathogenic, criteria provided, single submitter	clinical testing	Myriad Genetics, Inc.	Jun 27, 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. -
Likely pathogenic, criteria provided, single submitter	clinical testing	Labcorp Genetics (formerly Invitae), Labcorp	Jun 22, 2020	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. Donor and acceptor splice site variants 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). Algorithms developed to predict the effect of sequence changes on RNA splicing suggest that this variant may disrupt the consensus splice site, but this prediction has not been confirmed by published transcriptional studies. This variant has not been reported in the literature in individuals with CHEK2-related conditions. ClinVar contains an entry for this variant (Variation ID: 439093). This variant is not present in population databases (ExAC no frequency). This sequence change affects an acceptor splice site in intron 7 of the CHEK2 gene. It is expected to disrupt RNA splicing and likely results in an absent or disrupted protein product. -
Likely pathogenic, criteria provided, single submitter	clinical testing	Baylor Genetics	Oct 18, 2023	- -

Hereditary cancer-predisposing syndrome Pathogenic:2

Likely pathogenic, criteria provided, single submitter	clinical testing	Color Diagnostics, LLC DBA Color Health	Jun 20, 2023	This variant alters 13 basepairs in the intron 7 splice acceptor site of the CHEK2 gene, including a canonical splice site nucleotide at the -2 position. Splice site prediction tools predict that this variant may have a significant impact on RNA splicing. To our knowledge, RNA studies have not been reported for this variant. This variant has not been reported in individuals affected with hereditary cancer in the literature. However, other canonical splice site variants, impacting the -2 and -1 positions in this splice acceptor site, have been reported as disease-causing in ClinVar (variation ID: 240758, 822474) and have been observed in two affected and two unaffected individuals in a breast cancer case-control study (PMID: 30287823). 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. -
Likely pathogenic, criteria provided, single submitter	clinical testing	Ambry Genetics	Mar 04, 2022	The c.847-14_847-2del13insGG intronic variant is located upstream from coding exon 7 in the CHEK2 gene. This variant results from a deletion of 13 nucleotides and the insertion of 2 nucleotides at positions c.847-14 to c.847-2. Using the BDGP and ESEfinder splice site prediction tools, this alteration is predicted to abolish the native splice acceptor site; however, direct evidence is unavailable. 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. -

not provided Pathogenic:1

Likely pathogenic, criteria provided, single submitter

clinical testing

Quest Diagnostics Nichols Institute San Juan Capistrano

Jun 18, 2024

The CHEK2 c.847-14_847-2delinsGG variant disrupts a canonical splice-acceptor site and is predicted to interfere with normal CHEK2 mRNA splicing. This variant has not been reported in individuals with CHEK2-related conditions in the published literature. However, there is supporting evidence that variants impacting the c.847-2 canonical splice site have been seen in individuals with breast cancer (PMID: 30287823 (2018)) and typically lead to loss of protein function (PMID: 16199547 (2005)). This variant has not been reported in large, multi-ethnic general populations (Genome Aggregation Database, http://gnomad.broadinstitute.org). Based on the available information, this variant is classified as likely pathogenic. -

Computational scores

Source: dbNSFP v4.3

Splicing

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

Publications

LitVar

Other links and lift over

dbSNP: rs1555917041; hg19: chr22-29099556;