rs886039731

chr22-28703552-CT-C

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.860del(p.Lys287ArgfsTer17) variant causes a frameshift change. The variant was absent in control chromosomes in GnomAD project. Variant has been reported in ClinVar as Likely pathogenic (★★). Synonymous variant affecting the same amino acid position (i.e. K287K) has been classified as Likely benign. Variant results in nonsense mediated mRNA decay.

• Frequency: Genomes: not found (cov: 31)
• Consequence: CHEK2 NM_007194.4 frameshift
• Clinical Significance: Pathogenic/Likely pathogenic criteria provided, multiple submitters, no conflicts P:6
• Conservation: PhyloP100: 5.85

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: Loss of function variant, product undergoes nonsense mediated mRNA decay. LoF is a known mechanism of disease.
• PM2: Very rare variant in population databases, with high coverage
• PP5: Variant 22-28703552-CT-C is Pathogenic according to our data. Variant chr22-28703552-CT-C is described in ClinVar as [Likely_pathogenic]. Clinvar id is 265686.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.860del	p.Lys287ArgfsTer17	frameshift_variant	8/15	ENST00000404276.6

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Appris	UniProt
CHEK2	ENST00000404276.6	c.860del	p.Lys287ArgfsTer17	frameshift_variant	8/15	1	NM_007194.4	P2

Frequencies

GnomAD3 genomes Cov.: 31

GnomAD4 exome Cov.: 25

GnomAD4 genome Cov.: 31

ClinVar

Significance: Pathogenic/Likely pathogenic

Submissions summary: Pathogenic:6

Revision: criteria provided, multiple submitters, no conflicts

Submissions by phenotype

Familial cancer of breast Pathogenic:3

Pathogenic, criteria provided, single submitter	clinical testing	Myriad Genetics, Inc.	Mar 08, 2023	This variant is considered pathogenic. This variant creates a frameshift predicted to result in premature protein truncation. -
Likely pathogenic, criteria provided, single submitter	clinical testing	Counsyl	Sep 29, 2016	- -
Pathogenic, criteria provided, single submitter	clinical testing	Invitae	Nov 18, 2023	This sequence change creates a premature translational stop signal (p.Lys287Argfs*17) in the CHEK2 gene. It is expected to result in an absent or disrupted protein product. 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: 265686). Algorithms developed to predict the effect of sequence changes on RNA splicing suggest that this variant may disrupt the consensus splice site. For these reasons, this variant has been classified as Pathogenic. -

not provided Pathogenic:1

Likely pathogenic, criteria provided, single submitter

clinical testing

GeneDx

Aug 17, 2016

This deletion of one nucleotide in CHEK2 is denoted c.860delA at the cDNA level and p.Lys287ArgfsX17 (K287RfsX17) at the protein level. The normal sequence, with the base that is deleted in braces, is ATCA[A]GATT. The deletion causes a frameshift which changes a Lysine to an Arginine at codon 287, and creates a premature stop codon at position 17 of the new reading frame. Although this variant has not, to our knowledge, been reported in the literature, it is predicted to cause loss of normal protein function through either protein truncation or nonsense-mediated mRNA decay. Based on the currently available information, we consider this deletion to be a likely pathogenic variant. -

Hereditary cancer-predisposing syndrome Pathogenic:1

Pathogenic, criteria provided, single submitter

clinical testing

Ambry Genetics

Jan 09, 2023

The c.860delA pathogenic mutation, located in coding exon 7 of the CHEK2 gene, results from a deletion of one nucleotide at nucleotide position 860, causing a translational frameshift with a predicted alternate stop codon (p.K287Rfs*17). This alteration is expected to result in loss of function by premature protein truncation or nonsense-mediated mRNA decay. As such, this alteration is interpreted as a disease-causing mutation. -

Hereditary breast ovarian cancer syndrome Pathogenic:1

Likely pathogenic, criteria provided, single submitter

clinical testing

Women's Health and Genetics/Laboratory Corporation of America, LabCorp

Sep 29, 2020

Variant summary: CHEK2 c.860delA (p.Lys287ArgfsX17) results in a premature termination codon, predicted to cause a truncation of the encoded protein or absence of the protein due to nonsense mediated decay, which are commonly known mechanisms for disease. Truncations downstream of this position have been classified as pathogenic by our laboratory. The variant was absent in 225074 control chromosomes (gnomAD). c.860delA has been reported in the literature to be found in a cohort of women with ovarian cancer (Arvai_2019). These report(s) do not provide unequivocal conclusions about association of the variant with Hereditary Breast and Ovarian Cancer Syndrome. To our knowledge, no experimental evidence demonstrating an impact on protein function has been reported. Three clinical diagnostic laboratories have submitted clinical-significance assessments for this variant to ClinVar after 2014 without evidence for independent evaluation, and all of them classified the variant as pathogenic (1x) / likely pathogenic (2x). Based on the evidence outlined above, the variant was classified as likely pathogenic. -

Computational scores

Source: dbNSFP v4.3

Splicing

Name	Calibrated prediction	Score	Prediction
SpliceAI score (max)		0.27		Details are displayed if max score is > 0.2
DS_AL_spliceai		0.27		Position offset: 14

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

Publications

LitVar

Other links and lift over

dbSNP: rs886039731; hg19: chr22-29099540;