22-28703536-CAAA-CAAAA

Variant names:

• chr22-28703536-C-CA
• rs772683219
• NM_007194.4:c.876dupT

Variant summary

Our verdict is Pathogenic. The variant received 18 ACMG points: 18P and 0B. PVS1 PM2 PP5_Very_Strong

The NM_007194.4(CHEK2):​c.876dupT​(p.Asp293fs) variant causes a frameshift change involving the alteration of a non-conserved nucleotide. The variant was absent in control chromosomes in GnomAD project. Variant has been reported in ClinVar as Pathogenic (★★). Synonymous variant affecting the same amino acid position (i.e. F292F) has been classified as Likely benign. Variant results in nonsense mediated mRNA decay.

• Frequency:
  • Genomes: not found (cov: 31)
  • Exomes 𝑓: 0.0 (0 hom.)
  • Failed GnomAD Quality Control
• Consequence: CHEK2 NM_007194.4 frameshift
• Clinical Significance: Pathogenic criteria provided, multiple submitters, no conflicts P:4
• Conservation: PhyloP100: 2.39
• Publications: 7 publications found

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]

CHEK2 Gene-Disease associations (from GenCC):

• CHEK2-related cancer predisposition

  Inheritance: AD Classification: DEFINITIVE Submitted by: Ambry Genetics
• hereditary breast carcinoma

  Inheritance: AD Classification: DEFINITIVE, STRONG Submitted by: Labcorp Genetics (formerly Invitae), ClinGen
• Li-Fraumeni syndrome 2

  Inheritance: AD Classification: DEFINITIVE Submitted by: G2P
• acute myeloid leukemia

  Inheritance: AD Classification: MODERATE Submitted by: Genomics England PanelApp
• hereditary nonpolyposis colon cancer

  Inheritance: AD Classification: LIMITED Submitted by: ClinGen
• familial ovarian cancer

  Inheritance: AD Classification: NO_KNOWN Submitted by: ClinGen

ACMG classification

Our verdict: Pathogenic. The variant received 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 22-28703536-C-CA is Pathogenic according to our data. Variant chr22-28703536-C-CA is described in ClinVar as [Pathogenic]. Clinvar id is 234121.Status of the report is criteria_provided_multiple_submitters_no_conflicts, 2 stars.

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	MANE	Protein	UniProt
CHEK2	NM_007194.4	c.876dupT	p.Asp293fs	frameshift_variant	Exon 8 of 15	ENST00000404276.6	NP_009125.1

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	TSL	MANE	Protein	Appris	UniProt
CHEK2	ENST00000404276.6	c.876dupT	p.Asp293fs	frameshift_variant	Exon 8 of 15	1	NM_007194.4	ENSP00000385747.1

Frequencies

GnomAD3 genomes Cov.: 31

GnomAD4 exome Data not reliable, filtered out with message: AC0 AF: 0.00 AC: 0 AN: 1403768 Hom.: 0 Cov.: 25 AF XY: 0.00 AC XY: 0 AN XY: 699044

African (AFR) AF: 0.00 AC: 0 AN: 32286

American (AMR) AF: 0.00 AC: 0 AN: 41506

Ashkenazi Jewish (ASJ) AF: 0.00 AC: 0 AN: 25428

East Asian (EAS) AF: 0.00 AC: 0 AN: 39284

South Asian (SAS) AF: 0.00 AC: 0 AN: 82960

European-Finnish (FIN) AF: 0.00 AC: 0 AN: 52190

Middle Eastern (MID) AF: 0.00 AC: 0 AN: 5694

European-Non Finnish (NFE) AF: 0.00 AC: 0 AN: 1066018

Other (OTH) AF: 0.00 AC: 0 AN: 58402

GnomAD4 genome Cov.: 31

ClinVar

Significance: Pathogenic

Submissions summary: Pathogenic:4

Revision: criteria provided, multiple submitters, no conflicts

Submissions by phenotype

Familial cancer of breast Pathogenic:2

Jun 27, 2023

Myriad Genetics, Inc.

Significance: Pathogenic

Review Status: criteria provided, single submitter

Collection Method: clinical testing

This variant is considered pathogenic. This variant creates a termination codon and is predicted to result in premature protein truncation. -

Feb 28, 2022

Labcorp Genetics (formerly Invitae), Labcorp

Significance: Pathogenic

Review Status: criteria provided, single submitter

Collection Method: clinical testing

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. ClinVar contains an entry for this variant (Variation ID: 234121). This sequence change creates a premature translational stop signal (p.Asp293*) 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. -

not provided Pathogenic:1

Aug 10, 2017

GeneDx

Significance: Pathogenic

Review Status: criteria provided, single submitter

Collection Method: clinical testing

This variant is denoted CHEK2 c.876dupT->T at the cDNA level and p.Asp293Ter (D293X) at the protein level. The substitution creates a nonsense variant, which changes an Aspartic Acid to a premature stop codon (GAT>TGA), and is predicted to cause loss of normal protein function through either protein truncation or nonsense-mediated mRNA decay. This variant has not, to our knowledge, been published in the literature as a germline variant; however, it has been reported as a somatic variant in a diffuse large B cell lymphoma sample (de Miranda 2013) and is considered pathogenic. -

Hereditary cancer-predisposing syndrome Pathogenic:1

Feb 10, 2021

Ambry Genetics

Significance: Pathogenic

Review Status: criteria provided, single submitter

Collection Method: clinical testing

The c.876dupT pathogenic mutation, located in coding exon 7 of the CHEK2 gene, results from a duplication of T at nucleotide position 876, causing a translational frameshift with a predicted alternate stop codon (p.D293*). 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. -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
PhyloP100		2.4
Mutation Taster		=0/200	disease causing (ClinVar)

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: 30

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

Other links and lift over

dbSNP: rs772683219; hg19: chr22-29099524; COSMIC: COSV60424932;