22-28695242-G-T

Variant names:

• chr22-28695242-G-T
• rs762205611
• NM_007194.4:c.1260C>A

Variant summary

Our verdict is Pathogenic. The variant received 19 ACMG points: 19P and 0B. PVS1 PM2 PP3 PP5_Very_Strong

The NM_007194.4(CHEK2):​c.1260C>A​(p.Cys420*) variant causes a stop gained, splice region change involving the alteration of a non-conserved nucleotide. The variant was absent in control chromosomes in GnomAD project. In-silico tool predicts a pathogenic outcome for this variant. 2/3 splice prediction tools predicting alterations to normal splicing. Variant has been reported in ClinVar as Pathogenic (★★). Synonymous variant affecting the same amino acid position (i.e. C420C) has been classified as Likely benign. Variant results in nonsense mediated mRNA decay.

• Frequency:
  • Genomes: not found (cov: 32)
  • Exomes 𝑓: 0.0000014 (0 hom.)
  • Failed GnomAD Quality Control
• Consequence: CHEK2 NM_007194.4 stop_gained, splice_region
• Scores: Splicing: ADA: 0.9774
• Clinical Significance: Pathogenic criteria provided, multiple submitters, no conflicts P:3
• Conservation: PhyloP100: 3.31
• Publications: 3 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 19 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
• PP3: Splicing predictors support a deleterious effect. Scorers claiming Pathogenic: dbscSNV1_ADA, dbscSNV1_RF. No scorers claiming Uncertain. Scorers claiming Benign: max_spliceai.
• PP5: Variant 22-28695242-G-T is Pathogenic according to our data. Variant chr22-28695242-G-T is described in ClinVar as Pathogenic. ClinVar VariationId is 1762953.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.1260C>A	p.Cys420*	stop_gained, splice_region_variant	Exon 12 of 15	ENST00000404276.6	NP_009125.1

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	TSL	MANE	Protein	Appris	UniProt
CHEK2	ENST00000404276.6	c.1260C>A	p.Cys420*	stop_gained, splice_region_variant	Exon 12 of 15	1	NM_007194.4	ENSP00000385747.1

Frequencies

GnomAD3 genomes Cov.: 32

GnomAD2 exomes AF: 0.00000400 AC: 1 AN: 250074 AF XY: 0.00000739

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 FIN exome AF: 0.00

Gnomad NFE exome AF: 0.00000885

Gnomad OTH exome AF: 0.00

GnomAD4 exome Data not reliable, filtered out with message: AS_VQSR AF: 0.00000145 AC: 2 AN: 1383118 Hom.: 0 Cov.: 22 AF XY: 0.00000144 AC XY: 1 AN XY: 692498

African (AFR) AF: 0.00 AC: 0 AN: 31852

American (AMR) AF: 0.00 AC: 0 AN: 44580

Ashkenazi Jewish (ASJ) AF: 0.00 AC: 0 AN: 25606

East Asian (EAS) AF: 0.0000254 AC: 1 AN: 39324

South Asian (SAS) AF: 0.00 AC: 0 AN: 84664

European-Finnish (FIN) AF: 0.00 AC: 0 AN: 53312

Middle Eastern (MID) AF: 0.00 AC: 0 AN: 5594

European-Non Finnish (NFE) AF: 9.61e-7 AC: 1 AN: 1040422

Other (OTH) AF: 0.00 AC: 0 AN: 57764

GnomAD4 genome Cov.: 32

ExAC AF: 0.00000824 AC: 1

ClinVar

Significance: Pathogenic

Submissions summary: Pathogenic:3

Revision: criteria provided, multiple submitters, no conflicts

Submissions by phenotype

Familial cancer of breast Pathogenic:2

Jun 28, 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.

Jan 10, 2024

Labcorp Genetics (formerly Invitae), Labcorp

Significance: Pathogenic

Review Status: criteria provided, single submitter

Collection Method: clinical testing

This sequence change creates a premature translational stop signal (p.Cys420*) 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 present in population databases (rs762205611, gnomAD 0.0009%). 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: 1762953). For these reasons, this variant has been classified as Pathogenic.

Hereditary cancer-predisposing syndrome Pathogenic:1

Jul 17, 2024

Ambry Genetics

Significance: Pathogenic

Review Status: criteria provided, single submitter

Collection Method: clinical testing

The p.C420* pathogenic mutation (also known as c.1260C>A), located in coding exon 11 of the CHEK2 gene, results from a C to A substitution at nucleotide position 1260. This changes the amino acid from a cysteine to a stop codon within coding exon 11. 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
BayesDel_addAF	Pathogenic	0.60	D
BayesDel_noAF	Pathogenic	0.62
CADD	Pathogenic	45
DANN	Uncertain	0.99
DEOGEN2	Benign	0.0	.;.;.;.;.;.;.;.;.
Eigen	Pathogenic	0.86
Eigen_PC	Pathogenic	0.74
FATHMM_MKL	Uncertain	0.94	D
LIST_S2	Benign	0.0	.;.;.;.;.;.;.;.;.
M_CAP	Benign	0.034	D
MetaRNN	Benign	0.0	.;.;.;.;.;.;.;.;.
MutationAssessor	Benign	0.0	.;.;.;.;.;.;.;.;.
PhyloP100		3.3
PROVEAN	Benign	0.0	.;.;.;.;.;.;.;.;.
REVEL	Benign	0.0
Sift	Pathogenic	0.0	.;.;.;.;.;.;.;.;.
Sift4G	Pathogenic	0.0	.;.;.;.;.;.;.;.;.
Vest4		0.96
GERP RS		4.8
Mutation Taster		=0/200	disease causing (fs/PTC)

Splicing

Name	Calibrated prediction	Score	Prediction
dbscSNV1_ADA	Pathogenic	0.98
dbscSNV1_RF	Pathogenic	0.81
SpliceAI score (max)		0.090		Details are displayed if max score is > 0.2

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

Other links and lift over

dbSNP: rs762205611; hg19: chr22-29091230;