22-28695250-T-C

Variant names:

• chr22-28695250-T-C
• rs863224747
• NM_007194.4:c.1260-8A>G

Variant summary

Our verdict is Uncertain significance. The variant received 3 ACMG points: 3P and 0B. PP3_Moderate PP5

The NM_007194.4(CHEK2):​c.1260-8A>G variant causes a splice region, intron change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.00000538 in 1,486,622 control chromosomes in the GnomAD database, with no homozygous occurrence. There is a variant allele frequency bias in the population database for this variant (GnomAdExome4), which may indicate mosaicism or somatic mutations in the reference population data. In-silico tool predicts a benign outcome for this variant. 3/3 splice prediction tools predicting alterations to normal splicing. Variant has been reported in ClinVar as Conflicting classifications of pathogenicity (no stars).

• Frequency:
  • Genomes: 𝑓 0.0000066 (0 hom., cov: 32)
  • Exomes 𝑓: 0.0000052 (0 hom.)
• Consequence: CHEK2 NM_007194.4 splice_region, intron
• Scores: Splicing: ADA: 0.9998
• Clinical Significance: Conflicting classifications of pathogenicity criteria provided, conflicting classifications P:7 U:4
• Conservation: PhyloP100: 0.512
• Publications: 1 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: Uncertain_significance. The variant received 3 ACMG points.

• PP3: Splicing predictors support a deleterious effect. Scorers claiming Pathogenic: dbscSNV1_ADA, dbscSNV1_RF, max_spliceai. No scorers claiming Uncertain. No scorers claiming Benign.
• PP5: Variant 22-28695250-T-C is Pathogenic according to our data. Variant chr22-28695250-T-C is described in ClinVar as Conflicting_classifications_of_pathogenicity. ClinVar VariationId is 216641.

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	MANE	Protein	UniProt
CHEK2	NM_007194.4	c.1260-8A>G		splice_region_variant, intron_variant	Intron 11 of 14	ENST00000404276.6	NP_009125.1

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	TSL	MANE	Protein	Appris	UniProt
CHEK2	ENST00000404276.6	c.1260-8A>G		splice_region_variant, intron_variant	Intron 11 of 14	1	NM_007194.4	ENSP00000385747.1

Frequencies

GnomAD3 genomes AF: 0.00000657 AC: 1 AN: 152172 Hom.: 0 Cov.: 32

Gnomad AFR AF: 0.0000241

Gnomad AMI AF: 0.00

Gnomad AMR AF: 0.00

Gnomad ASJ AF: 0.00

Gnomad EAS AF: 0.00

Gnomad SAS AF: 0.00

Gnomad FIN AF: 0.00

Gnomad MID AF: 0.00

Gnomad NFE AF: 0.00

Gnomad OTH AF: 0.00

GnomAD4 exome AF: 0.00000525 AC: 7 AN: 1334450 Hom.: 0 Cov.: 20 AF XY: 0.00000596 AC XY: 4 AN XY: 670596

⚠️ The allele balance in gnomAD version 4 Exomes is significantly skewed from the expected value of 0.5.

African (AFR) AF: 0.00 AC: 0 AN: 30788

American (AMR) AF: 0.00 AC: 0 AN: 44492

Ashkenazi Jewish (ASJ) AF: 0.00 AC: 0 AN: 25290

East Asian (EAS) AF: 0.0000256 AC: 1 AN: 39122

South Asian (SAS) AF: 0.00 AC: 0 AN: 83620

European-Finnish (FIN) AF: 0.00 AC: 0 AN: 53288

Middle Eastern (MID) AF: 0.000181 AC: 1 AN: 5516

European-Non Finnish (NFE) AF: 0.00000502 AC: 5 AN: 996154

Other (OTH) AF: 0.00 AC: 0 AN: 56180

⚠️ The allele balance in gnomAD4 Exomes is highly skewed from 0.5 (p-value = 0.00000167207), which strongly suggests a high chance of mosaicism in these individuals.

GnomAD4 genome AF: 0.00000657 AC: 1 AN: 152172 Hom.: 0 Cov.: 32 AF XY: 0.0000135 AC XY: 1 AN XY: 74346

African (AFR) AF: 0.0000241 AC: 1 AN: 41442

American (AMR) AF: 0.00 AC: 0 AN: 15268

Ashkenazi Jewish (ASJ) AF: 0.00 AC: 0 AN: 3470

East Asian (EAS) AF: 0.00 AC: 0 AN: 5200

South Asian (SAS) AF: 0.00 AC: 0 AN: 4828

European-Finnish (FIN) AF: 0.00 AC: 0 AN: 10616

Middle Eastern (MID) AF: 0.00 AC: 0 AN: 314

European-Non Finnish (NFE) AF: 0.00 AC: 0 AN: 68030

Other (OTH) AF: 0.00 AC: 0 AN: 2092

Alfa AF: 0.00 Hom.: 0

Bravo AF: 0.00000378

ClinVar

Significance: Conflicting classifications of pathogenicity

Submissions summary: Pathogenic:7 Uncertain:4

Revision: criteria provided, conflicting classifications

Submissions by phenotype

not provided Pathogenic:2 Uncertain:3

-

Laboratory of Diagnostic Genome Analysis, Leiden University Medical Center (LUMC)

Significance: Uncertain significance

Review Status: no assertion criteria provided

Collection Method: clinical testing

- -

Mar 24, 2025

GeneDx

Significance: Likely pathogenic

Review Status: criteria provided, single submitter

Collection Method: clinical testing

Not observed at significant frequency in large population cohorts (gnomAD); This variant is associated with the following publications: (PMID: 23054060, 31050813, 37725924) -

-

Joint Genome Diagnostic Labs from Nijmegen and Maastricht, Radboudumc and MUMC+

Significance: Uncertain significance

Review Status: no assertion criteria provided

Collection Method: clinical testing

- -

Nov 01, 2024

CeGaT Center for Human Genetics Tuebingen

Significance: Uncertain significance

Review Status: criteria provided, single submitter

Collection Method: clinical testing

CHEK2: PVS1:Strong, PS3:Supporting -

Mar 04, 2025

Center for Genomic Medicine, Rigshospitalet, Copenhagen University Hospital

Significance: Likely pathogenic

Review Status: criteria provided, single submitter

Collection Method: clinical testing

- -

Familial cancer of breast Pathogenic:2 Uncertain:1

Aug 25, 2017

Counsyl

Significance: Uncertain significance

Review Status: no assertion criteria provided

Collection Method: clinical testing

This submission and the accompanying classification are no longer maintained by the submitter. For more information on current observations and classification, please contact variantquestions@myriad.com. -

Mar 24, 2024

Baylor Genetics

Significance: Likely pathogenic

Review Status: criteria provided, single submitter

Collection Method: clinical testing

- -

Jan 07, 2025

Labcorp Genetics (formerly Invitae), Labcorp

Significance: Pathogenic

Review Status: criteria provided, single submitter

Collection Method: clinical testing

This sequence change falls in intron 11 of the CHEK2 gene. It does not directly change the encoded amino acid sequence of the CHEK2 protein. RNA analysis indicates that this variant induces altered splicing and may result in an absent or altered protein product. This variant is not present in population databases (gnomAD no frequency). This variant has been observed in individual(s) with breast cancer (PMID: 31050813). ClinVar contains an entry for this variant (Variation ID: 216641). Studies have shown that this variant results in activation of a cryptic splice site, and produces a non-functional protein and/or introduces a premature termination codon (PMID: 31050813; internal data). For these reasons, this variant has been classified as Pathogenic. -

Hereditary cancer-predisposing syndrome Pathogenic:2

Jul 25, 2023

Ambry Genetics

Significance: Pathogenic

Review Status: criteria provided, single submitter

Collection Method: clinical testing

The c.1260-8A>G intronic pathogenic mutation results from an A to G substitution 8 nucleotides upstream from coding exon 11 in the CHEK2 gene. This nucleotide position is well conserved in available vertebrate species. In silico splice site analysis predicts that this alteration will weaken the native splice acceptor site and will result in the creation or strengthening of a novel splice acceptor site. RNA studies have demonstrated that this alteration results in abnormal splicing in the set of samples tested (Ambry internal data; Kleiblova P et al. Int. J. Cancer, 2019 10;145:1782-1797). Based on the supporting evidence, this alteration is interpreted as a disease-causing mutation. -

Jan 26, 2023

Color Diagnostics, LLC DBA Color Health

Significance: Likely pathogenic

Review Status: criteria provided, single submitter

Collection Method: clinical testing

This variant causes an A to G nucleotide substitution at the -8 position of intron 11 of the CHEK2 gene. RNA studies with multiple carrier individuals have shown that this variant creates a new splice acceptor site that results in the inclusion of 7 intronic nucleotides and, subsequently, frameshift and premature protein translation start signal (PMID: 31050813; ClinVar SCV002681983.1). This variant has been reported in an individual affected with familial breast cancer (PMID: 31050813) and in several unaffected individuals (PMID: 31050813). 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. -

Hereditary breast ovarian cancer syndrome Pathogenic:1

Oct 08, 2023

German Consortium for Hereditary Breast and Ovarian Cancer, University Hospital Cologne

Significance: Likely pathogenic

Review Status: criteria provided, single submitter

Collection Method: curation

Splice Prediction positive, Splice effect experimentally proven by Kleiblova et al. 2019. According to the ACMG standard criteria we chose these criteria: PS3 (strong pathogenic): Splice effect experimentally proven by Kleiblova et al. 2019 and Ambry Genetics, PM2 (supporting pathogenic): Absent from gnomAD, PP3 (supporting pathogenic): SpliceAI Score 0.99 -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
BayesDel_noAF	Benign	-0.43
CADD	Uncertain	24
DANN	Benign	0.84
PhyloP100		0.51
Mutation Taster		=0/100	disease causing

Splicing

Name	Calibrated prediction	Score	Prediction
dbscSNV1_ADA	Pathogenic	1.0
dbscSNV1_RF	Pathogenic	0.95
SpliceAI score (max)		0.99		Details are displayed if max score is > 0.2
DS_AG_spliceai		0.99		Position offset: -1
DS_AL_spliceai		0.93		Position offset: -8

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

Other links and lift over

dbSNP: rs863224747; hg19: chr22-29091238;