22-28695243-C-T

Variant names:

• chr22-28695243-C-T
• rs786201906
• NM_007194.4:c.1260-1G>A

Variant summary

Our verdict is Uncertain significance. The variant received 4 ACMG points: 4P and 0B. PVS1_Moderate PM2

The NM_007194.4(CHEK2):​c.1260-1G>A variant causes a splice acceptor, intron change. The variant allele was found at a frequency of 0.00000657 in 152,128 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a pathogenic 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: 0.0 (0 hom.)
  • Failed GnomAD Quality Control
• Consequence: CHEK2 NM_007194.4 splice_acceptor, intron
• Scores: Splicing: ADA: 1.000
• Clinical Significance: Conflicting classifications of pathogenicity criteria provided, conflicting classifications P:1 U:5
• Conservation: PhyloP100: 6.26
• Publications: 4 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 4 ACMG points.

• PVS1: Splicing +-2 bp (donor or acceptor) variant, product NOT destroyed by NMD, known LOF gene, truncates exone, which is 0.071078435 fraction of the gene. Cryptic splice site detected, with MaxEntScore 3.4, offset of 6, new splice context is: ctaccaatattaaaccttAGtgg. Cryptic site results in inframe 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

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	MANE	Protein	UniProt
CHEK2	NM_007194.4	c.1260-1G>A		splice_acceptor_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.1260-1G>A		splice_acceptor_variant, intron_variant	Intron 11 of 14	1	NM_007194.4	ENSP00000385747.1

Frequencies

GnomAD3 genomes AF: 0.00000657 AC: 1 AN: 152128 Hom.: 0 Cov.: 32

Gnomad AFR AF: 0.00

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: 0.000478

GnomAD4 exome Data not reliable, filtered out with message: AC0;AS_VQSR AF: 0.00 AC: 0 AN: 1384696 Hom.: 0 Cov.: 22 AF XY: 0.00 AC XY: 0 AN XY: 693138

African (AFR) AF: 0.00 AC: 0 AN: 31890

American (AMR) AF: 0.00 AC: 0 AN: 44576

Ashkenazi Jewish (ASJ) AF: 0.00 AC: 0 AN: 25624

East Asian (EAS) AF: 0.00 AC: 0 AN: 39340

South Asian (SAS) AF: 0.00 AC: 0 AN: 84666

European-Finnish (FIN) AF: 0.00 AC: 0 AN: 53316

Middle Eastern (MID) AF: 0.00 AC: 0 AN: 5604

European-Non Finnish (NFE) AF: 0.00 AC: 0 AN: 1041886

Other (OTH) AF: 0.00 AC: 0 AN: 57794

GnomAD4 genome AF: 0.00000657 AC: 1 AN: 152128 Hom.: 0 Cov.: 32 AF XY: 0.0000135 AC XY: 1 AN XY: 74322

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

African (AFR) AF: 0.00 AC: 0 AN: 41420

American (AMR) AF: 0.00 AC: 0 AN: 15260

Ashkenazi Jewish (ASJ) AF: 0.00 AC: 0 AN: 3468

East Asian (EAS) AF: 0.00 AC: 0 AN: 5204

South Asian (SAS) AF: 0.00 AC: 0 AN: 4822

European-Finnish (FIN) AF: 0.00 AC: 0 AN: 10602

Middle Eastern (MID) AF: 0.00 AC: 0 AN: 316

European-Non Finnish (NFE) AF: 0.00 AC: 0 AN: 68034

Other (OTH) AF: 0.000478 AC: 1 AN: 2090

⚠️ The allele balance in gnomAD version 4 Genomes is significantly skewed from the expected value of 0.5. (p-value = 0.000000), which strongly suggests a high chance of mosaicism in these individuals.

ClinVar

Significance: Conflicting classifications of pathogenicity

Submissions summary: Pathogenic:1 Uncertain:5

Revision: criteria provided, conflicting classifications

Submissions by phenotype

Hereditary cancer-predisposing syndrome Uncertain:2

Jun 06, 2025

Ambry Genetics

Significance: Uncertain significance

Review Status: criteria provided, single submitter

Collection Method: clinical testing

The c.1260-1G>A intronic variant results from a G to A substitution one nucleotide upstream from coding exon 11 of the CHEK2 gene. 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. This nucleotide position is highly 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 primarily results in a transcript predicted to lead to a protein with an in-frame deletion of two amino acids; however, the exact functional impact of the deleted amino acids is unknown at this time (Ambry internal data). Since supporting evidence is limited at this time, the clinical significance of this alteration remains unclear. -

Sep 26, 2023

Color Diagnostics, LLC DBA Color Health

Significance: Uncertain significance

Review Status: criteria provided, single submitter

Collection Method: clinical testing

This variant causes a G>A nucleotide substitution at the -1 position of intron 11 of the CHEK2 protein. Splice site prediction tools predict the weakening of the canonical acceptor site and strengthening of an in-frame cryptic acceptor, resulting in the loss of two amino acids. To our knowledge, RNA studies have not been reported for this variant. This variant has been reported in an individual affected with esophageal adenocarcinoma (PMID: 37507074). This variant has not been identified in the general population by the Genome Aggregation Database (gnomAD). The available evidence is insufficient to determine the role of this variant in disease conclusively. Therefore, this variant is classified as a Variant of Uncertain Significance. -

CHEK2-related cancer predisposition Pathogenic:1

May 22, 2020

Illumina Laboratory Services, Illumina

Significance: Likely pathogenic

Review Status: criteria provided, single submitter

Collection Method: clinical testing

The CHEK2 c.1260-1G>A variant occurs in a canonical splice site (acceptor) and is therefore predicted to disrupt or distort the normal gene product. A literature search was performed for the gene and cDNA change. No publications were identified through this search. This variant is not reported in a region of good sequencing coverage in the Genome Aggregation Database, indicating it is rare. Based on the variant's rarity and the known significance of loss of function variants in the CHEK2 gene, the c.1260-1G>A variant is classified as likely pathogenic for CHEK2-related cancer susceptibility. -

not specified Uncertain:1

Mar 04, 2025

Center for Genomic Medicine, Rigshospitalet, Copenhagen University Hospital

Significance: Uncertain significance

Review Status: criteria provided, single submitter

Collection Method: clinical testing

- -

Familial cancer of breast Uncertain:1

Sep 12, 2024

Labcorp Genetics (formerly Invitae), Labcorp

Significance: Uncertain significance

Review Status: criteria provided, single submitter

Collection Method: clinical testing

This sequence change affects an acceptor splice site in intron 11 of the CHEK2 gene. RNA analysis indicates that disruption of this splice site induces altered splicing and likely results in the loss of 2 amino acid residue(s), but is expected to preserve the integrity of the reading-frame. This variant is not present in population databases (gnomAD no frequency). Disruption of this splice site has been observed in individual(s) with esophageal adenocarcinoma (PMID: 37507074). ClinVar contains an entry for this variant (Variation ID: 185068). Studies have shown that disruption of this splice site results in the activation of a cryptic splice site in exon 12 (internal data). In summary, the available evidence is currently insufficient to determine the role of this variant in disease. Therefore, it has been classified as a Variant of Uncertain Significance. -

Hereditary breast ovarian cancer syndrome Uncertain:1

Apr 07, 2025

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

Significance: Uncertain significance

Review Status: criteria provided, single submitter

Collection Method: curation

According to the ACMG SVI adaptation criteria we chose these criteria: PVS1 (medium pathogenic): PVS1 decision tree as per Tayoun (2018, PMID: 30192042): GT-AG splice sites -->Use of a cryptic splice site preserves reading frame (Splice AI predicts canonical AL & AG at -7bp) --> LoF variants in this exon are not frequent in the general population and exon is present in biologically-relevant transcript(s) --> Variant removes <10% of protein --> Moderate, PM2 (supporting pathogenic): ansent from gnomAD v2; 1x het in gnomAD v3/4 -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
BayesDel_addAF	Pathogenic	0.45	D
BayesDel_noAF	Pathogenic	0.41
CADD	Pathogenic	34
DANN	Uncertain	1.0
Eigen	Pathogenic	1.2
Eigen_PC	Pathogenic	1.1
FATHMM_MKL	Pathogenic	0.98	D
PhyloP100		6.3
GERP RS		5.8
Mutation Taster		=0/100	disease causing (ClinVar)

Splicing

Name	Calibrated prediction	Score	Prediction
dbscSNV1_ADA	Pathogenic	1.0
dbscSNV1_RF	Pathogenic	0.86
SpliceAI score (max)		0.94		Details are displayed if max score is > 0.2
DS_AG_spliceai		0.63		Position offset: -7
DS_AL_spliceai		0.94		Position offset: -1

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

Other links and lift over

dbSNP: rs786201906; hg19: chr22-29091231;