22-28725372-A-G

Variant names:

• chr22-28725372-A-G
• rs121908700
• NM_007194.4:c.320-5T>C

Variant summary

Our verdict is Likely benign. The variant received -1 ACMG points: 2P and 3B. PM2 BP4_Moderate BP6

The NM_007194.4(CHEK2):​c.320-5T>C variant causes a splice region, intron change. The variant was absent in control chromosomes in GnomAD project. In-silico tool predicts a benign outcome for this variant. 3/3 splice prediction tools predict no significant impact on normal splicing. Variant has been reported in ClinVar as Conflicting classifications of pathogenicity (no stars).

• Frequency:
  • Genomes: 𝑓 0.0 (0 hom., cov: 32)
  • Failed GnomAD Quality Control
• Consequence: CHEK2 NM_007194.4 splice_region, intron
• Scores: Splicing: ADA: 0.01041
• Clinical Significance: Conflicting classifications of pathogenicity criteria provided, conflicting classifications U:1 B:3
• Conservation: PhyloP100: 3.95
• Publications: 12 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: Likely_benign. The variant received -1 ACMG points.

• PM2: Very rare variant in population databases, with high coverage
• BP4: Computational evidence support a benign effect (BayesDel_noAF=-0.38).
• BP6: Variant 22-28725372-A-G is Benign according to our data. Variant chr22-28725372-A-G is described in ClinVar as Conflicting_classifications_of_pathogenicity. ClinVar VariationId is 483404.

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	MANE	Protein	UniProt
CHEK2	NM_007194.4	c.320-5T>C		splice_region_variant, intron_variant	Intron 2 of 14	ENST00000404276.6	NP_009125.1

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	TSL	MANE	Protein	Appris	UniProt
CHEK2	ENST00000404276.6	c.320-5T>C		splice_region_variant, intron_variant	Intron 2 of 14	1	NM_007194.4	ENSP00000385747.1

Frequencies

GnomAD3 genomes AF: 0.00 AC: 0 AN: 152224 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: 0.00

GnomAD4 exome Cov.: 32

GnomAD4 genome Data not reliable, filtered out with message: AC0 AF: 0.00 AC: 0 AN: 152224 Hom.: 0 Cov.: 32 AF XY: 0.00 AC XY: 0 AN XY: 74372

African (AFR) AF: 0.00 AC: 0 AN: 41458

American (AMR) AF: 0.00 AC: 0 AN: 15270

Ashkenazi Jewish (ASJ) AF: 0.00 AC: 0 AN: 3472

East Asian (EAS) AF: 0.00 AC: 0 AN: 5202

South Asian (SAS) AF: 0.00 AC: 0 AN: 4832

European-Finnish (FIN) AF: 0.00 AC: 0 AN: 10628

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

European-Non Finnish (NFE) AF: 0.00 AC: 0 AN: 68042

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

Alfa AF: 0.00 Hom.: 0

Bravo AF: 0.0000189

ClinVar

Significance: Conflicting classifications of pathogenicity

Submissions summary: Uncertain:1 Benign:3

Revision: criteria provided, conflicting classifications

Submissions by phenotype

Familial cancer of breast Benign:2

Sep 26, 2022

Labcorp Genetics (formerly Invitae), Labcorp

Significance: Likely benign

Review Status: criteria provided, single submitter

Collection Method: clinical testing

Oct 02, 2024

Myriad Genetics, Inc.

Significance: Likely benign

Review Status: criteria provided, single submitter

Collection Method: clinical testing

This variant is considered likely benign. This variant is intronic and is not expected to impact mRNA splicing.

Hereditary cancer-predisposing syndrome Uncertain:1

Aug 29, 2024

Ambry Genetics

Significance: Uncertain significance

Review Status: criteria provided, single submitter

Collection Method: clinical testing

The c.320-5T>C intronic variant results from a T to C substitution 5 nucleotides upstream from coding exon 2 in the CHEK2 gene. This nucleotide position is highly conserved in available vertebrate species. In silico splice site analysis predicts that this alteration will not have any significant effect on splicing; however, direct evidence is insufficient at this time (Ambry internal data). Based on the available evidence, the clinical significance of this variant remains unclear.

not specified Benign:1

Apr 22, 2025

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

Significance: Likely benign

Review Status: criteria provided, single submitter

Collection Method: clinical testing

Variant summary: CHEK2 c.320-5T>C alters a conserved nucleotide located at a position not widely known to affect splicing. Consensus agreement among computation tools predict no significant impact on normal splicing. However, these predictions have yet to be confirmed by functional studies. The variant was absent in 250794 control chromosomes. The available data on variant occurrences in the general population are insufficient to allow any conclusion about variant significance. c.320-5T>C has been observed in one individual affected with Triple-Negative Breast Cancer, without strong evidence for causality (Guglielmi_2021). 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. The following publications have been ascertained in the context of this evaluation (PMID: 34299313, 36521553). ClinVar contains an entry for this variant (Variation ID: 483404). Based on the evidence outlined above, the variant was classified as likely benign.

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
BayesDel_noAF	Benign	-0.38
CADD	Benign	11
DANN	Benign	0.91
PhyloP100		3.9

Splicing

Name	Calibrated prediction	Score	Prediction
dbscSNV1_ADA	Benign	0.010
dbscSNV1_RF	Benign	0.038
SpliceAI score (max)		0.010		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: rs121908700; hg19: chr22-29121360;