chr22-28689132-T-C

Position:

• chr22-28689132-T-C

Variant summary

Our verdict is Uncertain significance. Variant got 3 ACMG points: 3P and 0B. PM2 PP5

The NM_007194.4(CHEK2):​c.1542+3A>G 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. 2/3 splice prediction tools predicting alterations to normal splicing. Variant has been reported in ClinVar as Conflicting classifications of pathogenicity (no stars).

• Frequency: Genomes: not found (cov: 32)
• Consequence: CHEK2 NM_007194.4 splice_region, intron
• Scores: Splicing: ADA: 0.9997
• Clinical Significance: Conflicting classifications of pathogenicity criteria provided, conflicting classifications P:2 U:5
• Conservation: PhyloP100: 4.63

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 (HGNC:):

ACMG classification

Verdict is Uncertain_significance. Variant got 3 ACMG points.

• PM2: Very rare variant in population databases, with high coverage
• PP5: Variant 22-28689132-T-C is Pathogenic according to our data. Variant chr22-28689132-T-C is described in ClinVar as [Conflicting_classifications_of_pathogenicity]. Clinvar id is 410067.We mark this variant Likely_pathogenic, oryginal submissions are: {Uncertain_significance=4, Likely_pathogenic=2}.

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	Protein	UniProt
CHEK2	NM_007194.4	c.1542+3A>G		splice_region_variant, intron_variant		ENST00000404276.6	NP_009125.1

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Protein	Appris	UniProt
CHEK2	ENST00000404276.6	c.1542+3A>G		splice_region_variant, intron_variant		1	NM_007194.4	ENSP00000385747.1

Frequencies

GnomAD3 genomes Cov.: 32

GnomAD4 exome Cov.: 28

GnomAD4 genome Cov.: 32

ClinVar

Significance: Conflicting classifications of pathogenicity

Submissions summary: Pathogenic:2 Uncertain:5

Revision: criteria provided, conflicting classifications

Submissions by phenotype

not provided Pathogenic:1 Uncertain:2

Uncertain significance, criteria provided, single submitter	clinical testing	Women's Health and Genetics/Laboratory Corporation of America, LabCorp	Mar 24, 2017	Variant summary: c.1542+3A>G in CHEK2 gene is an intronic change that involves a mildly conserved nucleotide. 3/5 programs in Alamut predict that this variant will affect the normal splicing pattern, however no functional studies supporting this notion were published at the time of evaluation. The variant is absent from the control population datasets of ExAC and gnomAD and has not, to our knowledge, been reported in affected individuals in published reports or cited by reputable databases/clinical laboratories. Considering all, the variant was classified as VUS. -
Likely pathogenic, criteria provided, single submitter	clinical testing	GeneDx	Oct 06, 2023	In silico analysis suggests this variant may impact gene splicing; Not observed at significant frequency in large population cohorts (gnomAD); Has not been previously published as pathogenic or benign to our knowledge -
Uncertain significance, criteria provided, single submitter	clinical testing	Quest Diagnostics Nichols Institute San Juan Capistrano	Nov 10, 2024	- -

Hereditary cancer-predisposing syndrome Pathogenic:1 Uncertain:1

Likely pathogenic, criteria provided, single submitter	clinical testing	Ambry Genetics	Nov 16, 2023	The c.1542+3A>G intronic variant results from an A to G substitution 3 nucleotides after coding exon 13 in the CHEK2 gene. This nucleotide position is highly conserved in available vertebrate species. In silico splice site analysis predicts that this alteration may result in the creation or strengthening of a novel splice donor site. RNA studies have demonstrated this alteration results in abnormal splicing in the set of samples tested leading to a predicted shift in reading frame (Ambry internal data). Frameshifts are typically deleterious in nature, however, this frameshift occurs at the C- terminus of CHEK2, and is not expected to trigger nonsense-mediated mRNA decay. However, the frameshifted amino acids are predicted to disrupt the nuclear localization signal of the protein (Zannini L et al. J Biol Chem. 2003 Oct 24;278(43):42346-51). Based on the majority of available evidence to date, this variant is likely to be pathogenic. -
Uncertain significance, criteria provided, single submitter	clinical testing	Color Diagnostics, LLC DBA Color Health	Jul 27, 2021	This variant causes an A>G nucleotide substitution at the +3 position of intron 14 of the CHEK2 gene. Splice site prediction tools predict that this variant may have a significant impact on RNA splicing. Although this prediction has not been confirmed in published RNA studies, this variant may result in an absent or disrupted protein product. To our knowledge, functional studies have not been performed for this variant. This variant has not been reported in individuals affected with hereditary cancer in the literature. 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. -

Familial cancer of breast Uncertain:2

Uncertain significance, criteria provided, single submitter	clinical testing	Labcorp Genetics (formerly Invitae), Labcorp	Oct 26, 2022	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. Variants that disrupt the consensus splice site are a relatively common cause of aberrant splicing (PMID: 17576681, 9536098). Algorithms developed to predict the effect of sequence changes on RNA splicing suggest that this variant may create or strengthen a splice site. ClinVar contains an entry for this variant (Variation ID: 410067). This variant has not been reported in the literature in individuals affected with CHEK2-related conditions. This variant is not present in population databases (gnomAD no frequency). This sequence change falls in intron 14 of the CHEK2 gene. It does not directly change the encoded amino acid sequence of the CHEK2 protein. It affects a nucleotide within the consensus splice site. -
Uncertain significance, criteria provided, single submitter	clinical testing	Baylor Genetics	Sep 21, 2023	- -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
BayesDel_noAF	Benign	-0.43
CADD	Pathogenic	27
DANN	Benign	0.79

Splicing

Name	Calibrated prediction	Score	Prediction
dbscSNV1_ADA	Pathogenic	1.0
dbscSNV1_RF	Pathogenic	0.77
SpliceAI score (max)		0.46		Details are displayed if max score is > 0.2
DS_DG_spliceai		0.46		Position offset: 15

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

Publications

LitVar

Other links and lift over

dbSNP: rs1060502722; hg19: chr22-29085120;