22-28710010-T-G

Position:

• chr22-28710010-T-G

Variant summary

Our verdict is Uncertain significance. Variant got 2 ACMG points: 2P and 0B. PM2

The NM_007194.4(CHEK2):​c.842A>C​(p.Asn281Thr) variant causes a missense change. The variant allele was found at a frequency of 0.000000736 in 1,359,044 control chromosomes in the GnomAD database, with no homozygous occurrence. Variant has been reported in ClinVar as Uncertain significance (★★).

• Frequency:
  • Genomes: not found (cov: 32)
  • Exomes 𝑓: 7.4e-7 (0 hom.)
• Consequence: CHEK2 NM_007194.4 missense
• Clinical Significance: Uncertain significance criteria provided, multiple submitters, no conflicts U:4
• Conservation: PhyloP100: 4.83

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]

ACMG classification

Verdict is Uncertain_significance. Variant got 2 ACMG points.

• PM2: Very rare variant in population databases, with high coverage

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	Protein	UniProt
CHEK2	NM_007194.4	c.842A>C	p.Asn281Thr	missense_variant	7/15	ENST00000404276.6	NP_009125.1

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Protein	Appris	UniProt
CHEK2	ENST00000404276.6	c.842A>C	p.Asn281Thr	missense_variant	7/15	1	NM_007194.4	ENSP00000385747	P2

Frequencies

GnomAD3 genomes Cov.: 32

GnomAD4 exome AF: 7.36e-7 AC: 1 AN: 1359044 Hom.: 0 Cov.: 23 AF XY: 0.00 AC XY: 0 AN XY: 681522

Gnomad4 AFR exome AF: 0.00

Gnomad4 AMR exome AF: 0.00

Gnomad4 ASJ exome AF: 0.00

Gnomad4 EAS exome AF: 0.00

Gnomad4 SAS exome AF: 0.00

Gnomad4 FIN exome AF: 0.00

Gnomad4 NFE exome AF: 0.00

Gnomad4 OTH exome AF: 0.0000176

GnomAD4 genome Cov.: 32

ClinVar

Significance: Uncertain significance

Submissions summary: Uncertain:4

Revision: criteria provided, multiple submitters, no conflicts

Submissions by phenotype

Hereditary cancer-predisposing syndrome Uncertain:2

Uncertain significance, criteria provided, single submitter	clinical testing	Color Diagnostics, LLC DBA Color Health	Jul 26, 2022	This missense variant replaces asparagine with threonine at codon 281 of the CHEK2 protein. Computational prediction suggests that this variant may not impact protein structure and function (internally defined REVEL score threshold <= 0.5, PMID: 27666373). To our knowledge, functional studies have not been reported 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. -
Uncertain significance, criteria provided, single submitter	clinical testing	Ambry Genetics	May 04, 2024	The p.N281T variant (also known as c.842A>C), located in coding exon 6 of the CHEK2 gene, results from an A to C substitution at nucleotide position 842. The asparagine at codon 281 is replaced by threonine, an amino acid with similar properties. This variant was reported in 0/60,466 breast cancer cases and in 1/53,461 controls (Dorling et al. N Engl J Med. 2021 02;384:428-439). This amino acid position is well conserved in available vertebrate species. In addition, this alteration is predicted to be tolerated by in silico analysis. Since supporting evidence is limited at this time, the clinical significance of this alteration remains unclear. -

not provided Uncertain:1

Uncertain significance, criteria provided, single submitter

clinical testing

GeneDx

Sep 13, 2019

Not observed in large population cohorts (Lek 2016); In silico analysis, which includes protein predictors and evolutionary conservation, supports a deleterious effect; Has not been previously published as pathogenic or benign to our knowledge -

Familial cancer of breast Uncertain:1

Uncertain significance, criteria provided, single submitter

clinical testing

Labcorp Genetics (formerly Invitae), Labcorp

Jan 04, 2024

This sequence change replaces asparagine, which is neutral and polar, with threonine, which is neutral and polar, at codon 281 of the CHEK2 protein (p.Asn281Thr). This variant is not present in population databases (gnomAD no frequency). 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: 230234). An algorithm developed to predict the effect of missense changes on protein structure and function (PolyPhen-2) suggests that this variant is likely to be tolerated. 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. -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Benign	0.14
BayesDel_addAF	Benign	-0.063	T
BayesDel_noAF	Benign	-0.33
CADD	Uncertain	24
DANN	Uncertain	0.99
DEOGEN2	Benign	0.26	T;.;T;.;T;.;T;.;.;.;.;.
Eigen	Benign	0.045
Eigen_PC	Benign	0.18
FATHMM_MKL	Uncertain	0.92	D
LIST_S2	Uncertain	0.94	.;D;.;D;.;D;D;D;.;D;D;D
M_CAP	Benign	0.025	T
MetaRNN	Uncertain	0.44	T;T;T;T;T;T;T;T;T;T;T;T
MetaSVM	Benign	-0.76	T
MutationAssessor	Benign	0.69	N;N;N;.;N;.;N;.;N;.;.;.
MutationTaster	Benign	0.81	D;D;D;D;D;D;D;D;D;D;D
PrimateAI	Uncertain	0.57	T
PROVEAN	Uncertain	-2.4	N;N;N;.;N;N;.;N;N;D;.;D
REVEL	Benign	0.082
Sift	Benign	0.063	T;D;T;.;T;T;.;D;D;D;.;D
Sift4G	Benign	0.32	T;T;T;.;T;T;.;T;T;T;.;.
Polyphen		0.0090	B;B;B;.;B;B;B;P;B;.;.;.
Vest4		0.41
MutPred		0.43		Loss of sheet (P = 0.0817);Loss of sheet (P = 0.0817);Loss of sheet (P = 0.0817);.;Loss of sheet (P = 0.0817);.;Loss of sheet (P = 0.0817);.;Loss of sheet (P = 0.0817);.;.;.;
MVP		0.76
MPC		0.038
ClinPred		0.70	D
GERP RS		5.0
RBP_binding_hub_radar		0.0
RBP_regulation_power_radar		1.7
Varity_R		0.34
gMVP		0.27

Splicing

Name	Calibrated prediction	Score	Prediction
SpliceAI score (max)		0.0		Details are displayed if max score is > 0.2

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

Publications

LitVar

Other links and lift over

dbSNP: rs587782196; hg19: chr22-29105998;