22-28725014-G-C

Variant names:

• chr22-28725014-G-C
• rs780782542
• NM_007194.4:c.555C>G

Variant summary

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

The NM_007194.4(CHEK2):​c.555C>G​(p.Asn185Lys) variant causes a missense change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.000000684 in 1,461,812 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: 6.8e-7 (0 hom.)
• Consequence: CHEK2 NM_007194.4 missense
• Clinical Significance: Uncertain significance criteria provided, multiple submitters, no conflicts U:2
• Conservation: PhyloP100: 2.65

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 rank	MANE	Protein	UniProt
CHEK2	NM_007194.4	c.555C>G	p.Asn185Lys	missense_variant	Exon 4 of 15	ENST00000404276.6	NP_009125.1

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	TSL	MANE	Protein	Appris	UniProt
CHEK2	ENST00000404276.6	c.555C>G	p.Asn185Lys	missense_variant	Exon 4 of 15	1	NM_007194.4	ENSP00000385747.1

Frequencies

GnomAD3 genomes Cov.: 32

GnomAD3 exomes AF: 0.00000398 AC: 1 AN: 251420 Hom.: 0 AF XY: 0.00 AC XY: 0 AN XY: 135898

Gnomad AFR exome AF: 0.00

Gnomad AMR exome AF: 0.00

Gnomad ASJ exome AF: 0.00

Gnomad EAS exome AF: 0.0000544

Gnomad SAS exome AF: 0.00

Gnomad FIN exome AF: 0.00

Gnomad NFE exome AF: 0.00

Gnomad OTH exome AF: 0.00

GnomAD4 exome AF: 6.84e-7 AC: 1 AN: 1461812 Hom.: 0 Cov.: 32 AF XY: 0.00000138 AC XY: 1 AN XY: 727208

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: 8.99e-7

Gnomad4 OTH exome AF: 0.00

GnomAD4 genome Cov.: 32

ExAC AF: 0.00000824 AC: 1

ClinVar

Significance: Uncertain significance

Submissions summary: Uncertain:2

Revision: criteria provided, multiple submitters, no conflicts

Submissions by phenotype

Familial cancer of breast Uncertain:1

Nov 05, 2024

Labcorp Genetics (formerly Invitae), Labcorp

Significance: Uncertain significance

Review Status: criteria provided, single submitter

Collection Method: clinical testing

This sequence change replaces asparagine, which is neutral and polar, with lysine, which is basic and polar, at codon 185 of the CHEK2 protein (p.Asn185Lys). This variant is present in population databases (rs780782542, gnomAD 0.006%). 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: 479555). 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 disruptive. 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 cancer-predisposing syndrome Uncertain:1

Sep 01, 2022

Ambry Genetics

Significance: Uncertain significance

Review Status: criteria provided, single submitter

Collection Method: clinical testing

The p.N185K variant (also known as c.555C>G), located in coding exon 3 of the CHEK2 gene, results from a C to G substitution at nucleotide position 555. The asparagine at codon 185 is replaced by lysine, an amino acid with similar properties. This alteration behaved as semi-functional in an in vivo, yeast-based growth rate assay (Delimitsou A et al. Hum Mutat, 2019 05;40:631-648). This amino acid position is well conserved in available vertebrate species. In addition, the in silico prediction for this alteration is inconclusive. Since supporting evidence is limited at this time, the clinical significance of this alteration remains unclear. -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Pathogenic	0.97
BayesDel_addAF	Benign	-0.038	T
BayesDel_noAF	Benign	-0.12
CADD	Uncertain	24
DANN	Uncertain	1.0
DEOGEN2	Uncertain	0.56	D;.;D;D;.;D;.;.;D
Eigen	Uncertain	0.35
Eigen_PC	Uncertain	0.28
FATHMM_MKL	Uncertain	0.93	D
LIST_S2	Uncertain	0.88	.;D;.;.;D;D;.;D;D
M_CAP	Uncertain	0.12	D
MetaRNN	Uncertain	0.68	D;D;D;D;D;D;D;D;D
MetaSVM	Uncertain	0.58	D
MutationAssessor	Pathogenic	3.1	M;M;M;M;.;M;M;.;.
PrimateAI	Uncertain	0.52	T
PROVEAN	Pathogenic	-4.9	D;D;D;D;D;.;D;D;.
REVEL	Uncertain	0.59
Sift	Uncertain	0.0060	D;D;D;D;D;.;D;D;.
Sift4G	Uncertain	0.0090	D;D;D;D;D;.;D;D;D
Polyphen		0.99	D;D;D;D;D;D;D;.;.
Vest4		0.56
MutPred		0.49		Gain of MoRF binding (P = 0.0367);Gain of MoRF binding (P = 0.0367);Gain of MoRF binding (P = 0.0367);Gain of MoRF binding (P = 0.0367);.;Gain of MoRF binding (P = 0.0367);Gain of MoRF binding (P = 0.0367);.;Gain of MoRF binding (P = 0.0367);
MVP		0.92
MPC		0.16
ClinPred		0.98	D
GERP RS		4.8
RBP_binding_hub_radar		0.0
RBP_regulation_power_radar		1.7
Varity_R		0.83
gMVP		0.62

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: rs780782542; hg19: chr22-29121002;