chr22-28689191-G-C

Position:

• chr22-28689191-G-C

Variant summary

Our verdict is Likely benign. Variant got -2 ACMG points: 2P and 4B. PM2 BP4_Strong

The NM_007194.4(CHEK2):​c.1486C>G​(p.Gln496Glu) variant causes a missense change involving the alteration of a non-conserved nucleotide. The variant was absent in control chromosomes in GnomAD project. In-silico tool predicts a benign outcome for this variant. 15/21 in silico tools predict a benign outcome for this variant. Variant has been reported in ClinVar as Uncertain significance (★★).

• Frequency: Genomes: not found (cov: 32)
• Consequence: CHEK2 NM_007194.4 missense
• Clinical Significance: Uncertain significance criteria provided, multiple submitters, no conflicts U:2
• Conservation: PhyloP100: 0.521

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 Likely_benign. Variant got -2 ACMG points.

• PM2: Very rare variant in population databases, with high coverage
• BP4: Computational evidence support a benign effect (MetaRNN=0.032060206).

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	Protein	UniProt
CHEK2	NM_007194.4	c.1486C>G	p.Gln496Glu	missense_variant	14/15	ENST00000404276.6	NP_009125.1

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Protein	Appris	UniProt
CHEK2	ENST00000404276.6	c.1486C>G	p.Gln496Glu	missense_variant	14/15	1	NM_007194.4	ENSP00000385747	P2

Frequencies

GnomAD3 genomes Cov.: 32

GnomAD4 exome Cov.: 29

GnomAD4 genome Cov.: 32

ClinVar

Significance: Uncertain significance

Submissions summary: Uncertain:2

Revision: criteria provided, multiple submitters, no conflicts

Submissions by phenotype

Hereditary cancer-predisposing syndrome Uncertain:1

Uncertain significance, criteria provided, single submitter

clinical testing

Ambry Genetics

Jul 20, 2018

The p.Q496E variant (also known as c.1486C>G), located in coding exon 13 of the CHEK2 gene, results from a C to G substitution at nucleotide position 1486. The glutamine at codon 496 is replaced by glutamic acid, an amino acid with highly similar properties. This amino acid position is not 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. -

Familial cancer of breast Uncertain:1

Uncertain significance, criteria provided, single submitter

clinical testing

Labcorp Genetics (formerly Invitae), Labcorp

Apr 19, 2022

This sequence change replaces glutamine, which is neutral and polar, with glutamic acid, which is acidic and polar, at codon 496 of the CHEK2 protein (p.Gln496Glu). 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: 819345). Algorithms developed to predict the effect of missense changes on protein structure and function output the following: SIFT: "Tolerated"; PolyPhen-2: "Benign"; Align-GVGD: "Class C0". The glutamic acid amino acid residue is found in multiple mammalian species, which suggests that this missense change does not adversely affect protein function. 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	0.068
BayesDel_addAF	Benign	-0.24	T
BayesDel_noAF	Benign	-0.58
CADD	Benign	7.1
DANN	Benign	0.094
DEOGEN2	Benign	0.076	T;.;T;.;T;.;T;.;.
Eigen	Benign	-1.4
Eigen_PC	Benign	-1.3
FATHMM_MKL	Benign	0.42	N
LIST_S2	Benign	0.69	.;T;.;T;.;T;T;T;.
M_CAP	Benign	0.011	T
MetaRNN	Benign	0.032	T;T;T;T;T;T;T;T;T
MetaSVM	Benign	-0.98	T
MutationAssessor	Benign	-0.14	N;.;N;.;N;.;N;.;.
MutationTaster	Benign	1.0	N;N;N;N;N;N;N;N;N;N;N
PrimateAI	Benign	0.33	T
PROVEAN	Benign	0.18	N;N;N;.;N;N;.;N;N
REVEL	Benign	0.036
Sift	Benign	0.69	T;T;T;.;T;T;.;T;T
Sift4G	Benign	1.0	T;T;T;.;T;T;.;T;T
Polyphen		0.0	B;B;B;.;B;B;B;B;B
Vest4		0.19
MutPred		0.24		Gain of helix (P = 0.062);.;Gain of helix (P = 0.062);.;Gain of helix (P = 0.062);.;Gain of helix (P = 0.062);.;.;
MVP		0.31
MPC		0.020
ClinPred		0.020	T
GERP RS		-2.5
Varity_R		0.075
gMVP		0.33

Splicing

Name	Calibrated prediction	Score	Prediction
SpliceAI score (max)		0.020		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: rs756250205; hg19: chr22-29085179;