22-28725088-C-G

Variant names:

• chr22-28725088-C-G
• rs1555926951
• NM_007194.4:c.481G>C

Variant summary

Our verdict is Uncertain significance. The variant received 4 ACMG points: 4P and 0B. PM1 PM2

The NM_007194.4(CHEK2):​c.481G>C​(p.Glu161Gln) variant causes a missense change. The variant allele was found at a frequency of 0.000000684 in 1,461,820 control chromosomes in the GnomAD database, with no homozygous occurrence. Variant has been reported in ClinVar as Uncertain significance (★★). Another variant affecting the same amino acid position, but resulting in a different missense (i.e. E161D) has been classified 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: 5.65
• Publications: 1 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: Uncertain_significance. The variant received 4 ACMG points.

• PM1: In a hotspot region, there are 5 aminoacids with missense pathogenic changes in the window of +-8 aminoacids around while only 1 benign, 69 uncertain in NM_007194.4
• PM2: Very rare variant in population databases, with high coverage

Variant Effect in Transcripts

ACMG analysis was done for transcript: NM_007194.4. You can select a different transcript below to see updated ACMG assignments.

RefSeq Transcripts

Selected	Gene	Transcript	Tags	HGVSc	HGVSp	Effect	Exon Rank	Protein	UniProt
	CHEK2	NM_007194.4	MANE Select	c.481G>C	p.Glu161Gln	missense	Exon 4 of 15	NP_009125.1
	CHEK2	NM_001005735.3		c.610G>C	p.Glu204Gln	missense	Exon 5 of 16	NP_001005735.1
	CHEK2	NM_001438293.1		c.574G>C	p.Glu192Gln	missense	Exon 5 of 16	NP_001425222.1

Ensembl Transcripts

Selected	Gene	Transcript	Tags	HGVSc	HGVSp	Effect	Exon Rank	Protein	UniProt
	CHEK2	ENST00000404276.6	TSL:1 MANE Select	c.481G>C	p.Glu161Gln	missense	Exon 4 of 15	ENSP00000385747.1
	CHEK2	ENST00000382580.6	TSL:1	c.610G>C	p.Glu204Gln	missense	Exon 5 of 16	ENSP00000372023.2
	CHEK2	ENST00000416671.5	TSL:1	n.481G>C		non_coding_transcript_exon	Exon 4 of 16	ENSP00000402225.1

Frequencies

GnomAD3 genomes Cov.: 32

GnomAD4 exome AF: 6.84e-7 AC: 1 AN: 1461820 Hom.: 0 Cov.: 32 AF XY: 0.00 AC XY: 0 AN XY: 727210

⚠️ The allele balance in gnomAD version 4 Exomes is significantly skewed from the expected value of 0.5.

African (AFR) AF: 0.00 AC: 0 AN: 33480

American (AMR) AF: 0.00 AC: 0 AN: 44724

Ashkenazi Jewish (ASJ) AF: 0.00 AC: 0 AN: 26132

East Asian (EAS) AF: 0.00 AC: 0 AN: 39680

South Asian (SAS) AF: 0.00 AC: 0 AN: 86256

European-Finnish (FIN) AF: 0.00 AC: 0 AN: 53420

Middle Eastern (MID) AF: 0.00 AC: 0 AN: 5768

European-Non Finnish (NFE) AF: 0.00 AC: 0 AN: 1111966

Other (OTH) AF: 0.0000166 AC: 1 AN: 60394

⚠️ The allele balance in gnomAD4 Exomes is highly skewed from 0.5 (p-value = 0), which strongly suggests a high chance of mosaicism in these individuals.

GnomAD4 genome Cov.: 32

ClinVar

Significance: Uncertain significance

Submissions summary: Uncertain:2

Revision: criteria provided, multiple submitters, no conflicts

Submissions by phenotype

Familial cancer of breast Uncertain:1

Apr 10, 2017

Labcorp Genetics (formerly Invitae), Labcorp

Significance: Uncertain significance

Review Status: criteria provided, single submitter

Collection Method: clinical testing

In summary, this variant is a novel missense change with uncertain impact on protein function. It has been classified as a Variant of Uncertain Significance. Algorithms developed to predict the effect of missense changes on protein structure and function (SIFT, PolyPhen-2, Align-GVGD) all suggest that this variant is likely to be disruptive, but these predictions have not been confirmed by published functional studies. This variant is not present in population databases (ExAC no frequency) and has not been reported in the literature in individuals with a CHEK2-related disease. This sequence change replaces glutamic acid with glutamine at codon 161 of the CHEK2 protein (p.Glu161Gln). The glutamic acid residue is highly conserved and there is a small physicochemical difference between glutamic acid and glutamine.

Hereditary cancer-predisposing syndrome Uncertain:1

Feb 20, 2019

Ambry Genetics

Significance: Uncertain significance

Review Status: criteria provided, single submitter

Collection Method: clinical testing

The p.E161Q variant (also known as c.481G>C), located in coding exon 3 of the CHEK2 gene, results from a G to C substitution at nucleotide position 481. The glutamic acid at codon 161 is replaced by glutamine, an amino acid with highly similar properties. This amino acid position is highly conserved in available vertebrate species. In addition, this alteration is predicted to be deleterious by in silico analysis. Since supporting evidence is limited at this time, the clinical significance of this alteration remains unclear.

Computational scores

Source: dbNSFP v4.9

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Uncertain	0.49
BayesDel_addAF	Pathogenic	0.26	D
BayesDel_noAF	Pathogenic	0.14
CADD	Uncertain	25
DANN	Uncertain	1.0
DEOGEN2	Benign	0.37	T
Eigen	Uncertain	0.45
Eigen_PC	Uncertain	0.54
FATHMM_MKL	Pathogenic	0.98	D
LIST_S2	Uncertain	0.88	D
M_CAP	Benign	0.050	D
MetaRNN	Uncertain	0.71	D
MetaSVM	Uncertain	0.55	D
MutationAssessor	Uncertain	2.1	M
PhyloP100		5.7
PrimateAI	Uncertain	0.73	T
PROVEAN	Benign	-1.3	N
REVEL	Uncertain	0.58
Sift	Benign	0.14	T
Sift4G	Benign	0.21	T
Polyphen		0.25	B
Vest4		0.75
MutPred		0.40		Loss of stability (P = 0.1291)
MVP		0.94
MPC		0.077
ClinPred		0.80	D
GERP RS		5.9
RBP_binding_hub_radar		0.0
RBP_regulation_power_radar		1.0
Varity_R		0.50
gMVP		0.65
Mutation Taster		=52/48	polymorphism

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

Other links and lift over

dbSNP: rs1555926951; hg19: chr22-29121076;