22-28725100-T-C

Variant names:

• chr22-28725100-T-C
• rs748262921
• NM_007194.4:c.469A>G

Variant summary

Our verdict is Uncertain significance. The variant received 4 ACMG points: 6P and 2B. PM1 PM2 PM5 BP4_Moderate

The NM_007194.4(CHEK2):​c.469A>G​(p.Ile157Val) variant causes a missense change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.00000274 in 1,461,842 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a benign outcome for this variant. 17/22 in silico tools predict a benign outcome for this variant. 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. I157S) has been classified as Likely pathogenic.

• Frequency:
  • Genomes: not found (cov: 32)
  • Exomes 𝑓: 0.0000027 (0 hom.)
• Consequence: CHEK2 NM_007194.4 missense
• Clinical Significance: Uncertain significance criteria provided, single submitter U:1
• Conservation: PhyloP100: 2.78
• Publications: 3 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 2 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
• PM5: Other missense variant is known to change same aminoacid residue: Variant chr22-28725099-A-C is described in ClinVar as Conflicting_classifications_of_pathogenicity. ClinVar VariationId is 265327.
• BP4: Computational evidence support a benign effect (MetaRNN=0.098380744).

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.469A>G	p.Ile157Val	missense	Exon 4 of 15	NP_009125.1
	CHEK2	NM_001005735.3		c.598A>G	p.Ile200Val	missense	Exon 5 of 16	NP_001005735.1
	CHEK2	NM_001438293.1		c.562A>G	p.Ile188Val	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.469A>G	p.Ile157Val	missense	Exon 4 of 15	ENSP00000385747.1
	CHEK2	ENST00000382580.6	TSL:1	c.598A>G	p.Ile200Val	missense	Exon 5 of 16	ENSP00000372023.2
	CHEK2	ENST00000416671.5	TSL:1	n.469A>G		non_coding_transcript_exon	Exon 4 of 16	ENSP00000402225.1

Frequencies

GnomAD3 genomes Cov.: 32

GnomAD2 exomes AF: 0.00000398 AC: 1 AN: 251414 AF XY: 0.00000736

Gnomad AFR exome AF: 0.00

Gnomad AMR exome AF: 0.00

Gnomad ASJ exome AF: 0.00

Gnomad EAS 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: 0.00000274 AC: 4 AN: 1461842 Hom.: 0 Cov.: 32 AF XY: 0.00000413 AC XY: 3 AN XY: 727220

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

American (AMR) AF: 0.0000224 AC: 1 AN: 44724

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

East Asian (EAS) AF: 0.00 AC: 0 AN: 39678

South Asian (SAS) AF: 0.0000232 AC: 2 AN: 86256

European-Finnish (FIN) AF: 0.00 AC: 0 AN: 53416

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

European-Non Finnish (NFE) AF: 0.00 AC: 0 AN: 1111994

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

GnomAD4 genome Cov.: 32

ExAC AF: 0.00000824 AC: 1

ClinVar

Significance: Uncertain significance

Submissions summary: Uncertain:1

Revision: criteria provided, single submitter

Submissions by phenotype

Familial cancer of breast Uncertain:1

Oct 24, 2021

Labcorp Genetics (formerly Invitae), Labcorp

Significance: Uncertain significance

Review Status: criteria provided, single submitter

Collection Method: clinical testing

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. This variant disrupts the p.Ile157 amino acid residue in CHEK2. Other variant(s) that disrupt this residue have been determined to be pathogenic (PMID: 11298456, 11571648, 12049740, 15239132, 15492928, 22419737, 22799331, 23296741, 23713947, 24599715). This suggests that this residue is clinically significant, and that variants that disrupt this residue are likely to be disease-causing. 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 tolerated. This variant has not been reported in the literature in individuals affected with CHEK2-related conditions. This variant is present in population databases (rs748262921, ExAC 0.006%). This sequence change replaces isoleucine with valine at codon 157 of the CHEK2 protein (p.Ile157Val). The isoleucine residue is moderately conserved and there is a small physicochemical difference between isoleucine and valine.

Computational scores

Source: dbNSFP v4.9

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Benign	0.073
BayesDel_addAF	Benign	-0.064	T
BayesDel_noAF	Benign	-0.23
CADD	Benign	17
DANN	Benign	0.85
DEOGEN2	Benign	0.21	T
Eigen	Benign	-0.40
Eigen_PC	Benign	-0.13
FATHMM_MKL	Benign	0.70	D
LIST_S2	Benign	0.79	T
M_CAP	Benign	0.023	T
MetaRNN	Benign	0.098	T
MetaSVM	Benign	-0.57	T
MutationAssessor	Benign	-0.48	N
PhyloP100		2.8
PrimateAI	Benign	0.48	T
PROVEAN	Benign	-0.020	N
REVEL	Benign	0.21
Sift	Benign	0.60	T
Sift4G	Benign	1.0	T
Polyphen		0.0050	B
Vest4		0.35
MutPred		0.33		Gain of phosphorylation at Y159 (P = 0.1454)
MVP		0.75
MPC		0.019
ClinPred		0.12	T
GERP RS		5.9
RBP_binding_hub_radar		0.0
RBP_regulation_power_radar		1.7
Varity_R		0.11
gMVP		0.20
Mutation Taster		=78/22	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: rs748262921; hg19: chr22-29121088;