22-28699843-C-T

Variant names:

• chr22-28699843-C-T
• rs563752762
• NM_007194.4:c.1003G>A

Variant summary

Our verdict is Uncertain significance. The variant received 3 ACMG points: 3P and 0B. PM2 PP3

The NM_007194.4(CHEK2):​c.1003G>A​(p.Val335Met) variant causes a missense change. The variant allele was found at a frequency of 0.00000206 in 1,458,944 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a pathogenic 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. V335L) has been classified as Uncertain significance.

• Frequency:
  • Genomes: not found (cov: 31)
  • Exomes 𝑓: 0.0000021 (0 hom.)
• Consequence: CHEK2 NM_007194.4 missense
• Clinical Significance: Uncertain significance criteria provided, multiple submitters, no conflicts U:3
• Conservation: PhyloP100: 6.67
• Publications: 13 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 3 ACMG points.

• PM2: Very rare variant in population databases, with high coverage
• PP3: MetaRNN computational evidence supports a deleterious effect, 0.806

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	MANE	Protein	UniProt
CHEK2	NM_007194.4	c.1003G>A	p.Val335Met	missense_variant	Exon 9 of 15	ENST00000404276.6	NP_009125.1

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	TSL	MANE	Protein	Appris	UniProt
CHEK2	ENST00000404276.6	c.1003G>A	p.Val335Met	missense_variant	Exon 9 of 15	1	NM_007194.4	ENSP00000385747.1

Frequencies

GnomAD3 genomes Cov.: 31

GnomAD2 exomes AF: 0.00000398 AC: 1 AN: 251458 AF XY: 0.00

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: 0.00000879

Gnomad OTH exome AF: 0.00

GnomAD4 exome AF: 0.00000206 AC: 3 AN: 1458944 Hom.: 0 Cov.: 29 AF XY: 0.00000138 AC XY: 1 AN XY: 726046

⚠️ 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: 33418

American (AMR) AF: 0.00 AC: 0 AN: 44720

Ashkenazi Jewish (ASJ) AF: 0.00 AC: 0 AN: 26124

East Asian (EAS) AF: 0.00 AC: 0 AN: 39688

South Asian (SAS) AF: 0.00 AC: 0 AN: 86190

European-Finnish (FIN) AF: 0.00 AC: 0 AN: 53414

Middle Eastern (MID) AF: 0.00 AC: 0 AN: 5762

European-Non Finnish (NFE) AF: 0.00000180 AC: 2 AN: 1109334

Other (OTH) AF: 0.0000166 AC: 1 AN: 60294

⚠️ The allele balance in gnomAD4 Exomes is highly skewed from 0.5 (p-value = 0.000000), which strongly suggests a high chance of mosaicism in these individuals.

GnomAD4 genome Cov.: 31

Alfa AF: 0.0000279 Hom.: 0

Bravo AF: 0.00000378

ClinVar

Significance: Uncertain significance

Submissions summary: Uncertain:3

Revision: criteria provided, multiple submitters, no conflicts

Submissions by phenotype

Familial cancer of breast Uncertain:2

Oct 18, 2024

Labcorp Genetics (formerly Invitae), Labcorp

Significance: Uncertain significance

Review Status: criteria provided, single submitter

Collection Method: clinical testing

This sequence change replaces valine, which is neutral and non-polar, with methionine, which is neutral and non-polar, at codon 335 of the CHEK2 protein (p.Val335Met). The frequency data for this variant in the population databases is considered unreliable, as metrics indicate poor data quality at this position in the gnomAD database. 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: 142375). 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. -

Feb 10, 2024

Baylor Genetics

Significance: Uncertain significance

Review Status: criteria provided, single submitter

Collection Method: clinical testing

- -

Hereditary cancer-predisposing syndrome Uncertain:1

Aug 07, 2024

Ambry Genetics

Significance: Uncertain significance

Review Status: criteria provided, single submitter

Collection Method: clinical testing

The p.V335M variant (also known as c.1003G>A), located in coding exon 8 of the CHEK2 gene, results from a G to A substitution at nucleotide position 1003. The valine at codon 335 is replaced by methionine, an amino acid with highly similar properties. This amino acid position is highly conserved in available vertebrate species. In addition, the in silico prediction for this alteration is inconclusive. Based on the available evidence, the clinical significance of this variant remains unclear. -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Pathogenic	0.58
BayesDel_addAF	Pathogenic	0.25	D
BayesDel_noAF	Uncertain	0.12
CADD	Uncertain	25
DANN	Uncertain	1.0
DEOGEN2	Benign	0.34	T;.;T;.;T;.;T;.;.;.;.;.
Eigen	Uncertain	0.35
Eigen_PC	Uncertain	0.25
FATHMM_MKL	Uncertain	0.96	D
LIST_S2	Uncertain	0.91	.;D;.;D;.;D;D;D;.;D;D;D
M_CAP	Benign	0.073	D
MetaRNN	Pathogenic	0.81	D;D;D;D;D;D;D;D;D;D;D;D
MetaSVM	Benign	-0.46	T
MutationAssessor	Benign	1.6	L;L;L;.;L;.;L;.;L;.;.;.
PhyloP100		6.7
PrimateAI	Uncertain	0.78	T
PROVEAN	Uncertain	-2.7	D;D;D;.;D;D;.;D;D;N;.;D
REVEL	Uncertain	0.42
Sift	Uncertain	0.0010	D;D;D;.;D;D;.;D;D;D;.;D
Sift4G	Uncertain	0.0020	D;D;D;.;D;D;.;D;D;D;.;.
Polyphen		1.0	D;D;D;.;D;D;D;D;D;.;.;.
Vest4		0.91
MutPred		0.65		Loss of catalytic residue at V335 (P = 0.0132);Loss of catalytic residue at V335 (P = 0.0132);Loss of catalytic residue at V335 (P = 0.0132);.;Loss of catalytic residue at V335 (P = 0.0132);.;Loss of catalytic residue at V335 (P = 0.0132);.;Loss of catalytic residue at V335 (P = 0.0132);.;.;.;
MVP		0.76
MPC		0.16
ClinPred		0.97	D
GERP RS		4.7
RBP_binding_hub_radar		0.0
RBP_regulation_power_radar		1.1
Varity_R		0.89
gMVP		0.63
Mutation Taster		=43/57	disease causing

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: rs563752762; hg19: chr22-29095831;