rs769436449

Positions:

• chr22-28699936-T-A
• chr22-28699936-T-C

Variant summary

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

The ENST00000404276.6(CHEK2):​c.910A>T​(p.Met304Leu) variant causes a missense, splice region change. The variant allele was found at a frequency of 0.00000137 in 1,460,020 control chromosomes in the GnomAD database, with no homozygous occurrence. 2/3 splice prediction tools predict no significant impact on normal splicing. 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. M304I) has been classified as Uncertain significance.

• Frequency:
  • Genomes: not found (cov: 31)
  • Exomes 𝑓: 0.0000014 (0 hom.)
• Consequence: CHEK2 ENST00000404276.6 missense, splice_region
• Scores: Splicing: ADA: 0.8217
• Clinical Significance: Uncertain significance criteria provided, multiple submitters, no conflicts U:2
• Conservation: PhyloP100: 6.76

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/exons	MANE	Protein	UniProt
CHEK2	NM_007194.4	c.910A>T	p.Met304Leu	missense_variant, splice_region_variant	9/15	ENST00000404276.6	NP_009125.1

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Protein	Appris	UniProt
CHEK2	ENST00000404276.6	c.910A>T	p.Met304Leu	missense_variant, splice_region_variant	9/15	1	NM_007194.4	ENSP00000385747	P2

Frequencies

GnomAD3 genomes Cov.: 31

GnomAD4 exome AF: 0.00000137 AC: 2 AN: 1460020 Hom.: 0 Cov.: 29 AF XY: 0.00000138 AC XY: 1 AN XY: 726230

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: 0.0000116

Gnomad4 FIN exome AF: 0.00

Gnomad4 NFE exome AF: 9.00e-7

Gnomad4 OTH exome AF: 0.00

GnomAD4 genome Cov.: 31

ClinVar

Significance: Uncertain significance

Submissions summary: Uncertain:2

Revision: criteria provided, multiple submitters, no conflicts

Submissions by phenotype

Familial cancer of breast Uncertain:1

Uncertain significance, criteria provided, single submitter

clinical testing

Labcorp Genetics (formerly Invitae), Labcorp

Dec 14, 2023

This sequence change replaces methionine, which is neutral and non-polar, with leucine, which is neutral and non-polar, at codon 304 of the CHEK2 protein (p.Met304Leu). 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: 229861). 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 tolerated. 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

Uncertain significance, criteria provided, single submitter

clinical testing

Ambry Genetics

Sep 20, 2022

The p.M304L variant (also known as c.910A>T), located in coding exon 8 of the CHEK2 gene, results from an A to T substitution at nucleotide position 910. The methionine at codon 304 is replaced by leucine, 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. 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	Uncertain	0.54
BayesDel_addAF	Uncertain	0.070	D
BayesDel_noAF	Benign	-0.14
CADD	Pathogenic	27
DANN	Uncertain	0.98
DEOGEN2	Benign	0.17	T;.;T;.;T;.;T;.;.;.;.;.
Eigen	Uncertain	0.49
Eigen_PC	Uncertain	0.54
FATHMM_MKL	Uncertain	0.97	D
LIST_S2	Uncertain	0.92	.;D;.;D;.;D;D;D;.;D;D;D
M_CAP	Benign	0.026	D
MetaRNN	Uncertain	0.64	D;D;D;D;D;D;D;D;D;D;D;D
MetaSVM	Benign	-0.98	T
MutationAssessor	Benign	0.35	N;N;N;.;N;.;N;.;N;.;.;.
MutationTaster	Benign	1.0	D;D;D;D;D;D;D;D;D;D;D
PrimateAI	Uncertain	0.74	T
PROVEAN	Benign	-1.7	N;N;N;.;N;N;.;N;N;N;.;N
REVEL	Benign	0.16
Sift	Uncertain	0.022	D;D;D;.;D;D;.;D;D;T;.;D
Sift4G	Uncertain	0.031	D;D;D;.;D;D;.;T;D;D;.;.
Polyphen		0.95	P;B;P;.;P;P;P;P;B;.;.;.
Vest4		0.71
MutPred		0.63		Gain of catalytic residue at M304 (P = 0.0366);Gain of catalytic residue at M304 (P = 0.0366);Gain of catalytic residue at M304 (P = 0.0366);.;Gain of catalytic residue at M304 (P = 0.0366);.;Gain of catalytic residue at M304 (P = 0.0366);.;Gain of catalytic residue at M304 (P = 0.0366);.;.;.;
MVP		0.62
MPC		0.021
ClinPred		0.83	D
GERP RS		5.7
RBP_binding_hub_radar		0.0
RBP_regulation_power_radar		1.7
Varity_R		0.86
gMVP		0.49

Splicing

Name	Calibrated prediction	Score	Prediction
dbscSNV1_ADA	Benign	0.82
dbscSNV1_RF	Pathogenic	0.83
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: rs769436449; hg19: chr22-29095924;