rs587782441

chr22-28696984-G-Achr22-28696984-G-C

Variant summary

Our verdict is Likely pathogenic. Variant got 8 ACMG points: 8P and 0B. PM1 PM2 PP3_Strong

The NM_007194.4(CHEK2):c.1012C>T(p.Leu338Phe) variant causes a missense change involving the alteration of a conserved nucleotide. The variant allele was found at a frequency of 0.00000137 in 1,455,990 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. L338H) has been classified as Uncertain significance.

• Frequency:
  • Genomes: not found (cov: 32)
  • Exomes 𝑓: 0.0000014 (0 hom.)
• Consequence: CHEK2 NM_007194.4 missense
• Clinical Significance: Uncertain significance criteria provided, multiple submitters, no conflicts U:9
• Conservation: PhyloP100: 7.84

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_pathogenic. Variant got 8 ACMG points.

• PM1: In a hotspot region, there are 2 aminoacids with missense pathogenic changes in the window of +-8 aminoacids around while only 0 benign, 16 uncertain in NM_007194.4
• PM2: Very rare variant in population databases, with high coverage
• PP3: MetaRNN computational evidence supports a deleterious effect, 0.943

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	UniProt
CHEK2	NM_007194.4	c.1012C>T	p.Leu338Phe	missense_variant	10/15	ENST00000404276.6

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Appris	UniProt
CHEK2	ENST00000404276.6	c.1012C>T	p.Leu338Phe	missense_variant	10/15	1	NM_007194.4	P2

Frequencies

GnomAD3 genomes Cov.: 32

GnomAD4 exome AF: 0.00000137 AC: 2 AN: 1455990 Hom.: 0 Cov.: 29 AF XY: 0.00 AC XY: 0 AN XY: 724756

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: 0.00

Gnomad4 FIN exome AF: 0.00

Gnomad4 NFE exome AF: 0.00000181

Gnomad4 OTH exome AF: 0.00

GnomAD4 genome Cov.: 32

ClinVar

Significance: Uncertain significance

Submissions summary: Uncertain:9

Revision: criteria provided, multiple submitters, no conflicts

Submissions by phenotype

Hereditary cancer-predisposing syndrome Uncertain:4

Uncertain significance, criteria provided, single submitter	clinical testing	GeneKor MSA	Aug 01, 2018	- -
Uncertain significance, criteria provided, single submitter	clinical testing	Ambry Genetics	Sep 12, 2023	The p.L338F variant (also known as c.1012C>T), located in coding exon 9 of the CHEK2 gene, results from a C to T substitution at nucleotide position 1012. The leucine at codon 338 is replaced by phenylalanine, an amino acid with highly similar properties. This alteration has been reported in 1/1197 individuals from Greece, Romania, and Turkey undergoing evaluation for inherited cancer predisposition (Tsaousis GN et al. BMC Cancer, 2019 Jun;19:535). In another study, this variant was not detected in 60,466 breast cancer cases and seen in 2/53,461 controls (Dorling et al. N Engl J Med. 2021 02;384:428-439). This alteration behaved as functional in an in vivo, yeast-based growth rate assay (Delimitsou A et al. Hum Mutat, 2019 05;40:631-648). 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. -
Uncertain significance, criteria provided, single submitter	clinical testing	Color Diagnostics, LLC DBA Color Health	Jun 09, 2021	This missense variant replaces leucine with phenylalanine at codon 338 of the CHEK2 protein. Computational prediction suggests that this variant may have deleterious impact on protein structure and function (internally defined REVEL score threshold >= 0.7, PMID: 27666373). A yeast-based experimental functional assay demonstrated no impact to CHEK2 DNA damage repair activity (PMID: 30851065). This variant has not been reported in individuals affected with hereditary cancer in the literature. This variant has not been identified in the general population by the Genome Aggregation Database (gnomAD). The available evidence is insufficient to determine the role of this variant in disease conclusively. Therefore, this variant is classified as a Variant of Uncertain Significance. -
Uncertain significance, criteria provided, single submitter	curation	Sema4, Sema4	Dec 16, 2021	- -

Familial cancer of breast Uncertain:3

Uncertain significance, criteria provided, single submitter	clinical testing	Myriad Genetics, Inc.	Mar 09, 2023	This variant is classified as a variant of uncertain significance as there is insufficient evidence to determine its impact on protein function and/or cancer risk. -
Uncertain significance, criteria provided, single submitter	clinical testing	Invitae	Nov 16, 2023	This sequence change replaces leucine, which is neutral and non-polar, with phenylalanine, which is neutral and non-polar, at codon 338 of the CHEK2 protein (p.Leu338Phe). This variant is not present in population databases (gnomAD no frequency). This missense change has been observed in individual(s) with features of hereditary cancer (PMID: 31159747, 34326862). ClinVar contains an entry for this variant (Variation ID: 142406). 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. Experimental studies have shown that this missense change does not substantially affect CHEK2 function (PMID: 30851065). 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. -
Uncertain significance, criteria provided, single submitter	clinical testing	Counsyl	Jun 16, 2017	- -

not provided Uncertain:2

Uncertain significance, criteria provided, single submitter	clinical testing	Quest Diagnostics Nichols Institute San Juan Capistrano	May 18, 2021	- -
Uncertain significance, criteria provided, single submitter	clinical testing	GeneDx	Mar 29, 2018	This variant is denoted CHEK2 c.1012C>T at the cDNA level, p.Leu338Phe (L338F) at the protein level, and results in the change of a Leucine to a Phenylalanine (CTT>TTT). This variant has not, to our knowledge, been published in the literature as pathogenic or benign. CHEK2 Leu338Phe was not observed in large population cohorts (Lek 2016). This variant is located in the kinase domain (Cai 2009, Roeb 2012). In silico analysis, which includes protein predictors and evolutionary conservation, supports a deleterious effect. Based on currently available evidence, it is unclear whether CHEK2 Leu338Phe is a pathogenic or benign variant. We consider it to be a variant of uncertain significance. -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Pathogenic	0.97
BayesDel_addAF	Pathogenic	0.37	D
BayesDel_noAF	Pathogenic	0.29
Cadd	Pathogenic	32
Dann	Pathogenic	1.0
DEOGEN2	Benign	0.40	T;T;.;T;.;T;.;.;.;.
Eigen	Pathogenic	0.96
Eigen_PC	Pathogenic	0.90
FATHMM_MKL	Pathogenic	0.98	D
M_CAP	Uncertain	0.11	D
MetaRNN	Pathogenic	0.94	D;D;D;D;D;D;D;D;D;D
MetaSVM	Uncertain	0.28	D
MutationAssessor	Uncertain	2.6	M;M;.;M;.;M;.;.;.;.
MutationTaster	Benign	1.0	D;D;D;D;D;D;D;D;D;D;D
PrimateAI	Uncertain	0.77	T
PROVEAN	Uncertain	-3.8	D;D;.;D;D;.;D;D;.;D
REVEL	Pathogenic	0.81
Sift	Pathogenic	0.0	D;D;.;D;D;.;D;D;.;D
Sift4G	Pathogenic	0.0	D;D;.;D;D;.;D;D;.;.
Polyphen		1.0	D;D;.;D;D;D;D;.;.;.
Vest4		0.82
MutPred		0.82		Loss of stability (P = 0.2166);Loss of stability (P = 0.2166);.;Loss of stability (P = 0.2166);.;Loss of stability (P = 0.2166);.;.;.;.;
MVP		0.97
MPC		0.17
ClinPred		1.0	D
GERP RS		5.5
RBP_binding_hub_radar		0.0
RBP_regulation_power_radar		1.7
Varity_R		0.98
gMVP		0.74

Splicing

Name	Calibrated prediction	Score	Prediction
SpliceAI score (max)		0.080		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: rs587782441; hg19: chr22-29092972;