chr22-28703556-A-G

Position:

• chr22-28703556-A-G

Variant summary

Our verdict is Uncertain significance. Variant got 4 ACMG points: 4P and 0B. PM2 PP3_Moderate

The NM_007194.4(CHEK2):​c.857T>C​(p.Ile286Thr) variant causes a missense change. The variant allele was found at a frequency of 0.00000284 in 1,408,030 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 (★★).

• Frequency:
  • Genomes: not found (cov: 31)
  • Exomes 𝑓: 0.0000028 (0 hom.)
• Consequence: CHEK2 NM_007194.4 missense
• Clinical Significance: Uncertain significance criteria provided, multiple submitters, no conflicts U:4
• Conservation: PhyloP100: 6.79

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 (HGNC:):

ACMG classification

Verdict is Uncertain_significance. Variant got 4 ACMG points.

• PM2: Very rare variant in population databases, with high coverage
• PP3: MetaRNN computational evidence supports a deleterious effect, 0.89

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	Protein	UniProt
CHEK2	NM_007194.4	c.857T>C	p.Ile286Thr	missense_variant	8/15	ENST00000404276.6	NP_009125.1

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Protein	Appris	UniProt
CHEK2	ENST00000404276.6	c.857T>C	p.Ile286Thr	missense_variant	8/15	1	NM_007194.4	ENSP00000385747.1

Frequencies

GnomAD3 genomes Cov.: 31

GnomAD4 exome AF: 0.00000284 AC: 4 AN: 1408030 Hom.: 0 Cov.: 25 AF XY: 0.00000428 AC XY: 3 AN XY: 701180

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: 0.00000374

Gnomad4 OTH exome AF: 0.00

GnomAD4 genome Cov.: 31

ClinVar

Significance: Uncertain significance

Submissions summary: Uncertain:4

Revision: criteria provided, multiple submitters, no conflicts

Submissions by phenotype

Hereditary cancer-predisposing syndrome Uncertain:2

Uncertain significance, criteria provided, single submitter	clinical testing	Color Diagnostics, LLC DBA Color Health	Jan 18, 2019	- -
Uncertain significance, criteria provided, single submitter	clinical testing	Ambry Genetics	Jul 25, 2023	The p.I286T variant (also known as c.857T>C), located in coding exon 7 of the CHEK2 gene, results from a T to C substitution at nucleotide position 857. The isoleucine at codon 286 is replaced by threonine, an amino acid with similar properties. In one study, this alteration was observed in 1/12,490 male controls and not detected in 7,051 unselected female breast cancer patients, 53 male breast cancer patients or 11,241 female controls of Japanese ancestry (Momozawa Y et al. Nat Commun, 2018 10;9:4083). 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. -

not provided Uncertain:1

Uncertain significance, criteria provided, single submitter

clinical testing

GeneDx

Oct 05, 2022

Not observed at significant frequency in large population cohorts (gnomAD); In silico analysis supports that this missense variant has a deleterious effect on protein structure/function; Not observed in any breast cancer cases, but was observed in unaffected controls (Momozawa et al., 2018); This variant is associated with the following publications: (PMID: 22419737, 19782031, 30287823) -

Familial cancer of breast Uncertain:1

Uncertain significance, criteria provided, single submitter

clinical testing

Labcorp Genetics (formerly Invitae), Labcorp

Sep 27, 2023

This sequence change replaces isoleucine, which is neutral and non-polar, with threonine, which is neutral and polar, at codon 286 of the CHEK2 protein (p.Ile286Thr). 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: 489884). 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. -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Pathogenic	0.93
BayesDel_addAF	Pathogenic	0.34	D
BayesDel_noAF	Pathogenic	0.26
CADD	Pathogenic	27
DANN	Uncertain	1.0
DEOGEN2	Benign	0.35	T;.;T;.;T;.;T;.;.;.;.;.
Eigen	Uncertain	0.39
Eigen_PC	Uncertain	0.47
FATHMM_MKL	Pathogenic	0.97	D
LIST_S2	Uncertain	0.95	.;D;.;D;.;D;D;D;.;D;D;D
M_CAP	Benign	0.076	D
MetaRNN	Pathogenic	0.89	D;D;D;D;D;D;D;D;D;D;D;D
MetaSVM	Benign	-0.70	T
MutationAssessor	Benign	2.0	M;M;M;.;M;.;M;.;M;.;.;.
PrimateAI	Uncertain	0.77	T
PROVEAN	Pathogenic	-4.6	D;D;D;.;D;D;.;D;D;D;.;D
REVEL	Pathogenic	0.68
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		0.99	D;P;D;.;D;D;D;D;P;.;.;.
Vest4		0.95
MutPred		0.77		Loss of stability (P = 0.0166);Loss of stability (P = 0.0166);Loss of stability (P = 0.0166);.;Loss of stability (P = 0.0166);.;Loss of stability (P = 0.0166);.;Loss of stability (P = 0.0166);.;.;.;
MVP		0.76
MPC		0.16
ClinPred		1.0	D
GERP RS		5.4
RBP_binding_hub_radar		0.0
RBP_regulation_power_radar		1.7
Varity_R		0.88
gMVP		0.66

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: rs1555917019; hg19: chr22-29099544;