chr22-28699930-C-T

Position:

• chr22-28699930-C-T

Variant summary

Our verdict is Likely pathogenic. Variant got 6 ACMG points: 6P and 0B. PM2 PM5 PP3_Moderate

The NM_007194.4(CHEK2):​c.916G>A​(p.Gly306Arg) variant causes a missense change. The variant allele was found at a frequency of 0.000000684 in 1,461,018 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 nucleotide change resulting in same amino acid change has been previously reported as Uncertain significancein ClinVar. Another variant affecting the same amino acid position, but resulting in a different missense (i.e. G306A) has been classified as Likely pathogenic.

• Frequency:
  • Genomes: not found (cov: 31)
  • Exomes 𝑓: 6.8e-7 (0 hom.)
• Consequence: CHEK2 NM_007194.4 missense
• Clinical Significance: Uncertain significance criteria provided, multiple submitters, no conflicts U:4
• Conservation: PhyloP100: 6.67

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 6 ACMG points.

• PM2: Very rare variant in population databases, with high coverage
• PM5: Other missense variant is known to change same aminoacid residue: Variant chr22-28699929-C-G is described in ClinVar as [Conflicting_classifications_of_pathogenicity]. Clinvar id is 128089.We mark this variant Likely_pathogenic, oryginal submissions are: {Uncertain_significance=9, Likely_pathogenic=5, not_provided=1}.
• PP3: MetaRNN computational evidence supports a deleterious effect, 0.927

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	UniProt
CHEK2	NM_007194.4	c.916G>A	p.Gly306Arg	missense_variant	9/15	ENST00000404276.6

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Appris	UniProt
CHEK2	ENST00000404276.6	c.916G>A	p.Gly306Arg	missense_variant	9/15	1	NM_007194.4	P2

Frequencies

GnomAD3 genomes Cov.: 31

GnomAD4 exome AF: 6.84e-7 AC: 1 AN: 1461018 Hom.: 0 Cov.: 30 AF XY: 0.00 AC XY: 0 AN XY: 726802

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: 9.00e-7

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

Familial cancer of breast Uncertain:2

Uncertain significance, criteria provided, single submitter	clinical testing	Invitae	Jan 30, 2024	This sequence change replaces glycine, which is neutral and non-polar, with arginine, which is basic and polar, at codon 306 of the CHEK2 protein (p.Gly306Arg). 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: 156500). 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. -
Uncertain significance, no assertion criteria provided	clinical testing	Pathway Genomics	Jul 24, 2014	- -

not provided Uncertain:1

Uncertain significance, criteria provided, single submitter

clinical testing

GeneDx

Feb 17, 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; Has not been previously published as pathogenic or benign to our knowledge; This variant is associated with the following publications: (PMID: 22419737, 19782031) -

Hereditary cancer-predisposing syndrome Uncertain:1

Uncertain significance, criteria provided, single submitter

clinical testing

Ambry Genetics

Apr 14, 2022

The p.G306R variant (also known as c.916G>A), located in coding exon 8 of the CHEK2 gene, results from a G to A substitution at nucleotide position 916. The glycine at codon 306 is replaced by arginine, an amino acid with dissimilar properties. 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. -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Pathogenic	0.99
BayesDel_addAF	Pathogenic	0.34	D
BayesDel_noAF	Pathogenic	0.25
CADD	Pathogenic	27
DANN	Pathogenic	1.0
DEOGEN2	Benign	0.38	T;.;T;.;T;.;T;.;.;.;.;.
Eigen	Uncertain	0.58
Eigen_PC	Uncertain	0.63
FATHMM_MKL	Uncertain	0.97	D
LIST_S2	Uncertain	0.95	.;D;.;D;.;D;D;D;.;D;D;D
M_CAP	Uncertain	0.17	D
MetaRNN	Pathogenic	0.93	D;D;D;D;D;D;D;D;D;D;D;D
MetaSVM	Pathogenic	0.94	D
MutationAssessor	Uncertain	2.6	M;M;M;.;M;.;M;.;M;.;.;.
MutationTaster	Benign	1.0	D;D;D;D;D;D;D;D;D;D;D
PrimateAI	Uncertain	0.78	T
PROVEAN	Pathogenic	-7.5	D;D;D;.;D;D;.;D;D;D;.;D
REVEL	Uncertain	0.64
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		0.95
MutPred		0.81		Gain of solvent accessibility (P = 0.1319);Gain of solvent accessibility (P = 0.1319);Gain of solvent accessibility (P = 0.1319);.;Gain of solvent accessibility (P = 0.1319);.;Gain of solvent accessibility (P = 0.1319);.;Gain of solvent accessibility (P = 0.1319);.;.;.;
MVP		0.71
MPC		0.17
ClinPred		1.0	D
GERP RS		5.7
Varity_R		0.96
gMVP		0.80

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

Publications

LitVar

Other links and lift over

dbSNP: rs587783051; hg19: chr22-29095918; COSMIC: COSV60416663;