22-28734610-T-C

Position:

• chr22-28734610-T-C

Variant summary

Our verdict is Likely benign. Variant got -2 ACMG points: 2P and 4B. PM2 BP4_Strong

The NM_007194.4(CHEK2):​c.112A>G​(p.Ile38Val) variant causes a missense change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.00000205 in 1,461,876 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a benign outcome for this variant. 15/21 in silico tools predict a benign outcome for this variant. Variant has been reported in ClinVar 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: -0.0170

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_benign. Variant got -2 ACMG points.

• PM2: Very rare variant in population databases, with high coverage
• BP4: Computational evidence support a benign effect (MetaRNN=0.02486518).

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	Protein	UniProt
CHEK2	NM_007194.4	c.112A>G	p.Ile38Val	missense_variant	2/15	ENST00000404276.6	NP_009125.1

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Protein	Appris	UniProt
CHEK2	ENST00000404276.6	c.112A>G	p.Ile38Val	missense_variant	2/15	1	NM_007194.4	ENSP00000385747	P2

Frequencies

GnomAD3 genomes Cov.: 31

GnomAD3 exomes AF: 0.00000399 AC: 1 AN: 250756 Hom.: 0 AF XY: 0.00000738 AC XY: 1 AN XY: 135498

Gnomad AFR exome AF: 0.00

Gnomad AMR exome AF: 0.0000289

Gnomad ASJ exome AF: 0.00

Gnomad EAS exome AF: 0.00

Gnomad SAS exome AF: 0.00

Gnomad FIN exome AF: 0.00

Gnomad NFE exome AF: 0.00

Gnomad OTH exome AF: 0.00

GnomAD4 exome AF: 0.00000205 AC: 3 AN: 1461876 Hom.: 0 Cov.: 33 AF XY: 0.00000275 AC XY: 2 AN XY: 727234

Gnomad4 AFR exome AF: 0.00

Gnomad4 AMR exome AF: 0.0000224

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: 0.00000180

Gnomad4 OTH exome AF: 0.00

GnomAD4 genome Cov.: 31

ExAC AF: 0.00000824 AC: 1

ClinVar

Significance: Uncertain significance

Submissions summary: Uncertain:3

Revision: criteria provided, multiple submitters, no conflicts

Submissions by phenotype

Hereditary cancer-predisposing syndrome Uncertain:2

Uncertain significance, criteria provided, single submitter	clinical testing	Ambry Genetics	Feb 10, 2023	The p.I38V variant (also known as c.112A>G), located in coding exon 1 of the CHEK2 gene, results from an A to G substitution at nucleotide position 112. The isoleucine at codon 38 is replaced by valine, an amino acid with highly similar properties. This amino acid position is poorly conserved in available vertebrate species. In addition, this alteration is predicted to be tolerated 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	Mar 10, 2020	This missense variant replaces isoleucine with valine at codon 38 of the CHEK2 protein. Computational prediction suggests that this variant may not impact protein structure and function (internally defined REVEL score threshold <= 0.5, PMID: 27666373). Splice site prediction tools suggest that this variant may not impact RNA splicing. To our knowledge, functional studies have not been reported for this variant. This variant has not been reported in individuals affected with hereditary cancer in the literature. This variant has been identified in 1/250756 chromosomes 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. -

Familial cancer of breast Uncertain:1

Uncertain significance, criteria provided, single submitter

clinical testing

Labcorp Genetics (formerly Invitae), Labcorp

Nov 01, 2023

This sequence change replaces isoleucine, which is neutral and non-polar, with valine, which is neutral and non-polar, at codon 38 of the CHEK2 protein (p.Ile38Val). This variant is present in population databases (rs774192195, gnomAD 0.003%). 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: 583047). 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. -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Benign	0.066
BayesDel_addAF	Benign	-0.20	T
BayesDel_noAF	Benign	-0.45
CADD	Benign	1.0
DANN	Benign	0.26
DEOGEN2	Benign	0.071	T;.;T;T;.;T;.;.;.;.;T;.;.
Eigen	Benign	-1.4
Eigen_PC	Benign	-1.4
FATHMM_MKL	Benign	0.026	N
LIST_S2	Benign	0.30	.;T;.;.;T;T;T;.;T;T;T;T;T
M_CAP	Benign	0.027	D
MetaRNN	Benign	0.025	T;T;T;T;T;T;T;T;T;T;T;T;T
MetaSVM	Benign	-0.56	T
MutationAssessor	Benign	0.34	N;N;N;N;N;N;N;N;.;.;.;.;.
MutationTaster	Benign	1.0	N;N;N;N;N;N;N;N;N;N;N
PrimateAI	Benign	0.30	T
PROVEAN	Benign	0.25	N;N;N;N;N;.;N;N;N;N;N;.;.
REVEL	Benign	0.033
Sift	Benign	0.51	T;T;T;T;T;.;T;T;T;T;T;.;.
Sift4G	Benign	0.28	T;T;T;T;T;.;T;T;T;T;T;.;.
Polyphen		0.0	B;B;B;B;B;B;B;B;.;.;.;.;.
Vest4		0.064
MutPred		0.24		Gain of catalytic residue at I38 (P = 0.0544);Gain of catalytic residue at I38 (P = 0.0544);Gain of catalytic residue at I38 (P = 0.0544);Gain of catalytic residue at I38 (P = 0.0544);Gain of catalytic residue at I38 (P = 0.0544);Gain of catalytic residue at I38 (P = 0.0544);Gain of catalytic residue at I38 (P = 0.0544);Gain of catalytic residue at I38 (P = 0.0544);Gain of catalytic residue at I38 (P = 0.0544);Gain of catalytic residue at I38 (P = 0.0544);Gain of catalytic residue at I38 (P = 0.0544);Gain of catalytic residue at I38 (P = 0.0544);Gain of catalytic residue at I38 (P = 0.0544);
MVP		0.39
MPC		0.019
ClinPred		0.023	T
GERP RS		-2.7
RBP_binding_hub_radar		0.0
RBP_regulation_power_radar		1.1
Varity_R		0.015
gMVP		0.069

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: rs774192195; hg19: chr22-29130598;