NM_007194.4:c.127A>G

Variant names:

Variant summary

Our verdict is Likely benign. The variant received -5 ACMG points: 0P and 5B. BP4_StrongBS2_Supporting

The NM_007194.4(CHEK2):c.127A>G(p.Thr43Ala) variant causes a missense change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.00000479 in 1,461,886 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a benign outcome for this variant. 16/22 in silico tools predict a benign 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. T43I) has been classified as Uncertain significance.

Frequency

Genomes: not found (cov: 31)

Exomes 𝑓: 0.0000048 ( 0 hom. )

Consequence

CHEK2
NM_007194.4 missense

Scores

Clinical Significance

Uncertain significance criteria provided, multiple submitters, no conflicts U:3

Conservation

PhyloP100: 0.761

Publications

4 publications found

Variant links:

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 Gene-Disease associations (from GenCC):

CHEK2-related cancer predisposition
Inheritance: AD Classification: DEFINITIVE Submitted by: Ambry Genetics
hereditary breast carcinoma
Inheritance: AD Classification: DEFINITIVE, STRONG Submitted by: Labcorp Genetics (formerly Invitae), ClinGen
Li-Fraumeni syndrome 2
Inheritance: AD Classification: DEFINITIVE Submitted by: G2P
acute myeloid leukemia
Inheritance: AD Classification: MODERATE Submitted by: Genomics England PanelApp
hereditary nonpolyposis colon cancer
Inheritance: AD Classification: LIMITED Submitted by: ClinGen
familial ovarian cancer
Inheritance: AD Classification: NO_KNOWN Submitted by: ClinGen

CHEK2 links:

Genome browser will be placed here

ACMG classification

Classification was made for transcript

Our verdict: Likely_benign. The variant received -5 ACMG points.

BP4

Computational evidence support a benign effect (MetaRNN=0.053281814).

BS2

High AC in GnomAdExome4 at 7 AD gene. Variant has AC lower than other variant known as pathogenic in the gene, so the strength is limited to Supporting.

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	MANE	Protein	UniProt
CHEK2	NM_007194.4 link	c.127A>G	p.Thr43Ala	missense_variant	Exon 2 of 15	ENST00000404276.6	NP_009125.1	O96017-1

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	TSL	MANE	Protein	Appris	UniProt
CHEK2	ENST00000404276.6 link	c.127A>G	p.Thr43Ala	missense_variant	Exon 2 of 15	1	NM_007194.4	ENSP00000385747.1		O96017-1

Frequencies

GnomAD3 genomes

Cov.:

GnomAD2 exomes

AF:

0.0000159

AC:

AN:

251162

AF XY:

0.0000147

show subpopulations

Gnomad AFR exome

AF:

0.00

Gnomad AMR exome

AF:

0.0000867

Gnomad ASJ exome

AF:

0.0000993

Gnomad EAS 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:

0.00000479

AC:

AN:

1461886

Hom.:

Cov.:

AF XY:

0.00000550

AC XY:

AN XY:

727242

show subpopulations

African (AFR)

AF:

0.00

AC:

AN:

33480

American (AMR)

AF:

0.0000671

AC:

AN:

44722

Ashkenazi Jewish (ASJ)

AF:

0.0000383

AC:

AN:

26136

East Asian (EAS)

AF:

0.00

AC:

AN:

39700

South Asian (SAS)

AF:

0.00

AC:

AN:

86258

European-Finnish (FIN)

AF:

0.00

AC:

AN:

53418

Middle Eastern (MID)

AF:

0.00

AC:

AN:

5766

European-Non Finnish (NFE)

AF:

0.00000270

AC:

AN:

1112010

Other (OTH)

AF:

0.00

AC:

AN:

60396

Allele Balance Distribution

Red line indicates average allele balance

Average allele balance: 0.454

Heterozygous variant carriers

0.00

0.20

0.40

0.60

0.80

0.95

Allele balance

Age Distribution

Exome Het

Variant carriers

<30

30-35

35-40

40-45

45-50

50-55

55-60

60-65

65-70

70-75

75-80

>80

Age

GnomAD4 genome

Cov.:

Alfa

AF:

0.000111

Hom.:

ExAC

AF:

0.0000165

AC:

ClinVar

Significance: Uncertain significance

Submissions summary: Uncertain:3

Revision: criteria provided, multiple submitters, no conflicts

LINK: link

Submissions by phenotype

Hereditary cancer-predisposing syndrome

Uncertain:2

May 02, 2019

Color Diagnostics, LLC DBA Color Health

Significance:Uncertain significance

Review Status:criteria provided, single submitter

Collection Method:clinical testing

- -

Jun 13, 2025

Ambry Genetics

Significance:Uncertain significance

Review Status:criteria provided, single submitter

Collection Method:clinical testing

The p.T43A variant (also known as c.127A>G), located in coding exon 1 of the CHEK2 gene, results from an A to G substitution at nucleotide position 127. The threonine at codon 43 is replaced by alanine, an amino acid with similar properties. This alteration has been reported in at least one subject in a study of 13087 breast cancer cases and 5488 control individuals in the UK (Decker B et al. J Med Genet, 2017 11;54:732-741). This amino acid position is poorly conserved in available vertebrate species. In addition, this alteration is predicted to be tolerated by in silico analysis. Based on the available evidence, the clinical significance of this variant remains unclear. -

Familial cancer of breast

Uncertain:1

Aug 08, 2024

Labcorp Genetics (formerly Invitae), Labcorp

Significance:Uncertain significance

Review Status:criteria provided, single submitter

Collection Method:clinical testing

This sequence change replaces threonine, which is neutral and polar, with alanine, which is neutral and non-polar, at codon 43 of the CHEK2 protein (p.Thr43Ala). This variant is present in population databases (rs749158713, gnomAD 0.009%). 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: 582006). An algorithm developed to predict the effect of missense changes on protein structure and function outputs the following: PolyPhen-2: "Benign". The alanine amino acid residue is found in multiple mammalian species, which suggests that this missense change does not adversely affect protein function. 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

0.062

BayesDel_addAF

Benign

-0.18

BayesDel_noAF

Benign

-0.30

CADD

Benign

(source)

DANN

Benign

0.90

DEOGEN2

Benign

0.12

T;.;T;T;.;T;.;.;.;.;T;.;.

Eigen

Benign

-0.82

Eigen_PC

Benign

-0.78

FATHMM_MKL

Benign

0.33

LIST_S2

Benign

0.73

.;T;.;.;T;T;T;.;T;T;T;T;T

M_CAP

Benign

0.034

MetaRNN

Benign

0.053

T;T;T;T;T;T;T;T;T;T;T;T;T

MetaSVM

Benign

-0.50

MutationAssessor

Benign

1.7

L;L;L;L;L;L;L;L;.;.;.;.;.

PhyloP100

0.76

PrimateAI

Benign

0.33

PROVEAN

Benign

-0.36

N;N;N;N;N;.;N;N;N;N;N;.;.

REVEL

Benign

0.046

Sift

Benign

0.46

T;T;T;T;T;.;D;T;T;T;T;.;.

Sift4G

Benign

0.26

T;T;T;T;T;.;T;T;T;T;T;.;.

Polyphen

0.0010

B;B;B;B;B;B;B;B;.;.;.;.;.

Vest4

0.065

MutPred

0.16

Loss of phosphorylation at T43 (P = 0.0323);Loss of phosphorylation at T43 (P = 0.0323);Loss of phosphorylation at T43 (P = 0.0323);Loss of phosphorylation at T43 (P = 0.0323);Loss of phosphorylation at T43 (P = 0.0323);Loss of phosphorylation at T43 (P = 0.0323);Loss of phosphorylation at T43 (P = 0.0323);Loss of phosphorylation at T43 (P = 0.0323);Loss of phosphorylation at T43 (P = 0.0323);Loss of phosphorylation at T43 (P = 0.0323);Loss of phosphorylation at T43 (P = 0.0323);Loss of phosphorylation at T43 (P = 0.0323);Loss of phosphorylation at T43 (P = 0.0323);

MVP

0.85

MPC

0.020

ClinPred

0.022

GERP RS

0.61

PromoterAI

0.020

Neutral

(source)

RBP_binding_hub_radar

0.0

RBP_regulation_power_radar

1.1

Varity_R

0.019

gMVP

0.25

Mutation Taster

=86/14

polymorphism

(source)

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

You must be logged in to view publications. This limit was set because tens of millions (!) of queries from AI bots are generated daily.

Variant summary

Frequency

Consequence

Scores

Clinical Significance

Conservation

Publications

ACMG classification

Transcripts

RefSeq

Ensembl

Frequencies

Age Distribution

ClinVar

Submissions by phenotype

Computational scores

Splicing

Publications

Other links and lift over