22-28725093-T-C

Variant names:

• chr22-28725093-T-C
• rs1060502718
• NM_007194.4:c.476A>G

Variant summary

Our verdict is Likely pathogenic. The variant received 6 ACMG points: 6P and 0B. PM1 PM2 PP3_Moderate

The NM_007194.4(CHEK2):​c.476A>G​(p.Tyr159Cys) variant causes a missense change. The variant allele was found at a frequency of 0.00000205 in 1,461,806 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. Y159H) has been classified as Uncertain significance.

• Frequency:
  • Genomes: not found (cov: 32)
  • Exomes 𝑓: 0.0000021 (0 hom.)
• Consequence: CHEK2 NM_007194.4 missense
• Clinical Significance: Uncertain significance criteria provided, multiple submitters, no conflicts U:4
• Conservation: PhyloP100: 3.96
• Publications: 5 publications found

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

ACMG classification

Our verdict: Likely_pathogenic. The variant received 6 ACMG points.

• PM1: In a hotspot region, there are 6 aminoacids with missense pathogenic changes in the window of +-8 aminoacids around while only 1 benign, 69 uncertain in NM_007194.4
• PM2: Very rare variant in population databases, with high coverage
• PP3: MetaRNN computational evidence supports a deleterious effect, 0.903

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	MANE	Protein	UniProt
CHEK2	NM_007194.4	c.476A>G	p.Tyr159Cys	missense_variant	Exon 4 of 15	ENST00000404276.6	NP_009125.1

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	TSL	MANE	Protein	Appris	UniProt
CHEK2	ENST00000404276.6	c.476A>G	p.Tyr159Cys	missense_variant	Exon 4 of 15	1	NM_007194.4	ENSP00000385747.1

Frequencies

GnomAD3 genomes Cov.: 32

GnomAD2 exomes AF: 0.00000398 AC: 1 AN: 251416 AF XY: 0.00

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 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: 1461806 Hom.: 0 Cov.: 32 AF XY: 0.00000138 AC XY: 1 AN XY: 727210

African (AFR) AF: 0.00 AC: 0 AN: 33478

American (AMR) AF: 0.0000224 AC: 1 AN: 44724

Ashkenazi Jewish (ASJ) AF: 0.00 AC: 0 AN: 26132

East Asian (EAS) AF: 0.00 AC: 0 AN: 39678

South Asian (SAS) AF: 0.00 AC: 0 AN: 86256

European-Finnish (FIN) AF: 0.00 AC: 0 AN: 53416

Middle Eastern (MID) AF: 0.00 AC: 0 AN: 5768

European-Non Finnish (NFE) AF: 0.00000180 AC: 2 AN: 1111960

Other (OTH) AF: 0.00 AC: 0 AN: 60394

GnomAD4 genome Cov.: 32

ClinVar

Significance: Uncertain significance

Submissions summary: Uncertain:4

Revision: criteria provided, multiple submitters, no conflicts

Submissions by phenotype

Hereditary cancer-predisposing syndrome Uncertain:2

Mar 25, 2024

Ambry Genetics

Significance: Uncertain significance

Review Status: criteria provided, single submitter

Collection Method: clinical testing

The p.Y159C variant (also known as c.476A>G), located in coding exon 3 of the CHEK2 gene, results from an A to G substitution at nucleotide position 476. The tyrosine at codon 159 is replaced by cysteine, an amino acid with highly dissimilar properties. This alteration has been reported in at least one breast cancer patient 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 variant was also identified in a cohort of 3579 African males diagnosed with prostate cancer who underwent multi-gene panel testing of 19 DNA repair and cancer predisposition genes (Matejcic M et al. JCO Precis Oncol, 2020 Jan;4:32-43). 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. -

Jun 20, 2024

Color Diagnostics, LLC DBA Color Health

Significance: Uncertain significance

Review Status: criteria provided, single submitter

Collection Method: clinical testing

This missense variant replaces tyrosine with cysteine at codon 159 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). To our knowledge, functional studies have not been reported for this variant. This variant has not been reported in individuals affected with CHEK2-related disorders in the literature. This variant has been identified in 1/251416 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. -

not provided Uncertain:1

Jul 29, 2021

Quest Diagnostics Nichols Institute San Juan Capistrano

Significance: Uncertain significance

Review Status: criteria provided, single submitter

Collection Method: clinical testing

- -

Familial cancer of breast Uncertain:1

Apr 30, 2024

Labcorp Genetics (formerly Invitae), Labcorp

Significance: Uncertain significance

Review Status: criteria provided, single submitter

Collection Method: clinical testing

This sequence change replaces tyrosine, which is neutral and polar, with cysteine, which is neutral and slightly polar, at codon 159 of the CHEK2 protein (p.Tyr159Cys). This variant is present in population databases (no rsID available, 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: 410058). 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	Benign	0.32
BayesDel_addAF	Pathogenic	0.38	D
BayesDel_noAF	Pathogenic	0.39
CADD	Pathogenic	26
DANN	Uncertain	1.0
DEOGEN2	Uncertain	0.63	D;.;D;D;.;D;.;.;D;.;.
Eigen	Pathogenic	0.74
Eigen_PC	Pathogenic	0.71
FATHMM_MKL	Uncertain	0.92	D
LIST_S2	Uncertain	0.93	.;D;.;.;D;D;.;D;D;D;D
M_CAP	Uncertain	0.12	D
MetaRNN	Pathogenic	0.90	D;D;D;D;D;D;D;D;D;D;D
MetaSVM	Pathogenic	0.88	D
MutationAssessor	Pathogenic	3.0	M;M;M;M;.;M;M;.;.;.;.
PhyloP100		4.0
PrimateAI	Uncertain	0.74	T
PROVEAN	Pathogenic	-6.5	D;D;D;D;D;.;D;D;.;.;.
REVEL	Pathogenic	0.84
Sift	Uncertain	0.0030	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;.;.;.;.
Vest4		0.80
MutPred		0.68		Gain of catalytic residue at I157 (P = 0.1497);Gain of catalytic residue at I157 (P = 0.1497);Gain of catalytic residue at I157 (P = 0.1497);Gain of catalytic residue at I157 (P = 0.1497);.;Gain of catalytic residue at I157 (P = 0.1497);Gain of catalytic residue at I157 (P = 0.1497);.;Gain of catalytic residue at I157 (P = 0.1497);Gain of catalytic residue at I157 (P = 0.1497);Gain of catalytic residue at I157 (P = 0.1497);
MVP		0.98
MPC		0.17
ClinPred		0.95	D
GERP RS		5.9
RBP_binding_hub_radar		0.0
RBP_regulation_power_radar		1.7
Varity_R		0.92
gMVP		0.77
Mutation Taster		=25/75	disease causing

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

Other links and lift over

dbSNP: rs1060502718; hg19: chr22-29121081; COSMIC: COSV60425978;