22-28696941-T-C

Variant names:

• chr22-28696941-T-C
• rs764181318
• NM_007194.4:c.1055A>G

Variant summary

Our verdict is Likely pathogenic. The variant received 8 ACMG points: 8P and 0B. PM1 PM2 PP3_Strong

The NM_007194.4(CHEK2):​c.1055A>G​(p.Asn352Ser) variant causes a missense change. The variant allele was found at a frequency of 0.00000137 in 1,461,332 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. N352Y) has been classified as Uncertain significance.

• Frequency:
  • Genomes: not found (cov: 33)
  • Exomes 𝑓: 0.0000014 (0 hom.)
• Consequence: CHEK2 NM_007194.4 missense
• Clinical Significance: Uncertain significance criteria provided, multiple submitters, no conflicts U:6
• Conservation: PhyloP100: 6.29
• Publications: 9 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 8 ACMG points.

• PM1: In a hotspot region, there are 3 aminoacids with missense pathogenic changes in the window of +-8 aminoacids around while only 1 benign, 58 uncertain in NM_007194.4
• PM2: Very rare variant in population databases, with high coverage
• PP3: MetaRNN computational evidence supports a deleterious effect, 0.967

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	MANE	Protein	UniProt
CHEK2	NM_007194.4	c.1055A>G	p.Asn352Ser	missense_variant	Exon 10 of 15	ENST00000404276.6	NP_009125.1

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	TSL	MANE	Protein	Appris	UniProt
CHEK2	ENST00000404276.6	c.1055A>G	p.Asn352Ser	missense_variant	Exon 10 of 15	1	NM_007194.4	ENSP00000385747.1

Frequencies

GnomAD3 genomes Cov.: 33

GnomAD2 exomes AF: 0.00000398 AC: 1 AN: 251290 AF XY: 0.00000736

Gnomad AFR exome AF: 0.00

Gnomad AMR exome AF: 0.00

Gnomad ASJ exome AF: 0.00

Gnomad EAS exome AF: 0.00

Gnomad FIN exome AF: 0.00

Gnomad NFE exome AF: 0.00000880

Gnomad OTH exome AF: 0.00

GnomAD4 exome AF: 0.00000137 AC: 2 AN: 1461332 Hom.: 0 Cov.: 30 AF XY: 0.00000275 AC XY: 2 AN XY: 727000

⚠️ The allele balance in gnomAD version 4 Exomes is significantly skewed from the expected value of 0.5.

African (AFR) AF: 0.00 AC: 0 AN: 33472

American (AMR) AF: 0.00 AC: 0 AN: 44716

Ashkenazi Jewish (ASJ) AF: 0.00 AC: 0 AN: 26134

East Asian (EAS) AF: 0.00 AC: 0 AN: 39688

South Asian (SAS) AF: 0.00 AC: 0 AN: 86234

European-Finnish (FIN) AF: 0.00 AC: 0 AN: 53390

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

European-Non Finnish (NFE) AF: 0.00000180 AC: 2 AN: 1111546

Other (OTH) AF: 0.00 AC: 0 AN: 60384

⚠️ The allele balance in gnomAD4 Exomes is highly skewed from 0.5 (p-value = 0.0296732), which strongly suggests a high chance of mosaicism in these individuals.

GnomAD4 genome Cov.: 33

ExAC AF: 0.00000824 AC: 1

EpiCase AF: 0.00

EpiControl AF: 0.0000593

ClinVar

Significance: Uncertain significance

Submissions summary: Uncertain:6

Revision: criteria provided, multiple submitters, no conflicts

Submissions by phenotype

Hereditary cancer-predisposing syndrome Uncertain:3

Oct 12, 2021

Color Diagnostics, LLC DBA Color Health

Significance: Uncertain significance

Review Status: criteria provided, single submitter

Collection Method: clinical testing

This missense variant replaces asparagine with serine at codon 352 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 hereditary cancer in the literature. This variant has been identified in 1/251290 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.

Jan 07, 2025

Molecular Diagnostics Laboratory, Catalan Institute of Oncology

Significance: Uncertain significance

Review Status: criteria provided, single submitter

Collection Method: clinical testing

PM2_Supporting, PP3_Moderate, c.1055A>G, located in exon 10 of the CHEK2 gene, is predicted to result in the substitution of asparagine by serine at codon 352, p.(Asn352Ser). This is a not strongly conserved amino acid in a functionally relevant domain. This variant is found in 1/268184 alleles at a frequency of 0,0003% in the gnomAD v2.1.1 database, non-cancer dataset (PM2_supporting). The SpliceAI algorithm predicts no significant impact on splicing. The REVEL meta-predictor score for this variant (0.89) suggests a deleterious effect on protein function according to Pejaver 2022 thresholds (PMID: 36413997) (PP3_Moderate). To our knowledge, neither relevant clinical data nor well-established functional studies have been reported for this variant. In a case-control study, it was reported in 1 out of 53,461 healthy controls and none of the 60,466 breast cancer cases (PMID:33471991). This variant has been reported in the ClinVar database (3x uncertain significance), and has not been classified in the LOVD. Based on currently available information, the variant c.1055A>G should be considered an uncertain significance variant, according to ACMG/AMP classification guidelines.

Jun 01, 2023

Ambry Genetics

Significance: Uncertain significance

Review Status: criteria provided, single submitter

Collection Method: clinical testing

The p.N352S variant (also known as c.1055A>G), located in coding exon 9 of the CHEK2 gene, results from an A to G substitution at nucleotide position 1055. The asparagine at codon 352 is replaced by serine, an amino acid with highly similar properties. This variant was identified in a study of 882 Chinese individuals who underwent multi-gene panel testing for HBOC risk assessment (Shao D et al. Cancer Sci, 2020 Feb;111:647-657). This amino acid position is highly conserved in available vertebrate species. In addition, the in silico prediction for this alteration is inconclusive. Since supporting evidence is limited at this time, the clinical significance of this alteration remains unclear.

not specified Uncertain:1

Mar 06, 2023

Women's Health and Genetics/Laboratory Corporation of America, LabCorp

Significance: Uncertain significance

Review Status: criteria provided, single submitter

Collection Method: clinical testing

Variant summary: CHEK2 c.1055A>G (p.Asn352Ser) results in a conservative amino acid change in the encoded protein sequence. Four of five in-silico tools predict a damaging effect of the variant on protein function. The variant allele was found at a frequency of 4e-06 in 251290 control chromosomes. The available data on variant occurrences in the general population are insufficient to allow any conclusion about variant significance. c.1055A>G has been reported in the literature in individuals affected with HBOC. This report does not provide unequivocal conclusions about association of the variant with Prostate Cancer. To our knowledge, no experimental evidence demonstrating an impact on protein function has been reported. Three clinical diagnostic laboratories have submitted clinical-significance assessments for this variant to ClinVar after 2014 without evidence for independent evaluation. All laboratories classified the variant as uncertain significance. Based on the evidence outlined above, the variant was classified as uncertain significance.

not provided Uncertain:1

Dec 05, 2024

GeneDx

Significance: Uncertain significance

Review Status: criteria provided, single submitter

Collection Method: clinical testing

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; Observed in an individual with a personal and/or family history of breast and/or ovarian cancer (PMID: 31742824); This variant is associated with the following publications: (PMID: 22419737, 19782031, 31742824)

Familial cancer of breast Uncertain:1

May 03, 2023

Labcorp Genetics (formerly Invitae), Labcorp

Significance: Uncertain significance

Review Status: criteria provided, single submitter

Collection Method: clinical testing

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. This sequence change replaces asparagine, which is neutral and polar, with serine, which is neutral and polar, at codon 352 of the CHEK2 protein (p.Asn352Ser). This variant is present in population databases (rs764181318, gnomAD 0.0009%). 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: 489871). 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.

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Pathogenic	1.0
BayesDel_addAF	Pathogenic	0.22	D
BayesDel_noAF	Uncertain	0.080
CADD	Pathogenic	26
DANN	Uncertain	1.0
DEOGEN2	Benign	0.41	T;T;.;T;.;T;.;.;.
Eigen	Pathogenic	0.92
Eigen_PC	Pathogenic	0.83
FATHMM_MKL	Uncertain	0.97	D
LIST_S2	Benign	0.0	.;.;D;.;D;D;D;D;D
M_CAP	Uncertain	0.21	D
MetaRNN	Pathogenic	0.97	D;D;D;D;D;D;D;D;D
MetaSVM	Pathogenic	1.1	D
MutationAssessor	Pathogenic	3.4	M;M;.;M;.;M;.;.;.
PhyloP100		6.3
PrimateAI	Uncertain	0.72	T
PROVEAN	Pathogenic	-4.7	D;D;.;D;D;.;D;D;.
REVEL	Pathogenic	0.89
Sift	Pathogenic	0.0	D;D;.;D;D;.;D;D;.
Sift4G	Pathogenic	0.0	D;D;.;D;D;.;D;D;.
Vest4		0.96
ClinPred		0.99	D
GERP RS		5.7
Varity_R		0.97
gMVP		0.85
Mutation Taster		=26/74	disease causing

Splicing

Name	Calibrated prediction	Score	Prediction
SpliceAI score (max)		0.010		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: rs764181318; hg19: chr22-29092929;