22-28725091-T-C
Variant summary
Our verdict is Likely benign. The variant received -1 ACMG points: 2P and 3B. PM1BP4_ModerateBS2_Supporting
The NM_007194.4(CHEK2):c.478A>G(p.Ile160Val) variant causes a missense change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.00000991 in 1,614,048 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts 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. I160L) has been classified as Likely benign.
Frequency
Consequence
NM_007194.4 missense
Scores
Clinical Significance
Conservation
Publications
- CHEK2-related cancer predispositionInheritance: AD Classification: DEFINITIVE Submitted by: Ambry Genetics
- hereditary breast carcinomaInheritance: AD Classification: DEFINITIVE, STRONG Submitted by: Labcorp Genetics (formerly Invitae), ClinGen
- Li-Fraumeni syndrome 2Inheritance: AD Classification: DEFINITIVE Submitted by: G2P
- acute myeloid leukemiaInheritance: AD Classification: MODERATE Submitted by: Genomics England PanelApp
- hereditary nonpolyposis colon cancerInheritance: AD Classification: LIMITED Submitted by: ClinGen
- familial ovarian cancerInheritance: AD Classification: NO_KNOWN Submitted by: ClinGen
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ACMG classification
Our verdict: Likely_benign. The variant received -1 ACMG points.
Variant Effect in Transcripts
ACMG analysis was done for transcript: NM_007194.4. You can select a different transcript below to see updated ACMG assignments.
RefSeq Transcripts
| Selected | Gene | Transcript | Tags | HGVSc | HGVSp | Effect | Exon Rank | Protein | UniProt |
|---|---|---|---|---|---|---|---|---|---|
| CHEK2 | NM_007194.4 | MANE Select | c.478A>G | p.Ile160Val | missense | Exon 4 of 15 | NP_009125.1 | ||
| CHEK2 | NM_001005735.3 | c.607A>G | p.Ile203Val | missense | Exon 5 of 16 | NP_001005735.1 | |||
| CHEK2 | NM_001438293.1 | c.571A>G | p.Ile191Val | missense | Exon 5 of 16 | NP_001425222.1 |
Ensembl Transcripts
| Selected | Gene | Transcript | Tags | HGVSc | HGVSp | Effect | Exon Rank | Protein | UniProt |
|---|---|---|---|---|---|---|---|---|---|
| CHEK2 | ENST00000404276.6 | TSL:1 MANE Select | c.478A>G | p.Ile160Val | missense | Exon 4 of 15 | ENSP00000385747.1 | ||
| CHEK2 | ENST00000382580.6 | TSL:1 | c.607A>G | p.Ile203Val | missense | Exon 5 of 16 | ENSP00000372023.2 | ||
| CHEK2 | ENST00000416671.5 | TSL:1 | n.478A>G | non_coding_transcript_exon | Exon 4 of 16 | ENSP00000402225.1 |
Frequencies
GnomAD3 genomes AF: 0.0000197 AC: 3AN: 152228Hom.: 0 Cov.: 32 show subpopulations
GnomAD2 exomes AF: 0.00000398 AC: 1AN: 251414 AF XY: 0.00 show subpopulations
GnomAD4 exome AF: 0.00000889 AC: 13AN: 1461820Hom.: 0 Cov.: 32 AF XY: 0.00000825 AC XY: 6AN XY: 727212 show subpopulations
Age Distribution
GnomAD4 genome AF: 0.0000197 AC: 3AN: 152228Hom.: 0 Cov.: 32 AF XY: 0.0000134 AC XY: 1AN XY: 74376 show subpopulations
Age Distribution
ClinVar
Submissions by phenotype
Familial cancer of breast Uncertain:2
This sequence change replaces isoleucine, which is neutral and non-polar, with valine, which is neutral and non-polar, at codon 160 of the CHEK2 protein (p.Ile160Val). This variant is present in population databases (no rsID available, gnomAD 0.008%). This missense change has been observed in individual(s) with breast cancer (PMID: 36003761). ClinVar contains an entry for this variant (Variation ID: 232725). 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.
Hereditary cancer-predisposing syndrome Uncertain:2
This missense variant replaces isoleucine with valine at codon 160 of the CHEK2 protein. Computational prediction suggests that this variant may not impact protein structure and function. To our knowledge, functional studies have not been reported for this variant. This variant has been reported in individuals affected with breast cancer (PMID: 33471991; Leiden Open Variation Database DB-ID CHEK2_000071, 36003761; Color internal data) and in an individual affected with familial breast and thyroid cancer (PMID: 32443704). One of the individuals affected with breast cancer also carried a pathogenic variant in the BRCA2 gene that could explain the observed phenotype (PMID: 36003761). This variant has been identified in 3/282814 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.
The p.I160V variant (also known as c.478A>G), located in coding exon 3 of the CHEK2 gene, results from an A to G substitution at nucleotide position 478. The isoleucine at codon 160 is replaced by valine, an amino acid with highly similar properties. This alteration has been identified in an individual diagnosed with breast cancer (Megid TBC et al. Front Oncol, 2022 Aug;12:873395). This alteration has also been identified in an individual diagnosed with renal cell cancer (Yngvadottir B et al. Hum Mol Genet, 2022 Aug;31:3001-3011). This variant was reported as functional in a study assessing CHEK2-complementation through quantification of KAP1 phosphorylation and CHK2 autophosphorylation in human RPE1-CHEK2-knockout cells (Stolarova L et al. Clin Cancer Res, 2023 Aug;29:3037-3050). This amino acid position is highly conserved in available vertebrate species. In addition, the in silico prediction for this alteration is inconclusive. Based on the available evidence, the clinical significance of this variant remains unclear.
not provided Uncertain:1
Variant summary: The CHEK2 c.478A>G (p.Ile160Val) variant involves the alteration of a conserved nucleotide. 3/4 in silico tools predict a benign outcome for this variant (SNPs&GO not captured due to low reliability index). This variant is absent from 121352 control chromosomes. In addition, a clinical diagnostic laboratory/reputable database classified this variant as uncertain significance. The variant of interest has not, to our knowledge, been reported in affected individuals via publications nor evaluated for functional impact by in vivo/vitro studies. Because of the absence of clinical information and the lack of functional studies, the variant is classified as a variant of uncertain significance (VUS) until additional information becomes available.
CHEK2-related cancer predisposition Uncertain:1
This variant was determined to be of uncertain significance according to ACMG Guidelines, 2015 [PMID:25741868].
Computational scores
Source:
Splicing
Find out detailed SpliceAI scores and Pangolin per-transcript scores at