rs1555894697

Variant summary

Our verdict is Uncertain significance. The variant received 2 ACMG points: 2P and 0B. PM2

The NM_005198.5(CHKB):​c.577G>A​(p.Glu193Lys) variant causes a missense change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.000000684 in 1,460,938 control chromosomes in the GnomAD database, with no homozygous occurrence. Variant has been reported in ClinVar as Uncertain significance (★).

Frequency

Genomes: not found (cov: 32)
Exomes 𝑓: 6.8e-7 ( 0 hom. )

Consequence

CHKB
NM_005198.5 missense

Scores

6
13

Clinical Significance

Uncertain significance criteria provided, single submitter U:1

Conservation

PhyloP100: 3.29

Publications

0 publications found
Variant links:
Genes affected
CHKB (HGNC:1938): (choline kinase beta) Choline kinase (CK) and ethanolamine kinase (EK) catalyze the phosphorylation of choline/ethanolamine to phosphocholine/phosphoethanolamine. This is the first enzyme in the biosynthesis of phosphatidylcholine/phosphatidylethanolamine in all animal cells. The highly purified CKs from mammalian sources and their recombinant gene products have been shown to have EK activity also, indicating that both activities reside on the same protein. The choline kinase-like protein encoded by CHKL belongs to the choline/ethanolamine kinase family; however, its exact function is not known. Read-through transcripts are expressed from this locus that include exons from the downstream CPT1B locus. [provided by RefSeq, Jun 2009]
CHKB-CPT1B (HGNC:41998): (CHKB-CPT1B readthrough (NMD candidate)) The genes CHKB and CPT1B are adjacent on chromosome 22 and read-through transcripts are expressed that include exons from both loci. The read-through transcripts are candidates for nonsense-mediated mRNA decay (NMD) and are unlikely to express proteins. [provided by RefSeq, Jun 2009]

Genome browser will be placed here

ACMG classification

Classification was made for transcript

Our verdict: Uncertain_significance. The variant received 2 ACMG points.

PM2
Very rare variant in population databases, with high coverage;

Transcripts

RefSeq

Gene Transcript HGVSc HGVSp Effect Exon rank MANE Protein UniProt
CHKBNM_005198.5 linkc.577G>A p.Glu193Lys missense_variant Exon 4 of 11 ENST00000406938.3 NP_005189.2
CHKB-CPT1BNR_027928.2 linkn.795G>A non_coding_transcript_exon_variant Exon 4 of 30

Ensembl

Gene Transcript HGVSc HGVSp Effect Exon rank TSL MANE Protein Appris UniProt
CHKBENST00000406938.3 linkc.577G>A p.Glu193Lys missense_variant Exon 4 of 11 1 NM_005198.5 ENSP00000384400.3

Frequencies

GnomAD3 genomes
Cov.:
32
GnomAD4 exome
AF:
6.84e-7
AC:
1
AN:
1460938
Hom.:
0
Cov.:
32
AF XY:
0.00000138
AC XY:
1
AN XY:
726716
show subpopulations
African (AFR)
AF:
0.00
AC:
0
AN:
33470
American (AMR)
AF:
0.00
AC:
0
AN:
44688
Ashkenazi Jewish (ASJ)
AF:
0.00
AC:
0
AN:
26130
East Asian (EAS)
AF:
0.00
AC:
0
AN:
39688
South Asian (SAS)
AF:
0.00
AC:
0
AN:
86208
European-Finnish (FIN)
AF:
0.00
AC:
0
AN:
52706
Middle Eastern (MID)
AF:
0.00
AC:
0
AN:
5764
European-Non Finnish (NFE)
AF:
8.99e-7
AC:
1
AN:
1111904
Other (OTH)
AF:
0.00
AC:
0
AN:
60380
Allele Balance Distribution
Red line indicates average allele balance
Average allele balance: 0.525
Heterozygous variant carriers
0
0
1
1
2
2
0.00
0.20
0.40
0.60
0.80
0.95
Allele balance

Age Distribution

Exome Het
Variant carriers
0
2
4
6
8
10
<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.:
32
Alfa
AF:
0.00
Hom.:
0
Bravo
AF:
0.00000378

ClinVar

Significance: Uncertain significance
Submissions summary: Uncertain:1
Revision: criteria provided, single submitter
LINK: link

Submissions by phenotype

Megaconial type congenital muscular dystrophy Uncertain:1
Jun 27, 2022
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. Algorithms developed to predict the effect of missense changes on protein structure and function (SIFT, PolyPhen-2, Align-GVGD) all suggest that this variant is likely to be tolerated. This sequence change replaces glutamic acid, which is acidic and polar, with lysine, which is basic and polar, at codon 193 of the CHKB protein (p.Glu193Lys). This variant is not present in population databases (gnomAD no frequency). This variant has not been reported in the literature in individuals affected with CHKB-related conditions. ClinVar contains an entry for this variant (Variation ID: 468475). -

Computational scores

Source: dbNSFP v4.3

Name
Calibrated prediction
Score
Prediction
AlphaMissense
Benign
0.18
BayesDel_addAF
Benign
-0.048
T
BayesDel_noAF
Benign
-0.31
CADD
Uncertain
25
DANN
Uncertain
1.0
DEOGEN2
Benign
0.18
T
Eigen
Benign
0.012
Eigen_PC
Benign
0.16
FATHMM_MKL
Uncertain
0.91
D
LIST_S2
Uncertain
0.95
D
M_CAP
Benign
0.0090
T
MetaRNN
Uncertain
0.54
D
MetaSVM
Benign
-0.98
T
MutationAssessor
Benign
1.1
L
PhyloP100
3.3
PrimateAI
Uncertain
0.56
T
PROVEAN
Uncertain
-2.4
N
REVEL
Benign
0.093
Sift
Benign
0.14
T
Sift4G
Benign
0.18
T
Polyphen
0.24
B
Vest4
0.64
MutPred
0.52
Gain of MoRF binding (P = 0.003);
MVP
0.74
ClinPred
0.87
D
GERP RS
5.0
RBP_binding_hub_radar
0.0
RBP_regulation_power_radar
1.7
Varity_R
0.58
gMVP
0.55
Mutation Taster
=80/20
polymorphism

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

Other links and lift over

dbSNP: rs1555894697; hg19: chr22-51019853; API