rs147485527

Variant summary

Our verdict is Benign. The variant received -9 ACMG points: 0P and 9B. BP4_StrongBP6BS1

The NM_005198.5(CHKB):​c.902C>T​(p.Thr301Ile) variant causes a missense change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.000179 in 1,614,072 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 Conflicting classifications of pathogenicity (no stars).

Frequency

Genomes: 𝑓 0.00024 ( 0 hom., cov: 32)
Exomes 𝑓: 0.00017 ( 0 hom. )

Consequence

CHKB
NM_005198.5 missense

Scores

1
18

Clinical Significance

Conflicting classifications of pathogenicity criteria provided, conflicting classifications U:1B:1

Conservation

PhyloP100: 1.18

Publications

1 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: Benign. The variant received -9 ACMG points.

BP4
Computational evidence support a benign effect (MetaRNN=0.0412865).
BP6
Variant 22-50579999-G-A is Benign according to our data. Variant chr22-50579999-G-A is described in ClinVar as Conflicting_classifications_of_pathogenicity. ClinVar VariationId is 468477.
BS1
Variant frequency is greater than expected in population amr. GnomAd4 allele frequency = 0.000243 (37/152296) while in subpopulation AMR AF = 0.00131 (20/15302). AF 95% confidence interval is 0.000865. There are 0 homozygotes in GnomAd4. There are 21 alleles in the male GnomAd4 subpopulation. Median coverage is 32. This position passed quality control check.

Transcripts

RefSeq

Gene Transcript HGVSc HGVSp Effect Exon rank MANE Protein UniProt
CHKBNM_005198.5 linkc.902C>T p.Thr301Ile missense_variant Exon 8 of 11 ENST00000406938.3 NP_005189.2 Q9Y259-1A0A024R4X4
CHKB-CPT1BNR_027928.2 linkn.1120C>T non_coding_transcript_exon_variant Exon 8 of 30

Ensembl

Gene Transcript HGVSc HGVSp Effect Exon rank TSL MANE Protein Appris UniProt
CHKBENST00000406938.3 linkc.902C>T p.Thr301Ile missense_variant Exon 8 of 11 1 NM_005198.5 ENSP00000384400.3 Q9Y259-1
CHKB-CPT1BENST00000453634.5 linkn.-247C>T upstream_gene_variant 5 ENSP00000457031.1 H3BT56

Frequencies

GnomAD3 genomes
AF:
0.000243
AC:
37
AN:
152178
Hom.:
0
Cov.:
32
show subpopulations
Gnomad AFR
AF:
0.00
Gnomad AMI
AF:
0.00
Gnomad AMR
AF:
0.00131
Gnomad ASJ
AF:
0.000576
Gnomad EAS
AF:
0.00
Gnomad SAS
AF:
0.000413
Gnomad FIN
AF:
0.00
Gnomad MID
AF:
0.00
Gnomad NFE
AF:
0.000176
Gnomad OTH
AF:
0.000478
GnomAD2 exomes
AF:
0.000217
AC:
54
AN:
249004
AF XY:
0.000237
show subpopulations
Gnomad AFR exome
AF:
0.00
Gnomad AMR exome
AF:
0.000463
Gnomad ASJ exome
AF:
0.000497
Gnomad EAS exome
AF:
0.00
Gnomad FIN exome
AF:
0.00
Gnomad NFE exome
AF:
0.000216
Gnomad OTH exome
AF:
0.000327
GnomAD4 exome
AF:
0.000172
AC:
252
AN:
1461776
Hom.:
0
Cov.:
32
AF XY:
0.000188
AC XY:
137
AN XY:
727182
show subpopulations
African (AFR)
AF:
0.00
AC:
0
AN:
33478
American (AMR)
AF:
0.000492
AC:
22
AN:
44722
Ashkenazi Jewish (ASJ)
AF:
0.000344
AC:
9
AN:
26134
East Asian (EAS)
AF:
0.00
AC:
0
AN:
39700
South Asian (SAS)
AF:
0.000406
AC:
35
AN:
86258
European-Finnish (FIN)
AF:
0.00
AC:
0
AN:
53340
Middle Eastern (MID)
AF:
0.000347
AC:
2
AN:
5768
European-Non Finnish (NFE)
AF:
0.000147
AC:
163
AN:
1111984
Other (OTH)
AF:
0.000348
AC:
21
AN:
60392
Allele Balance Distribution
Red line indicates average allele balance
Average allele balance: 0.483
Heterozygous variant carriers
0
16
32
49
65
81
0.00
0.20
0.40
0.60
0.80
0.95
Allele balance

Age Distribution

Exome Het
Variant carriers
0
10
20
30
40
50
<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
AF:
0.000243
AC:
37
AN:
152296
Hom.:
0
Cov.:
32
AF XY:
0.000282
AC XY:
21
AN XY:
74464
show subpopulations
African (AFR)
AF:
0.00
AC:
0
AN:
41562
American (AMR)
AF:
0.00131
AC:
20
AN:
15302
Ashkenazi Jewish (ASJ)
AF:
0.000576
AC:
2
AN:
3472
East Asian (EAS)
AF:
0.00
AC:
0
AN:
5178
South Asian (SAS)
AF:
0.000414
AC:
2
AN:
4834
European-Finnish (FIN)
AF:
0.00
AC:
0
AN:
10610
Middle Eastern (MID)
AF:
0.00
AC:
0
AN:
294
European-Non Finnish (NFE)
AF:
0.000176
AC:
12
AN:
68016
Other (OTH)
AF:
0.000473
AC:
1
AN:
2116
Allele Balance Distribution
Red line indicates average allele balance
Average allele balance: 0.479
Heterozygous variant carriers
0
3
6
8
11
14
0.00
0.20
0.40
0.60
0.80
0.95
Allele balance

Age Distribution

Genome 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
Alfa
AF:
0.000386
Hom.:
0
Bravo
AF:
0.000291
TwinsUK
AF:
0.000270
AC:
1
ALSPAC
AF:
0.00
AC:
0
ESP6500AA
AF:
0.00
AC:
0
ESP6500EA
AF:
0.000349
AC:
3
ExAC
AF:
0.000206
AC:
25
EpiCase
AF:
0.000382
EpiControl
AF:
0.000415

ClinVar

Significance: Conflicting classifications of pathogenicity
Submissions summary: Uncertain:1Benign:1
Revision: criteria provided, conflicting classifications
LINK: link

Submissions by phenotype

Megaconial type congenital muscular dystrophy Uncertain:1
Jan 30, 2025
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 isoleucine, which is neutral and non-polar, at codon 301 of the CHKB protein (p.Thr301Ile). This variant is present in population databases (rs147485527, gnomAD 0.05%). This missense change has been observed in individual(s) with congenital muscular dystrophy with mitochondrial structural abnormalities (PMID: 21665002, 25326637). ClinVar contains an entry for this variant (Variation ID: 468477). Invitae Evidence Modeling of protein sequence and biophysical properties (such as structural, functional, and spatial information, amino acid conservation, physicochemical variation, residue mobility, and thermodynamic stability) indicates that this missense variant is not expected to disrupt CHKB protein function with a negative predictive value of 80%. Experimental studies have shown that this missense change does not substantially affect CHKB function (PMID: 21665002). 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. -

not provided Benign:1
Mar 01, 2023
CeGaT Center for Human Genetics Tuebingen
Significance:Likely benign
Review Status:criteria provided, single submitter
Collection Method:clinical testing

CHKB: BP4 -

Computational scores

Source: dbNSFP v4.3

Name
Calibrated prediction
Score
Prediction
AlphaMissense
Benign
0.10
BayesDel_addAF
Benign
-0.40
T
BayesDel_noAF
Benign
-0.48
CADD
Benign
19
DANN
Uncertain
0.97
DEOGEN2
Benign
0.16
T
Eigen
Benign
-0.49
Eigen_PC
Benign
-0.40
FATHMM_MKL
Benign
0.38
N
LIST_S2
Benign
0.65
T
M_CAP
Benign
0.024
T
MetaRNN
Benign
0.041
T
MetaSVM
Benign
-0.95
T
MutationAssessor
Benign
1.2
L
PhyloP100
1.2
PrimateAI
Benign
0.35
T
PROVEAN
Benign
-1.6
N
REVEL
Benign
0.085
Sift
Benign
0.15
T
Sift4G
Benign
0.14
T
Polyphen
0.023
B
Vest4
0.35
MVP
0.66
ClinPred
0.024
T
GERP RS
1.6
RBP_binding_hub_radar
0.0
RBP_regulation_power_radar
1.0
Varity_R
0.18
gMVP
0.42
Mutation Taster
=86/14
polymorphism

Splicing

Name
Calibrated prediction
Score
Prediction
SpliceAI score (max)
0.020
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: rs147485527; hg19: chr22-51018428; API