rs371751084

Variant summary

Our verdict is Likely pathogenic. The variant received 6 ACMG points: 6P and 0B. PM2PP3_ModeratePP5_Moderate

The NM_005198.5(CHKB):​c.722A>G​(p.Asn241Ser) variant causes a missense change involving the alteration of a conserved nucleotide. The variant allele was found at a frequency of 0.0000173 in 1,613,892 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 Likely pathogenic (★).

Frequency

Genomes: 𝑓 0.000013 ( 0 hom., cov: 32)
Exomes 𝑓: 0.000018 ( 0 hom. )

Consequence

CHKB
NM_005198.5 missense

Scores

7
8
3

Clinical Significance

Likely pathogenic criteria provided, single submitter P:1

Conservation

PhyloP100: 8.00

Publications

5 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: Likely_pathogenic. The variant received 6 ACMG points.

PM2
Very rare variant in population databases, with high coverage;
PP3
MetaRNN computational evidence supports a deleterious effect, 0.927
PP5
Variant 22-50580372-T-C is Pathogenic according to our data. Variant chr22-50580372-T-C is described in ClinVar as Likely_pathogenic. ClinVar VariationId is 342172.Status of the report is criteria_provided_single_submitter, 1 stars.

Variant Effect in Transcripts

ACMG analysis was done for transcript: NM_005198.5. You can select a different transcript below to see updated ACMG assignments.

RefSeq Transcripts

Selected
GeneTranscriptTagsHGVScHGVSpEffectExon RankProteinUniProt
CHKB
NM_005198.5
MANE Select
c.722A>Gp.Asn241Ser
missense
Exon 6 of 11NP_005189.2
CHKB-CPT1B
NR_027928.2
n.940A>G
non_coding_transcript_exon
Exon 6 of 30

Ensembl Transcripts

Selected
GeneTranscriptTagsHGVScHGVSpEffectExon RankProteinUniProt
CHKB
ENST00000406938.3
TSL:1 MANE Select
c.722A>Gp.Asn241Ser
missense
Exon 6 of 11ENSP00000384400.3
CHKB
ENST00000481673.5
TSL:1
n.1172A>G
non_coding_transcript_exon
Exon 5 of 10
CHKB
ENST00000463053.1
TSL:3
n.871A>G
non_coding_transcript_exon
Exon 7 of 7

Frequencies

GnomAD3 genomes
AF:
0.0000131
AC:
2
AN:
152140
Hom.:
0
Cov.:
32
show subpopulations
Gnomad AFR
AF:
0.0000241
Gnomad AMI
AF:
0.00
Gnomad AMR
AF:
0.00
Gnomad ASJ
AF:
0.00
Gnomad EAS
AF:
0.00
Gnomad SAS
AF:
0.00
Gnomad FIN
AF:
0.00
Gnomad MID
AF:
0.00
Gnomad NFE
AF:
0.0000147
Gnomad OTH
AF:
0.00
GnomAD2 exomes
AF:
0.00000795
AC:
2
AN:
251474
AF XY:
0.0000147
show subpopulations
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:
0.00000879
Gnomad OTH exome
AF:
0.00
GnomAD4 exome
AF:
0.0000178
AC:
26
AN:
1461752
Hom.:
0
Cov.:
33
AF XY:
0.0000179
AC XY:
13
AN XY:
727162
show subpopulations
African (AFR)
AF:
0.00
AC:
0
AN:
33480
American (AMR)
AF:
0.0000447
AC:
2
AN:
44724
Ashkenazi Jewish (ASJ)
AF:
0.00
AC:
0
AN:
26136
East Asian (EAS)
AF:
0.00
AC:
0
AN:
39700
South Asian (SAS)
AF:
0.0000348
AC:
3
AN:
86256
European-Finnish (FIN)
AF:
0.00
AC:
0
AN:
53292
Middle Eastern (MID)
AF:
0.00
AC:
0
AN:
5764
European-Non Finnish (NFE)
AF:
0.0000171
AC:
19
AN:
1112006
Other (OTH)
AF:
0.0000331
AC:
2
AN:
60394
Allele Balance Distribution
Red line indicates average allele balance
Average allele balance: 0.481
Heterozygous variant carriers
0
3
5
8
10
13
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
AF:
0.0000131
AC:
2
AN:
152140
Hom.:
0
Cov.:
32
AF XY:
0.0000135
AC XY:
1
AN XY:
74326
show subpopulations
African (AFR)
AF:
0.0000241
AC:
1
AN:
41412
American (AMR)
AF:
0.00
AC:
0
AN:
15280
Ashkenazi Jewish (ASJ)
AF:
0.00
AC:
0
AN:
3470
East Asian (EAS)
AF:
0.00
AC:
0
AN:
5194
South Asian (SAS)
AF:
0.00
AC:
0
AN:
4818
European-Finnish (FIN)
AF:
0.00
AC:
0
AN:
10620
Middle Eastern (MID)
AF:
0.00
AC:
0
AN:
316
European-Non Finnish (NFE)
AF:
0.0000147
AC:
1
AN:
68024
Other (OTH)
AF:
0.00
AC:
0
AN:
2094
Allele Balance Distribution
Red line indicates average allele balance
Average allele balance: 0.500
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

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:
0.0000453
Hom.:
0
Bravo
AF:
0.0000264
ESP6500AA
AF:
0.000227
AC:
1
ESP6500EA
AF:
0.00
AC:
0
ExAC
AF:
0.0000165
AC:
2

ClinVar

Significance: Likely pathogenic
Submissions summary: Pathogenic:1
Revision: criteria provided, single submitter
LINK: link

Submissions by phenotype

Megaconial type congenital muscular dystrophy Pathogenic:1
May 22, 2024
Labcorp Genetics (formerly Invitae), Labcorp
Significance:Likely pathogenic
Review Status:criteria provided, single submitter
Collection Method:clinical testing

This sequence change replaces asparagine, which is neutral and polar, with serine, which is neutral and polar, at codon 241 of the CHKB protein (p.Asn241Ser). This variant is present in population databases (rs371751084, gnomAD 0.007%). This missense change has been observed in individuals with congenital muscular dystrophy (PMID: 23692895, 26548592). ClinVar contains an entry for this variant (Variation ID: 342172). Advanced modeling of protein sequence and biophysical properties (such as structural, functional, and spatial information, amino acid conservation, physicochemical variation, residue mobility, and thermodynamic stability) performed at Invitae indicates that this missense variant is expected to disrupt CHKB protein function with a positive predictive value of 80%. In summary, the currently available evidence indicates that the variant is pathogenic, but additional data are needed to prove that conclusively. Therefore, this variant has been classified as Likely Pathogenic.

Computational scores

Source: dbNSFP v4.9

Name
Calibrated prediction
Score
Prediction
AlphaMissense
Pathogenic
0.71
BayesDel_addAF
Benign
-0.049
T
BayesDel_noAF
Benign
-0.13
CADD
Pathogenic
34
DANN
Uncertain
1.0
DEOGEN2
Uncertain
0.48
T
Eigen
Pathogenic
0.78
Eigen_PC
Pathogenic
0.75
FATHMM_MKL
Pathogenic
1.0
D
LIST_S2
Uncertain
0.97
D
M_CAP
Benign
0.060
D
MetaRNN
Pathogenic
0.93
D
MetaSVM
Uncertain
0.049
D
MutationAssessor
Uncertain
2.5
M
PhyloP100
8.0
PrimateAI
Uncertain
0.57
T
PROVEAN
Pathogenic
-4.5
D
REVEL
Uncertain
0.64
Sift
Pathogenic
0.0
D
Sift4G
Uncertain
0.019
D
Polyphen
0.99
D
Vest4
0.94
MVP
0.84
ClinPred
0.98
D
GERP RS
5.4
RBP_binding_hub_radar
0.0
RBP_regulation_power_radar
1.7
Varity_R
0.84
gMVP
0.83
Mutation Taster
=24/76
disease causing

Splicing

Name
Calibrated prediction
Score
Prediction
SpliceAI score (max)
0.49
Details are displayed if max score is > 0.2
DS_AG_spliceai
0.49
Position offset: -1

Find out detailed SpliceAI scores and Pangolin per-transcript scores at spliceailookup.broadinstitute.org

Publications

Other links and lift over

dbSNP: rs371751084; hg19: chr22-51018801; API