22-50580390-G-C

Variant names:

Variant summary

Our verdict is Uncertain significance. The variant received 4 ACMG points: 4P and 0B. PM2PP3_Moderate

The NM_005198.5(CHKB):c.704C>G(p.Pro235Arg) variant causes a missense change involving the alteration of a conserved nucleotide. The variant allele was found at a frequency of 0.00000434 in 1,613,930 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. P235L) has been classified as Uncertain significance.

Frequency

Genomes: 𝑓 0.0000066 ( 0 hom., cov: 32)

Exomes 𝑓: 0.0000041 ( 0 hom. )

Consequence

CHKB
NM_005198.5 missense

Scores

Clinical Significance

Uncertain significance criteria provided, single submitter U:1

Conservation

PhyloP100: 9.98

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 links:

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]

CHKB-CPT1B links:

Genome browser will be placed here

ACMG classification

Classification was made for transcript

Our verdict: Uncertain_significance. The variant received 4 ACMG points.

PM2

Very rare variant in population databases, with high coverage;

PP3

MetaRNN computational evidence supports a deleterious effect, 0.9

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	Gene	Transcript	Tags	HGVSc	HGVSp	Effect	Exon Rank	Protein	UniProt
	CHKB	NM_005198.5	MANE Select	c.704C>G	p.Pro235Arg	missense	Exon 6 of 11	NP_005189.2
	CHKB-CPT1B	NR_027928.2		n.922C>G		non_coding_transcript_exon	Exon 6 of 30

Ensembl Transcripts

Gene	Transcript	Tags	HGVSc	HGVSp	Effect	Exon Rank	Protein
CHKB	ENST00000406938.3	TSL:1 MANE Select	c.704C>G	p.Pro235Arg	missense	Exon 6 of 11	ENSP00000384400.3
CHKB	ENST00000481673.5	TSL:1	n.1154C>G		non_coding_transcript_exon	Exon 5 of 10
CHKB	ENST00000463053.1	TSL:3	n.853C>G		non_coding_transcript_exon	Exon 7 of 7

Frequencies

GnomAD3 genomes

AF:

0.00000657

AC:

AN:

152180

Hom.:

Cov.:

show subpopulations

Gnomad AFR

AF:

0.00

Gnomad AMI

AF:

0.00

Gnomad AMR

AF:

0.0000655

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:

0.00

Gnomad OTH

AF:

0.00

GnomAD2 exomes

AF:

0.00000795

AC:

AN:

251480

AF XY:

0.00

show subpopulations

Gnomad AFR exome

AF:

0.00

Gnomad AMR exome

AF:

0.0000578

Gnomad ASJ exome

AF:

0.00

Gnomad EAS exome

AF:

0.00

Gnomad FIN exome

AF:

0.00

Gnomad NFE exome

AF:

0.00

Gnomad OTH exome

AF:

0.00

GnomAD4 exome

AF:

0.00000410

AC:

AN:

1461750

Hom.:

Cov.:

AF XY:

0.00000138

AC XY:

AN XY:

727160

show subpopulations

African (AFR)

AF:

0.00

AC:

AN:

33480

American (AMR)

AF:

0.000112

AC:

AN:

44724

Ashkenazi Jewish (ASJ)

AF:

0.00

AC:

AN:

26136

East Asian (EAS)

AF:

0.00

AC:

AN:

39700

South Asian (SAS)

AF:

0.00

AC:

AN:

86256

European-Finnish (FIN)

AF:

0.00

AC:

AN:

53292

Middle Eastern (MID)

AF:

0.00

AC:

AN:

5768

European-Non Finnish (NFE)

AF:

0.00

AC:

AN:

1112000

Other (OTH)

AF:

0.0000166

AC:

AN:

60394

Allele Balance Distribution

Red line indicates average allele balance

Average allele balance: 0.500

Heterozygous variant carriers

0.00

0.20

0.40

0.60

0.80

0.95

Allele balance

Age Distribution

Exome Het

Variant carriers

<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:

0.00000657

AC:

AN:

152180

Hom.:

Cov.:

AF XY:

0.0000135

AC XY:

AN XY:

74346

show subpopulations

African (AFR)

AF:

0.00

AC:

AN:

41432

American (AMR)

AF:

0.0000655

AC:

AN:

15268

Ashkenazi Jewish (ASJ)

AF:

0.00

AC:

AN:

3472

East Asian (EAS)

AF:

0.00

AC:

AN:

5198

South Asian (SAS)

AF:

0.00

AC:

AN:

4834

European-Finnish (FIN)

AF:

0.00

AC:

AN:

10618

Middle Eastern (MID)

AF:

0.00

AC:

AN:

316

European-Non Finnish (NFE)

AF:

0.00

AC:

AN:

68040

Other (OTH)

AF:

0.00

AC:

AN:

2090

Allele Balance Distribution

Red line indicates average allele balance

Average allele balance: 0.475

Heterozygous variant carriers

0.00

0.20

0.40

0.60

0.80

0.95

Allele balance

Alfa

AF:

0.00

Hom.:

Bravo

AF:

0.00000756

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

Mar 08, 2022

Labcorp Genetics (formerly Invitae), Labcorp

Significance:Uncertain significance

Review Status:criteria provided, single submitter

Collection Method:clinical testing

This sequence change replaces proline, which is neutral and non-polar, with arginine, which is basic and polar, at codon 235 of the CHKB protein (p.Pro235Arg). This variant is present in population databases (rs199847760, gnomAD 0.006%). This variant has not been reported in the literature in individuals affected with CHKB-related conditions. Algorithms developed to predict the effect of missense changes on protein structure and function are either unavailable or do not agree on the potential impact of this missense change (SIFT: "Tolerated"; PolyPhen-2: "Probably Damaging"; Align-GVGD: "Class C0"). 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.

Computational scores

Source: dbNSFP v4.9

Name

Calibrated prediction

Score

Prediction

AlphaMissense

Uncertain

0.39

BayesDel_addAF

Pathogenic

0.21

BayesDel_noAF

Pathogenic

0.24

CADD

Pathogenic

(source)

DANN

Uncertain

1.0

DEOGEN2

Benign

0.36

Eigen

Pathogenic

0.77

Eigen_PC

Pathogenic

0.74

FATHMM_MKL

Pathogenic

1.0

LIST_S2

Uncertain

0.94

M_CAP

Benign

0.084

MetaRNN

Pathogenic

0.90

MetaSVM

Benign

-0.40

MutationAssessor

Uncertain

2.0

PhyloP100

PrimateAI

Uncertain

0.73

PROVEAN

Pathogenic

-7.8

REVEL

Uncertain

0.62

Sift

Uncertain

0.0020

Sift4G

Uncertain

0.0030

Polyphen

1.0

Vest4

0.91

MutPred

0.71

Loss of glycosylation at T232 (P = 0.0285)

MVP

0.89

ClinPred

0.99

GERP RS

5.4

RBP_binding_hub_radar

0.0

RBP_regulation_power_radar

1.7

Varity_R

0.88

gMVP

0.83

Mutation Taster

=40/60

disease causing

(source)

Splicing

Name

Calibrated prediction

Score

Prediction

SpliceAI score (max)

0.040

Details are displayed if max score is > 0.2

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

Publications

You must be logged in to view publications. This limit was set because tens of millions (!) of queries from AI bots are generated daily.

Variant summary

Frequency

Consequence

Scores

Clinical Significance

Conservation

Publications

ACMG classification

Variant Effect in Transcripts

RefSeq Transcripts

Ensembl Transcripts

Frequencies

Age Distribution

ClinVar

Submissions by phenotype

Computational scores

Splicing

Publications

Other links and lift over