rs147485527

Positions:

Variant summary

Our verdict is Benign. Variant got -7 ACMG points: 2P and 9B. PM2BP4_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. 15/20 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

Clinical Significance

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

Conservation

PhyloP100: 1.18

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 made for transcript

Verdict is Benign. Variant got -7 ACMG points.

PM2

Very rare variant in population databases, with high coverage;

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 id is 468477.We mark this variant Likely_benign, oryginal submissions are: {Uncertain_significance=1, Likely_benign=1}. Variant chr22-50579999-G-A is described in Lovd as [Likely_benign].

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 male gnomad4 subpopulation. Median coverage is 32. This position pass quality control queck.

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	Protein	UniProt
CHKB	NM_005198.5 link	c.902C>T	p.Thr301Ile	missense_variant	8/11	ENST00000406938.3	NP_005189.2	Q9Y259-1A0A024R4X4
CHKB-CPT1B	NR_027928.2 link	n.1120C>T		non_coding_transcript_exon_variant	8/30

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Protein	Appris	UniProt
CHKB	ENST00000406938.3 link	c.902C>T	p.Thr301Ile	missense_variant	8/11	1	NM_005198.5	ENSP00000384400.3		Q9Y259-1

Frequencies

GnomAD3 genomes

AF:

0.000243

AC:

AN:

152178

Hom.:

Cov.:

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

GnomAD3 exomes

AF:

0.000217

AC:

AN:

249004

Hom.:

AF XY:

0.000237

AC XY:

AN XY:

134806

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 SAS exome

AF:

0.000229

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.:

Cov.:

AF XY:

0.000188

AC XY:

137

AN XY:

727182

show subpopulations

Gnomad4 AFR exome

AF:

0.00

Gnomad4 AMR exome

AF:

0.000492

Gnomad4 ASJ exome

AF:

0.000344

Gnomad4 EAS exome

AF:

0.00

Gnomad4 SAS exome

AF:

0.000406

Gnomad4 FIN exome

AF:

0.00

Gnomad4 NFE exome

AF:

0.000147

Gnomad4 OTH exome

AF:

0.000348

GnomAD4 genome

AF:

0.000243

AC:

AN:

152296

Hom.:

Cov.:

AF XY:

0.000282

AC XY:

AN XY:

74464

show subpopulations

Gnomad4 AFR

AF:

0.00

Gnomad4 AMR

AF:

0.00131

Gnomad4 ASJ

AF:

0.000576

Gnomad4 EAS

AF:

0.00

Gnomad4 SAS

AF:

0.000414

Gnomad4 FIN

AF:

0.00

Gnomad4 NFE

AF:

0.000176

Gnomad4 OTH

AF:

0.000473

Alfa

AF:

0.000155

Hom.:

Bravo

AF:

0.000291

TwinsUK

AF:

0.000270

AC:

ALSPAC

AF:

0.00

AC:

ESP6500AA

AF:

0.00

AC:

ESP6500EA

AF:

0.000349

AC:

ExAC

AF:

0.000206

AC:

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

Uncertain significance, criteria provided, single submitter

clinical testing

Labcorp Genetics (formerly Invitae), Labcorp

Jan 30, 2025

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

Likely benign, criteria provided, single submitter

clinical testing

CeGaT Center for Human Genetics Tuebingen

Mar 01, 2023

CHKB: BP4 -

Computational scores

Source: dbNSFP v4.3

Name

Calibrated prediction

Score

Prediction

AlphaMissense

Benign

0.10

BayesDel_addAF

Benign

-0.40

BayesDel_noAF

Benign

-0.48

CADD

Benign

DANN

Uncertain

0.97

DEOGEN2

Benign

0.16

Eigen

Benign

-0.49

Eigen_PC

Benign

-0.40

FATHMM_MKL

Benign

0.38

LIST_S2

Benign

0.65

M_CAP

Benign

0.024

MetaRNN

Benign

0.041

MetaSVM

Benign

-0.95

MutationAssessor

Benign

1.2

PrimateAI

Benign

0.35

PROVEAN

Benign

-1.6

REVEL

Benign

0.085

Sift

Benign

0.15

Sift4G

Benign

0.14

Polyphen

0.023

Vest4

0.35

MVP

0.66

ClinPred

0.024

GERP RS

1.6

RBP_binding_hub_radar

0.0

RBP_regulation_power_radar

1.0

Varity_R

0.18

gMVP

0.42

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

LitVar

Below is the list of publications found by LitVar. It may be empty.

Variant summary

Frequency

Consequence

Scores

Clinical Significance

Conservation

ACMG classification

Transcripts

RefSeq

Ensembl

Frequencies

ClinVar

Submissions by phenotype

Computational scores

Splicing

Publications

LitVar

Other links and lift over