22-50580198-A-T

Variant names:

Variant summary

Our verdict is Pathogenic. Variant got 12 ACMG points: 12P and 0B. PVS1PM2PP5_Moderate

The NM_005198.5(CHKB):c.810T>A(p.Tyr270*) variant causes a stop gained change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.0000204 in 1,613,748 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 Pathogenic (★). Variant results in nonsense mediated mRNA decay.

Frequency

Genomes: 𝑓 0.000020 ( 0 hom., cov: 32)

Exomes 𝑓: 0.000021 ( 0 hom. )

Consequence

CHKB
NM_005198.5 stop_gained

Scores

Clinical Significance

Pathogenic criteria provided, single submitter P:3

Conservation

PhyloP100: -0.0180

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 Pathogenic. Variant got 12 ACMG points.

PVS1

Loss of function variant, product undergoes nonsense mediated mRNA decay. LoF is a known mechanism of disease.

PM2

Very rare variant in population databases, with high coverage;

PP5

Variant 22-50580198-A-T is Pathogenic according to our data. Variant chr22-50580198-A-T is described in ClinVar as [Pathogenic]. Clinvar id is 30952.Status of the report is criteria_provided_single_submitter, 1 stars. Variant chr22-50580198-A-T is described in Lovd as [Pathogenic].

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	MANE	Protein	UniProt
CHKB	NM_005198.5 link	c.810T>A	p.Tyr270*	stop_gained	Exon 7 of 11	ENST00000406938.3	NP_005189.2	Q9Y259-1A0A024R4X4
CHKB-CPT1B	NR_027928.2 link	n.1028T>A		non_coding_transcript_exon_variant	Exon 7 of 30

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	TSL	MANE	Protein	Appris	UniProt
CHKB	ENST00000406938.3 link	c.810T>A	p.Tyr270*	stop_gained	Exon 7 of 11	1	NM_005198.5	ENSP00000384400.3		Q9Y259-1

Frequencies

GnomAD3 genomes

AF:

0.0000197

AC:

AN:

152202

Hom.:

Cov.:

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:

0.0000294

Gnomad OTH

AF:

0.00

GnomAD3 exomes

AF:

0.00000798

AC:

AN:

250764

Hom.:

AF XY:

0.00

AC XY:

AN XY:

135630

show subpopulations

Gnomad AFR exome

AF:

0.00

Gnomad AMR exome

AF:

0.00

Gnomad ASJ exome

AF:

0.00

Gnomad EAS exome

AF:

0.00

Gnomad SAS exome

AF:

0.00

Gnomad FIN exome

AF:

0.00

Gnomad NFE exome

AF:

0.0000177

Gnomad OTH exome

AF:

0.00

GnomAD4 exome

AF:

0.0000205

AC:

AN:

1461546

Hom.:

Cov.:

AF XY:

0.0000289

AC XY:

AN XY:

727046

show subpopulations

Gnomad4 AFR exome

AF:

0.0000299

Gnomad4 AMR exome

AF:

0.00

Gnomad4 ASJ exome

AF:

0.00

Gnomad4 EAS exome

AF:

0.00

Gnomad4 SAS exome

AF:

0.00

Gnomad4 FIN exome

AF:

0.00

Gnomad4 NFE exome

AF:

0.0000252

Gnomad4 OTH exome

AF:

0.0000166

GnomAD4 genome

AF:

0.0000197

AC:

AN:

152202

Hom.:

Cov.:

AF XY:

0.0000403

AC XY:

AN XY:

74362

show subpopulations

Gnomad4 AFR

AF:

0.0000241

Gnomad4 AMR

AF:

0.00

Gnomad4 ASJ

AF:

0.00

Gnomad4 EAS

AF:

0.00

Gnomad4 SAS

AF:

0.00

Gnomad4 FIN

AF:

0.00

Gnomad4 NFE

AF:

0.0000294

Gnomad4 OTH

AF:

0.00

Alfa

AF:

0.0000688

Hom.:

Bravo

AF:

0.0000264

ExAC

AF:

0.00000824

AC:

ClinVar

Significance: Pathogenic

Submissions summary: Pathogenic:3

Revision: criteria provided, single submitter

LINK: link

Submissions by phenotype

Megaconial type congenital muscular dystrophy

Pathogenic:2

Nov 01, 2014

OMIM

Significance: Pathogenic

Review Status: no assertion criteria provided

Collection Method: literature only

- -

Jan 31, 2024

Labcorp Genetics (formerly Invitae), Labcorp

Significance: Pathogenic

Review Status: criteria provided, single submitter

Collection Method: clinical testing

This sequence change creates a premature translational stop signal (p.Tyr270*) in the CHKB gene. It is expected to result in an absent or disrupted protein product. Loss-of-function variants in CHKB are known to be pathogenic (PMID: 21665002). This variant is present in population databases (rs750764003, gnomAD 0.002%). This premature translational stop signal has been observed in individuals with congenital muscular dystrophy (PMID: 21665002, 26006750). ClinVar contains an entry for this variant (Variation ID: 30952). For these reasons, this variant has been classified as Pathogenic. -

CHKB-related disorder

Pathogenic:1

May 30, 2024

PreventionGenetics, part of Exact Sciences

Significance: Pathogenic

Review Status: no assertion criteria provided

Collection Method: clinical testing

The CHKB c.810T>A variant is predicted to result in premature protein termination (p.Tyr270*). This variant was reported in individuals with autosomal recessive congenital muscular dystrophy and mitochondrial enlargement (Mitsuhashi et al. 2011. PubMed ID: 21665002; Castro-Gago et al. 2014. PubMed ID: 24997086). This variant is reported in 0.0023% of alleles in individuals of European (Non-Finnish) descent in gnomAD. Nonsense variants in CHKB are expected to be pathogenic. This variant is interpreted as pathogenic. -

Computational scores

Source: dbNSFP v4.3

Name

Calibrated prediction

Score

Prediction

BayesDel_addAF

Pathogenic

0.61

BayesDel_noAF

Pathogenic

0.56

CADD

Pathogenic

DANN

Uncertain

0.99

Eigen

Benign

0.095

Eigen_PC

Benign

-0.13

FATHMM_MKL

Uncertain

0.83

Vest4

0.93

GERP RS

-3.1

Splicing

Name

Calibrated prediction

Score

Prediction

SpliceAI score (max)

0.010

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