rs762082236

Positions:

chr21-43774668-T-C

Variant summary

Our verdict is Likely pathogenic. Variant got 6 ACMG points: 6P and 0B. PM1PM2PP3_Moderate

The NM_000100.4(CSTB):c.158A>G(p.Tyr53Cys) variant causes a missense change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.00000868 in 1,613,484 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 (★★).

Frequency

Genomes: 𝑓 0.000020 ( 0 hom., cov: 33)

Exomes 𝑓: 0.0000075 ( 0 hom. )

Consequence

CSTB
NM_000100.4 missense

Scores

Clinical Significance

Uncertain significance criteria provided, multiple submitters, no conflicts U:3

Conservation

PhyloP100: 0.441

Variant links:

Genes affected

CSTB (HGNC:2482): (cystatin B) The cystatin superfamily encompasses proteins that contain multiple cystatin-like sequences. Some of the members are active cysteine protease inhibitors, while others have lost or perhaps never acquired this inhibitory activity. There are three inhibitory families in the superfamily, including the type 1 cystatins (stefins), type 2 cystatins and kininogens. This gene encodes a stefin that functions as an intracellular thiol protease inhibitor. The protein is able to form a dimer stabilized by noncovalent forces, inhibiting papain and cathepsins l, h and b. The protein is thought to play a role in protecting against the proteases leaking from lysosomes. Evidence indicates that mutations in this gene are responsible for the primary defects in patients with progressive myoclonic epilepsy (EPM1). One type of mutation responsible for EPM1 is the expansion in the promoter region of this gene of a CCCCGCCCCGCG repeat from 2-3 copies to 30-78 copies. [provided by RefSeq, Jul 2016]

CSTB links:

Genome browser will be placed here

ACMG classification

Classification made for transcript

Verdict is Likely_pathogenic. Variant got 6 ACMG points.

PM1

In a chain Cystatin-B (size 97) in uniprot entity CYTB_HUMAN there are 6 pathogenic changes around while only 2 benign (75%) in NM_000100.4

PM2

Very rare variant in population databases, with high coverage;

PP3

MetaRNN computational evidence supports a deleterious effect, 0.854

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	Protein	UniProt
CSTB	NM_000100.4 linkuse as main transcript	c.158A>G	p.Tyr53Cys	missense_variant	2/3	ENST00000291568.7	NP_000091.1

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Protein	Appris
CSTB	ENST00000291568.7 linkuse as main transcript	c.158A>G	p.Tyr53Cys	missense_variant	2/3	1	NM_000100.4	ENSP00000291568	P1
CSTB	ENST00000640406.1 linkuse as main transcript	c.158A>G	p.Tyr53Cys	missense_variant	2/2	2		ENSP00000492672
CSTB	ENST00000639959.1 linkuse as main transcript	c.36-338A>G		intron_variant		5		ENSP00000492123
CSTB	ENST00000675996.1 linkuse as main transcript	n.583A>G		non_coding_transcript_exon_variant	2/3

Frequencies

GnomAD3 genomes

AF:

0.0000197

AC:

AN:

152152

Hom.:

Cov.:

show subpopulations

Gnomad AFR

AF:

0.0000483

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

GnomAD3 exomes

AF:

0.0000119

AC:

AN:

251458

Hom.:

AF XY:

0.00000736

AC XY:

AN XY:

135912

show subpopulations

Gnomad AFR exome

AF:

0.00

Gnomad AMR exome

AF:

0.0000578

Gnomad ASJ exome

AF:

0.00

Gnomad EAS exome

AF:

0.0000544

Gnomad SAS 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:

0.00000753

AC:

AN:

1461332

Hom.:

Cov.:

AF XY:

0.00000550

AC XY:

AN XY:

727006

show subpopulations

Gnomad4 AFR exome

AF:

0.0000299

Gnomad4 AMR exome

AF:

0.0000894

Gnomad4 ASJ exome

AF:

0.00

Gnomad4 EAS exome

AF:

0.0000252

Gnomad4 SAS exome

AF:

0.00

Gnomad4 FIN exome

AF:

0.00

Gnomad4 NFE exome

AF:

0.00000360

Gnomad4 OTH exome

AF:

0.0000166

GnomAD4 genome

AF:

0.0000197

AC:

AN:

152152

Hom.:

Cov.:

AF XY:

0.0000135

AC XY:

AN XY:

74322

show subpopulations

Gnomad4 AFR

AF:

0.0000483

Gnomad4 AMR

AF:

0.0000655

Gnomad4 ASJ

AF:

0.00

Gnomad4 EAS

AF:

0.00

Gnomad4 SAS

AF:

0.00

Gnomad4 FIN

AF:

0.00

Gnomad4 NFE

AF:

0.00

Gnomad4 OTH

AF:

0.00

Alfa

AF:

0.0000329

Hom.:

Bravo

AF:

0.0000264

ExAC

AF:

0.00000824

AC:

ClinVar

Significance: Uncertain significance

Submissions summary: Uncertain:3

Revision: criteria provided, multiple submitters, no conflicts

LINK: link

Submissions by phenotype

Inborn genetic diseases

Uncertain:1

Uncertain significance, criteria provided, single submitter

clinical testing

Ambry Genetics

Dec 28, 2020

The c.158A>G (p.Y53C) alteration is located in exon 2 (coding exon 2) of the CSTB gene. This alteration results from a A to G substitution at nucleotide position 158, causing the tyrosine (Y) at amino acid position 53 to be replaced by a cysteine (C). The p.Y53C alteration is predicted to be tolerated by in silico analysis. Based on insufficient or conflicting evidence, the clinical significance of this alteration remains unclear. -

Unverricht-Lundborg syndrome

Uncertain:1

Uncertain significance, criteria provided, single submitter

clinical testing

Knight Diagnostic Laboratories, Oregon Health and Sciences University

Apr 19, 2019

- -

Progressive myoclonic epilepsy

Uncertain:1

Uncertain significance, criteria provided, single submitter

clinical testing

Labcorp Genetics (formerly Invitae), Labcorp

Oct 17, 2022

This sequence change replaces tyrosine, which is neutral and polar, with cysteine, which is neutral and slightly polar, at codon 53 of the CSTB protein (p.Tyr53Cys). This variant is present in population databases (rs762082236, gnomAD 0.006%). This variant has not been reported in the literature in individuals affected with CSTB-related conditions. ClinVar contains an entry for this variant (Variation ID: 566232). 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: "Deleterious"; PolyPhen-2: "Benign"; Align-GVGD: "Class C45"). 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 v4.3

Name

Calibrated prediction

Score

Prediction

AlphaMissense

Benign

0.24

BayesDel_addAF

Benign

-0.0058

BayesDel_noAF

Uncertain

-0.070

CADD

Benign

DANN

Uncertain

0.99

DEOGEN2

Uncertain

0.47

T;.

Eigen

Benign

-0.28

Eigen_PC

Benign

-0.43

FATHMM_MKL

Benign

0.63

LIST_S2

Uncertain

0.97

D;D

M_CAP

Benign

0.055

MetaRNN

Pathogenic

0.85

D;D

MetaSVM

Uncertain

0.44

MutationTaster

Benign

1.0

PrimateAI

Uncertain

0.60

PROVEAN

Pathogenic

-7.5

D;.

REVEL

Uncertain

0.47

Sift

Uncertain

0.0010

D;.

Sift4G

Uncertain

0.0030

D;.

Polyphen

1.0

D;.

Vest4

0.81

MVP

0.69

MPC

0.25

ClinPred

0.81

GERP RS

-0.015

RBP_binding_hub_radar

0.0

RBP_regulation_power_radar

1.1

Varity_R

0.87

gMVP

0.80

Splicing

Name

Calibrated prediction

Score

Prediction

SpliceAI score (max)

0.0

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