chr21-43774296-C-T

Variant summary

Our verdict is Uncertain significance. Variant got 3 ACMG points: 4P and 1B. PM1PM2BP4

The NM_000100.4(CSTB):​c.203G>A​(p.Arg68Gln) variant causes a missense change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.00000889 in 1,461,848 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a benign outcome for this variant. No clinical diagnostic laboratories have submitted clinical-significance assessments for this variant to ClinVar.

Frequency

Genomes: not found (cov: 33)
Exomes 𝑓: 0.0000089 ( 0 hom. )

Consequence

CSTB
NM_000100.4 missense

Scores

4
14

Clinical Significance

Not reported in ClinVar

Conservation

PhyloP100: 1.96
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]

Genome browser will be placed here

ACMG classification

Classification made for transcript

Verdict is Uncertain_significance. Variant got 3 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;
BP4
Computational evidence support a benign effect (MetaRNN=0.3323329).

Transcripts

RefSeq

Gene Transcript HGVSc HGVSp Effect #exon/exons MANE Protein UniProt
CSTBNM_000100.4 linkuse as main transcriptc.203G>A p.Arg68Gln missense_variant 3/3 ENST00000291568.7 NP_000091.1 P04080Q76LA1

Ensembl

Gene Transcript HGVSc HGVSp Effect #exon/exons TSL MANE Protein Appris UniProt
CSTBENST00000291568.7 linkuse as main transcriptc.203G>A p.Arg68Gln missense_variant 3/31 NM_000100.4 ENSP00000291568.6 P04080

Frequencies

GnomAD3 genomes
Cov.:
33
GnomAD3 exomes
AF:
0.0000119
AC:
3
AN:
251456
Hom.:
0
AF XY:
0.00000736
AC XY:
1
AN XY:
135920
show subpopulations
Gnomad AFR exome
AF:
0.00
Gnomad AMR exome
AF:
0.00
Gnomad ASJ exome
AF:
0.00
Gnomad EAS exome
AF:
0.0000544
Gnomad SAS exome
AF:
0.00
Gnomad FIN exome
AF:
0.00
Gnomad NFE exome
AF:
0.0000176
Gnomad OTH exome
AF:
0.00
GnomAD4 exome
AF:
0.00000889
AC:
13
AN:
1461848
Hom.:
0
Cov.:
31
AF XY:
0.00000825
AC XY:
6
AN XY:
727218
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:
0.00000989
Gnomad4 OTH exome
AF:
0.0000166
GnomAD4 genome
Cov.:
33
ExAC
AF:
0.00000824
AC:
1
EpiCase
AF:
0.00
EpiControl
AF:
0.0000593

ClinVar

Not reported in ClinVar

Computational scores

Source: dbNSFP v4.3

Name
Calibrated prediction
Score
Prediction
AlphaMissense
Benign
0.19
BayesDel_addAF
Benign
-0.25
T
BayesDel_noAF
Benign
-0.42
CADD
Benign
16
DANN
Uncertain
0.99
DEOGEN2
Benign
0.37
T
Eigen
Benign
-0.36
Eigen_PC
Benign
-0.39
FATHMM_MKL
Benign
0.55
D
LIST_S2
Benign
0.82
T
M_CAP
Benign
0.0086
T
MetaRNN
Benign
0.33
T
MetaSVM
Benign
-1.0
T
PrimateAI
Uncertain
0.54
T
PROVEAN
Uncertain
-2.7
D
REVEL
Benign
0.14
Sift
Benign
0.070
T
Sift4G
Uncertain
0.055
T
Polyphen
0.47
P
Vest4
0.35
MutPred
0.63
Loss of sheet (P = 0.0817);
MVP
0.099
MPC
0.20
ClinPred
0.68
D
GERP RS
3.6
RBP_binding_hub_radar
0.0
RBP_regulation_power_radar
1.1
Varity_R
0.54
gMVP
0.62

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.

Other links and lift over

dbSNP: rs757707761; hg19: chr21-45194177; API