rs138337167

Variant summary

Our verdict is Likely benign. The variant received -2 ACMG points: 0P and 2B. BP4_Moderate

The NM_000100.4(CSTB):​c.269C>G​(p.Ala90Gly) variant causes a missense change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.000018 in 1,614,126 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a benign outcome for this variant. 16/21 in silico tools predict a benign 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. A90T) has been classified as Uncertain significance.

Frequency

Genomes: 𝑓 0.000020 ( 0 hom., cov: 33)
Exomes 𝑓: 0.000018 ( 0 hom. )

Consequence

CSTB
NM_000100.4 missense

Scores

18

Clinical Significance

Uncertain significance criteria provided, single submitter U:1

Conservation

PhyloP100: 0.650

Publications

1 publications found
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 Gene-Disease associations (from GenCC):
  • Unverricht-Lundborg syndrome
    Inheritance: AR Classification: DEFINITIVE, STRONG, SUPPORTIVE Submitted by: ClinGen, G2P, Orphanet, Labcorp Genetics (formerly Invitae)
  • keratolytic winter erythema
    Inheritance: AD Classification: MODERATE Submitted by: PanelApp Australia
  • genetic developmental and epileptic encephalopathy
    Inheritance: AR Classification: MODERATE Submitted by: ClinGen
  • autosomal recessive hypohidrotic ectodermal dysplasia
    Inheritance: AR Classification: SUPPORTIVE Submitted by: Orphanet

Genome browser will be placed here

ACMG classification

Classification was made for transcript

Our verdict: Likely_benign. The variant received -2 ACMG points.

BP4
Computational evidence support a benign effect (MetaRNN=0.077572554).

Transcripts

RefSeq

Gene Transcript HGVSc HGVSp Effect Exon rank MANE Protein UniProt
CSTBNM_000100.4 linkc.269C>G p.Ala90Gly missense_variant Exon 3 of 3 ENST00000291568.7 NP_000091.1 P04080Q76LA1

Ensembl

Gene Transcript HGVSc HGVSp Effect Exon rank TSL MANE Protein Appris UniProt
CSTBENST00000291568.7 linkc.269C>G p.Ala90Gly missense_variant Exon 3 of 3 1 NM_000100.4 ENSP00000291568.6 P04080
CSTBENST00000639959.1 linkc.134C>G p.Ala45Gly missense_variant Exon 2 of 2 5 ENSP00000492123.1 A0A1W2PQG6
CSTBENST00000675996.1 linkn.694C>G non_coding_transcript_exon_variant Exon 3 of 3
CSTBENST00000640406.1 linkc.*344C>G 3_prime_UTR_variant Exon 2 of 2 2 ENSP00000492672.1 A0A1W2PS52

Frequencies

GnomAD3 genomes
AF:
0.0000197
AC:
3
AN:
152236
Hom.:
0
Cov.:
33
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
GnomAD4 exome
AF:
0.0000178
AC:
26
AN:
1461890
Hom.:
0
Cov.:
31
AF XY:
0.0000138
AC XY:
10
AN XY:
727248
show subpopulations
African (AFR)
AF:
0.0000299
AC:
1
AN:
33480
American (AMR)
AF:
0.00
AC:
0
AN:
44724
Ashkenazi Jewish (ASJ)
AF:
0.00
AC:
0
AN:
26136
East Asian (EAS)
AF:
0.00
AC:
0
AN:
39700
South Asian (SAS)
AF:
0.00
AC:
0
AN:
86258
European-Finnish (FIN)
AF:
0.00
AC:
0
AN:
53420
Middle Eastern (MID)
AF:
0.00
AC:
0
AN:
5768
European-Non Finnish (NFE)
AF:
0.0000225
AC:
25
AN:
1112008
Other (OTH)
AF:
0.00
AC:
0
AN:
60396
Allele Balance Distribution
Red line indicates average allele balance
Average allele balance: 0.488
Heterozygous variant carriers
0
3
5
8
10
13
0.00
0.20
0.40
0.60
0.80
0.95
Allele balance

Age Distribution

Exome Het
Variant carriers
0
2
4
6
8
10
<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:
0.0000197
AC:
3
AN:
152236
Hom.:
0
Cov.:
33
AF XY:
0.0000269
AC XY:
2
AN XY:
74370
show subpopulations
African (AFR)
AF:
0.0000241
AC:
1
AN:
41462
American (AMR)
AF:
0.00
AC:
0
AN:
15280
Ashkenazi Jewish (ASJ)
AF:
0.00
AC:
0
AN:
3470
East Asian (EAS)
AF:
0.00
AC:
0
AN:
5198
South Asian (SAS)
AF:
0.00
AC:
0
AN:
4838
European-Finnish (FIN)
AF:
0.00
AC:
0
AN:
10624
Middle Eastern (MID)
AF:
0.00
AC:
0
AN:
316
European-Non Finnish (NFE)
AF:
0.0000294
AC:
2
AN:
68042
Other (OTH)
AF:
0.00
AC:
0
AN:
2094
Allele Balance Distribution
Red line indicates average allele balance
Average allele balance: 0.492
Heterozygous variant carriers
0
1
1
2
2
3
0.00
0.20
0.40
0.60
0.80
0.95
Allele balance

Age Distribution

Genome Het
Variant carriers
0
2
4
6
8
10
<30
30-35
35-40
40-45
45-50
50-55
55-60
60-65
65-70
70-75
75-80
>80
Age
Alfa
AF:
0.0000847
Hom.:
0
Bravo
AF:
0.0000227
ESP6500AA
AF:
0.00
AC:
0
ESP6500EA
AF:
0.000116
AC:
1
EpiCase
AF:
0.0000545
EpiControl
AF:
0.00

ClinVar

Significance: Uncertain significance
Submissions summary: Uncertain:1
Revision: criteria provided, single submitter
LINK: link

Submissions by phenotype

Progressive myoclonic epilepsy Uncertain:1
Jan 15, 2024
Labcorp Genetics (formerly Invitae), Labcorp
Significance:Uncertain significance
Review Status:criteria provided, single submitter
Collection Method:clinical testing

This sequence change replaces alanine, which is neutral and non-polar, with glycine, which is neutral and non-polar, at codon 90 of the CSTB protein (p.Ala90Gly). This variant is present in population databases (rs138337167, gnomAD 0.007%). 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: 840825). Algorithms developed to predict the effect of missense changes on protein structure and function output the following: SIFT: "Not Available"; PolyPhen-2: "Benign"; Align-GVGD: "Not Available". The glycine amino acid residue is found in multiple mammalian species, which suggests that this missense change does not adversely affect protein function. Algorithms developed to predict the effect of sequence changes on RNA splicing suggest that this variant may create or strengthen a splice site. 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
0.077
BayesDel_addAF
Benign
-0.20
T
BayesDel_noAF
Benign
-0.53
CADD
Benign
12
DANN
Benign
0.95
DEOGEN2
Benign
0.18
T
Eigen
Benign
-0.80
Eigen_PC
Benign
-0.83
FATHMM_MKL
Benign
0.10
N
LIST_S2
Benign
0.25
T
M_CAP
Benign
0.026
D
MetaRNN
Benign
0.078
T
MetaSVM
Benign
-0.85
T
PhyloP100
0.65
PrimateAI
Benign
0.32
T
PROVEAN
Benign
-1.3
N
REVEL
Benign
0.12
Sift
Benign
0.19
T
Sift4G
Benign
0.16
T
Polyphen
0.0020
B
Vest4
0.036
MVP
0.37
MPC
0.14
ClinPred
0.042
T
GERP RS
1.5
Varity_R
0.33
gMVP
0.17
Mutation Taster
=96/4
polymorphism

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

Other links and lift over

dbSNP: rs138337167; hg19: chr21-45194111; API