1-43427358-G-T

Variant summary

Our verdict is Uncertain significance. The variant received 0 ACMG points: 0P and 0B.

The NM_001365999.1(SZT2):​c.3511G>T​(p.Gly1171Trp) variant causes a missense change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.0000818 in 1,613,974 control chromosomes in the GnomAD database, with no homozygous occurrence. 12/20 in silico tools predict a benign outcome for this variant. Variant has been reported in ClinVar as Uncertain significance (★★).

Frequency

Genomes: 𝑓 0.000026 ( 0 hom., cov: 32)
Exomes 𝑓: 0.000088 ( 0 hom. )

Consequence

SZT2
NM_001365999.1 missense

Scores

4
14

Clinical Significance

Uncertain significance criteria provided, multiple submitters, no conflicts U:5

Conservation

PhyloP100: 0.601

Publications

3 publications found
Variant links:
Genes affected
SZT2 (HGNC:29040): (SZT2 subunit of KICSTOR complex) The protein encoded by this gene is expressed in the brain, predominantly in the parietal and frontal cortex as well as in dorsal root ganglia. It is localized to the peroxisome, and is implicated in resistance to oxidative stress. It likely functions by increasing superoxide dismutase (SOD) activity, but itself has no direct SOD activity. Studies in mice show that this gene confers low seizure threshold, and may also enhance epileptogenesis. [provided by RefSeq, Jun 2011]
SZT2 Gene-Disease associations (from GenCC):
  • developmental and epileptic encephalopathy, 18
    Inheritance: AR Classification: DEFINITIVE, STRONG Submitted by: Ambry Genetics, Labcorp Genetics (formerly Invitae), G2P, Illumina
  • genetic developmental and epileptic encephalopathy
    Inheritance: AR Classification: DEFINITIVE Submitted by: ClinGen
  • undetermined early-onset epileptic encephalopathy
    Inheritance: AD Classification: SUPPORTIVE Submitted by: Orphanet

Genome browser will be placed here

ACMG classification

Classification was made for transcript

Our verdict: Uncertain_significance. The variant received 0 ACMG points.

Transcripts

RefSeq

Gene Transcript HGVSc HGVSp Effect Exon rank MANE Protein UniProt
SZT2NM_001365999.1 linkc.3511G>T p.Gly1171Trp missense_variant Exon 25 of 72 ENST00000634258.3 NP_001352928.1
SZT2NM_015284.4 linkc.3340G>T p.Gly1114Trp missense_variant Exon 24 of 71 NP_056099.3

Ensembl

Gene Transcript HGVSc HGVSp Effect Exon rank TSL MANE Protein Appris UniProt
SZT2ENST00000634258.3 linkc.3511G>T p.Gly1171Trp missense_variant Exon 25 of 72 5 NM_001365999.1 ENSP00000489255.1
SZT2ENST00000562955.2 linkc.3340G>T p.Gly1114Trp missense_variant Exon 24 of 71 5 ENSP00000457168.1
SZT2ENST00000470139.1 linkn.*378G>T non_coding_transcript_exon_variant Exon 16 of 18 2 ENSP00000492726.1
SZT2ENST00000470139.1 linkn.*378G>T 3_prime_UTR_variant Exon 16 of 18 2 ENSP00000492726.1

Frequencies

GnomAD3 genomes
AF:
0.0000263
AC:
4
AN:
152234
Hom.:
0
Cov.:
32
show subpopulations
Gnomad AFR
AF:
0.00
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:
0.0000441
Gnomad OTH
AF:
0.000478
GnomAD2 exomes
AF:
0.0000915
AC:
23
AN:
251282
AF XY:
0.000103
show subpopulations
Gnomad AFR exome
AF:
0.00
Gnomad AMR exome
AF:
0.0000289
Gnomad ASJ exome
AF:
0.0000993
Gnomad EAS exome
AF:
0.00
Gnomad FIN exome
AF:
0.00
Gnomad NFE exome
AF:
0.000158
Gnomad OTH exome
AF:
0.00
GnomAD4 exome
AF:
0.0000876
AC:
128
AN:
1461740
Hom.:
0
Cov.:
31
AF XY:
0.0000976
AC XY:
71
AN XY:
727158
show subpopulations
African (AFR)
AF:
0.00
AC:
0
AN:
33478
American (AMR)
AF:
0.0000895
AC:
4
AN:
44704
Ashkenazi Jewish (ASJ)
AF:
0.0000765
AC:
2
AN:
26128
East Asian (EAS)
AF:
0.00
AC:
0
AN:
39698
South Asian (SAS)
AF:
0.000104
AC:
9
AN:
86198
European-Finnish (FIN)
AF:
0.00
AC:
0
AN:
53410
Middle Eastern (MID)
AF:
0.000694
AC:
4
AN:
5766
European-Non Finnish (NFE)
AF:
0.0000899
AC:
100
AN:
1111970
Other (OTH)
AF:
0.000149
AC:
9
AN:
60388
Allele Balance Distribution
Red line indicates average allele balance
Average allele balance: 0.477
Heterozygous variant carriers
0
8
16
24
32
40
0.00
0.20
0.40
0.60
0.80
0.95
Allele balance

Age Distribution

Exome Het
Variant carriers
0
4
8
12
16
20
<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:
0.0000263
AC:
4
AN:
152234
Hom.:
0
Cov.:
32
AF XY:
0.0000403
AC XY:
3
AN XY:
74366
show subpopulations
⚠️ The allele balance in gnomAD version 4 Genomes is significantly skewed from the expected value of 0.5.
African (AFR)
AF:
0.00
AC:
0
AN:
41458
American (AMR)
AF:
0.00
AC:
0
AN:
15288
Ashkenazi Jewish (ASJ)
AF:
0.00
AC:
0
AN:
3472
East Asian (EAS)
AF:
0.00
AC:
0
AN:
5194
South Asian (SAS)
AF:
0.00
AC:
0
AN:
4834
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:
0.0000441
AC:
3
AN:
68044
Other (OTH)
AF:
0.000478
AC:
1
AN:
2092
⚠️ The allele balance in gnomAD version 4 Genomes is significantly skewed from the expected value of 0.5. (p-value = 0.0404278), which strongly suggests a high chance of mosaicism in these individuals.
Allele Balance Distribution
Red line indicates average allele balance
Average allele balance: 0.400
Heterozygous variant carriers
0
0
1
1
2
2
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:
0.0000983
Hom.:
0
Bravo
AF:
0.0000642
TwinsUK
AF:
0.00
AC:
0
ALSPAC
AF:
0.000259
AC:
1
ESP6500AA
AF:
0.00
AC:
0
ESP6500EA
AF:
0.000116
AC:
1
ExAC
AF:
0.0000988
AC:
12
EpiCase
AF:
0.0000545
EpiControl
AF:
0.000237

ClinVar

Significance: Uncertain significance
Submissions summary: Uncertain:5
Revision: criteria provided, multiple submitters, no conflicts
LINK: link

Submissions by phenotype

Developmental and epileptic encephalopathy, 18 Uncertain:2
Apr 11, 2023
Genome-Nilou Lab
Significance:Uncertain significance
Review Status:criteria provided, single submitter
Collection Method:clinical testing

- -

Oct 31, 2018
Fulgent Genetics, Fulgent Genetics
Significance:Uncertain significance
Review Status:criteria provided, single submitter
Collection Method:clinical testing

- -

not provided Uncertain:2
Jul 26, 2022
Labcorp Genetics (formerly Invitae), Labcorp
Significance:Uncertain significance
Review Status:criteria provided, single submitter
Collection Method:clinical testing

This sequence change replaces glycine, which is neutral and non-polar, with tryptophan, which is neutral and slightly polar, at codon 1114 of the SZT2 protein (p.Gly1114Trp). This variant is present in population databases (rs201767217, gnomAD 0.02%). This variant has not been reported in the literature in individuals affected with SZT2-related conditions. ClinVar contains an entry for this variant (Variation ID: 411945). Algorithms developed to predict the effect of missense changes on protein structure and function (SIFT, PolyPhen-2, Align-GVGD) all suggest that this variant is likely to be disruptive. 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. -

Apr 23, 2025
GeneDx
Significance:Uncertain significance
Review Status:criteria provided, single submitter
Collection Method:clinical testing

In silico analysis indicates that this missense variant does not alter protein structure/function; Has not been previously published as pathogenic or benign to our knowledge -

Inborn genetic diseases Uncertain:1
Oct 12, 2024
Ambry Genetics
Significance:Uncertain significance
Review Status:criteria provided, single submitter
Collection Method:clinical testing

The c.3340G>T (p.G1114W) alteration is located in exon 24 (coding exon 24) of the SZT2 gene. This alteration results from a G to T substitution at nucleotide position 3340, causing the glycine (G) at amino acid position 1114 to be replaced by a tryptophan (W). Based on insufficient or conflicting evidence, the clinical significance of this alteration remains unclear. -

Computational scores

Source: dbNSFP v4.3

Name
Calibrated prediction
Score
Prediction
AlphaMissense
Benign
0.19
BayesDel_addAF
Benign
-0.25
T
BayesDel_noAF
Benign
-0.33
CADD
Benign
21
DANN
Uncertain
0.98
DEOGEN2
Benign
0.052
T;.
Eigen
Uncertain
0.22
Eigen_PC
Benign
0.16
FATHMM_MKL
Benign
0.16
N
LIST_S2
Benign
0.80
T;T
M_CAP
Benign
0.012
T
MetaRNN
Uncertain
0.44
T;T
MetaSVM
Benign
-0.91
T
MutationAssessor
Benign
0.69
N;.
PhyloP100
0.60
PrimateAI
Benign
0.31
T
PROVEAN
Benign
-1.5
.;N
Sift
Benign
0.030
.;D
Sift4G
Uncertain
0.028
D;D
Polyphen
0.97
.;D
Vest4
0.59
MVP
0.29
MPC
0.60
ClinPred
0.16
T
GERP RS
4.9
RBP_binding_hub_radar
0.0
RBP_regulation_power_radar
1.7
Varity_R
0.088
gMVP
0.48
Mutation Taster
=84/16
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: rs201767217; hg19: chr1-43893029; API