rs143880787

Variant summary

Our verdict is Uncertain significance. Variant got 3 ACMG points: 3P and 0B. PM2PP3

The NM_001365999.1(SZT2):​c.2812G>A​(p.Ala938Thr) variant causes a missense, splice region change involving the alteration of a conserved nucleotide. The variant allele was found at a frequency of 0.000171 in 1,613,696 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a benign outcome for this variant. 2/3 splice prediction tools predicting alterations to normal splicing. 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. A938V) has been classified as Uncertain significance.

Frequency

Genomes: 𝑓 0.00032 ( 0 hom., cov: 32)
Exomes 𝑓: 0.00016 ( 0 hom. )

Consequence

SZT2
NM_001365999.1 missense, splice_region

Scores

5
7
6
Splicing: ADA: 0.9694
2

Clinical Significance

Uncertain significance criteria provided, multiple submitters, no conflicts P:1U:8

Conservation

PhyloP100: 9.48
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]

Genome browser will be placed here

ACMG classification

Classification made for transcript

Verdict is Uncertain_significance. Variant got 3 ACMG points.

PM2
Very rare variant in population databases, with high coverage;
PP3
Splicing scoreres supports a deletorius effect: Scorers claiming Pathogenic: dbscSNV1_ADA, dbscSNV1_RF. No scorers claiming Uncertain. Scorers claiming Benign: max_spliceai.

Transcripts

RefSeq

Gene Transcript HGVSc HGVSp Effect Exon rank MANE Protein UniProt
SZT2NM_001365999.1 linkc.2812G>A p.Ala938Thr missense_variant, splice_region_variant Exon 19 of 72 ENST00000634258.3 NP_001352928.1
SZT2NM_015284.4 linkc.2812G>A p.Ala938Thr missense_variant, splice_region_variant Exon 19 of 71 NP_056099.3 Q5T011-5

Ensembl

Gene Transcript HGVSc HGVSp Effect Exon rank TSL MANE Protein Appris UniProt
SZT2ENST00000634258.3 linkc.2812G>A p.Ala938Thr missense_variant, splice_region_variant Exon 19 of 72 5 NM_001365999.1 ENSP00000489255.1 Q5T011-1
SZT2ENST00000562955.2 linkc.2812G>A p.Ala938Thr missense_variant, splice_region_variant Exon 19 of 71 5 ENSP00000457168.1 Q5T011-5
SZT2ENST00000470139.1 linkn.1543G>A splice_region_variant, non_coding_transcript_exon_variant Exon 10 of 18 2 ENSP00000492726.1 A0A1W2PRY5

Frequencies

GnomAD3 genomes
AF:
0.000322
AC:
49
AN:
152152
Hom.:
0
Cov.:
32
show subpopulations
Gnomad AFR
AF:
0.00
Gnomad AMI
AF:
0.00
Gnomad AMR
AF:
0.00
Gnomad ASJ
AF:
0.000288
Gnomad EAS
AF:
0.00
Gnomad SAS
AF:
0.00
Gnomad FIN
AF:
0.000754
Gnomad MID
AF:
0.00
Gnomad NFE
AF:
0.000588
Gnomad OTH
AF:
0.00
GnomAD3 exomes
AF:
0.000239
AC:
60
AN:
251080
Hom.:
0
AF XY:
0.000184
AC XY:
25
AN XY:
135694
show subpopulations
Gnomad AFR exome
AF:
0.00
Gnomad AMR exome
AF:
0.00
Gnomad ASJ exome
AF:
0.000298
Gnomad EAS exome
AF:
0.00
Gnomad SAS exome
AF:
0.00
Gnomad FIN exome
AF:
0.000233
Gnomad NFE exome
AF:
0.000449
Gnomad OTH exome
AF:
0.000163
GnomAD4 exome
AF:
0.000155
AC:
227
AN:
1461544
Hom.:
0
Cov.:
32
AF XY:
0.000171
AC XY:
124
AN XY:
727042
show subpopulations
Gnomad4 AFR exome
AF:
0.00
Gnomad4 AMR exome
AF:
0.00
Gnomad4 ASJ exome
AF:
0.000230
Gnomad4 EAS exome
AF:
0.00
Gnomad4 SAS exome
AF:
0.00
Gnomad4 FIN exome
AF:
0.000169
Gnomad4 NFE exome
AF:
0.000184
Gnomad4 OTH exome
AF:
0.000116
GnomAD4 genome
AF:
0.000322
AC:
49
AN:
152152
Hom.:
0
Cov.:
32
AF XY:
0.000309
AC XY:
23
AN XY:
74318
show subpopulations
Gnomad4 AFR
AF:
0.00
Gnomad4 AMR
AF:
0.00
Gnomad4 ASJ
AF:
0.000288
Gnomad4 EAS
AF:
0.00
Gnomad4 SAS
AF:
0.00
Gnomad4 FIN
AF:
0.000754
Gnomad4 NFE
AF:
0.000588
Gnomad4 OTH
AF:
0.00
Alfa
AF:
0.000356
Hom.:
1
Bravo
AF:
0.000178
ESP6500AA
AF:
0.00
AC:
0
ESP6500EA
AF:
0.000698
AC:
6
ExAC
AF:
0.000329
AC:
40
EpiCase
AF:
0.000327
EpiControl
AF:
0.0000593

ClinVar

Significance: Uncertain significance
Submissions summary: Pathogenic:1Uncertain:8
Revision: criteria provided, multiple submitters, no conflicts
LINK: link

Submissions by phenotype

Developmental and epileptic encephalopathy, 18 Uncertain:3
Sep 04, 2020
Baylor Genetics
Significance: Uncertain significance
Review Status: criteria provided, single submitter
Collection Method: clinical testing

This variant was determined to be of uncertain significance according to ACMG Guidelines, 2015 [PMID:25741868]. -

Apr 11, 2023
Genome-Nilou Lab
Significance: Uncertain significance
Review Status: criteria provided, single submitter
Collection Method: clinical testing

- -

Jul 19, 2019
Centre for Mendelian Genomics, University Medical Centre Ljubljana
Significance: Uncertain significance
Review Status: criteria provided, single submitter
Collection Method: clinical testing

This variant was classified as: Uncertain significance. The available evidence on this variant's pathogenicity is insufficient or conflicting. The following ACMG criteria were applied in classifying this variant: PP5. -

not provided Uncertain:3
Jan 22, 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 threonine, which is neutral and polar, at codon 938 of the SZT2 protein (p.Ala938Thr). This variant is present in population databases (rs143880787, gnomAD 0.05%). This missense change has been observed in individual(s) with Rolandic epilepsy (PMID: 29358611). ClinVar contains an entry for this variant (Variation ID: 433087). An algorithm developed to predict the effect of missense changes on protein structure and function (PolyPhen-2) suggests 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. -

Feb 27, 2025
GeneDx
Significance: Uncertain significance
Review Status: criteria provided, single submitter
Collection Method: clinical testing

Observed in a patient with childhood focal epilepsy with centro-temporal spikes through whole exome sequencing, however, a second SZT2 variant was not reported (PMID: 29358611); In silico analysis supports that this missense variant has a deleterious effect on protein structure/function; This variant is associated with the following publications: (PMID: 29358611) -

Apr 01, 2020
CeGaT Center for Human Genetics Tuebingen
Significance: Uncertain significance
Review Status: criteria provided, single submitter
Collection Method: clinical testing

- -

Self-limited epilepsy with centrotemporal spikes Pathogenic:1
Jan 01, 2017
Bioinformatics Core, Luxembourg Center for Systems Biomedicine
Significance: Pathogenic
Review Status: no assertion criteria provided
Collection Method: case-control

CAADphred>15 -

See cases Uncertain:1
Sep 06, 2024
Institute of Human Genetics, University Hospital Muenster
Significance: Uncertain significance
Review Status: criteria provided, single submitter
Collection Method: clinical testing

ACMG categories: PM2,PP3 -

SZT2-related disorder Uncertain:1
Aug 28, 2024
PreventionGenetics, part of Exact Sciences
Significance: Uncertain significance
Review Status: no assertion criteria provided
Collection Method: clinical testing

The SZT2 c.2812G>A variant is predicted to result in the amino acid substitution p.Ala938Thr. This variant was reported as a single heterozygote in an individual with Rolandic epilepsy (Bobbili et al. 2018. PubMed ID: 29358611, Supplemental Table 1); however, no additional information was provided to support causation. This variant is reported in 0.044% of alleles in individuals of European (Non-Finnish) descent in gnomAD, which is more common than expected for a primary cause of disease. At this time, the clinical significance of this variant is uncertain due to the absence of conclusive functional and genetic evidence. -

Computational scores

Source: dbNSFP v4.3

Name
Calibrated prediction
Score
Prediction
AlphaMissense
Benign
0.21
BayesDel_addAF
Benign
-0.056
T
BayesDel_noAF
Uncertain
0.020
CADD
Pathogenic
29
DANN
Pathogenic
1.0
DEOGEN2
Benign
0.28
T;.
Eigen
Pathogenic
0.92
Eigen_PC
Pathogenic
0.94
FATHMM_MKL
Pathogenic
1.0
D
LIST_S2
Uncertain
0.95
D;D
M_CAP
Benign
0.0063
T
MetaRNN
Benign
0.36
T;T
MetaSVM
Uncertain
-0.26
T
MutationAssessor
Uncertain
2.1
M;M
PrimateAI
Uncertain
0.55
T
PROVEAN
Uncertain
-2.5
.;D
Sift
Uncertain
0.0080
.;D
Sift4G
Pathogenic
0.0
D;D
Polyphen
1.0
.;D
Vest4
0.62
MVP
0.60
MPC
0.79
ClinPred
0.46
T
GERP RS
6.2
Varity_R
0.53
gMVP
0.38

Splicing

Name
Calibrated prediction
Score
Prediction
dbscSNV1_ADA
Pathogenic
0.97
dbscSNV1_RF
Pathogenic
0.78
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: rs143880787; hg19: chr1-43891311; API