rs532357677

Variant summary

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

The NM_001365999.1(SZT2):​c.4721G>A​(p.Arg1574Gln) variant causes a missense change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.0000291 in 1,612,880 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a benign outcome for this variant. 11/19 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. R1574W) has been classified as Uncertain significance.

Frequency

Genomes: 𝑓 0.000053 ( 0 hom., cov: 32)
Exomes 𝑓: 0.000027 ( 0 hom. )

Consequence

SZT2
NM_001365999.1 missense

Scores

6
11

Clinical Significance

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

Conservation

PhyloP100: 3.07

Publications

0 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: Likely_benign. The variant received -2 ACMG points.

BP4
Computational evidence support a benign effect (MetaRNN=0.15724438).

Transcripts

RefSeq

Gene Transcript HGVSc HGVSp Effect Exon rank MANE Protein UniProt
SZT2NM_001365999.1 linkc.4721G>A p.Arg1574Gln missense_variant Exon 32 of 72 ENST00000634258.3 NP_001352928.1
SZT2NM_015284.4 linkc.4550G>A p.Arg1517Gln missense_variant Exon 31 of 71 NP_056099.3 Q5T011-5

Ensembl

Gene Transcript HGVSc HGVSp Effect Exon rank TSL MANE Protein Appris UniProt
SZT2ENST00000634258.3 linkc.4721G>A p.Arg1574Gln missense_variant Exon 32 of 72 5 NM_001365999.1 ENSP00000489255.1 Q5T011-1
SZT2ENST00000562955.2 linkc.4550G>A p.Arg1517Gln missense_variant Exon 31 of 71 5 ENSP00000457168.1 Q5T011-5
SZT2ENST00000478140.1 linkn.*39G>A downstream_gene_variant 2

Frequencies

GnomAD3 genomes
AF:
0.0000526
AC:
8
AN:
152218
Hom.:
0
Cov.:
32
show subpopulations
Gnomad AFR
AF:
0.0000482
Gnomad AMI
AF:
0.00
Gnomad AMR
AF:
0.00
Gnomad ASJ
AF:
0.00
Gnomad EAS
AF:
0.00
Gnomad SAS
AF:
0.000207
Gnomad FIN
AF:
0.00
Gnomad MID
AF:
0.00
Gnomad NFE
AF:
0.0000588
Gnomad OTH
AF:
0.000478
GnomAD2 exomes
AF:
0.0000200
AC:
5
AN:
249678
AF XY:
0.0000296
show subpopulations
Gnomad AFR exome
AF:
0.0000618
Gnomad AMR exome
AF:
0.00
Gnomad ASJ exome
AF:
0.00
Gnomad EAS 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:
0.0000267
AC:
39
AN:
1460544
Hom.:
0
Cov.:
32
AF XY:
0.0000317
AC XY:
23
AN XY:
726602
show subpopulations
African (AFR)
AF:
0.0000299
AC:
1
AN:
33480
American (AMR)
AF:
0.00
AC:
0
AN:
44724
Ashkenazi Jewish (ASJ)
AF:
0.0000383
AC:
1
AN:
26128
East Asian (EAS)
AF:
0.00
AC:
0
AN:
39700
South Asian (SAS)
AF:
0.000220
AC:
19
AN:
86256
European-Finnish (FIN)
AF:
0.00
AC:
0
AN:
52120
Middle Eastern (MID)
AF:
0.00
AC:
0
AN:
5768
European-Non Finnish (NFE)
AF:
0.0000144
AC:
16
AN:
1111978
Other (OTH)
AF:
0.0000331
AC:
2
AN:
60390
Allele Balance Distribution
Red line indicates average allele balance
Average allele balance: 0.484
Heterozygous variant carriers
0
3
6
8
11
14
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:
0.0000525
AC:
8
AN:
152336
Hom.:
0
Cov.:
32
AF XY:
0.0000537
AC XY:
4
AN XY:
74486
show subpopulations
African (AFR)
AF:
0.0000481
AC:
2
AN:
41574
American (AMR)
AF:
0.00
AC:
0
AN:
15302
Ashkenazi Jewish (ASJ)
AF:
0.00
AC:
0
AN:
3472
East Asian (EAS)
AF:
0.00
AC:
0
AN:
5188
South Asian (SAS)
AF:
0.000207
AC:
1
AN:
4832
European-Finnish (FIN)
AF:
0.00
AC:
0
AN:
10618
Middle Eastern (MID)
AF:
0.00
AC:
0
AN:
294
European-Non Finnish (NFE)
AF:
0.0000588
AC:
4
AN:
68032
Other (OTH)
AF:
0.000473
AC:
1
AN:
2114
Allele Balance Distribution
Red line indicates average allele balance
Average allele balance: 0.563
Heterozygous variant carriers
0
1
2
2
3
4
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:
0.000161
Hom.:
0
Bravo
AF:
0.0000189
ExAC
AF:
0.0000330
AC:
4

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:3
Dec 08, 2022
Institute of Human Genetics, University of Leipzig Medical Center
Significance:Uncertain significance
Review Status:criteria provided, single submitter
Collection Method:clinical testing

This variant was identified together with NM_015284.4:c.8640del in the same patient. Criteria applied: PM2_SUP, PM5_SUP -

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

- -

-
Neuberg Centre For Genomic Medicine, NCGM
Significance:Uncertain significance
Review Status:criteria provided, single submitter
Collection Method:clinical testing

The observed missense variant c.4721G>A(p.Arg1574Gln) in SZT2 gene has not been reported previously as a pathogenic variant nor as a benign variant, to our knowledge. The c.4721G>A variant has 0.004% allele frequency in gnomAD Exomes.This variant has been reported to the ClinVar database as Uncertain Significance. However, study on multiple affected individuals and the functional impact of the variant is not available.The amino acid Arginine at position 1574 is changed to a Glutamine changing protein sequence and it might alter its composition and physico-chemical properties. The amino acid change p.Arg1574Gln in SZT2 is predicted as conserved by GERP++ and PhyloP across 100 vertebrates. For these reasons, this variant has been classified as Uncertain Significance. -

Inborn genetic diseases Uncertain:1
Apr 13, 2022
Ambry Genetics
Significance:Uncertain significance
Review Status:criteria provided, single submitter
Collection Method:clinical testing

The c.4550G>A (p.R1517Q) alteration is located in exon 31 (coding exon 31) of the SZT2 gene. This alteration results from a G to A substitution at nucleotide position 4550, causing the arginine (R) at amino acid position 1517 to be replaced by a glutamine (Q). Based on insufficient or conflicting evidence, the clinical significance of this alteration remains unclear. -

not provided Uncertain:1
May 24, 2022
Labcorp Genetics (formerly Invitae), Labcorp
Significance:Uncertain significance
Review Status:criteria provided, single submitter
Collection Method:clinical testing

This sequence change replaces arginine, which is basic and polar, with glutamine, which is neutral and polar, at codon 1517 of the SZT2 protein (p.Arg1517Gln). This variant is present in population databases (rs532357677, gnomAD 0.01%). 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: 411940). Algorithms developed to predict the effect of missense changes on protein structure and function output the following: SIFT: "Tolerated"; PolyPhen-2: "Possibly Damaging"; Align-GVGD: "Class C0". The glutamine 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
0.14
BayesDel_addAF
Benign
-0.16
T
BayesDel_noAF
Benign
-0.16
CADD
Uncertain
24
DANN
Uncertain
1.0
DEOGEN2
Benign
0.20
T;.
Eigen
Uncertain
0.45
Eigen_PC
Uncertain
0.50
FATHMM_MKL
Uncertain
0.83
D
LIST_S2
Uncertain
0.90
D;D
M_CAP
Benign
0.0079
T
MetaRNN
Benign
0.16
T;T
MetaSVM
Benign
-0.93
T
PhyloP100
3.1
PrimateAI
Benign
0.41
T
PROVEAN
Benign
-1.8
.;N
Sift
Uncertain
0.018
.;D
Sift4G
Benign
0.073
T;T
Polyphen
0.98
.;D
Vest4
0.21
MutPred
0.37
.;Loss of methylation at R1517 (P = 0.0463);
MVP
0.47
MPC
0.89
ClinPred
0.95
D
GERP RS
5.8
Varity_R
0.055
gMVP
0.40
Mutation Taster
=85/15
polymorphism

Splicing

Name
Calibrated prediction
Score
Prediction
SpliceAI score (max)
0.070
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: rs532357677; hg19: chr1-43896407; COSMIC: COSV100987676; COSMIC: COSV100987676; API