NM_001365999.1:c.368A>G

Variant summary

Our verdict is Uncertain significance. Variant got 0 ACMG points: 2P and 2B. PM2BP4_Moderate

The NM_001365999.1(SZT2):​c.368A>G​(p.His123Arg) variant causes a missense change. The variant allele was found at a frequency of 0.000336 in 1,613,818 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a benign outcome for this variant. 13/21 in silico tools predict a benign outcome for this variant. Variant has been reported in ClinVar as Uncertain significance (★★).

Frequency

Genomes: 𝑓 0.00020 ( 0 hom., cov: 32)
Exomes 𝑓: 0.00035 ( 0 hom. )

Consequence

SZT2
NM_001365999.1 missense

Scores

2
17

Clinical Significance

Uncertain significance criteria provided, multiple submitters, no conflicts U:7

Conservation

PhyloP100: 7.02
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]

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ACMG classification

Classification made for transcript

Verdict is Uncertain_significance. Variant got 0 ACMG points.

PM2
Very rare variant in population databases, with high coverage;
BP4
Computational evidence support a benign effect (MetaRNN=0.1403892).

Transcripts

RefSeq

Gene Transcript HGVSc HGVSp Effect Exon rank MANE Protein UniProt
SZT2NM_001365999.1 linkc.368A>G p.His123Arg missense_variant Exon 4 of 72 ENST00000634258.3 NP_001352928.1
SZT2NM_015284.4 linkc.368A>G p.His123Arg missense_variant Exon 4 of 71 NP_056099.3 Q5T011-5

Ensembl

Gene Transcript HGVSc HGVSp Effect Exon rank TSL MANE Protein Appris UniProt
SZT2ENST00000634258.3 linkc.368A>G p.His123Arg missense_variant Exon 4 of 72 5 NM_001365999.1 ENSP00000489255.1 Q5T011-1

Frequencies

GnomAD3 genomes
AF:
0.000197
AC:
30
AN:
152128
Hom.:
0
Cov.:
32
show subpopulations
Gnomad AFR
AF:
0.0000965
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:
0.000377
Gnomad MID
AF:
0.00
Gnomad NFE
AF:
0.000309
Gnomad OTH
AF:
0.000478
GnomAD3 exomes
AF:
0.000171
AC:
43
AN:
251186
Hom.:
0
AF XY:
0.000177
AC XY:
24
AN XY:
135742
show subpopulations
Gnomad AFR exome
AF:
0.000185
Gnomad AMR exome
AF:
0.0000869
Gnomad ASJ exome
AF:
0.00
Gnomad EAS exome
AF:
0.00
Gnomad SAS exome
AF:
0.00
Gnomad FIN exome
AF:
0.000278
Gnomad NFE exome
AF:
0.000255
Gnomad OTH exome
AF:
0.000327
GnomAD4 exome
AF:
0.000350
AC:
512
AN:
1461690
Hom.:
0
Cov.:
30
AF XY:
0.000331
AC XY:
241
AN XY:
727146
show subpopulations
Gnomad4 AFR exome
AF:
0.000119
Gnomad4 AMR exome
AF:
0.000112
Gnomad4 ASJ exome
AF:
0.00
Gnomad4 EAS exome
AF:
0.00
Gnomad4 SAS exome
AF:
0.00
Gnomad4 FIN exome
AF:
0.000169
Gnomad4 NFE exome
AF:
0.000413
Gnomad4 OTH exome
AF:
0.000580
GnomAD4 genome
AF:
0.000197
AC:
30
AN:
152128
Hom.:
0
Cov.:
32
AF XY:
0.000242
AC XY:
18
AN XY:
74312
show subpopulations
Gnomad4 AFR
AF:
0.0000965
Gnomad4 AMR
AF:
0.00
Gnomad4 ASJ
AF:
0.00
Gnomad4 EAS
AF:
0.00
Gnomad4 SAS
AF:
0.00
Gnomad4 FIN
AF:
0.000377
Gnomad4 NFE
AF:
0.000309
Gnomad4 OTH
AF:
0.000478
Alfa
AF:
0.000650
Hom.:
0
Bravo
AF:
0.000200
TwinsUK
AF:
0.00
AC:
0
ALSPAC
AF:
0.000259
AC:
1
ESP6500AA
AF:
0.000227
AC:
1
ESP6500EA
AF:
0.000465
AC:
4
ExAC
AF:
0.000181
AC:
22
EpiCase
AF:
0.000327
EpiControl
AF:
0.000237

ClinVar

Significance: Uncertain significance
Submissions summary: Uncertain:7
Revision: criteria provided, multiple submitters, no conflicts
LINK: link

Submissions by phenotype

not provided Uncertain:4
Sep 07, 2022
Labcorp Genetics (formerly Invitae), Labcorp
Significance: Uncertain significance
Review Status: criteria provided, single submitter
Collection Method: clinical testing

This sequence change replaces histidine, which is basic and polar, with arginine, which is basic and polar, at codon 123 of the SZT2 protein (p.His123Arg). This variant is present in population databases (rs147519875, gnomAD 0.03%). 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: 411939). 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 arginine amino acid residue is found in multiple mammalian species, which suggests that this missense change does not adversely affect protein function. 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. -

Mar 28, 2019
Athena Diagnostics
Significance: Uncertain significance
Review Status: criteria provided, single submitter
Collection Method: clinical testing

- -

Nov 01, 2019
CeGaT Center for Human Genetics Tuebingen
Significance: Uncertain significance
Review Status: criteria provided, single submitter
Collection Method: clinical testing

- -

Apr 24, 2024
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 -

Developmental and epileptic encephalopathy, 18 Uncertain:1
Apr 11, 2023
Genome-Nilou Lab
Significance: Uncertain significance
Review Status: criteria provided, single submitter
Collection Method: clinical testing

- -

not specified Uncertain:1
Feb 05, 2025
Women's Health and Genetics/Laboratory Corporation of America, LabCorp
Significance: Uncertain significance
Review Status: criteria provided, single submitter
Collection Method: clinical testing

Variant summary: SZT2 c.368A>G (p.His123Arg) results in a non-conservative amino acid change in the encoded protein sequence. Three of four in-silico tools predict a benign effect of the variant on protein function. The variant allele was found at a frequency of 0.00017 in 251186 control chromosomes. This frequency is not significantly higher than estimated for a pathogenic variant in SZT2 causing Early Infantile Epileptic Encephalopathy 18, allowing no conclusion about variant significance. To our knowledge, no occurrence of c.368A>G in individuals affected with Early Infantile Epileptic Encephalopathy 18 and no experimental evidence demonstrating its impact on protein function have been reported. ClinVar contains an entry for this variant (Variation ID: 411939). Based on the evidence outlined above, the variant was classified as uncertain significance. -

Inborn genetic diseases Uncertain:1
Jan 16, 2018
Ambry Genetics
Significance: Uncertain significance
Review Status: criteria provided, single submitter
Collection Method: clinical testing

The p.H123R variant (also known as c.368A>G), located in coding exon 4 of the SZT2 gene, results from an A to G substitution at nucleotide position 368. The histidine at codon 123 is replaced by arginine, an amino acid with highly similar properties. This amino acid position is not well conserved in available vertebrate species. In addition, this alteration is predicted to be tolerated by in silico analysis. Since supporting evidence is limited at this time, the clinical significance of this alteration remains unclear. -

Computational scores

Source: dbNSFP v4.3

Name
Calibrated prediction
Score
Prediction
AlphaMissense
Benign
0.080
BayesDel_addAF
Benign
-0.39
T
BayesDel_noAF
Benign
-0.46
CADD
Benign
22
DANN
Benign
0.95
DEOGEN2
Benign
0.046
.;T;.
Eigen
Benign
-0.14
Eigen_PC
Benign
0.11
FATHMM_MKL
Uncertain
0.95
D
LIST_S2
Benign
0.81
T;T;T
M_CAP
Benign
0.0073
T
MetaRNN
Benign
0.14
T;T;T
MetaSVM
Benign
-1.1
T
MutationAssessor
Benign
1.4
.;L;L
PrimateAI
Uncertain
0.77
T
PROVEAN
Benign
-2.3
N;.;N
REVEL
Benign
0.083
Sift
Benign
0.66
T;.;T
Sift4G
Benign
0.53
T;T;T
Polyphen
0.0010
B;.;.
Vest4
0.40
MVP
0.36
MPC
1.1
ClinPred
0.081
T
GERP RS
4.6
Varity_R
0.20
gMVP
0.53

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: rs147519875; hg19: chr1-43870091; COSMIC: COSV99080219; API