NM_001365999.1:c.7474C>T

Variant names:

Variant summary

Our verdict is Benign. Variant got -13 ACMG points: 0P and 13B. BP4_StrongBP6BS1BS2

The NM_001365999.1(SZT2):c.7474C>T(p.Arg2492Trp) variant causes a missense change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.000263 in 1,614,118 control chromosomes in the GnomAD database, including 3 homozygotes. In-silico tool predicts a benign outcome for this variant. Variant has been reported in ClinVar as Conflicting classifications of pathogenicity (no stars). Another variant affecting the same amino acid position, but resulting in a different missense (i.e. R2492Q) has been classified as Uncertain significance.

Frequency

Genomes: 𝑓 0.00020 ( 0 hom., cov: 32)

Exomes 𝑓: 0.00027 ( 3 hom. )

Consequence

SZT2
NM_001365999.1 missense

Scores

Clinical Significance

Conflicting classifications of pathogenicity criteria provided, conflicting classifications P:1U:4B:2

Conservation

PhyloP100: 2.01

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 links:

Genome browser will be placed here

ACMG classification

Classification made for transcript

Verdict is Benign. Variant got -13 ACMG points.

BP4

Computational evidence support a benign effect (MetaRNN=0.008697331).

BP6

Variant 1-43441343-C-T is Benign according to our data. Variant chr1-43441343-C-T is described in ClinVar as [Conflicting_classifications_of_pathogenicity]. Clinvar id is 589892.We mark this variant Likely_benign, oryginal submissions are: {Likely_benign=2, Uncertain_significance=4}. Variant chr1-43441343-C-T is described in Lovd as [Likely_benign].

BS1

Variant frequency is greater than expected in population sas. gnomad4_exome allele frequency = 0.000269 (393/1461878) while in subpopulation SAS AF= 0.00366 (316/86254). AF 95% confidence interval is 0.00333. There are 3 homozygotes in gnomad4_exome. There are 286 alleles in male gnomad4_exome subpopulation. Median coverage is 40. This position pass quality control queck.

BS2

High Homozygotes in GnomAdExome4 at 3 AR gene

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	MANE	Protein	UniProt
SZT2	NM_001365999.1 link	c.7474C>T	p.Arg2492Trp	missense_variant	Exon 53 of 72	ENST00000634258.3	NP_001352928.1
SZT2	NM_015284.4 link	c.7303C>T	p.Arg2435Trp	missense_variant	Exon 52 of 71		NP_056099.3	Q5T011-5

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	TSL	MANE	Protein	UniProt
SZT2	ENST00000634258.3 link	c.7474C>T	p.Arg2492Trp	missense_variant	Exon 53 of 72	5	NM_001365999.1	ENSP00000489255.1	Q5T011-1
SZT2	ENST00000562955.2 link	c.7303C>T	p.Arg2435Trp	missense_variant	Exon 52 of 71	5		ENSP00000457168.1	Q5T011-5
SZT2	ENST00000648058.1 link	n.3928C>T		non_coding_transcript_exon_variant	Exon 21 of 40
SZT2	ENST00000649403.1 link	n.2224C>T		non_coding_transcript_exon_variant	Exon 18 of 37

Frequencies

GnomAD3 genomes

AF:

0.000184

AC:

AN:

152122

Hom.:

Cov.:

show subpopulations

Gnomad AFR

AF:

0.000217

Gnomad AMI

AF:

0.00

Gnomad AMR

AF:

0.00

Gnomad ASJ

AF:

0.00

Gnomad EAS

AF:

0.00

Gnomad SAS

AF:

0.00374

Gnomad FIN

AF:

0.00

Gnomad MID

AF:

0.00

Gnomad NFE

AF:

0.0000147

Gnomad OTH

AF:

0.00

GnomAD3 exomes

AF:

0.000358

AC:

AN:

251444

Hom.:

AF XY:

0.000515

AC XY:

AN XY:

135894

show subpopulations

Gnomad AFR exome

AF:

0.000123

Gnomad AMR exome

AF:

0.0000289

Gnomad ASJ exome

AF:

0.00

Gnomad EAS exome

AF:

0.000109

Gnomad SAS exome

AF:

0.00258

Gnomad FIN exome

AF:

0.00

Gnomad NFE exome

AF:

0.0000176

Gnomad OTH exome

AF:

0.000652

GnomAD4 exome

AF:

0.000269

AC:

393

AN:

1461878

Hom.:

Cov.:

AF XY:

0.000393

AC XY:

286

AN XY:

727240

show subpopulations

Gnomad4 AFR exome

AF:

0.00

Gnomad4 AMR exome

AF:

0.0000224

Gnomad4 ASJ exome

AF:

0.00

Gnomad4 EAS exome

AF:

0.000101

Gnomad4 SAS exome

AF:

0.00366

Gnomad4 FIN exome

AF:

0.00

Gnomad4 NFE exome

AF:

0.0000351

Gnomad4 OTH exome

AF:

0.000546

GnomAD4 genome

AF:

0.000204

AC:

AN:

152240

Hom.:

Cov.:

AF XY:

0.000255

AC XY:

AN XY:

74442

show subpopulations

Gnomad4 AFR

AF:

0.000217

Gnomad4 AMR

AF:

0.00

Gnomad4 ASJ

AF:

0.00

Gnomad4 EAS

AF:

0.00

Gnomad4 SAS

AF:

0.00395

Gnomad4 FIN

AF:

0.00

Gnomad4 NFE

AF:

0.0000147

Gnomad4 OTH

AF:

0.000946

Bravo

AF:

0.000102

ESP6500AA

AF:

0.000227

AC:

ESP6500EA

AF:

0.00

AC:

ExAC

AF:

0.000338

AC:

Asia WGS

AF:

0.00693

AC:

AN:

3478

EpiCase

AF:

0.0000545

EpiControl

AF:

0.00

ClinVar

Significance: Conflicting classifications of pathogenicity

Submissions summary: Pathogenic:1Uncertain:4Benign:2

Revision: criteria provided, conflicting classifications

LINK: link

Submissions by phenotype

Developmental and epileptic encephalopathy, 18

Pathogenic:1Uncertain:3

Jan 18, 2022

Revvity Omics, Revvity

Significance: Uncertain significance

Review Status: criteria provided, single submitter

Collection Method: clinical testing

- -

Dec 21, 2023

Victorian Clinical Genetics Services, Murdoch Childrens Research Institute

Significance: Uncertain significance

Review Status: criteria provided, single submitter

Collection Method: clinical testing

Based on the classification scheme VCGS_Germline_v1.3.4, this variant is classified as VUS-3C. Following criteria are met: 0102 - Loss of function is a known mechanism of disease in this gene and is associated with developmental and epileptic encephalopathy 18 (MIM#615476). (I) 0106 - This gene is associated with autosomal recessive disease. (I) 0200 - Variant is predicted to result in a missense amino acid change from arginine to tryptophan. (I) 0251 - This variant is heterozygous. (I) 0304 - Variant is present in gnomAD (v2) <0.01 for a recessive condition (89 heterozygotes, 1 homozygote). (SP) 0309 - An alternative amino acid change at the same position has been observed in gnomAD (v2) (2 heterozygotes, 0 homozygotes). (I) 0502 - Missense variant with conflicting in silico predictions and uninformative conservation. (I) 0604 - Variant is not located in an established domain, motif, hotspot or informative constraint region. (I) 0710 - Another missense variant comparable to the one identified in this case has inconclusive previous evidence for pathogenicity. This alternative change (p.(Arg2435Gln)) has been reported as a VUS (ClinVar). (I) 0808 - Previous reports of pathogenicity for this variant are conflicting. This variant has been reported as likely benign, and as a VUS (ClinVar, LOVD). It has also been observed in a single compound heterozygous individual with features including tonic spasms, microcephaly and early onset epileptic encephalopathy (PMID: 28556953). (I) 0905 - No published segregation evidence has been identified for this variant. (I) 1007 - No published functional evidence has been identified for this variant. (I) 1205 - This variant has been shown to be maternally inherited (by trio analysis). (I) Legend: (SP) - Supporting pathogenic, (I) - Information, (SB) - Supporting benign -

Feb 19, 2021

OMIM

Significance: Pathogenic

Review Status: no assertion criteria provided

Collection Method: literature only

- -

Feb 09, 2022

Department of Pathology and Laboratory Medicine, Sinai Health System

Significance: Uncertain significance

Review Status: criteria provided, single submitter

Collection Method: research

- -

not provided

Benign:2

Apr 07, 2020

GeneDx

Significance: Likely benign

Review Status: criteria provided, single submitter

Collection Method: clinical testing

See Variant Classification Assertion Criteria. -

Jan 05, 2025

Labcorp Genetics (formerly Invitae), Labcorp

Significance: Likely benign

Review Status: criteria provided, single submitter

Collection Method: clinical testing

- -

Inborn genetic diseases

Uncertain:1

Dec 27, 2017

Ambry Genetics

Significance: Uncertain significance

Review Status: criteria provided, single submitter

Collection Method: clinical testing

The p.R2435W variant (also known as c.7303C>T), located in coding exon 52 of the SZT2 gene, results from a C to T substitution at nucleotide position 7303. The arginine at codon 2435 is replaced by tryptophan, an amino acid with dissimilar properties. This alteration has been described in an individual with early onset epileptic encephalopathy who was compound heterozygous for another missense alteration (Tshuchida N et al. Clin. Genet., 2017 May; epub ahead of print). This amino acid position is well conserved in available vertebrate species. In addition, the in silico prediction for this alteration is inconclusive. 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

0.20

BayesDel_addAF

Benign

-0.19

BayesDel_noAF

Uncertain

-0.040

CADD

Uncertain

DANN

Uncertain

1.0

DEOGEN2

Benign

0.14

T;.

Eigen

Uncertain

0.34

Eigen_PC

Uncertain

0.31

FATHMM_MKL

Uncertain

0.93

LIST_S2

Uncertain

0.90

D;D

M_CAP

Benign

0.023

MetaRNN

Benign

0.0087

T;T

MetaSVM

Benign

-0.92

MutationAssessor

Benign

1.8

L;.

PrimateAI

Uncertain

0.74

PROVEAN

Benign

-2.1

.;N

Sift

Uncertain

0.0080

.;D

Sift4G

Pathogenic

0.0010

D;D

Polyphen

1.0

.;D

Vest4

0.49

MVP

0.23

MPC

0.56

ClinPred

0.076

GERP RS

4.5

RBP_binding_hub_radar

0.0

RBP_regulation_power_radar

1.7

Varity_R

0.32

gMVP

0.52

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.

Variant summary

Frequency

Consequence

Scores

Clinical Significance

Conservation

ACMG classification

Transcripts

RefSeq

Ensembl

Frequencies

ClinVar

Submissions by phenotype

Computational scores

Splicing

Publications

LitVar

Other links and lift over