Genetic Variant SZT2:p.Thr2980Ile (chr1-43446201-C-T) – ACMG Classification: Uncertain_significance (2 pts)

Variant summary

Our verdict is Uncertain significance. Variant got 2 ACMG points: 2P and 0B. PM2

The NM_001365999.1(SZT2):c.8939C>T(p.Thr2980Ile) variant causes a missense change. The variant allele was found at a frequency of 0.0000161 in 1,614,140 control chromosomes in the GnomAD database, with no homozygous occurrence. Variant has been reported in ClinVar as Uncertain significance (★★).

Frequency

Genomes: 𝑓 0.0000066 ( 0 hom., cov: 33)

Exomes 𝑓: 0.000017 ( 0 hom. )

Consequence

SZT2
NM_001365999.1 missense

Scores

Clinical Significance

Uncertain significance criteria provided, multiple submitters, no conflicts P:1U:3

Conservation

PhyloP100: 4.66

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:

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ACMG classification

Classification made for transcript

Verdict is Uncertain_significance. Variant got 2 ACMG points.

PM2

Very rare variant in population databases, with high coverage;

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	MANE	Protein	UniProt
SZT2	NM_001365999.1 link	c.8939C>T	p.Thr2980Ile	missense_variant	Exon 64 of 72	ENST00000634258.3	NP_001352928.1
SZT2	NM_015284.4 link	c.8768C>T	p.Thr2923Ile	missense_variant	Exon 63 of 71		NP_056099.3	Q5T011-5

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	TSL	MANE	Protein	Appris	UniProt
SZT2	ENST00000634258.3 link	c.8939C>T	p.Thr2980Ile	missense_variant	Exon 64 of 72	5	NM_001365999.1	ENSP00000489255.1		Q5T011-1

Frequencies

GnomAD3 genomes

AF:

0.00000657

AC:

AN:

152252

Hom.:

Cov.:

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:

0.0000147

Gnomad OTH

AF:

0.00

GnomAD3 exomes

AF:

0.0000199

AC:

AN:

251456

Hom.:

AF XY:

0.0000221

AC XY:

AN XY:

135910

show subpopulations

Gnomad AFR exome

AF:

0.00

Gnomad AMR exome

AF:

0.00

Gnomad ASJ exome

AF:

0.00

Gnomad EAS exome

AF:

0.00

Gnomad SAS exome

AF:

0.0000327

Gnomad FIN exome

AF:

0.00

Gnomad NFE exome

AF:

0.0000352

Gnomad OTH exome

AF:

0.00

GnomAD4 exome

AF:

0.0000171

AC:

AN:

1461888

Hom.:

Cov.:

AF XY:

0.0000179

AC XY:

AN XY:

727244

show subpopulations

Gnomad4 AFR exome

AF:

0.00

Gnomad4 AMR exome

AF:

0.00

Gnomad4 ASJ exome

AF:

0.00

Gnomad4 EAS exome

AF:

0.00

Gnomad4 SAS exome

AF:

0.0000116

Gnomad4 FIN exome

AF:

0.00

Gnomad4 NFE exome

AF:

0.0000144

Gnomad4 OTH exome

AF:

0.0000993

GnomAD4 genome

AF:

0.00000657

AC:

AN:

152252

Hom.:

Cov.:

AF XY:

0.00

AC XY:

AN XY:

74382

show subpopulations

Gnomad4 AFR

AF:

0.00

Gnomad4 AMR

AF:

0.00

Gnomad4 ASJ

AF:

0.00

Gnomad4 EAS

AF:

0.00

Gnomad4 SAS

AF:

0.00

Gnomad4 FIN

AF:

0.00

Gnomad4 NFE

AF:

0.0000147

Gnomad4 OTH

AF:

0.00

Alfa

AF:

0.000102

Hom.:

Bravo

AF:

0.0000189

ExAC

AF:

0.00000824

AC:

ClinVar

Significance: Uncertain significance

Submissions summary: Pathogenic:1Uncertain:3

Revision: criteria provided, multiple submitters, no conflicts

LINK: link

Submissions by phenotype

not provided

Uncertain:2

Jan 07, 2022

Labcorp Genetics (formerly Invitae), Labcorp

Significance: Uncertain significance

Review Status: criteria provided, single submitter

Collection Method: clinical testing

This sequence change replaces threonine, which is neutral and polar, with isoleucine, which is neutral and non-polar, at codon 2923 of the SZT2 protein (p.Thr2923Ile). This variant is present in population databases (rs766294629, gnomAD 0.003%). This missense change has been observed in individual(s) with clinical features of Rolandic epilepsy (PMID: 29358611). ClinVar contains an entry for this variant (Variation ID: 433096). Algorithms developed to predict the effect of missense changes on protein structure and function are either unavailable or do not agree on the potential impact of this missense change (SIFT: "Tolerated"; PolyPhen-2: "Possibly Damaging"; Align-GVGD: "Class C25"). 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. -

Sep 28, 2023

GeneDx

Significance: Uncertain significance

Review Status: criteria provided, single submitter

Collection Method: clinical testing

Reported homozygous in an individual with persistent elevations of urine L-3-hydroxyisobutyric acid in published literature; however, a homozygous variant in another gene was identified that was more likely to explain phenotype (Sasarman et al., 2022); Not observed at significant frequency in large population cohorts (gnomAD); In silico analysis supports that this missense variant does not alter protein structure/function; This variant is associated with the following publications: (PMID: 35174513) -

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 -

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

- -

Computational scores

Source: dbNSFP v4.3

Name

Calibrated prediction

Score

Prediction

AlphaMissense

Benign

0.15

BayesDel_addAF

Benign

-0.097

BayesDel_noAF

Benign

-0.28

CADD

Uncertain

DANN

Uncertain

1.0

DEOGEN2

Benign

0.13

T;.

Eigen

Benign

0.032

Eigen_PC

Benign

0.17

FATHMM_MKL

Uncertain

0.91

LIST_S2

Uncertain

0.93

D;D

M_CAP

Benign

0.0041

MetaRNN

Uncertain

0.44

T;T

MetaSVM

Benign

-1.0

MutationAssessor

Benign

1.7

L;.

PrimateAI

Uncertain

0.51

PROVEAN

Benign

-1.8

.;N

Sift

Benign

0.10

.;T

Sift4G

Benign

0.16

T;T

Polyphen

0.48

P;B

Vest4

0.70

MVP

0.26

MPC

0.88

ClinPred

0.83

GERP RS

5.2

Varity_R

0.17

gMVP

0.40

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