1-43447922-T-C

Position:

• chr1-43447922-T-C

Variant summary

Our verdict is Uncertain significance. Variant got 3 ACMG points: 3P and 0B. PM2 PP2

The NM_001365999.1(SZT2):​c.9514T>C​(p.Cys3172Arg) variant causes a missense change. The variant allele was found at a frequency of 0.00000137 in 1,461,888 control chromosomes in the GnomAD database, with no homozygous occurrence. Variant has been reported in ClinVar as Uncertain significance (★).

• Frequency:
  • Genomes: not found (cov: 32)
  • Exomes 𝑓: 0.0000014 (0 hom.)
• Consequence: SZT2 NM_001365999.1 missense
• Clinical Significance: Uncertain significance criteria provided, single submitter U:1
• Conservation: PhyloP100: 4.30

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-AS1 (HGNC:41225): (SZT2 antisense RNA 1)

ACMG classification

Verdict is Uncertain_significance. Variant got 3 ACMG points.

• PM2: Very rare variant in population databases, with high coverage
• PP2: Missense variant in gene, where missense usually causes diseases (based on misZ statistic), SZT2. . Gene score misZ 2.5968 (greater than the threshold 3.09). Trascript score misZ 4.0086 (greater than threshold 3.09). GenCC has associacion of gene with undetermined early-onset epileptic encephalopathy, developmental and epileptic encephalopathy, 18, developmental and epileptic encephalopathy.

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	Protein	UniProt
SZT2	NM_001365999.1	c.9514T>C	p.Cys3172Arg	missense_variant	68/72	ENST00000634258.3	NP_001352928.1
SZT2-AS1	NR_046744.1	n.553A>G		non_coding_transcript_exon_variant	2/2
SZT2	NM_015284.4	c.9343T>C	p.Cys3115Arg	missense_variant	67/71		NP_056099.3

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Protein	Appris	UniProt
SZT2	ENST00000634258.3	c.9514T>C	p.Cys3172Arg	missense_variant	68/72	5	NM_001365999.1	ENSP00000489255	P1
SZT2-AS1	ENST00000396885.2	n.553A>G		non_coding_transcript_exon_variant	2/2	3

Frequencies

GnomAD3 genomes Cov.: 32

GnomAD3 exomes AF: 0.00000398 AC: 1 AN: 251436 Hom.: 0 AF XY: 0.00000736 AC XY: 1 AN XY: 135892

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: 0.00

Gnomad FIN exome AF: 0.00

Gnomad NFE exome AF: 0.00000879

Gnomad OTH exome AF: 0.00

GnomAD4 exome AF: 0.00000137 AC: 2 AN: 1461888 Hom.: 0 Cov.: 32 AF XY: 0.00000275 AC XY: 2 AN XY: 727246

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: 0.00

Gnomad4 FIN exome AF: 0.00

Gnomad4 NFE exome AF: 8.99e-7

Gnomad4 OTH exome AF: 0.0000166

GnomAD4 genome Cov.: 32

ClinVar

Significance: Uncertain significance

Submissions summary: Uncertain:1

Revision: criteria provided, single submitter

Submissions by phenotype

not provided Uncertain:1

Uncertain significance, criteria provided, single submitter

clinical testing

Labcorp Genetics (formerly Invitae), Labcorp

Nov 27, 2023

This sequence change replaces cysteine, which is neutral and slightly polar, with arginine, which is basic and polar, at codon 3115 of the SZT2 protein (p.Cys3115Arg). This variant is present in population databases (no rsID available, gnomAD 0.0009%). 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: 2070808). Advanced modeling of protein sequence and biophysical properties (such as structural, functional, and spatial information, amino acid conservation, physicochemical variation, residue mobility, and thermodynamic stability) performed at Invitae indicates that this missense variant is not expected to disrupt SZT2 protein function with a negative predictive value of 80%. 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	0.25
BayesDel_addAF	Uncertain	0.019	T
BayesDel_noAF	Benign	-0.21
CADD	Uncertain	24
DANN	Benign	0.94
DEOGEN2	Benign	0.084	T;.
Eigen	Benign	-0.12
Eigen_PC	Benign	0.076
FATHMM_MKL	Uncertain	0.88	D
LIST_S2	Uncertain	0.88	D;D
M_CAP	Benign	0.0017	T
MetaRNN	Uncertain	0.59	D;D
MetaSVM	Benign	-1.0	T
MutationAssessor	Benign	0.69	N;.
MutationTaster	Benign	0.99	D;D
PrimateAI	Uncertain	0.60	T
PROVEAN	Benign	-0.51	.;N
Sift	Benign	0.18	.;T
Sift4G	Benign	0.20	T;T
Polyphen		0.11	B;B
Vest4		0.84
MutPred		0.46		Gain of disorder (P = 0.0412);.;
MVP		0.38
MPC		0.49
ClinPred		0.32	T
GERP RS		4.5
Varity_R		0.63
gMVP		0.59

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

Other links and lift over

dbSNP: rs1451264032; hg19: chr1-43913593;