chr1-43443446-C-A

Variant names:

• chr1-43443446-C-A
• rs374031590
• NM_001365999.1:c.8594C>A

Variant summary

Our verdict is Uncertain significance. The variant received 0 ACMG points: 2P and 2B. PM2 BP4_Moderate

The NM_001365999.1(SZT2):​c.8594C>A​(p.Pro2865His) variant causes a missense change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.000000684 in 1,461,870 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a benign outcome for this variant. 12/20 in silico tools predict a benign outcome for this variant. No clinical diagnostic laboratories have submitted clinical-significance assessments for this variant to ClinVar. Another variant affecting the same amino acid position, but resulting in a different missense (i.e. P2865R) has been classified as Uncertain significance.

• Frequency:
  • Genomes: not found (cov: 32)
  • Exomes 𝑓: 6.8e-7 (0 hom.)
• Consequence: SZT2 NM_001365999.1 missense
• Clinical Significance: Not reported in ClinVar
• Conservation: PhyloP100: 0.386
• Publications: 0 publications found

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

ACMG classification

Our verdict: Uncertain_significance. The variant received 0 ACMG points.

• PM2: Very rare variant in population databases, with high coverage
• BP4: Computational evidence support a benign effect (MetaRNN=0.25835907).

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	MANE	Protein	UniProt
SZT2	NM_001365999.1	c.8594C>A	p.Pro2865His	missense_variant	Exon 61 of 72	ENST00000634258.3	NP_001352928.1
SZT2	NM_015284.4	c.8423C>A	p.Pro2808His	missense_variant	Exon 60 of 71		NP_056099.3

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	TSL	MANE	Protein	Appris	UniProt
SZT2	ENST00000634258.3	c.8594C>A	p.Pro2865His	missense_variant	Exon 61 of 72	5	NM_001365999.1	ENSP00000489255.1

Frequencies

GnomAD3 genomes Cov.: 32

GnomAD4 exome AF: 6.84e-7 AC: 1 AN: 1461870 Hom.: 0 Cov.: 36 AF XY: 0.00000138 AC XY: 1 AN XY: 727234

⚠️ The allele balance in gnomAD version 4 Exomes is significantly skewed from the expected value of 0.5.

African (AFR) AF: 0.00 AC: 0 AN: 33476

American (AMR) AF: 0.00 AC: 0 AN: 44722

Ashkenazi Jewish (ASJ) AF: 0.00 AC: 0 AN: 26136

East Asian (EAS) AF: 0.00 AC: 0 AN: 39700

South Asian (SAS) AF: 0.00 AC: 0 AN: 86258

European-Finnish (FIN) AF: 0.00 AC: 0 AN: 53414

Middle Eastern (MID) AF: 0.00 AC: 0 AN: 5768

European-Non Finnish (NFE) AF: 8.99e-7 AC: 1 AN: 1112002

Other (OTH) AF: 0.00 AC: 0 AN: 60394

⚠️ The allele balance in gnomAD4 Exomes is highly skewed from 0.5 (p-value = 0), which strongly suggests a high chance of mosaicism in these individuals.

GnomAD4 genome Cov.: 32

ClinVar

Not reported in ClinVar

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Benign	0.14
BayesDel_addAF	Benign	-0.091	T
BayesDel_noAF	Benign	-0.37
CADD	Uncertain	25
DANN	Uncertain	0.98
DEOGEN2	Benign	0.15	T;.
Eigen	Benign	0.18
Eigen_PC	Benign	0.20
FATHMM_MKL	Benign	0.53	D
LIST_S2	Benign	0.75	T;T
M_CAP	Benign	0.0071	T
MetaRNN	Benign	0.26	T;T
MetaSVM	Benign	-0.99	T
MutationAssessor	Benign	1.2	L;.
PhyloP100		0.39
PrimateAI	Uncertain	0.56	T
PROVEAN	Benign	-1.4	.;N
Sift	Uncertain	0.015	.;D
Sift4G	Uncertain	0.060	T;T
Polyphen		0.99	.;D
Vest4		0.43
MutPred		0.24		.;Loss of glycosylation at P2808 (P = 0.0297);
MVP		0.33
MPC		0.55
ClinPred		0.51	D
GERP RS		5.4
Varity_R		0.13
gMVP		0.37
Mutation Taster		=57/43	polymorphism

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

Other links and lift over

dbSNP: rs374031590; hg19: chr1-43909117;