rs918734456

Positions:

• chr2-165374830-A-G
• chr2-165374830-A-T

Variant summary

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

The NM_001040142.2(SCN2A):​c.4118A>G​(p.Glu1373Gly) 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 1,461,454 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: 6.8e-7 (0 hom.)
• Consequence: SCN2A NM_001040142.2 missense
• Clinical Significance: Uncertain significance criteria provided, single submitter U:1
• Conservation: PhyloP100: 3.29

Genes affected

SCN2A (HGNC:10588): (sodium voltage-gated channel alpha subunit 2) Voltage-gated sodium channels are transmembrane glycoprotein complexes composed of a large alpha subunit with four repeat domains, each of which is composed of six membrane-spanning segments, and one or more regulatory beta subunits. Voltage-gated sodium channels function in the generation and propagation of action potentials in neurons and muscle. This gene encodes one member of the sodium channel alpha subunit gene family. Allelic variants of this gene are associated with seizure disorders and autism spectrum disorder. Alternative splicing results in multiple transcript variants. [provided by RefSeq, Nov 2016]

SCN2A (HGNC:):

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), SCN2A. . Trascript score misZ 8.7114 (greater than threshold 3.09). GenCC has associacion of gene with seizures, benign familial infantile, 3, Dravet syndrome, benign familial neonatal-infantile seizures, malignant migrating partial seizures of infancy, complex neurodevelopmental disorder, developmental and epileptic encephalopathy, 11, developmental and epileptic encephalopathy, West syndrome, benign familial infantile epilepsy, episodic ataxia, type 9.

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	Protein	UniProt
SCN2A	NM_001040142.2	c.4118A>G	p.Glu1373Gly	missense_variant	22/27	ENST00000375437.7	NP_001035232.1
SCN2A	NM_001371246.1	c.4118A>G	p.Glu1373Gly	missense_variant	22/27	ENST00000631182.3	NP_001358175.1

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Protein	Appris	UniProt
SCN2A	ENST00000375437.7	c.4118A>G	p.Glu1373Gly	missense_variant	22/27	5	NM_001040142.2	ENSP00000364586.2
SCN2A	ENST00000631182.3	c.4118A>G	p.Glu1373Gly	missense_variant	22/27	5	NM_001371246.1	ENSP00000486885.1
SCN2A	ENST00000283256.10	c.4118A>G	p.Glu1373Gly	missense_variant	22/27	1		ENSP00000283256.6

Frequencies

GnomAD3 genomes Cov.: 32

GnomAD4 exome AF: 6.84e-7 AC: 1 AN: 1461454 Hom.: 0 Cov.: 32 AF XY: 0.00 AC XY: 0 AN XY: 727020

Gnomad4 AFR exome AF: 0.00

Gnomad4 AMR exome AF: 0.0000224

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: 0.00

Gnomad4 OTH exome AF: 0.00

GnomAD4 genome Cov.: 32

ClinVar

Significance: Uncertain significance

Submissions summary: Uncertain:1

Revision: criteria provided, single submitter

Submissions by phenotype

Seizures, benign familial infantile, 3;C3150987:Developmental and epileptic encephalopathy, 11 Uncertain:1

Uncertain significance, criteria provided, single submitter

clinical testing

Labcorp Genetics (formerly Invitae), Labcorp

Aug 16, 2022

This sequence change replaces glutamic acid, which is acidic and polar, with glycine, which is neutral and non-polar, at codon 1373 of the SCN2A protein (p.Glu1373Gly). This variant is not present in population databases (gnomAD no frequency). 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. Algorithms developed to predict the effect of missense changes on protein structure and function (SIFT, PolyPhen-2, Align-GVGD) all suggest that this variant is likely to be tolerated. ClinVar contains an entry for this variant (Variation ID: 574739). This variant has not been reported in the literature in individuals affected with SCN2A-related conditions. -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Benign	0.27
BayesDel_addAF	Uncertain	0.15	D
BayesDel_noAF	Uncertain	-0.020
CADD	Uncertain	25
DANN	Uncertain	1.0
DEOGEN2	Pathogenic	0.84	D;.;T;.;D;D;.
Eigen	Benign	-0.044
Eigen_PC	Benign	0.063
FATHMM_MKL	Uncertain	0.92	D
LIST_S2	Benign	0.63	T;.;T;.;.;.;T
M_CAP	Uncertain	0.13	D
MetaRNN	Uncertain	0.46	T;T;T;T;T;T;T
MetaSVM	Uncertain	0.29	D
MutationAssessor	Uncertain	2.4	M;M;.;M;M;M;M
PrimateAI	Uncertain	0.60	T
PROVEAN	Uncertain	-2.4	N;.;.;.;.;N;N
REVEL	Uncertain	0.52
Sift	Benign	0.23	T;.;.;.;.;T;T
Sift4G	Uncertain	0.048	D;.;.;D;.;D;D
Polyphen		0.079	B;B;.;B;B;B;B
Vest4		0.37
MutPred		0.45		Gain of catalytic residue at G1372 (P = 0.0732);Gain of catalytic residue at G1372 (P = 0.0732);.;Gain of catalytic residue at G1372 (P = 0.0732);Gain of catalytic residue at G1372 (P = 0.0732);Gain of catalytic residue at G1372 (P = 0.0732);Gain of catalytic residue at G1372 (P = 0.0732);
MVP		0.75
ClinPred		0.82	D
GERP RS		4.4
Varity_R		0.30
gMVP		0.93

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: rs918734456; hg19: chr2-166231340;