rs796053205

Positions:

• chr2-165323345-C-A
• chr2-165323345-C-T

Variant summary

Our verdict is Uncertain significance. Variant got 4 ACMG points: 4P and 0B. PM2 PP2 PP3

The NM_001040142.2(SCN2A):​c.1861C>A​(p.Arg621Ser) variant causes a missense change. The variant allele was found at a frequency of 0.00000205 in 1,461,880 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a pathogenic outcome for this variant. Variant has been reported in ClinVar as Uncertain significance (★). Another variant affecting the same amino acid position, but resulting in a different missense (i.e. R621C) has been classified as Uncertain significance.

• Frequency:
  • Genomes: not found (cov: 32)
  • Exomes 𝑓: 0.0000021 (0 hom.)
• Consequence: SCN2A NM_001040142.2 missense
• Clinical Significance: Uncertain significance criteria provided, single submitter U:1
• Conservation: PhyloP100: 4.91

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]

ACMG classification

Verdict is Uncertain_significance. Variant got 4 ACMG points.

• PM2: Very rare variant in population databases, with high coverage
• PP2: Missense variant where missense usually causes diseases, SCN2A
• PP3: MetaRNN computational evidence supports a deleterious effect, 0.819

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	UniProt
SCN2A	NM_001040142.2	c.1861C>A	p.Arg621Ser	missense_variant	12/27	ENST00000375437.7
SCN2A	NM_001371246.1	c.1861C>A	p.Arg621Ser	missense_variant	12/27	ENST00000631182.3

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Appris	UniProt
SCN2A	ENST00000375437.7	c.1861C>A	p.Arg621Ser	missense_variant	12/27	5	NM_001040142.2	P1
SCN2A	ENST00000631182.3	c.1861C>A	p.Arg621Ser	missense_variant	12/27	5	NM_001371246.1

Frequencies

GnomAD3 genomes Cov.: 32

GnomAD4 exome AF: 0.00000205 AC: 3 AN: 1461880 Hom.: 0 Cov.: 32 AF XY: 0.00000413 AC XY: 3 AN XY: 727242

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: 0.00000180

Gnomad4 OTH exome AF: 0.0000166

GnomAD4 genome Cov.: 32

Bravo AF: 0.00000378

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

Invitae

Apr 28, 2023

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. 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 SCN2A protein function. This variant has not been reported in the literature in individuals affected with SCN2A-related conditions. This variant is not present in population databases (gnomAD no frequency). This sequence change replaces arginine, which is basic and polar, with serine, which is neutral and polar, at codon 621 of the SCN2A protein (p.Arg621Ser). -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Pathogenic	0.74
BayesDel_addAF	Pathogenic	0.42	D
BayesDel_noAF	Pathogenic	0.37
CADD	Uncertain	24
DANN	Uncertain	1.0
DEOGEN2	Uncertain	0.79	D;.;T;.;D;D;.
Eigen	Uncertain	0.53
Eigen_PC	Uncertain	0.58
FATHMM_MKL	Uncertain	0.97	D
LIST_S2	Pathogenic	0.98	D;.;D;.;.;.;D
M_CAP	Pathogenic	0.42	D
MetaRNN	Pathogenic	0.82	D;D;D;D;D;D;D
MetaSVM	Pathogenic	0.96	D
MutationAssessor	Uncertain	2.6	M;M;.;M;M;M;M
MutationTaster	Benign	1.0	D;D;D;D
PrimateAI	Uncertain	0.56	T
PROVEAN	Pathogenic	-4.5	D;.;.;.;.;D;D
REVEL	Pathogenic	0.76
Sift	Uncertain	0.012	D;.;.;.;.;D;D
Sift4G	Benign	0.085	T;.;.;T;.;T;T
Polyphen		1.0	D;B;.;B;D;D;B
Vest4		0.60
MutPred		0.26		Loss of solvent accessibility (P = 0.0062);Loss of solvent accessibility (P = 0.0062);.;Loss of solvent accessibility (P = 0.0062);Loss of solvent accessibility (P = 0.0062);Loss of solvent accessibility (P = 0.0062);Loss of solvent accessibility (P = 0.0062);
MVP		0.95
ClinPred		0.98	D
GERP RS		5.6
Varity_R		0.51
gMVP		0.70

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: rs796053205; hg19: chr2-166179855;