2-165389232-C-T

Position:

• chr2-165389232-C-T

Variant summary

Our verdict is Likely pathogenic. Variant got 6 ACMG points: 6P and 0B. PM1 PM2 PP2 PP3

The NM_001040142.2(SCN2A):​c.5426C>T​(p.Ala1809Val) variant causes a missense change involving the alteration of a conserved nucleotide. The variant allele was found at a frequency of 0.00000205 in 1,461,840 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 (★).

• 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: 7.80

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 Likely_pathogenic. Variant got 6 ACMG points.

• PM1: In a repeat IV (size 298) in uniprot entity SCN2A_HUMAN there are 14 pathogenic changes around while only 0 benign (100%) in NM_001040142.2
• 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.
• PP3: MetaRNN computational evidence supports a deleterious effect, 0.837

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	Protein	UniProt
SCN2A	NM_001040142.2	c.5426C>T	p.Ala1809Val	missense_variant	27/27	ENST00000375437.7	NP_001035232.1
SCN2A	NM_001371246.1	c.5426C>T	p.Ala1809Val	missense_variant	27/27	ENST00000631182.3	NP_001358175.1

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Protein	Appris	UniProt
SCN2A	ENST00000375437.7	c.5426C>T	p.Ala1809Val	missense_variant	27/27	5	NM_001040142.2	ENSP00000364586.2
SCN2A	ENST00000631182.3	c.5426C>T	p.Ala1809Val	missense_variant	27/27	5	NM_001371246.1	ENSP00000486885.1
SCN2A	ENST00000283256.10	c.5426C>T	p.Ala1809Val	missense_variant	27/27	1		ENSP00000283256.6

Frequencies

GnomAD3 genomes Cov.: 32

GnomAD4 exome AF: 0.00000205 AC: 3 AN: 1461840 Hom.: 0 Cov.: 33 AF XY: 0.00000275 AC XY: 2 AN XY: 727220

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: 0.00000270

Gnomad4 OTH exome AF: 0.00

GnomAD4 genome Cov.: 32

Bravo AF: 0.00000756

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

Nov 27, 2023

This sequence change replaces alanine, which is neutral and non-polar, with valine, which is neutral and non-polar, at codon 1809 of the SCN2A protein (p.Ala1809Val). This variant is not present in population databases (gnomAD no frequency). This variant has not been reported in the literature in individuals affected with SCN2A-related conditions. ClinVar contains an entry for this variant (Variation ID: 533496). 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 expected to disrupt SCN2A protein function with a positive predictive value of 95%. 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	Pathogenic	0.92
BayesDel_addAF	Pathogenic	0.33	D
BayesDel_noAF	Pathogenic	0.23
CADD	Uncertain	24
DANN	Uncertain	1.0
DEOGEN2	Pathogenic	0.86	D;.;T;.;D;D;.
Eigen	Pathogenic	1.0
Eigen_PC	Pathogenic	0.93
FATHMM_MKL	Pathogenic	0.99	D
LIST_S2	Uncertain	0.90	D;.;D;.;.;.;D
M_CAP	Pathogenic	0.63	D
MetaRNN	Pathogenic	0.84	D;D;D;D;D;D;D
MetaSVM	Pathogenic	1.1	D
MutationAssessor	Pathogenic	3.8	H;H;.;H;H;H;H
PrimateAI	Uncertain	0.77	T
PROVEAN	Uncertain	-3.7	D;.;.;.;.;D;D
REVEL	Pathogenic	0.81
Sift	Pathogenic	0.0	D;.;.;.;.;D;D
Sift4G	Uncertain	0.0030	D;.;.;D;.;D;D
Polyphen		1.0	D;D;.;D;D;D;D
Vest4		0.74
MutPred		0.37		Loss of ubiquitination at K1804 (P = 0.0755);Loss of ubiquitination at K1804 (P = 0.0755);.;Loss of ubiquitination at K1804 (P = 0.0755);Loss of ubiquitination at K1804 (P = 0.0755);Loss of ubiquitination at K1804 (P = 0.0755);Loss of ubiquitination at K1804 (P = 0.0755);
MVP		0.98
ClinPred		1.0	D
GERP RS		5.6
Varity_R		0.67
gMVP		1.0

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: rs1553463646; hg19: chr2-166245742; COSMIC: COSV51836417;