rs1553462134

Positions:

• chr2-165380718-C-A
• chr2-165380718-C-G
• chr2-165380718-C-T

Variant summary

Our verdict is Likely pathogenic. Variant got 8 ACMG points: 8P and 0B. PM2 PM5 PP2 PP3_Moderate PP5

The NM_001040142.2(SCN2A):​c.4435C>A​(p.Gln1479Lys) variant causes a missense change involving the alteration of a conserved nucleotide. The variant was absent in control chromosomes in GnomAD project. In-silico tool predicts a pathogenic outcome for this variant. Variant has been reported in ClinVar as Conflicting classifications of pathogenicity (no stars). Another variant affecting the same amino acid position, but resulting in a different missense (i.e. Q1479P) has been classified as Likely pathogenic.

• Frequency: Genomes: not found (cov: 32)
• Consequence: SCN2A NM_001040142.2 missense
• Clinical Significance: Conflicting classifications of pathogenicity criteria provided, conflicting classifications P:2 U:1
• Conservation: PhyloP100: 7.83

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 8 ACMG points.

• PM2: Very rare variant in population databases, with high coverage
• PM5: Other missense variant is known to change same aminoacid residue: Variant chrnull-null-null-null is described in UniProt as null.
• 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, 0.892
• PP5: Variant 2-165380718-C-A is Pathogenic according to our data. Variant chr2-165380718-C-A is described in ClinVar as [Conflicting_classifications_of_pathogenicity]. Clinvar id is 436661.We mark this variant Likely_pathogenic, oryginal submissions are: {Uncertain_significance=1, Likely_pathogenic=2}.

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	Protein	UniProt
SCN2A	NM_001040142.2	c.4435C>A	p.Gln1479Lys	missense_variant	24/27	ENST00000375437.7	NP_001035232.1
SCN2A	NM_001371246.1	c.4435C>A	p.Gln1479Lys	missense_variant	24/27	ENST00000631182.3	NP_001358175.1

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Protein	Appris	UniProt
SCN2A	ENST00000375437.7	c.4435C>A	p.Gln1479Lys	missense_variant	24/27	5	NM_001040142.2	ENSP00000364586.2
SCN2A	ENST00000631182.3	c.4435C>A	p.Gln1479Lys	missense_variant	24/27	5	NM_001371246.1	ENSP00000486885.1
SCN2A	ENST00000283256.10	c.4435C>A	p.Gln1479Lys	missense_variant	24/27	1		ENSP00000283256.6

Frequencies

GnomAD3 genomes Cov.: 32

GnomAD4 exome Cov.: 28

GnomAD4 genome Cov.: 32

ClinVar

Significance: Conflicting classifications of pathogenicity

Submissions summary: Pathogenic:2 Uncertain:1

Revision: criteria provided, conflicting classifications

Submissions by phenotype

Developmental and epileptic encephalopathy, 11 Pathogenic:2

Likely pathogenic, criteria provided, single submitter	clinical testing	3billion	May 22, 2022	The variant is not observed in the gnomAD v2.1.1 dataset. Missense changes are a common disease-causing mechanism. In silico tool predictions suggest damaging effect of the variant on gene or gene product (REVEL: 0.90; 3Cnet: 0.99). Same nucleotide change resulting in same amino acid change has been previously reported to be associated with SCN2A related disorder (ClinVar ID: VCV000436661). However, the evidence of pathogenicity is insufficient at this time. A different missense change at the same codon (p.Gln1479His) has been reported as pathogenic/likely pathogenic with strong evidence (ClinVar ID: VCV001180106, VCV001308640). Therefore, this variant is classified as likely pathogenic according to the recommendation of ACMG/AMP guideline. -
Likely pathogenic, criteria provided, single submitter	clinical testing	Genetic Services Laboratory, University of Chicago	Jun 14, 2017	- -

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

Apr 26, 2023

ClinVar contains an entry for this variant (Variation ID: 436661). 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 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 glutamine, which is neutral and polar, with lysine, which is basic and polar, at codon 1479 of the SCN2A protein (p.Gln1479Lys). -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Pathogenic	0.93
BayesDel_addAF	Pathogenic	0.48	D
BayesDel_noAF	Pathogenic	0.45
CADD	Pathogenic	27
DANN	Uncertain	1.0
DEOGEN2	Pathogenic	0.97	D;.;T;.;D;D;.
Eigen	Uncertain	0.62
Eigen_PC	Uncertain	0.61
FATHMM_MKL	Pathogenic	0.98	D
LIST_S2	Uncertain	0.97	D;.;D;.;.;.;D
M_CAP	Pathogenic	0.85	D
MetaRNN	Pathogenic	0.89	D;D;D;D;D;D;D
MetaSVM	Pathogenic	1.1	D
MutationAssessor	Pathogenic	4.0	H;H;.;H;H;H;H
PrimateAI	Pathogenic	0.91	D
PROVEAN	Uncertain	-3.6	D;.;.;.;.;D;D
REVEL	Pathogenic	0.90
Sift	Pathogenic	0.0	D;.;.;.;.;D;D
Sift4G	Uncertain	0.032	D;.;.;D;.;D;D
Polyphen		0.082	B;P;.;P;B;B;P
Vest4		0.73
MutPred		0.52		Gain of methylation at Q1479 (P = 0.0096);Gain of methylation at Q1479 (P = 0.0096);.;Gain of methylation at Q1479 (P = 0.0096);Gain of methylation at Q1479 (P = 0.0096);Gain of methylation at Q1479 (P = 0.0096);Gain of methylation at Q1479 (P = 0.0096);
MVP		1.0
ClinPred		1.0	D
GERP RS		4.8
Varity_R		0.96
gMVP		0.99

Splicing

Name	Calibrated prediction	Score	Prediction
SpliceAI score (max)		0.12		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: rs1553462134; hg19: chr2-166237228;