rs796053156

chr2-165388685-G-A

Variant summary

Our verdict is Pathogenic. Variant got 10 ACMG points: 10P and 0B. PM1 PM2 PM5 PP2 PP3_Moderate PP5

The NM_001040142.2(SCN2A):c.4879G>A(p.Val1627Met) 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. V1627A) 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: 9.98

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 Pathogenic. Variant got 10 ACMG points.

• PM1: In a hotspot region, there are 11 aminoacids with missense pathogenic changes in the window of +-8 aminoacids around while only 0 benign, 3 uncertain in NM_001040142.2
• PM2: Very rare variant in population databases, with high coverage
• PM5: Other missense variant is known to change same aminoacid residue: Variant chr2-165388686-T-C is described in ClinVar as [Likely_pathogenic]. Clinvar id is 837982.Status of the report is criteria_provided_single_submitter, 1 stars.
• PP2: Missense variant where missense usually causes diseases, SCN2A
• PP3: MetaRNN computational evidence supports a deleterious effect, 0.924
• PP5: Variant 2-165388685-G-A is Pathogenic according to our data. Variant chr2-165388685-G-A is described in ClinVar as [Conflicting_classifications_of_pathogenicity]. Clinvar id is 207018.We mark this variant Likely_pathogenic, oryginal submissions are: {Pathogenic=2, Uncertain_significance=1}.

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	UniProt
SCN2A	NM_001040142.2	c.4879G>A	p.Val1627Met	missense_variant	27/27	ENST00000375437.7
SCN2A	NM_001371246.1	c.4879G>A	p.Val1627Met	missense_variant	27/27	ENST00000631182.3

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Appris	UniProt
SCN2A	ENST00000375437.7	c.4879G>A	p.Val1627Met	missense_variant	27/27	5	NM_001040142.2	P1
SCN2A	ENST00000631182.3	c.4879G>A	p.Val1627Met	missense_variant	27/27	5	NM_001371246.1

Frequencies

GnomAD3 genomes Cov.: 32

GnomAD4 exome Cov.: 31

GnomAD4 genome Cov.: 32

ClinVar

Significance: Conflicting classifications of pathogenicity

Submissions summary: Pathogenic:2 Uncertain:1

Revision: criteria provided, conflicting classifications

Submissions by phenotype

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

Pathogenic, criteria provided, single submitter

clinical testing

Invitae

Oct 25, 2022

This variant is not present in population databases (gnomAD no frequency). For these reasons, this variant has been classified as Pathogenic. 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. ClinVar contains an entry for this variant (Variation ID: 207018). This missense change has been observed in individual(s) with epilepsy and SCN2A-related disorders (PMID: 28379373; Invitae). In at least one individual the variant was observed to be de novo. This sequence change replaces valine, which is neutral and non-polar, with methionine, which is neutral and non-polar, at codon 1627 of the SCN2A protein (p.Val1627Met). -

not provided Pathogenic:1

Pathogenic, criteria provided, single submitter

clinical testing

CeGaT Center for Human Genetics Tuebingen

Nov 01, 2018

- -

not specified Uncertain:1

Uncertain significance, criteria provided, single submitter

clinical testing

GeneDx

Oct 24, 2013

p.Val1627Met (GTG>ATG): c.4879 G>A in exon 27 of the SCN2A gene (NM_021007.2). The Val627Met missense change has not been published as a mutation, nor has it been reported as a benign polymorphism to our knowledge. It was not observed in approximately 6,500 individuals of European and African American ancestry in the NHLBI Exome Sequencing Project, indicating it is not a common benign variant in these populations. This variant is a conservative substitution, as Valine and Methionine are both uncharged, non-polar amino acids. It alters a highly conserved position in the S4 segment of the fourth transmembrane domain of the protein. In silico analysis predicts this variant is probably damaging to the protein structure/function. Therefore, based on the currently available information, it is unclear whether Val627Met is a disease-causing mutation or a rare benign variant. The variant is found in INFANT-EPI panel(s). -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Pathogenic	0.98
BayesDel_addAF	Pathogenic	0.48	D
BayesDel_noAF	Pathogenic	0.45
Cadd	Uncertain	25
Dann	Uncertain	1.0
DEOGEN2	Pathogenic	0.95	D;.;T;.;D;D;.
Eigen	Pathogenic	0.99
Eigen_PC	Pathogenic	0.95
FATHMM_MKL	Pathogenic	0.99	D
LIST_S2	Uncertain	0.86	D;.;D;.;.;.;D
M_CAP	Pathogenic	0.79	D
MetaRNN	Pathogenic	0.92	D;D;D;D;D;D;D
MetaSVM	Pathogenic	1.1	D
MutationAssessor	Pathogenic	3.0	M;M;.;M;M;M;M
MutationTaster	Benign	1.0	D;D;D;D
PrimateAI	Pathogenic	0.93	D
PROVEAN	Uncertain	-2.6	D;.;.;.;.;D;D
REVEL	Pathogenic	0.88
Sift	Pathogenic	0.0	D;.;.;.;.;D;D
Sift4G	Uncertain	0.0070	D;.;.;D;.;D;D
Polyphen		1.0	D;D;.;D;D;D;D
Vest4		0.70
MutPred		0.70		Gain of MoRF binding (P = 0.1438);Gain of MoRF binding (P = 0.1438);.;Gain of MoRF binding (P = 0.1438);Gain of MoRF binding (P = 0.1438);Gain of MoRF binding (P = 0.1438);Gain of MoRF binding (P = 0.1438);
MVP		0.99
ClinPred		0.99	D
GERP RS		5.5
Varity_R		0.83
gMVP		0.95

Splicing

Name	Calibrated prediction	Score	Prediction
SpliceAI score (max)		0.030		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: rs796053156; hg19: chr2-166245195;