rs1553462227

Positions:

• chr2-165381148-T-C

Variant summary

Our verdict is Pathogenic. Variant got 17 ACMG points: 17P and 0B. PM1 PM2 PM5 PP2 PP3_Moderate PP5_Very_Strong

The NM_001040142.2(SCN2A):​c.4502T>C​(p.Met1501Thr) 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 Likely pathogenic (★★). Another variant affecting the same amino acid position, but resulting in a different missense (i.e. M1501I) has been classified as Likely pathogenic.

• Frequency:
  • Genomes: not found (cov: 32)
  • Exomes 𝑓: 0.0 (0 hom.)
  • Failed GnomAD Quality Control
• Consequence: SCN2A NM_001040142.2 missense
• Clinical Significance: Pathogenic/Likely pathogenic criteria provided, multiple submitters, no conflicts P:4
• Conservation: PhyloP100: 7.94

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 17 ACMG points.

• PM1: In a hotspot region, there are 5 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 chr2-165381147-A-G is described in ClinVar as [Likely_pathogenic]. Clinvar id is 1068258.Status of the report is criteria_provided_single_submitter, 1 stars.
• 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, 0.897
• PP5: Variant 2-165381148-T-C is Pathogenic according to our data. Variant chr2-165381148-T-C is described in ClinVar as [Likely_pathogenic]. Clinvar id is 533495.Status of the report is criteria_provided_multiple_submitters_no_conflicts, 2 stars.

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	UniProt
SCN2A	NM_001040142.2	c.4502T>C	p.Met1501Thr	missense_variant	25/27	ENST00000375437.7
SCN2A	NM_001371246.1	c.4502T>C	p.Met1501Thr	missense_variant	25/27	ENST00000631182.3

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Appris	UniProt
SCN2A	ENST00000375437.7	c.4502T>C	p.Met1501Thr	missense_variant	25/27	5	NM_001040142.2	P1
SCN2A	ENST00000631182.3	c.4502T>C	p.Met1501Thr	missense_variant	25/27	5	NM_001371246.1

Frequencies

GnomAD3 genomes Cov.: 32

GnomAD4 exome Data not reliable, filtered out with message: AC0 AF: 0.00 AC: 0 AN: 1440370 Hom.: 0 Cov.: 30 AF XY: 0.00 AC XY: 0 AN XY: 714468

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: 0.00

Gnomad4 OTH exome AF: 0.00

GnomAD4 genome Cov.: 32

ClinVar

Significance: Pathogenic/Likely pathogenic

Submissions summary: Pathogenic:4

Revision: criteria provided, multiple submitters, no conflicts

Submissions by phenotype

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

Pathogenic, criteria provided, single submitter

clinical testing

Invitae

Jan 23, 2024

This sequence change replaces methionine, which is neutral and non-polar, with threonine, which is neutral and polar, at codon 1501 of the SCN2A protein (p.Met1501Thr). This variant is not present in population databases (gnomAD no frequency). This missense change has been observed in individual(s) with clinical features of SCN2A-related conditions (Invitae). In at least one individual the variant was observed to be de novo. ClinVar contains an entry for this variant (Variation ID: 533495). 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%. For these reasons, this variant has been classified as Pathogenic. -

unclassified developmental and epileptic encephalopathy Pathogenic:1

Likely pathogenic, no assertion criteria provided

research

Department of Neurology, Children’s Hospital of Chongqing Medical University

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not provided Pathogenic:1

Likely pathogenic, criteria provided, single submitter

clinical testing

GeneDx

Oct 31, 2022

Not observed at significant frequency in large population cohorts (gnomAD); Missense variants in this gene are often considered pathogenic (HGMD); In silico analysis supports that this missense variant has a deleterious effect on protein structure/function; Has not been previously published as pathogenic or benign to our knowledge; This substitution is predicted to be in the cytoplasmic loop between the third and fourth homologous domains -

Complex neurodevelopmental disorder Pathogenic:1

Likely pathogenic, no assertion criteria provided

provider interpretation

GenomeConnect - Simons Searchlight

Jan 29, 2019

Submission from Simons Searchlight facilitated by GenomeConnect. Variant interpreted by the Simons Searchlight team most recently on 2019-01-29 and interpreted as Likely Pathogenic. Variant was initially reported on 2017-08-29 by GTR ID of laboratory name 500031. The reporting laboratory might also submit to ClinVar. -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Pathogenic	0.99
BayesDel_addAF	Pathogenic	0.45	D
BayesDel_noAF	Pathogenic	0.42
CADD	Uncertain	25
DANN	Uncertain	0.99
DEOGEN2	Pathogenic	0.87	D;.;T;.;D;D;.
Eigen	Uncertain	0.66
Eigen_PC	Uncertain	0.62
FATHMM_MKL	Pathogenic	0.98	D
LIST_S2	Uncertain	0.96	D;.;D;.;.;.;D
M_CAP	Pathogenic	0.81	D
MetaRNN	Pathogenic	0.90	D;D;D;D;D;D;D
MetaSVM	Pathogenic	1.1	D
MutationAssessor	Pathogenic	4.6	H;H;.;H;H;H;H
MutationTaster	Benign	1.0	D;D;D;D
PrimateAI	Pathogenic	0.95	D
PROVEAN	Pathogenic	-5.4	D;.;.;.;.;D;D
REVEL	Pathogenic	0.88
Sift	Uncertain	0.0050	D;.;.;.;.;D;D
Sift4G	Pathogenic	0.0	D;.;.;D;.;D;D
Polyphen		0.073	B;D;.;D;B;B;D
Vest4		0.71
MutPred		0.44		Loss of stability (P = 0.014);Loss of stability (P = 0.014);.;Loss of stability (P = 0.014);Loss of stability (P = 0.014);Loss of stability (P = 0.014);Loss of stability (P = 0.014);
MVP		0.95
ClinPred		0.99	D
GERP RS		4.8
Varity_R		0.77
gMVP		0.99

Splicing

Name	Calibrated prediction	Score	Prediction
SpliceAI score (max)		0.010		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: rs1553462227; hg19: chr2-166237658;