2-165389299-A-G

Position:

• chr2-165389299-A-G

Variant summary

Our verdict is Uncertain significance. Variant got 4 ACMG points: 5P and 1B. PM1 PM2 PP2 BP4

The NM_001040142.2(SCN2A):​c.5493A>G​(p.Ile1831Met) variant causes a missense change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.000000684 in 1,461,844 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a benign outcome for this variant. Variant has been reported in ClinVar as Uncertain significance (★★).

• Frequency:
  • Genomes: not found (cov: 32)
  • Exomes 𝑓: 6.8e-7 (0 hom.)
• Consequence: SCN2A NM_001040142.2 missense
• Clinical Significance: Uncertain significance criteria provided, multiple submitters, no conflicts U:2
• Conservation: PhyloP100: 1.44

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.

• PM1: In a topological_domain Cytoplasmic (size 229) in uniprot entity SCN2A_HUMAN there are 29 pathogenic changes around while only 7 benign (81%) 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.
• BP4: Computational evidence support a benign effect (MetaRNN=0.32895142).

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	UniProt
SCN2A	NM_001040142.2	c.5493A>G	p.Ile1831Met	missense_variant	27/27	ENST00000375437.7
SCN2A	NM_001371246.1	c.5493A>G	p.Ile1831Met	missense_variant	27/27	ENST00000631182.3

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Appris	UniProt
SCN2A	ENST00000375437.7	c.5493A>G	p.Ile1831Met	missense_variant	27/27	5	NM_001040142.2	P1
SCN2A	ENST00000631182.3	c.5493A>G	p.Ile1831Met	missense_variant	27/27	5	NM_001371246.1

Frequencies

GnomAD3 genomes Cov.: 32

GnomAD3 exomes AF: 0.00000398 AC: 1 AN: 251204 Hom.: 0 AF XY: 0.00000737 AC XY: 1 AN XY: 135750

Gnomad AFR exome AF: 0.0000615

Gnomad AMR exome AF: 0.00

Gnomad ASJ exome AF: 0.00

Gnomad EAS exome AF: 0.00

Gnomad SAS exome AF: 0.00

Gnomad FIN exome AF: 0.00

Gnomad NFE exome AF: 0.00

Gnomad OTH exome AF: 0.00

GnomAD4 exome AF: 6.84e-7 AC: 1 AN: 1461844 Hom.: 0 Cov.: 33 AF XY: 0.00000138 AC XY: 1 AN XY: 727218

Gnomad4 AFR exome AF: 0.0000299

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: Uncertain significance

Submissions summary: Uncertain:2

Revision: criteria provided, multiple submitters, no conflicts

Submissions by phenotype

not specified Uncertain:1

Uncertain significance, criteria provided, single submitter

clinical testing

Athena Diagnostics

Jan 11, 2017

- -

not provided Uncertain:1

Uncertain significance, criteria provided, single submitter

clinical testing

GeneDx

Dec 14, 2021

The majority of missense variants in this gene are considered pathogenic (Stenson et al., 2014); In silico analysis, which includes protein predictors and evolutionary conservation, supports that this variant does not alter protein structure/function; This substitution is predicted to be within the C-terminal cytoplasmic domain; Has not been previously published as pathogenic or benign to our knowledge; Not observed at significant frequency in large population cohorts (Lek et al., 2016) -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Benign	0.16
BayesDel_addAF	Uncertain	0.13	D
BayesDel_noAF	Uncertain	-0.050
CADD	Benign	20
DANN	Benign	0.89
DEOGEN2	Uncertain	0.51	D;.;T;.;D;D;.
Eigen	Benign	-0.030
Eigen_PC	Benign	0.050
FATHMM_MKL	Uncertain	0.92	D
LIST_S2	Benign	0.81	T;.;T;.;.;.;T
M_CAP	Uncertain	0.12	D
MetaRNN	Benign	0.33	T;T;T;T;T;T;T
MetaSVM	Uncertain	0.70	D
MutationAssessor	Benign	1.8	L;L;.;L;L;L;L
MutationTaster	Benign	0.95	D;D;D;D
PrimateAI	Uncertain	0.60	T
PROVEAN	Benign	-1.8	N;.;.;.;.;N;N
REVEL	Uncertain	0.49
Sift	Uncertain	0.011	D;.;.;.;.;D;D
Sift4G	Benign	0.16	T;.;.;T;.;T;T
Polyphen		0.010	B;B;.;B;B;B;B
Vest4		0.29
MutPred		0.43		Gain of solvent accessibility (P = 0.0365);Gain of solvent accessibility (P = 0.0365);.;Gain of solvent accessibility (P = 0.0365);Gain of solvent accessibility (P = 0.0365);Gain of solvent accessibility (P = 0.0365);Gain of solvent accessibility (P = 0.0365);
MVP		0.81
ClinPred		0.55	D
GERP RS		3.1
Varity_R		0.40
gMVP		0.95

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: rs1553463680; hg19: chr2-166245809;