rs1553589034

Positions:

• chr2-165365213-C-G

Variant summary

Our verdict is Uncertain significance. Variant got 2 ACMG points: 3P and 1B. PM2 PP2 BP4

The NM_001040142.2(SCN2A):​c.3470C>G​(p.Pro1157Arg) variant causes a missense change involving the alteration of a non-conserved nucleotide. The variant was absent in control chromosomes in GnomAD project. In-silico tool predicts a benign outcome for this variant. Variant has been reported in ClinVar as Uncertain significance (★). Another variant affecting the same amino acid position, but resulting in a different missense (i.e. P1157A) has been classified as Uncertain significance.

• Frequency: Genomes: not found (cov: 31)
• Consequence: SCN2A NM_001040142.2 missense
• Clinical Significance: Uncertain significance criteria provided, single submitter U:1
• Conservation: PhyloP100: 2.90

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 2 ACMG points.

• 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=0.4058224).

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	UniProt
SCN2A	NM_001040142.2	c.3470C>G	p.Pro1157Arg	missense_variant	18/27	ENST00000375437.7
SCN2A	NM_001371246.1	c.3470C>G	p.Pro1157Arg	missense_variant	18/27	ENST00000631182.3

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Appris	UniProt
SCN2A	ENST00000375437.7	c.3470C>G	p.Pro1157Arg	missense_variant	18/27	5	NM_001040142.2	P1
SCN2A	ENST00000631182.3	c.3470C>G	p.Pro1157Arg	missense_variant	18/27	5	NM_001371246.1

Frequencies

GnomAD3 genomes Cov.: 31

GnomAD4 exome Cov.: 32

GnomAD4 genome Cov.: 31

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

Invitae

Nov 16, 2017

This variant is not present in population databases (ExAC no frequency). 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. Algorithms developed to predict the effect of sequence changes on RNA splicing suggest that this variant may create or strengthen a splice site, but this prediction has not been confirmed by published transcriptional studies. Algorithms developed to predict the effect of missense changes on protein structure and function do not agree on the potential impact of this missense change (SIFT: "Deleterious"; PolyPhen-2: "Benign"; Align-GVGD: "Class C0"). This variant has not been reported in the literature in individuals with SCN2A-related disease. This sequence change replaces proline with arginine at codon 1157 of the SCN2A protein (p.Pro1157Arg). The proline residue is highly conserved and there is a moderate physicochemical difference between proline and arginine. -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Benign	0.11
BayesDel_addAF	Pathogenic	0.19	D
BayesDel_noAF	Uncertain	0.040
CADD	Benign	23
DANN	Benign	0.95
DEOGEN2	Uncertain	0.63	D;.;T;.;D;D;.
Eigen	Benign	0.032
Eigen_PC	Benign	0.12
FATHMM_MKL	Uncertain	0.95	D
LIST_S2	Uncertain	0.94	D;.;D;.;.;.;D
M_CAP	Benign	0.023	T
MetaRNN	Benign	0.41	T;T;T;T;T;T;T
MetaSVM	Benign	-0.60	T
MutationAssessor	Uncertain	2.5	M;M;.;M;M;M;M
MutationTaster	Benign	0.91	D;D;D;D
PrimateAI	Uncertain	0.54	T
PROVEAN	Uncertain	-2.8	D;.;.;.;.;D;D
REVEL	Uncertain	0.43
Sift	Benign	0.034	D;.;.;.;.;D;D
Sift4G	Benign	0.28	T;.;.;T;.;T;T
Polyphen		0.14	B;B;.;B;B;B;B
Vest4		0.32
MutPred		0.39		Gain of solvent accessibility (P = 0.0488);Gain of solvent accessibility (P = 0.0488);.;Gain of solvent accessibility (P = 0.0488);Gain of solvent accessibility (P = 0.0488);Gain of solvent accessibility (P = 0.0488);Gain of solvent accessibility (P = 0.0488);
MVP		0.97
ClinPred		0.82	D
GERP RS		5.8
Varity_R		0.36
gMVP		0.79

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: rs1553589034; hg19: chr2-166221723;