2-165146815-A-T

Position:

• chr2-165146815-A-T

Variant summary

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

The NM_006922.4(SCN3A):​c.1595T>A​(p.Val532Asp) variant causes a missense change. 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 (★).

• Frequency: Genomes: not found (cov: 31)
• Consequence: SCN3A NM_006922.4 missense
• Clinical Significance: Uncertain significance criteria provided, single submitter U:1
• Conservation: PhyloP100: 3.95

Genes affected

SCN3A (HGNC:10590): (sodium voltage-gated channel alpha subunit 3) Voltage-gated sodium channels are transmembrane glycoprotein complexes composed of a large alpha subunit with 24 transmembrane domains and one or more regulatory beta subunits. They are responsible for the generation and propagation of action potentials in neurons and muscle. This gene encodes one member of the sodium channel alpha subunit gene family, and is found in a cluster of five alpha subunit genes on chromosome 2. Multiple transcript variants encoding different isoforms have been found for this gene. [provided by RefSeq, Jul 2008]

ENSG00000236283 (HGNC:):

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), SCN3A. . Gene score misZ 4.618 (greater than the threshold 3.09). Trascript score misZ 6.3553 (greater than threshold 3.09). GenCC has associacion of gene with undetermined early-onset epileptic encephalopathy, developmental and epileptic encephalopathy, epilepsy, familial focal, with variable foci 4, developmental and epileptic encephalopathy, 62.
• BP4: Computational evidence support a benign effect (MetaRNN=0.38020006).

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	Protein	UniProt
SCN3A	NM_006922.4	c.1595T>A	p.Val532Asp	missense_variant	12/28	ENST00000283254.12	NP_008853.3

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Protein	Appris	UniProt
SCN3A	ENST00000283254.12	c.1595T>A	p.Val532Asp	missense_variant	12/28	1	NM_006922.4	ENSP00000283254.7

Frequencies

GnomAD3 genomes Cov.: 31

GnomAD4 exome Cov.: 30

GnomAD4 genome Cov.: 31

ClinVar

Significance: Uncertain significance

Submissions summary: Uncertain:1

Revision: criteria provided, single submitter

Submissions by phenotype

not provided Uncertain:1

Uncertain significance, criteria provided, single submitter

clinical testing

Labcorp Genetics (formerly Invitae), Labcorp

Jul 23, 2019

This sequence change replaces valine with aspartic acid at codon 532 of the SCN3A protein (p.Val532Asp). The valine residue is moderately conserved and there is a large physicochemical difference between valine and aspartic acid. This variant is not present in population databases (ExAC no frequency). This variant has not been reported in the literature in individuals with SCN3A-related conditions. Algorithms developed to predict the effect of missense changes on protein structure and function are either unavailable or do not agree on the potential impact of this missense change (SIFT: "Deleterious"; PolyPhen-2: "Possibly Damaging"; Align-GVGD: "Class C15"). 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. -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Benign	0.24
BayesDel_addAF	Uncertain	0.092	D
BayesDel_noAF	Benign	-0.11
CADD	Benign	23
DANN	Benign	0.97
DEOGEN2	Uncertain	0.68	D;.;.;.;.
Eigen	Benign	0.064
Eigen_PC	Uncertain	0.23
FATHMM_MKL	Uncertain	0.96	D
LIST_S2	Uncertain	0.97	D;D;D;D;D
M_CAP	Uncertain	0.094	D
MetaRNN	Benign	0.38	T;T;T;T;T
MetaSVM	Uncertain	0.31	D
MutationAssessor	Benign	0.69	N;N;.;N;.
PrimateAI	Uncertain	0.58	T
PROVEAN	Uncertain	-3.5	D;D;.;D;D
REVEL	Uncertain	0.37
Sift	Benign	0.067	T;T;.;T;T
Sift4G	Benign	0.22	T;T;.;T;T
Polyphen		0.0070	B;B;.;B;P
Vest4		0.53
MutPred		0.37		Gain of solvent accessibility (P = 0.0097);Gain of solvent accessibility (P = 0.0097);Gain of solvent accessibility (P = 0.0097);Gain of solvent accessibility (P = 0.0097);Gain of solvent accessibility (P = 0.0097);
MVP		0.46
MPC		1.5
ClinPred		0.89	D
GERP RS		5.7
Varity_R		0.57
gMVP		0.70

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: rs551260434; hg19: chr2-166003325;