2-165090155-T-G

Position:

• chr2-165090155-T-G

Variant summary

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

The NM_006922.4(SCN3A):​c.5998A>C​(p.Lys2000Gln) variant causes a missense change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.00000657 in 152,198 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: 𝑓 0.0000066 (0 hom., cov: 32)
• Consequence: SCN3A NM_006922.4 missense
• Clinical Significance: Uncertain significance criteria provided, single submitter U:1
• Conservation: PhyloP100: 1.85

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]

(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=0.38544407).

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	Protein	UniProt
SCN3A	NM_006922.4	c.5998A>C	p.Lys2000Gln	missense_variant	28/28	ENST00000283254.12	NP_008853.3

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Protein	Appris	UniProt
SCN3A	ENST00000283254.12	c.5998A>C	p.Lys2000Gln	missense_variant	28/28	1	NM_006922.4	ENSP00000283254	P1
	ENST00000638199.1	n.1144-965T>G		intron_variant, non_coding_transcript_variant		5

Frequencies

GnomAD3 genomes AF: 0.00000657 AC: 1 AN: 152198 Hom.: 0 Cov.: 32

Gnomad AFR AF: 0.0000241

Gnomad AMI AF: 0.00

Gnomad AMR AF: 0.00

Gnomad ASJ AF: 0.00

Gnomad EAS AF: 0.00

Gnomad SAS AF: 0.00

Gnomad FIN AF: 0.00

Gnomad MID AF: 0.00

Gnomad NFE AF: 0.00

Gnomad OTH AF: 0.00

GnomAD4 exome Cov.: 29

GnomAD4 genome AF: 0.00000657 AC: 1 AN: 152198 Hom.: 0 Cov.: 32 AF XY: 0.0000134 AC XY: 1 AN XY: 74352

Gnomad4 AFR AF: 0.0000241

Gnomad4 AMR AF: 0.00

Gnomad4 ASJ AF: 0.00

Gnomad4 EAS AF: 0.00

Gnomad4 SAS AF: 0.00

Gnomad4 FIN AF: 0.00

Gnomad4 NFE AF: 0.00

Gnomad4 OTH AF: 0.00

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

Nov 27, 2023

This sequence change replaces lysine, which is basic and polar, with glutamine, which is neutral and polar, at codon 2000 of the SCN3A protein (p.Lys2000Gln). This variant is not present in population databases (gnomAD no frequency). This variant has not been reported in the literature in individuals affected with SCN3A-related conditions. ClinVar contains an entry for this variant (Variation ID: 1968485). 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 not expected to disrupt SCN3A protein function with a negative predictive value of 95%. 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	0.16
BayesDel_addAF	Pathogenic	0.17	D
BayesDel_noAF	Uncertain	0.010
CADD	Benign	23
DANN	Uncertain	0.99
DEOGEN2	Benign	0.35	T;.;.;.
Eigen	Uncertain	0.28
Eigen_PC	Uncertain	0.41
FATHMM_MKL	Uncertain	0.95	D
LIST_S2	Uncertain	0.93	D;D;D;D
M_CAP	Uncertain	0.14	D
MetaRNN	Benign	0.39	T;T;T;T
MetaSVM	Pathogenic	1.0	D
MutationAssessor	Benign	0.81	L;L;.;.
MutationTaster	Benign	0.93	D;D;D;D
PrimateAI	Uncertain	0.59	T
PROVEAN	Benign	-1.4	N;N;.;N
REVEL	Uncertain	0.51
Sift	Uncertain	0.0010	D;D;.;D
Sift4G	Pathogenic	0.0	D;D;.;D
Polyphen		0.94, 0.57	.;P;.;P
Vest4		0.32
MutPred		0.33		Loss of methylation at K2000 (P = 0.0114);Loss of methylation at K2000 (P = 0.0114);.;.;
MVP		0.21
MPC		1.8
ClinPred		0.67	D
GERP RS		6.0
Varity_R		0.24
gMVP		0.41

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: rs1040498167; hg19: chr2-165946665;