rs878854906

Variant names:

• chr2-165090497-C-T
• rs878854906
• NM_006922.4:c.5656G>A

Variant summary

Our verdict is Uncertain significance. The variant received 1 ACMG points: 2P and 1B. PM2 BP4

The NM_006922.4(SCN3A):​c.5656G>A​(p.Val1886Ile) 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 (★). Synonymous variant affecting the same amino acid position (i.e. V1886V) has been classified as Likely benign.

• Frequency:
  • Genomes: not found (cov: 32)
  • Exomes 𝑓: 0.0 (0 hom.)
  • Failed GnomAD Quality Control
• Consequence: SCN3A NM_006922.4 missense
• Clinical Significance: Uncertain significance criteria provided, single submitter U:1
• Conservation: PhyloP100: 4.15
• Publications: 0 publications found

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]

SCN3A Gene-Disease associations (from GenCC):

• genetic developmental and epileptic encephalopathy

  Inheritance: AD Classification: DEFINITIVE Submitted by: Illumina, ClinGen
• developmental and epileptic encephalopathy, 62

  Inheritance: AD Classification: STRONG Submitted by: Labcorp Genetics (formerly Invitae)
• epilepsy, familial focal, with variable foci 4

  Inheritance: AD Classification: STRONG Submitted by: Labcorp Genetics (formerly Invitae), G2P
• undetermined early-onset epileptic encephalopathy

  Inheritance: AD Classification: SUPPORTIVE Submitted by: Orphanet

ENSG00000236283 (HGNC:):

ACMG classification

Our verdict: Uncertain_significance. The variant received 1 ACMG points.

• PM2: Very rare variant in population databases, with high coverage
• BP4: Computational evidence support a benign effect (MetaRNN=0.29998156).

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	MANE	Protein	UniProt
SCN3A	NM_006922.4	c.5656G>A	p.Val1886Ile	missense_variant	Exon 28 of 28	ENST00000283254.12	NP_008853.3

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	TSL	MANE	Protein	Appris	UniProt
SCN3A	ENST00000283254.12	c.5656G>A	p.Val1886Ile	missense_variant	Exon 28 of 28	1	NM_006922.4	ENSP00000283254.7

Frequencies

GnomAD3 genomes Cov.: 32

GnomAD4 exome Data not reliable, filtered out with message: AC0 AF: 0.00 AC: 0 AN: 1461762 Hom.: 0 Cov.: 32 AF XY: 0.00 AC XY: 0 AN XY: 727174

African (AFR) AF: 0.00 AC: 0 AN: 33466

American (AMR) AF: 0.00 AC: 0 AN: 44672

Ashkenazi Jewish (ASJ) AF: 0.00 AC: 0 AN: 26132

East Asian (EAS) AF: 0.00 AC: 0 AN: 39698

South Asian (SAS) AF: 0.00 AC: 0 AN: 86258

European-Finnish (FIN) AF: 0.00 AC: 0 AN: 53416

Middle Eastern (MID) AF: 0.00 AC: 0 AN: 5768

European-Non Finnish (NFE) AF: 0.00 AC: 0 AN: 1111958

Other (OTH) AF: 0.00 AC: 0 AN: 60394

GnomAD4 genome Cov.: 32

ClinVar

Significance: Uncertain significance

Submissions summary: Uncertain:1

Revision: criteria provided, single submitter

Submissions by phenotype

not provided Uncertain:1

Sep 08, 2022

Labcorp Genetics (formerly Invitae), Labcorp

Significance: Uncertain significance

Review Status: criteria provided, single submitter

Collection Method: clinical testing

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 missense changes on protein structure and function are either unavailable or do not agree on the potential impact of this missense change (SIFT: "Tolerated"; PolyPhen-2: "Possibly Damaging"; Align-GVGD: "Class C0"). ClinVar contains an entry for this variant (Variation ID: 240716). This variant has not been reported in the literature in individuals affected with SCN3A-related conditions. This variant is not present in population databases (gnomAD no frequency). This sequence change replaces valine, which is neutral and non-polar, with isoleucine, which is neutral and non-polar, at codon 1886 of the SCN3A protein (p.Val1886Ile). -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Benign	0.095
BayesDel_addAF	Uncertain	0.018	T
BayesDel_noAF	Benign	-0.21
CADD	Uncertain	24
DANN	Benign	0.94
DEOGEN2	Benign	0.26	T;.;.;.
Eigen	Uncertain	0.25
Eigen_PC	Uncertain	0.39
FATHMM_MKL	Uncertain	0.95	D
LIST_S2	Benign	0.58	T;T;T;T
M_CAP	Benign	0.034	D
MetaRNN	Benign	0.30	T;T;T;T
MetaSVM	Uncertain	0.74	D
MutationAssessor	Benign	1.4	L;L;.;.
PhyloP100		4.2
PrimateAI	Uncertain	0.68	T
PROVEAN	Benign	-0.60	N;N;.;N
REVEL	Uncertain	0.40
Sift	Benign	0.27	T;T;.;T
Sift4G	Benign	0.51	T;T;.;T
Polyphen		0.95, 0.047	.;P;.;B
Vest4		0.082
MutPred		0.28		Gain of catalytic residue at V1886 (P = 0.0391);Gain of catalytic residue at V1886 (P = 0.0391);.;.;
MVP		0.66
MPC		1.4
ClinPred		0.64	D
GERP RS		5.9
Varity_R		0.10
gMVP		0.64
Mutation Taster		=36/64	disease causing

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

Other links and lift over

dbSNP: rs878854906; hg19: chr2-165947007;