chr12-51769127-G-A

Variant names:

Variant summary

Our verdict is Likely benign. Variant got -4 ACMG points: 1P and 5B. PP2BP4BS2

The NM_001330260.2(SCN8A):c.3164G>A(p.Arg1055Gln) variant causes a missense change. The variant allele was found at a frequency of 0.0000335 in 1,613,090 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 Conflicting classifications of pathogenicity (no stars).

Frequency

Genomes: 𝑓 0.0000066 ( 0 hom., cov: 32)

Exomes 𝑓: 0.000036 ( 0 hom. )

Consequence

SCN8A
NM_001330260.2 missense

Scores

Clinical Significance

Conflicting classifications of pathogenicity criteria provided, conflicting classifications U:3B:1

Conservation

PhyloP100: 5.03

Variant links:

Genes affected

SCN8A (HGNC:10596): (sodium voltage-gated channel alpha subunit 8) This gene encodes a member of the sodium channel alpha subunit gene family. The encoded protein forms the ion pore region of the voltage-gated sodium channel. This protein is essential for the rapid membrane depolarization that occurs during the formation of the action potential in excitable neurons. Mutations in this gene are associated with cognitive disability, pancerebellar atrophy and ataxia. Alternate splicing results in multiple transcript variants.[provided by RefSeq, May 2010]

SCN8A links:

Genome browser will be placed here

ACMG classification

Classification made for transcript

Verdict is Likely_benign. Variant got -4 ACMG points.

PP2

Missense variant in the SCN8A gene, where missense mutations are typically associated with disease (based on misZ statistic). The gene has 213 curated pathogenic missense variants (we use a threshold of 10). The gene has 45 curated benign missense variants. Gene score misZ: 0.78755 (below the threshold of 3.09). Trascript score misZ: 10.436 (above the threshold of 3.09). GenCC associations: The gene is linked to myoclonus, familial, 2, infantile convulsions and choreoathetosis, cognitive impairment with or without cerebellar ataxia, undetermined early-onset epileptic encephalopathy, complex neurodevelopmental disorder, developmental and epileptic encephalopathy, 13, benign familial infantile epilepsy, seizures, benign familial infantile, 5.

BP4

Computational evidence support a benign effect (MetaRNN=0.3218215).

BS2

High AC in GnomAdExome4 at 53 AD gene.

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	MANE	Protein	UniProt
SCN8A	NM_001330260.2 link	c.3164G>A	p.Arg1055Gln	missense_variant	Exon 17 of 27	ENST00000627620.5	NP_001317189.1	Q9UQD0-2Q6B4S4
SCN8A	NM_014191.4 link	c.3164G>A	p.Arg1055Gln	missense_variant	Exon 17 of 27	ENST00000354534.11	NP_055006.1	Q9UQD0-1
SCN8A	NM_001177984.3 link	c.3164G>A	p.Arg1055Gln	missense_variant	Exon 17 of 26		NP_001171455.1	Q9UQD0-5
SCN8A	NM_001369788.1 link	c.3164G>A	p.Arg1055Gln	missense_variant	Exon 17 of 26		NP_001356717.1

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	TSL	MANE	Protein	UniProt
SCN8A	ENST00000354534.11 link	c.3164G>A	p.Arg1055Gln	missense_variant	Exon 17 of 27	1	NM_014191.4	ENSP00000346534.4	Q9UQD0-1
SCN8A	ENST00000627620.5 link	c.3164G>A	p.Arg1055Gln	missense_variant	Exon 17 of 27	5	NM_001330260.2	ENSP00000487583.2	Q9UQD0-2
SCN8A	ENST00000599343.5 link	c.3197G>A	p.Arg1066Gln	missense_variant	Exon 16 of 26	5		ENSP00000476447.3	Q9UQD0-3
SCN8A	ENST00000355133.7 link	c.3164G>A	p.Arg1055Gln	missense_variant	Exon 16 of 25	1		ENSP00000347255.4	Q9UQD0-5

Frequencies

GnomAD3 genomes

AF:

0.00000657

AC:

AN:

152208

Hom.:

Cov.:

show subpopulations

Gnomad AFR

AF:

0.00

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:

0.0000147

Gnomad OTH

AF:

0.00

GnomAD3 exomes

AF:

0.0000283

AC:

AN:

247078

Hom.:

AF XY:

0.0000224

AC XY:

AN XY:

134054

show subpopulations

Gnomad AFR exome

AF:

0.00

Gnomad AMR exome

AF:

0.00

Gnomad ASJ exome

AF:

0.00

Gnomad EAS exome

AF:

0.0000562

Gnomad SAS exome

AF:

0.0000659

Gnomad FIN exome

AF:

0.00

Gnomad NFE exome

AF:

0.0000357

Gnomad OTH exome

AF:

0.00

GnomAD4 exome

AF:

0.0000363

AC:

AN:

1460882

Hom.:

Cov.:

AF XY:

0.0000303

AC XY:

AN XY:

726656

show subpopulations

Gnomad4 AFR exome

AF:

0.0000299

Gnomad4 AMR exome

AF:

0.00

Gnomad4 ASJ exome

AF:

0.00

Gnomad4 EAS exome

AF:

0.0000252

Gnomad4 SAS exome

AF:

0.0000348

Gnomad4 FIN exome

AF:

0.00

Gnomad4 NFE exome

AF:

0.0000405

Gnomad4 OTH exome

AF:

0.0000497

GnomAD4 genome

AF:

0.00000657

AC:

AN:

152208

Hom.:

Cov.:

AF XY:

0.0000134

AC XY:

AN XY:

74360

show subpopulations

Gnomad4 AFR

AF:

0.00

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:

0.0000147

Gnomad4 OTH

AF:

0.00

Bravo

AF:

0.00000378

ExAC

AF:

0.0000330

AC:

ClinVar

Significance: Conflicting classifications of pathogenicity

Submissions summary: Uncertain:3Benign:1

Revision: criteria provided, conflicting classifications

LINK: link

Submissions by phenotype

not specified

Uncertain:1

Mar 14, 2017

Genetic Services Laboratory, University of Chicago

Significance: Uncertain significance

Review Status: criteria provided, single submitter

Collection Method: clinical testing

- -

Early infantile epileptic encephalopathy with suppression bursts

Uncertain:1

Oct 27, 2024

Labcorp Genetics (formerly Invitae), Labcorp

Significance: Uncertain significance

Review Status: criteria provided, single submitter

Collection Method: clinical testing

This sequence change replaces arginine, which is basic and polar, with glutamine, which is neutral and polar, at codon 1055 of the SCN8A protein (p.Arg1055Gln). This variant is present in population databases (rs756127631, gnomAD 0.007%). This variant has not been reported in the literature in individuals affected with SCN8A-related conditions. ClinVar contains an entry for this variant (Variation ID: 436670). Invitae Evidence Modeling of protein sequence and biophysical properties (such as structural, functional, and spatial information, amino acid conservation, physicochemical variation, residue mobility, and thermodynamic stability) indicates that this missense variant is not expected to disrupt SCN8A 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. -

Cognitive impairment with or without cerebellar ataxia;C3281191:Developmental and epileptic encephalopathy, 13;C4310728:Seizures, benign familial infantile, 5

Uncertain:1

Oct 31, 2018

Fulgent Genetics, Fulgent Genetics

Significance: Uncertain significance

Review Status: criteria provided, single submitter

Collection Method: clinical testing

- -

not provided

Benign:1

Jan 29, 2021

GeneDx

Significance: Likely benign

Review Status: criteria provided, single submitter

Collection Method: clinical testing

Missense variants in this gene are often considered pathogenic (Stenson et al., 2014); In silico analysis supports that this missense variant does not alter protein structure/function; Has not been previously published as pathogenic or benign to our knowledge; This substitution is predicted to be in the cytoplasmic loop between the second and third homologous domains -

Computational scores

Source: dbNSFP v4.3

Name

Calibrated prediction

Score

Prediction

AlphaMissense

Benign

0.13

BayesDel_addAF

Pathogenic

0.19

BayesDel_noAF

Pathogenic

0.22

CADD

Pathogenic

DANN

Pathogenic

1.0

DEOGEN2

Benign

0.34

T;.;.;.;.

Eigen

Uncertain

0.48

Eigen_PC

Uncertain

0.53

FATHMM_MKL

Pathogenic

0.99

LIST_S2

Uncertain

0.96

D;D;.;D;D

M_CAP

Uncertain

0.17

MetaRNN

Benign

0.32

T;T;T;T;T

MetaSVM

Uncertain

0.76

MutationAssessor

Benign

2.0

M;M;M;.;M

PrimateAI

Uncertain

0.60

PROVEAN

Benign

-1.2

N;N;N;.;.

REVEL

Pathogenic

0.71

Sift

Uncertain

0.0050

D;D;D;.;.

Sift4G

Benign

0.34

T;T;T;T;T

Polyphen

0.93

P;.;.;.;.

Vest4

0.39

MutPred

0.48

Gain of disorder (P = 0.1196);Gain of disorder (P = 0.1196);Gain of disorder (P = 0.1196);.;Gain of disorder (P = 0.1196);

MVP

0.96

MPC

1.8

ClinPred

0.21

GERP RS

4.5

Varity_R

0.24

gMVP

0.64

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

Below is the list of publications found by LitVar. It may be empty.

Variant summary

Frequency

Consequence

Scores

Clinical Significance

Conservation

ACMG classification

Transcripts

RefSeq

Ensembl

Frequencies

ClinVar

Submissions by phenotype

Computational scores

Splicing

Publications

LitVar

Other links and lift over