rs796053232

Variant names:

Variant summary

Our verdict is Likely benign. The variant received -2 ACMG points: 2P and 4B. PP2PP3BS2

The NM_001330260.2(SCN8A):c.457A>C(p.Asn153His) variant causes a missense change. The variant allele was found at a frequency of 0.0000199 in 1,610,540 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a pathogenic 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. N153K) has been classified as Uncertain significance.

Frequency

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

Exomes 𝑓: 0.000021 ( 0 hom. )

Consequence

SCN8A
NM_001330260.2 missense

Scores

Clinical Significance

Uncertain significance criteria provided, multiple submitters, no conflicts U:3

Conservation

PhyloP100: 6.19

Publications

0 publications found

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 Gene-Disease associations (from GenCC):

complex neurodevelopmental disorder
Inheritance: AD Classification: DEFINITIVE Submitted by: ClinGen
developmental and epileptic encephalopathy, 13
Inheritance: AD Classification: DEFINITIVE, STRONG Submitted by: Labcorp Genetics (formerly Invitae), G2P, Ambry Genetics
cognitive impairment with or without cerebellar ataxia
Inheritance: AD Classification: STRONG Submitted by: Ambry Genetics, Labcorp Genetics (formerly Invitae)
seizures, benign familial infantile, 5
Inheritance: AD Classification: STRONG Submitted by: Labcorp Genetics (formerly Invitae)
benign familial infantile epilepsy
Inheritance: AD Classification: SUPPORTIVE Submitted by: Orphanet
infantile convulsions and choreoathetosis
Inheritance: AD Classification: SUPPORTIVE Submitted by: Orphanet
undetermined early-onset epileptic encephalopathy
Inheritance: AD Classification: SUPPORTIVE Submitted by: Orphanet
myoclonus, familial, 2
Inheritance: AD Classification: LIMITED Submitted by: Ambry Genetics

SCN8A links:

Genome browser will be placed here

ACMG classification

Classification was made for transcript

Our verdict: Likely_benign. The variant received -2 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, developmental and epileptic encephalopathy, 13, undetermined early-onset epileptic encephalopathy, benign familial infantile epilepsy, complex neurodevelopmental disorder, seizures, benign familial infantile, 5, cognitive impairment with or without cerebellar ataxia, infantile convulsions and choreoathetosis.

PP3

MetaRNN computational evidence supports a deleterious effect, 0.824

BS2

High AC in GnomAdExome4 at 31 AD gene.

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	MANE	Protein	UniProt
SCN8A	NM_001330260.2 link	c.457A>C	p.Asn153His	missense_variant	Exon 4 of 27	ENST00000627620.5	NP_001317189.1	Q9UQD0-2Q6B4S4
SCN8A	NM_014191.4 link	c.457A>C	p.Asn153His	missense_variant	Exon 4 of 27	ENST00000354534.11	NP_055006.1	Q9UQD0-1
SCN8A	NM_001177984.3 link	c.457A>C	p.Asn153His	missense_variant	Exon 4 of 26		NP_001171455.1	Q9UQD0-5
SCN8A	NM_001369788.1 link	c.457A>C	p.Asn153His	missense_variant	Exon 4 of 26		NP_001356717.1

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	TSL	MANE	Protein	UniProt
SCN8A	ENST00000354534.11 link	c.457A>C	p.Asn153His	missense_variant	Exon 4 of 27	1	NM_014191.4	ENSP00000346534.4	Q9UQD0-1
SCN8A	ENST00000627620.5 link	c.457A>C	p.Asn153His	missense_variant	Exon 4 of 27	5	NM_001330260.2	ENSP00000487583.2	Q9UQD0-2
SCN8A	ENST00000599343.5 link	c.457A>C	p.Asn153His	missense_variant	Exon 3 of 26	5		ENSP00000476447.3	Q9UQD0-3
SCN8A	ENST00000355133.7 link	c.457A>C	p.Asn153His	missense_variant	Exon 3 of 25	1		ENSP00000347255.4	Q9UQD0-5

Frequencies

GnomAD3 genomes

AF:

0.00000657

AC:

AN:

152204

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

GnomAD2 exomes

AF:

0.00000802

AC:

AN:

249324

AF XY:

0.00000739

show subpopulations

Gnomad AFR exome

AF:

0.00

Gnomad AMR exome

AF:

0.00

Gnomad ASJ exome

AF:

0.00

Gnomad EAS exome

AF:

0.00

Gnomad FIN exome

AF:

0.00

Gnomad NFE exome

AF:

0.0000177

Gnomad OTH exome

AF:

0.00

GnomAD4 exome

AF:

0.0000213

AC:

AN:

1458336

Hom.:

Cov.:

AF XY:

0.0000152

AC XY:

AN XY:

725736

show subpopulations

African (AFR)

AF:

0.00

AC:

AN:

33394

American (AMR)

AF:

0.00

AC:

AN:

44638

Ashkenazi Jewish (ASJ)

AF:

0.00

AC:

AN:

26096

East Asian (EAS)

AF:

0.00

AC:

AN:

39660

South Asian (SAS)

AF:

0.00

AC:

AN:

86124

European-Finnish (FIN)

AF:

0.00

AC:

AN:

53394

Middle Eastern (MID)

AF:

0.00

AC:

AN:

5764

European-Non Finnish (NFE)

AF:

0.0000280

AC:

AN:

1109014

Other (OTH)

AF:

0.00

AC:

AN:

60252

Allele Balance Distribution

Red line indicates average allele balance

Average allele balance: 0.481

Heterozygous variant carriers

0.00

0.20

0.40

0.60

0.80

0.95

Allele balance

Age Distribution

Exome Het

Variant carriers

<30

30-35

35-40

40-45

45-50

50-55

55-60

60-65

65-70

70-75

75-80

>80

Age

GnomAD4 genome

AF:

0.00000657

AC:

AN:

152204

Hom.:

Cov.:

AF XY:

0.00

AC XY:

AN XY:

74368

show subpopulations

African (AFR)

AF:

0.00

AC:

AN:

41438

American (AMR)

AF:

0.00

AC:

AN:

15276

Ashkenazi Jewish (ASJ)

AF:

0.00

AC:

AN:

3470

East Asian (EAS)

AF:

0.00

AC:

AN:

5202

South Asian (SAS)

AF:

0.00

AC:

AN:

4826

European-Finnish (FIN)

AF:

0.00

AC:

AN:

10622

Middle Eastern (MID)

AF:

0.00

AC:

AN:

316

European-Non Finnish (NFE)

AF:

0.0000147

AC:

AN:

68050

Other (OTH)

AF:

0.00

AC:

AN:

2092

Allele Balance Distribution

Red line indicates average allele balance

Average allele balance: 0.575

Heterozygous variant carriers

0.00

0.20

0.40

0.60

0.80

0.95

Allele balance

Alfa

AF:

0.0000494

Hom.:

Bravo

AF:

0.0000113

ClinVar

Significance: Uncertain significance

Submissions summary: Uncertain:3

Revision: criteria provided, multiple submitters, no conflicts

LINK: link

Submissions by phenotype

Developmental and epileptic encephalopathy

Uncertain:1

Oct 29, 2024

Labcorp Genetics (formerly Invitae), Labcorp

Significance:Uncertain significance

Review Status:criteria provided, single submitter

Collection Method:clinical testing

This sequence change replaces asparagine, which is neutral and polar, with histidine, which is basic and polar, at codon 153 of the SCN8A protein (p.Asn153His). This variant is present in population databases (rs796053232, gnomAD 0.002%). 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: 207139). 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. -

not provided

Uncertain:1

Oct 23, 2017

GeneDx

Significance:Uncertain significance

Review Status:criteria provided, single submitter

Collection Method:clinical testing

p.Asn153His (AAC>CAC): c.457 A>C in exon 4 of the SCN8A gene (NM_014191.3). A variant of unknown significance has been identified in the SCN8A gene. The N153H variant has not been published as a mutation, nor has it been reported as a benign polymorphism to our knowledge. It was not observed in approximately 6,200 individuals of European and African American ancestry in the NHLBI Exome Sequencing Project, indicating it is not a common benign variant in these populations. This substitution alters a highly conserved position predicted to be within the extracellular loop between the S1 and S2 transmembrane segments of the first homologous domain. The N153H variant is a semi-conservative amino acid substitution, which may impact secondary protein structure as these residues differ in some properties. In silico analysis is inconsistent in its predictions as to whether or not the variant is damaging to the protein structure/function. Therefore, based on the currently available information, it is unclear whether this variant is a pathogenic mutation or a rare benign variant. The variant is found in EPILEPSY panel(s). -

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

- -

Computational scores

Source: dbNSFP v4.3

Name

Calibrated prediction

Score

Prediction

AlphaMissense

Benign

0.22

BayesDel_addAF

Uncertain

0.13

BayesDel_noAF

Uncertain

-0.030

CADD

Uncertain

(source)

DANN

Uncertain

0.99

DEOGEN2

Pathogenic

0.82

.;D;.;.;.;.;.

Eigen

Uncertain

0.63

Eigen_PC

Uncertain

0.63

FATHMM_MKL

Uncertain

0.97

LIST_S2

Uncertain

0.94

D;D;D;.;D;D;D

M_CAP

Pathogenic

0.36

MetaRNN

Pathogenic

0.82

D;D;D;D;D;D;D

MetaSVM

Pathogenic

1.1

MutationAssessor

Benign

1.9

.;L;L;L;L;L;.

PhyloP100

6.2

PrimateAI

Uncertain

0.70

PROVEAN

Uncertain

-3.5

.;D;D;D;.;.;.

REVEL

Pathogenic

0.81

Sift

Uncertain

0.0010

.;D;D;D;.;.;.

Sift4G

Uncertain

0.044

.;D;D;D;D;D;D

Polyphen

0.96, 0.99

.;P;.;.;D;.;.

Vest4

0.35, 0.33, 0.33, 0.36, 0.34

MVP

0.97

MPC

1.9

ClinPred

0.96

GERP RS

5.2

PromoterAI

0.021

Neutral

(source)

Varity_R

0.76

gMVP

0.86

Mutation Taster

=70/30

polymorphism

(source)

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

You must be logged in to view publications. This limit was set because tens of millions (!) of queries from AI bots are generated daily.

Variant summary

Frequency

Consequence

Scores

Clinical Significance

Conservation

Publications

ACMG classification

Transcripts

RefSeq

Ensembl

Frequencies

Age Distribution

ClinVar

Submissions by phenotype

Computational scores

Splicing

Publications

Other links and lift over