Variant summary

Our verdict is Likely benign. The variant received -2 ACMG points: 3P and 5B. PM1PP2BP4BS2

The NM_001330260.2(SCN8A):c.3272A>C(p.Asn1091Thr) variant causes a missense change. The variant allele was found at a frequency of 0.0000186 in 1,613,768 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 (★★). Another variant affecting the same amino acid position, but resulting in a different missense (i.e. N1091S) has been classified as Likely benign.

Frequency

Genomes: 𝑓 0.000033 ( 0 hom., cov: 32)

Exomes 𝑓: 0.000017 ( 0 hom. )

Consequence

SCN8A
NM_001330260.2 missense

Scores

Clinical Significance

Uncertain significance criteria provided, multiple submitters, no conflicts U:2

Conservation

PhyloP100: 5.33

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.

PM1

In a hotspot region, there are 2 aminoacids with missense pathogenic changes in the window of +-8 aminoacids around while only 2 benign, 15 uncertain in NM_001330260.2

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.

BP4

Computational evidence support a benign effect (MetaRNN=0.35739303).

BS2

High AC in GnomAd4 at 5 AD gene.

Variant Effect in Transcripts

ACMG analysis was done for transcript: NM_001330260.2. You can select a different transcript below to see updated ACMG assignments.

RefSeq Transcripts

Gene	Transcript	Tags	HGVSc	HGVSp	Effect	Exon Rank	Protein
SCN8A	NM_001330260.2	MANE Select	c.3272A>C	p.Asn1091Thr	missense	Exon 17 of 27	NP_001317189.1
SCN8A	NM_014191.4	MANE Plus Clinical	c.3272A>C	p.Asn1091Thr	missense	Exon 17 of 27	NP_055006.1
SCN8A	NM_001177984.3		c.3272A>C	p.Asn1091Thr	missense	Exon 17 of 26	NP_001171455.1

Ensembl Transcripts

Gene	Transcript	Tags	HGVSc	HGVSp	Effect	Exon Rank	Protein
SCN8A	ENST00000354534.11	TSL:1 MANE Plus Clinical	c.3272A>C	p.Asn1091Thr	missense	Exon 17 of 27	ENSP00000346534.4
SCN8A	ENST00000627620.5	TSL:5 MANE Select	c.3272A>C	p.Asn1091Thr	missense	Exon 17 of 27	ENSP00000487583.2
SCN8A	ENST00000599343.5	TSL:5	c.3305A>C	p.Asn1102Thr	missense	Exon 16 of 26	ENSP00000476447.3

Frequencies

GnomAD3 genomes

AF:

0.0000329

AC:

AN:

152072

Hom.:

Cov.:

show subpopulations

Gnomad AFR

AF:

0.0000242

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:

0.0000588

Gnomad OTH

AF:

0.00

GnomAD2 exomes

AF:

0.0000120

AC:

AN:

250140

AF XY:

0.00

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:

0.0000265

Gnomad OTH exome

AF:

0.00

GnomAD4 exome

AF:

0.0000171

AC:

AN:

1461696

Hom.:

Cov.:

AF XY:

0.0000124

AC XY:

AN XY:

727130

show subpopulations

African (AFR)

AF:

0.00

AC:

AN:

33480

American (AMR)

AF:

0.00

AC:

AN:

44724

Ashkenazi Jewish (ASJ)

AF:

0.00

AC:

AN:

26136

East Asian (EAS)

AF:

0.00

AC:

AN:

39700

South Asian (SAS)

AF:

0.00

AC:

AN:

86258

European-Finnish (FIN)

AF:

0.00

AC:

AN:

53402

Middle Eastern (MID)

AF:

0.00

AC:

AN:

5768

European-Non Finnish (NFE)

AF:

0.0000216

AC:

AN:

1111856

Other (OTH)

AF:

0.0000166

AC:

AN:

60372

Allele Balance Distribution

Red line indicates average allele balance

Average allele balance: 0.473

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:

0.0000329

AC:

AN:

152072

Hom.:

Cov.:

AF XY:

0.0000538

AC XY:

AN XY:

74300

show subpopulations

African (AFR)

AF:

0.0000242

AC:

AN:

41396

American (AMR)

AF:

0.00

AC:

AN:

15264

Ashkenazi Jewish (ASJ)

AF:

0.00

AC:

AN:

3466

East Asian (EAS)

AF:

0.00

AC:

AN:

5192

South Asian (SAS)

AF:

0.00

AC:

AN:

4822

European-Finnish (FIN)

AF:

0.00

AC:

AN:

10610

Middle Eastern (MID)

AF:

0.00

AC:

AN:

316

European-Non Finnish (NFE)

AF:

0.0000588

AC:

AN:

68004

Other (OTH)

AF:

0.00

AC:

AN:

2090

Allele Balance Distribution

Red line indicates average allele balance

Average allele balance: 0.485

Heterozygous variant carriers

0.00

0.20

0.40

0.60

0.80

0.95

Allele balance

Age Distribution

Genome 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

Alfa

AF:

0.00

Hom.:

Bravo

AF:

0.0000264

ExAC

AF:

0.0000165

AC:

EpiCase

AF:

0.0000545

EpiControl

AF:

0.00

ClinVar

ClinVar submissions as Germline

Significance:Uncertain significance

Revision:criteria provided, multiple submitters, no conflicts

View on ClinVar

Pathogenic

VUS

Benign

Condition

Developmental and epileptic encephalopathy (1)

Inborn genetic diseases (1)

Computational scores

Source: dbNSFP v4.9

Name

Calibrated prediction

Score

Prediction

AlphaMissense

Benign

0.24

BayesDel_addAF

Uncertain

0.080

BayesDel_noAF

Benign

-0.11

CADD

Uncertain

(source)

DANN

Uncertain

0.99

DEOGEN2

Uncertain

0.67

Eigen

Uncertain

0.40

Eigen_PC

Uncertain

0.46

FATHMM_MKL

Pathogenic

0.99

LIST_S2

Benign

0.82

M_CAP

Benign

0.082

MetaRNN

Benign

0.36

MetaSVM

Uncertain

0.062

MutationAssessor

Uncertain

2.2

PhyloP100

5.3

PrimateAI

Uncertain

0.61

PROVEAN

Uncertain

-2.7

REVEL

Uncertain

0.48

Sift

Uncertain

0.0030

Sift4G

Benign

0.19

Polyphen

0.47

Vest4

0.38

MutPred

0.40

Gain of glycosylation at N1091 (P = 0.0357)

MVP

0.78

MPC

1.5

ClinPred

0.62

GERP RS

5.1

Varity_R

0.46

gMVP

0.70

Mutation Taster

=10/90

disease causing

(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.

rs558738676

Variant summary

Frequency

Consequence

Scores

Clinical Significance

Conservation

Publications

ACMG classification

Variant Effect in Transcripts

RefSeq Transcripts

Ensembl Transcripts

Frequencies

Age Distribution

Age Distribution

ClinVar

ClinVar submissions as Germline

Computational scores

Splicing

Publications

Other links and lift over