Genetic Variant SCN8A:p.Val703Val (chr12-51746013-T-C) – ACMG Classification: Benign (-21 pts)

Variant summary

Our verdict is Benign. The variant received -21 ACMG points: 0P and 21B. BP4_StrongBP6_Very_StrongBP7BS1BS2

The NM_001330260.2(SCN8A):c.2109T>C(p.Val703Val) variant causes a synonymous change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.000561 in 1,609,592 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 Likely benign (★★).

Frequency

Genomes: 𝑓 0.00031 ( 0 hom., cov: 32)

Exomes 𝑓: 0.00059 ( 0 hom. )

Consequence

SCN8A
NM_001330260.2 synonymous

Scores

Clinical Significance

Likely benign criteria provided, multiple submitters, no conflicts B:7

Conservation

PhyloP100: -2.29

Publications

1 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, STRONG Submitted by: ClinGen, PanelApp Australia
developmental and epileptic encephalopathy, 13
Inheritance: AD, AR Classification: DEFINITIVE, STRONG, LIMITED Submitted by: G2P, Ambry Genetics, Labcorp Genetics (formerly Invitae), PanelApp Australia
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: Benign. The variant received -21 ACMG points.

BP4

Computational evidence support a benign effect (BayesDel_noAF=-0.5).

BP6

Variant 12-51746013-T-C is Benign according to our data. Variant chr12-51746013-T-C is described in ClinVar as Likely_benign. ClinVar VariationId is 413881.Status of the report is criteria_provided_multiple_submitters_no_conflicts, 2 stars.

BP7

Synonymous conserved (PhyloP=-2.29 with no splicing effect.

BS1

Variant frequency is greater than expected in population nfe. GnomAd4 allele frequency = 0.000309 (47/152156) while in subpopulation NFE AF = 0.000632 (43/68042). AF 95% confidence interval is 0.000482. There are 0 homozygotes in GnomAd4. There are 19 alleles in the male GnomAd4 subpopulation. Median coverage is 32. This position passed quality control check.

BS2

High AC in GnomAd4 at 47 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	UniProt
SCN8A	NM_001330260.2	MANE Select	c.2109T>C	p.Val703Val	synonymous	Exon 13 of 27	NP_001317189.1	Q9UQD0-2
SCN8A	NM_014191.4	MANE Plus Clinical	c.2109T>C	p.Val703Val	synonymous	Exon 13 of 27	NP_055006.1	Q9UQD0-1
SCN8A	NM_001177984.3		c.2109T>C	p.Val703Val	synonymous	Exon 13 of 26	NP_001171455.1	Q9UQD0-5

Ensembl Transcripts

Gene	Transcript	Tags	HGVSc	HGVSp	Effect	Exon Rank	Protein	UniProt
SCN8A	ENST00000354534.11	TSL:1 MANE Plus Clinical	c.2109T>C	p.Val703Val	synonymous	Exon 13 of 27	ENSP00000346534.4	Q9UQD0-1
SCN8A	ENST00000627620.5	TSL:5 MANE Select	c.2109T>C	p.Val703Val	synonymous	Exon 13 of 27	ENSP00000487583.2	Q9UQD0-2
SCN8A	ENST00000599343.5	TSL:5	c.2142T>C	p.Val714Val	synonymous	Exon 12 of 26	ENSP00000476447.3	Q9UQD0-3

Frequencies

GnomAD3 genomes

AF:

0.000309

AC:

AN:

152156

Hom.:

Cov.:

show subpopulations

Gnomad AFR

AF:

0.0000724

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:

0.000632

Gnomad OTH

AF:

0.000478

GnomAD2 exomes

AF:

0.000273

AC:

AN:

245036

AF XY:

0.000301

show subpopulations

Gnomad AFR exome

AF:

0.0000652

Gnomad AMR exome

AF:

0.0000298

Gnomad ASJ exome

AF:

0.00

Gnomad EAS exome

AF:

0.00

Gnomad FIN exome

AF:

0.00

Gnomad NFE exome

AF:

0.000582

Gnomad OTH exome

AF:

0.00

GnomAD4 exome

AF:

0.000587

AC:

856

AN:

1457436

Hom.:

Cov.:

AF XY:

0.000578

AC XY:

419

AN XY:

724728

show subpopulations

African (AFR)

AF:

0.0000601

AC:

AN:

33256

American (AMR)

AF:

0.0000226

AC:

AN:

44232

Ashkenazi Jewish (ASJ)

AF:

0.0000384

AC:

AN:

26018

East Asian (EAS)

AF:

0.00

AC:

AN:

39612

South Asian (SAS)

AF:

0.00

AC:

AN:

85032

European-Finnish (FIN)

AF:

0.0000750

AC:

AN:

53318

Middle Eastern (MID)

AF:

0.00

AC:

AN:

5754

European-Non Finnish (NFE)

AF:

0.000749

AC:

831

AN:

1110016

Other (OTH)

AF:

0.000282

AC:

AN:

60198

Allele Balance Distribution

Red line indicates average allele balance

Average allele balance: 0.463

Heterozygous variant carriers

118

157

196

0.00

0.20

0.40

0.60

0.80

0.95

Allele balance

Age Distribution

Exome Het

Variant carriers

108

144

180

<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:

0.000309

AC:

AN:

152156

Hom.:

Cov.:

AF XY:

0.000256

AC XY:

AN XY:

74316

show subpopulations

African (AFR)

AF:

0.0000724

AC:

AN:

41420

American (AMR)

AF:

0.00

AC:

AN:

15272

Ashkenazi Jewish (ASJ)

AF:

0.00

AC:

AN:

3468

East Asian (EAS)

AF:

0.00

AC:

AN:

5204

South Asian (SAS)

AF:

0.00

AC:

AN:

4830

European-Finnish (FIN)

AF:

0.00

AC:

AN:

10600

Middle Eastern (MID)

AF:

0.00

AC:

AN:

316

European-Non Finnish (NFE)

AF:

0.000632

AC:

AN:

68042

Other (OTH)

AF:

0.000478

AC:

AN:

2092

Allele Balance Distribution

Red line indicates average allele balance

Average allele balance: 0.488

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:

0.000639

Hom.:

Bravo

AF:

0.000370

ClinVar

ClinVar submissions

Significance:Likely benign

Revision:criteria provided, multiple submitters, no conflicts

View on ClinVar

Pathogenic

VUS

Benign

Condition

not provided (3)

Developmental and epileptic encephalopathy (1)

Inborn genetic diseases (1)

not specified (1)

SCN8A-related disorder (1)

Computational scores

Source: dbNSFP v4.9

Name

Calibrated prediction

Score

Prediction

BayesDel_noAF

Benign

-0.50

CADD

Benign

3.6

(source)

DANN

Benign

0.75

PhyloP100

-2.3

Mutation Taster

=100/0

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

Variant Effect in Transcripts

RefSeq Transcripts

Ensembl Transcripts

Frequencies

Age Distribution

Age Distribution

ClinVar

Computational scores

Splicing

Publications

Other links and lift over