rs746302474

Variant summary

Our verdict is Uncertain significance. Variant got 4 ACMG points: 4P and 0B. PM2PP2PP3

The NM_014191.4(SCN8A):c.3230A>G(p.Tyr1077Cys) variant causes a missense change involving the alteration of a conserved nucleotide. The variant allele was found at a frequency of 0.00000248 in 1,613,836 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. Y1077H) has been classified as Uncertain significance.

Frequency

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

Exomes 𝑓: 0.0000021 ( 0 hom. )

Consequence

SCN8A
NM_014191.4 missense

Scores

Clinical Significance

Uncertain significance criteria provided, single submitter U:1

Conservation

PhyloP100: 9.32

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:

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ACMG classification

Classification made for transcript

Verdict is Uncertain_significance. Variant got 4 ACMG points.

PM2

Very rare variant in population databases, with high coverage;

PP2

Missense variant where missense usually causes diseases, SCN8A

PP3

MetaRNN computational evidence supports a deleterious effect, 0.792

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE
SCN8A	NM_001330260.2 linkuse as main transcript	c.3230A>G	p.Tyr1077Cys	missense_variant	17/27	ENST00000627620.5
SCN8A	NM_014191.4 linkuse as main transcript	c.3230A>G	p.Tyr1077Cys	missense_variant	17/27	ENST00000354534.11
SCN8A	NM_001177984.3 linkuse as main transcript	c.3230A>G	p.Tyr1077Cys	missense_variant	17/26
SCN8A	NM_001369788.1 linkuse as main transcript	c.3230A>G	p.Tyr1077Cys	missense_variant	17/26

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Appris	UniProt
SCN8A	ENST00000354534.11 linkuse as main transcript	c.3230A>G	p.Tyr1077Cys	missense_variant	17/27	1	NM_014191.4	P4	Q9UQD0-1
SCN8A	ENST00000627620.5 linkuse as main transcript	c.3230A>G	p.Tyr1077Cys	missense_variant	17/27	5	NM_001330260.2	A1	Q9UQD0-2

Frequencies

GnomAD3 genomes

AF:

0.00000657

AC:

AN:

152246

Hom.:

Cov.:

show subpopulations

Gnomad AFR

AF:

0.0000241

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:

0.00

Gnomad OTH

AF:

0.00

GnomAD3 exomes

AF:

0.00000801

AC:

AN:

249576

Hom.:

AF XY:

0.00000740

AC XY:

AN XY:

135128

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 SAS 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:

0.00000205

AC:

AN:

1461590

Hom.:

Cov.:

AF XY:

0.00000138

AC XY:

AN XY:

727060

show subpopulations

Gnomad4 AFR exome

AF:

0.00

Gnomad4 AMR exome

AF:

0.00

Gnomad4 ASJ exome

AF:

0.00

Gnomad4 EAS exome

AF:

0.00

Gnomad4 SAS exome

AF:

0.00

Gnomad4 FIN exome

AF:

0.00

Gnomad4 NFE exome

AF:

0.00000270

Gnomad4 OTH exome

AF:

0.00

GnomAD4 genome

AF:

0.00000657

AC:

AN:

152246

Hom.:

Cov.:

AF XY:

0.00

AC XY:

AN XY:

74390

show subpopulations

Gnomad4 AFR

AF:

0.0000241

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:

0.00

Gnomad4 OTH

AF:

0.00

Alfa

AF:

0.0000480

Hom.:

Bravo

AF:

0.00000378

ExAC

AF:

0.0000165

AC:

EpiCase

AF:

0.00

EpiControl

AF:

0.0000593

ClinVar

Significance: Uncertain significance

Submissions summary: Uncertain:1

Revision: criteria provided, single submitter

LINK: link

Submissions by phenotype

Early infantile epileptic encephalopathy with suppression bursts

Uncertain:1

Uncertain significance, criteria provided, single submitter

clinical testing

Invitae

Mar 21, 2018

This sequence change replaces tyrosine with cysteine at codon 1077 of the SCN8A protein (p.Tyr1077Cys). The tyrosine residue is highly conserved and there is a large physicochemical difference between tyrosine and cysteine. This variant is present in population databases (rs746302474, ExAC 0.003%). This variant has not been reported in the literature in individuals with SCN8A-related disease. Algorithms developed to predict the effect of missense changes on protein structure and function do not agree on the potential impact of this missense change (SIFT: "Deleterious"; PolyPhen-2: "Benign"; Align-GVGD: "Class C0"). 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. -

Computational scores

Source: dbNSFP v4.3

Name

Calibrated prediction

Score

Prediction

AlphaMissense

Pathogenic

0.71

BayesDel_addAF

Pathogenic

0.28

BayesDel_noAF

Pathogenic

0.18

Cadd

Pathogenic

Dann

Uncertain

1.0

DEOGEN2

Uncertain

0.79

D;.;.;.;.

Eigen

Uncertain

0.50

Eigen_PC

Uncertain

0.56

FATHMM_MKL

Pathogenic

1.0

LIST_S2

Uncertain

0.91

D;D;.;D;D

M_CAP

Uncertain

0.14

MetaRNN

Pathogenic

0.79

D;D;D;D;D

MetaSVM

Uncertain

0.27

MutationAssessor

Uncertain

2.4

M;M;M;.;M

MutationTaster

Benign

1.0

D;D

PrimateAI

Pathogenic

0.90

PROVEAN

Pathogenic

-6.9

D;D;D;.;.

REVEL

Pathogenic

0.73

Sift

Uncertain

0.0010

D;D;D;.;.

Sift4G

Benign

0.14

T;T;T;T;T

Polyphen

0.63

P;.;.;.;.

Vest4

0.78

MutPred

0.57

Gain of methylation at K1076 (P = 0.031);Gain of methylation at K1076 (P = 0.031);Gain of methylation at K1076 (P = 0.031);.;Gain of methylation at K1076 (P = 0.031);

MVP

0.93

MPC

1.5

ClinPred

0.90

GERP RS

5.1

Varity_R

0.55

gMVP

0.70

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