rs1555229543

Variant names:

Variant summary

Our verdict is The variant received 14 classification points (ACMG Germline Pathogenicity v2019). PVS1PM2PP5_Strong

The NM_001330260.2(SCN8A):c.4754G>A (p.Trp1585*) variant causes a stop gained change involving the alteration of a conserved nucleotide. This is a loss-of-function variant that does not trigger NMD. The variant allele was found at a cumulative frequency of 0.000000684 (AC=1) in the gnomAD database across 1,461,694 control chromosomes (no homozygotes observed). The grpmax filtering allele frequency (95% CI) is 0.000000899. In-silico predictor (BayesDel (noAF)) classifies this variant as likely damaging/oncogenic. Splicing prediction tools (SpliceAI) predict no significant impact on normal splicing. The affected nucleotide is highly conserved across species (PhyloP 100-way vertebrate score: 10.00). Variant has been reported in ClinVar as Pathogenic/Likely Pathogenic (★★).

Frequency

Genomes: not found (cov: 32)

Exomes 𝑓: 6.8e-7 ( 0 hom. )

Consequence

SCN8A
NM_001330260.2 stop_gained

Scores

Clinical Significance

Likely pathogenic criteria provided, multiple submitters, no conflicts P:2

Conservation

PhyloP100: 10.0

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, STRONG Submitted by: PanelApp Australia, ClinGen
developmental and epileptic encephalopathy, 13
Inheritance: AD, AR Classification: DEFINITIVE, STRONG, LIMITED Submitted by: Ambry Genetics, PanelApp Australia, Labcorp Genetics (formerly Invitae), G2P
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
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

new If you want to explore the variant's impact on the transcript NM_001330260.2, check out the Mutation Effect Viewer. This is especially useful for frameshift variants or if you want to visualize the effect of exon loss / intron retention.

Classification according to ACMG Germline Pathogenicity v2019

Specifications for SCN8A are available in the ClinGen Criteria Specification Registry and recommended for reference when assigning criteria.

Classification was made for transcript

Our verdict: Pathogenic. The variant received 14 points.

PVS1

Non-NMD frameshift: ≥4 downstream pathogenic — very strong evidence preserved (PVS1); Stop-gained (exon 26 of 27) at amino acid 1585 of 1980; NMD not predicted. 98 pathogenic variants downstream support preserved loss-of-function impact.

PM2

Very rare in gnomAD for AD/XL gene (popmax AF < threshold/10) — PM2; GnomAD popmax AF = 0.000000899 — very rare for AD+AR gene (threshold 0.0001) — PM2 moderate.

PP5

ClinVar 2-star pathogenic — strong (PP5); ClinVar germline classification: Pathogenic/Likely Pathogenic, 2 star(s).

Variant Effect in Transcripts

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

RefSeq Transcripts

Gene	Transcript	Tags	HGVSc	HGVSp	Effect	Exon Rank	Protein	UniProt
SCN8A	NM_001330260.2	MANE Select	c.4754G>A	p.Trp1585*	stop_gained	Exon 26 of 27	NP_001317189.1	Q9UQD0-2
SCN8A	NM_014191.4	MANE Plus Clinical	c.4754G>A	p.Trp1585*	stop_gained	Exon 26 of 27	NP_055006.1	Q9UQD0-1
SCN8A	NM_001177984.3		c.4631G>A	p.Trp1544*	stop_gained	Exon 25 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.4754G>A	p.Trp1585*	stop_gained	Exon 26 of 27	ENSP00000346534.4	Q9UQD0-1
SCN8A	ENST00000627620.5	TSL:5 MANE Select	c.4754G>A	p.Trp1585*	stop_gained	Exon 26 of 27	ENSP00000487583.2	Q9UQD0-2
SCN8A	ENST00000599343.5	TSL:5	c.4787G>A	p.Trp1596*	stop_gained	Exon 25 of 26	ENSP00000476447.3	Q9UQD0-3

Frequencies

GnomAD3 genomes

Cov.:

GnomAD4 exome

AF:

6.84e-7

AC:

AN:

1461694

Hom.:

Cov.:

AF XY:

0.00

AC XY:

AN XY:

727128

show subpopulations

African (AFR)

AF:

0.00

AC:

AN:

33478

American (AMR)

AF:

0.00

AC:

AN:

44722

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:

86250

European-Finnish (FIN)

AF:

0.00

AC:

AN:

53400

Middle Eastern (MID)

AF:

0.00

AC:

AN:

5768

European-Non Finnish (NFE)

AF:

8.99e-7

AC:

AN:

1111866

Other (OTH)

AF:

0.00

AC:

AN:

60374

Allele Balance Distribution

Red line indicates average allele balance

Average allele balance: 0.425

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

Cov.:

ClinVar

ClinVar submissions

Significance:Likely pathogenic

Revision:criteria provided, multiple submitters, no conflicts

View on ClinVar

Pathogenic

VUS

Benign

Condition

Inborn genetic diseases (1)

not provided (1)

Computational scores

Source: dbNSFP v4.9

Name

Calibrated prediction

Score

Prediction

BayesDel_addAF

Pathogenic

0.62

BayesDel_noAF

Pathogenic

0.66

CADD

Pathogenic

(source)

DANN

Uncertain

1.0

Eigen

Pathogenic

1.0

Eigen_PC

Pathogenic

0.88

FATHMM_MKL

Pathogenic

0.99

PhyloP100

AlphaGenome AVI

Pathogenic

(source)

GPN-Star LLR

-11

(source)

GPN-Star score

(source)

Mutation Taster

=4/196

disease causing

(source)

Splicing

Name

Calibrated prediction

Score

Prediction

SpliceAI score (max)

0.0

Details are displayed if max score is > 0.2

Pangolin (max)

Benign

0.10

(source)

Pangolin loss

0.10

Position offset: 41

Find out detailed SpliceAI scores and Pangolin per-transcript scores at spliceailookup.broadinstitute.org

MaxEntScan Visualizer can be used to analyze the impact of this mutation on the neighboring sequence.

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

Classification according to ACMG Germline Pathogenicity v2019

Variant Effect in Transcripts

RefSeq Transcripts

Ensembl Transcripts

Frequencies

Age Distribution

ClinVar

Computational scores

Splicing

Publications

Other links and lift over