rs1060501012

Variant summary

Our verdict is Pathogenic. The variant received 14 ACMG points: 14P and 0B. PVS1PM2PP3_ModeratePP5_Moderate

The NM_001330260.2(SCN8A):​c.1339C>T​(p.Gln447*) variant causes a stop gained, splice region change involving the alteration of a conserved nucleotide. The variant allele was found at a frequency of 0.00000657 in 152,146 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a pathogenic outcome for this variant. 2/3 splice prediction tools predicting alterations to normal splicing. Variant has been reported in ClinVar as Pathogenic (★). Variant results in nonsense mediated mRNA decay.

Frequency

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

Consequence

SCN8A
NM_001330260.2 stop_gained, splice_region

Scores

5
1
1
Splicing: ADA: 0.9999
2

Clinical Significance

Pathogenic criteria provided, single submitter P:1

Conservation

PhyloP100: 7.49

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 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

Genome browser will be placed here

ACMG classification

Classification was made for transcript

Our verdict: Pathogenic. The variant received 14 ACMG points.

PVS1
Loss of function variant, product undergoes nonsense mediated mRNA decay. LoF is a known mechanism of disease.
PM2
Very rare variant in population databases, with high coverage;
PP3
Splicing predictors support a deleterious effect. Scorers claiming Pathogenic: dbscSNV1_ADA, dbscSNV1_RF. No scorers claiming Uncertain. Scorers claiming Benign: max_spliceai.
PP5
Variant 12-51705621-C-T is Pathogenic according to our data. Variant chr12-51705621-C-T is described in ClinVar as Pathogenic. ClinVar VariationId is 406260.Status of the report is criteria_provided_single_submitter, 1 stars.

Transcripts

RefSeq

Gene Transcript HGVSc HGVSp Effect Exon rank MANE Protein UniProt
SCN8ANM_001330260.2 linkc.1339C>T p.Gln447* stop_gained, splice_region_variant Exon 10 of 27 ENST00000627620.5 NP_001317189.1 Q9UQD0-2Q6B4S4
SCN8ANM_014191.4 linkc.1339C>T p.Gln447* stop_gained, splice_region_variant Exon 10 of 27 ENST00000354534.11 NP_055006.1 Q9UQD0-1
SCN8ANM_001177984.3 linkc.1339C>T p.Gln447* stop_gained, splice_region_variant Exon 10 of 26 NP_001171455.1 Q9UQD0-5
SCN8ANM_001369788.1 linkc.1339C>T p.Gln447* stop_gained, splice_region_variant Exon 10 of 26 NP_001356717.1

Ensembl

Gene Transcript HGVSc HGVSp Effect Exon rank TSL MANE Protein Appris UniProt
SCN8AENST00000354534.11 linkc.1339C>T p.Gln447* stop_gained, splice_region_variant Exon 10 of 27 1 NM_014191.4 ENSP00000346534.4 Q9UQD0-1
SCN8AENST00000627620.5 linkc.1339C>T p.Gln447* stop_gained, splice_region_variant Exon 10 of 27 5 NM_001330260.2 ENSP00000487583.2 Q9UQD0-2
SCN8AENST00000599343.5 linkc.1339C>T p.Gln447* stop_gained, splice_region_variant Exon 9 of 26 5 ENSP00000476447.3 Q9UQD0-3
SCN8AENST00000355133.7 linkc.1339C>T p.Gln447* stop_gained, splice_region_variant Exon 9 of 25 1 ENSP00000347255.4 Q9UQD0-5

Frequencies

GnomAD3 genomes
AF:
0.00000657
AC:
1
AN:
152146
Hom.:
0
Cov.:
32
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
GnomAD4 exome
Cov.:
31
GnomAD4 genome
AF:
0.00000657
AC:
1
AN:
152146
Hom.:
0
Cov.:
32
AF XY:
0.0000135
AC XY:
1
AN XY:
74320
show subpopulations
African (AFR)
AF:
0.00
AC:
0
AN:
41424
American (AMR)
AF:
0.00
AC:
0
AN:
15280
Ashkenazi Jewish (ASJ)
AF:
0.00
AC:
0
AN:
3472
East Asian (EAS)
AF:
0.00
AC:
0
AN:
5198
South Asian (SAS)
AF:
0.00
AC:
0
AN:
4818
European-Finnish (FIN)
AF:
0.00
AC:
0
AN:
10598
Middle Eastern (MID)
AF:
0.00
AC:
0
AN:
316
European-Non Finnish (NFE)
AF:
0.0000147
AC:
1
AN:
68040
Other (OTH)
AF:
0.00
AC:
0
AN:
2088
Allele Balance Distribution
Red line indicates average allele balance
Average allele balance: 0.675
Heterozygous variant carriers
0
0
1
1
2
2
0.00
0.20
0.40
0.60
0.80
0.95
Allele balance
Alfa
AF:
0.0000401
Hom.:
0
Bravo
AF:
0.00000378

ClinVar

Significance: Pathogenic
Submissions summary: Pathogenic:1
Revision: criteria provided, single submitter
LINK: link

Submissions by phenotype

Developmental and epileptic encephalopathy Pathogenic:1
Dec 02, 2021
Labcorp Genetics (formerly Invitae), Labcorp
Significance:Pathogenic
Review Status:criteria provided, single submitter
Collection Method:clinical testing

This variant is not present in population databases (gnomAD no frequency). For these reasons, this variant has been classified as Pathogenic. ClinVar contains an entry for this variant (Variation ID: 406260). This variant has not been reported in the literature in individuals affected with SCN8A-related conditions. This sequence change creates a premature translational stop signal (p.Gln447*) in the SCN8A gene. It is expected to result in an absent or disrupted protein product. Loss-of-function variants in SCN8A are known to be pathogenic (PMID: 19254928, 32651551). -

Computational scores

Source: dbNSFP v4.3

Name
Calibrated prediction
Score
Prediction
BayesDel_addAF
Pathogenic
0.54
D
BayesDel_noAF
Pathogenic
0.54
CADD
Pathogenic
43
DANN
Uncertain
1.0
Eigen
Pathogenic
1.1
Eigen_PC
Pathogenic
0.98
FATHMM_MKL
Pathogenic
0.97
D
PhyloP100
7.5
Vest4
0.77, 0.75, 0.76, 0.77, 0.75
GERP RS
5.0
Mutation Taster
=2/198
disease causing (fs/PTC)

Splicing

Name
Calibrated prediction
Score
Prediction
dbscSNV1_ADA
Pathogenic
1.0
dbscSNV1_RF
Pathogenic
0.98
SpliceAI score (max)
0.010
Details are displayed if max score is > 0.2

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

Publications

Other links and lift over

dbSNP: rs1060501012; hg19: chr12-52099405; API