rs376759643

Variant summary

Our verdict is Likely pathogenic. Variant got 8 ACMG points: 8P and 0B. PM1PM2PP2PP3_ModeratePP5

The NM_001330260.2(SCN8A):​c.5046C>G​(p.Ile1682Met) variant causes a missense change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.000000684 in 1,461,894 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 Conflicting classifications of pathogenicity (no stars). Synonymous variant affecting the same amino acid position (i.e. I1682I) has been classified as Likely benign.

Frequency

Genomes: not found (cov: 32)
Exomes 𝑓: 6.8e-7 ( 0 hom. )

Consequence

SCN8A
NM_001330260.2 missense

Scores

10
4
5

Clinical Significance

Conflicting classifications of pathogenicity criteria provided, conflicting classifications P:1

Conservation

PhyloP100: -6.58
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]

Genome browser will be placed here

ACMG classification

Classification made for transcript

Verdict is Likely_pathogenic. Variant got 8 ACMG points.

PM1
In a repeat IV (size 297) in uniprot entity SCN8A_HUMAN there are 79 pathogenic changes around while only 14 benign (85%) in NM_001330260.2
PM2
Very rare variant in population databases, with high coverage;
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, infantile convulsions and choreoathetosis, cognitive impairment with or without cerebellar ataxia, undetermined early-onset epileptic encephalopathy, complex neurodevelopmental disorder, developmental and epileptic encephalopathy, 13, benign familial infantile epilepsy, seizures, benign familial infantile, 5.
PP3
MetaRNN computational evidence supports a deleterious effect, 0.872
PP5
Variant 12-51806532-C-G is Pathogenic according to our data. Variant chr12-51806532-C-G is described in ClinVar as [Conflicting_classifications_of_pathogenicity]. Clinvar id is 3775337.We mark this variant Likely_pathogenic, oryginal submissions are: {Likely_pathogenic=1}.

Transcripts

RefSeq

Gene Transcript HGVSc HGVSp Effect Exon rank MANE Protein UniProt
SCN8ANM_001330260.2 linkc.5046C>G p.Ile1682Met missense_variant Exon 27 of 27 ENST00000627620.5 NP_001317189.1 Q9UQD0-2Q6B4S4
SCN8ANM_014191.4 linkc.5046C>G p.Ile1682Met missense_variant Exon 27 of 27 ENST00000354534.11 NP_055006.1 Q9UQD0-1
SCN8ANM_001177984.3 linkc.4923C>G p.Ile1641Met missense_variant Exon 26 of 26 NP_001171455.1 Q9UQD0-5
SCN8ANM_001369788.1 linkc.4923C>G p.Ile1641Met missense_variant Exon 26 of 26 NP_001356717.1

Ensembl

Gene Transcript HGVSc HGVSp Effect Exon rank TSL MANE Protein Appris UniProt
SCN8AENST00000354534.11 linkc.5046C>G p.Ile1682Met missense_variant Exon 27 of 27 1 NM_014191.4 ENSP00000346534.4 Q9UQD0-1
SCN8AENST00000627620.5 linkc.5046C>G p.Ile1682Met missense_variant Exon 27 of 27 5 NM_001330260.2 ENSP00000487583.2 Q9UQD0-2
SCN8AENST00000599343.5 linkc.5079C>G p.Ile1693Met missense_variant Exon 26 of 26 5 ENSP00000476447.3 Q9UQD0-3
SCN8AENST00000355133.7 linkc.4923C>G p.Ile1641Met missense_variant Exon 25 of 25 1 ENSP00000347255.4 Q9UQD0-5

Frequencies

GnomAD3 genomes
Cov.:
32
GnomAD4 exome
AF:
6.84e-7
AC:
1
AN:
1461894
Hom.:
0
Cov.:
33
AF XY:
0.00000138
AC XY:
1
AN XY:
727248
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:
8.99e-7
Gnomad4 OTH exome
AF:
0.00
GnomAD4 genome
Cov.:
32

ClinVar

Significance: Conflicting classifications of pathogenicity
Submissions summary: Pathogenic:1
Revision: criteria provided, conflicting classifications
LINK: link

Submissions by phenotype

Cognitive impairment with or without cerebellar ataxia Pathogenic:1
Oct 17, 2023
3billion
Significance: Likely pathogenic
Review Status: criteria provided, single submitter
Collection Method: clinical testing

The variant is not observed in the gnomAD v2.1.1 dataset. Predicted Consequence/Location: The variant is located in a mutational hot spot and/or well-established functional domain in which established pathogenic variants have been reported (PMID: 27270488, 35188110). Missense changes are a common disease-causing mechanism. In silico tool predictions suggest a damaging effect of the variant on gene or gene product [REVEL: 0.73 (>=0.6, sensitivity 0.68 and specificity 0.92)]. Therefore, this variant is classified as Likely pathogenic according to the recommendation of ACMG/AMP guideline. -

Computational scores

Source: dbNSFP v4.3

Name
Calibrated prediction
Score
Prediction
AlphaMissense
Pathogenic
0.60
BayesDel_addAF
Pathogenic
0.33
D
BayesDel_noAF
Pathogenic
0.24
CADD
Benign
1.7
DANN
Benign
0.97
DEOGEN2
Pathogenic
0.96
D;.;.;.;.
Eigen
Benign
-0.75
Eigen_PC
Benign
-1.1
FATHMM_MKL
Benign
0.042
N
LIST_S2
Uncertain
0.95
D;D;.;D;D
M_CAP
Pathogenic
0.78
D
MetaRNN
Pathogenic
0.87
D;D;D;D;D
MetaSVM
Pathogenic
1.0
D
MutationAssessor
Uncertain
2.9
M;.;.;.;M
PrimateAI
Pathogenic
0.86
D
PROVEAN
Uncertain
-2.7
D;D;.;.;.
REVEL
Pathogenic
0.73
Sift
Pathogenic
0.0
D;D;.;.;.
Sift4G
Uncertain
0.013
D;D;D;D;D
Polyphen
0.99
D;.;.;.;.
Vest4
0.75
MutPred
0.64
Gain of disorder (P = 0.0789);.;.;.;Gain of disorder (P = 0.0789);
MVP
0.94
MPC
2.2
ClinPred
0.99
D
GERP RS
-11
Varity_R
0.71
gMVP
0.96

Splicing

Name
Calibrated prediction
Score
Prediction
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

No publications associated with this variant yet.

Other links and lift over

hg19: chr12-52200316; API