rs368796221

Variant summary

Our verdict is Benign. The variant received -10 ACMG points: 1P and 11B. PP2BP4_ModerateBP6BS1BS2

The NM_001330260.2(SCN8A):​c.5761A>C​(p.Thr1921Pro) variant causes a missense change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.000179 in 1,613,886 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a benign outcome for this variant. 15/22 in silico tools predict a benign outcome for this variant. Variant has been reported in ClinVar as Conflicting classifications of pathogenicity (no stars). Another variant affecting the same amino acid position, but resulting in a different missense (i.e. T1921A) has been classified as Uncertain significance.

Frequency

Genomes: 𝑓 0.00011 ( 0 hom., cov: 32)
Exomes 𝑓: 0.00019 ( 0 hom. )

Consequence

SCN8A
NM_001330260.2 missense

Scores

1
18

Clinical Significance

Conflicting classifications of pathogenicity criteria provided, conflicting classifications U:1B:3

Conservation

PhyloP100: 1.01

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: Benign. The variant received -10 ACMG points.

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, developmental and epileptic encephalopathy, 13, undetermined early-onset epileptic encephalopathy, benign familial infantile epilepsy, complex neurodevelopmental disorder, seizures, benign familial infantile, 5, cognitive impairment with or without cerebellar ataxia, infantile convulsions and choreoathetosis.
BP4
Computational evidence support a benign effect (MetaRNN=0.09774271).
BP6
Variant 12-51807247-A-C is Benign according to our data. Variant chr12-51807247-A-C is described in ClinVar as Conflicting_classifications_of_pathogenicity. ClinVar VariationId is 207133.
BS1
Variant frequency is greater than expected in population nfe. GnomAdExome4 allele frequency = 0.000187 (273/1461712) while in subpopulation NFE AF = 0.000234 (260/1111870). AF 95% confidence interval is 0.00021. There are 0 homozygotes in GnomAdExome4. There are 126 alleles in the male GnomAdExome4 subpopulation. Median coverage is 33. This position passed quality control check.
BS2
High AC in GnomAd4 at 16 AD gene.

Transcripts

RefSeq

Gene Transcript HGVSc HGVSp Effect Exon rank MANE Protein UniProt
SCN8ANM_001330260.2 linkc.5761A>C p.Thr1921Pro missense_variant Exon 27 of 27 ENST00000627620.5 NP_001317189.1
SCN8ANM_014191.4 linkc.5761A>C p.Thr1921Pro missense_variant Exon 27 of 27 ENST00000354534.11 NP_055006.1
SCN8ANM_001177984.3 linkc.5638A>C p.Thr1880Pro missense_variant Exon 26 of 26 NP_001171455.1
SCN8ANM_001369788.1 linkc.5638A>C p.Thr1880Pro 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.5761A>C p.Thr1921Pro missense_variant Exon 27 of 27 1 NM_014191.4 ENSP00000346534.4
SCN8AENST00000627620.5 linkc.5761A>C p.Thr1921Pro missense_variant Exon 27 of 27 5 NM_001330260.2 ENSP00000487583.2
SCN8AENST00000599343.5 linkc.5794A>C p.Thr1932Pro missense_variant Exon 26 of 26 5 ENSP00000476447.3
SCN8AENST00000355133.7 linkc.5638A>C p.Thr1880Pro missense_variant Exon 25 of 25 1 ENSP00000347255.4

Frequencies

GnomAD3 genomes
AF:
0.000105
AC:
16
AN:
152174
Hom.:
0
Cov.:
32
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:
0.000220
Gnomad OTH
AF:
0.00
GnomAD2 exomes
AF:
0.000100
AC:
25
AN:
249240
AF XY:
0.0000814
show subpopulations
Gnomad AFR exome
AF:
0.0000646
Gnomad AMR exome
AF:
0.00
Gnomad ASJ exome
AF:
0.00
Gnomad EAS exome
AF:
0.00
Gnomad FIN exome
AF:
0.0000464
Gnomad NFE exome
AF:
0.000204
Gnomad OTH exome
AF:
0.00
GnomAD4 exome
AF:
0.000187
AC:
273
AN:
1461712
Hom.:
0
Cov.:
33
AF XY:
0.000173
AC XY:
126
AN XY:
727138
show subpopulations
African (AFR)
AF:
0.0000597
AC:
2
AN:
33480
American (AMR)
AF:
0.0000224
AC:
1
AN:
44724
Ashkenazi Jewish (ASJ)
AF:
0.00
AC:
0
AN:
26136
East Asian (EAS)
AF:
0.00
AC:
0
AN:
39700
South Asian (SAS)
AF:
0.00
AC:
0
AN:
86258
European-Finnish (FIN)
AF:
0.0000187
AC:
1
AN:
53402
Middle Eastern (MID)
AF:
0.00
AC:
0
AN:
5768
European-Non Finnish (NFE)
AF:
0.000234
AC:
260
AN:
1111870
Other (OTH)
AF:
0.000149
AC:
9
AN:
60374
Allele Balance Distribution
Red line indicates average allele balance
Average allele balance: 0.478
Heterozygous variant carriers
0
20
41
61
82
102
0.00
0.20
0.40
0.60
0.80
0.95
Allele balance

Age Distribution

Exome Het
Variant carriers
0
20
40
60
80
100
<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:
0.000105
AC:
16
AN:
152174
Hom.:
0
Cov.:
32
AF XY:
0.0000538
AC XY:
4
AN XY:
74332
show subpopulations
African (AFR)
AF:
0.0000241
AC:
1
AN:
41446
American (AMR)
AF:
0.00
AC:
0
AN:
15282
Ashkenazi Jewish (ASJ)
AF:
0.00
AC:
0
AN:
3472
East Asian (EAS)
AF:
0.00
AC:
0
AN:
5194
South Asian (SAS)
AF:
0.00
AC:
0
AN:
4822
European-Finnish (FIN)
AF:
0.00
AC:
0
AN:
10612
Middle Eastern (MID)
AF:
0.00
AC:
0
AN:
316
European-Non Finnish (NFE)
AF:
0.000220
AC:
15
AN:
68028
Other (OTH)
AF:
0.00
AC:
0
AN:
2090
Allele Balance Distribution
Red line indicates average allele balance
Average allele balance: 0.481
Heterozygous variant carriers
0
1
2
3
4
5
0.00
0.20
0.40
0.60
0.80
0.95
Allele balance

Age Distribution

Genome Het
Variant carriers
0
2
4
6
8
10
<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:
0.000199
Hom.:
0
Bravo
AF:
0.000125
TwinsUK
AF:
0.000270
AC:
1
ALSPAC
AF:
0.000778
AC:
3
ESP6500AA
AF:
0.00
AC:
0
ESP6500EA
AF:
0.000241
AC:
2
ExAC
AF:
0.0000662
AC:
8
EpiCase
AF:
0.0000545
EpiControl
AF:
0.000119

ClinVar

Significance: Conflicting classifications of pathogenicity
Submissions summary: Uncertain:1Benign:3
Revision: criteria provided, conflicting classifications
LINK: link

Submissions by phenotype

not provided Uncertain:1Benign:1
Sep 01, 2019
CeGaT Center for Human Genetics Tuebingen
Significance:Uncertain significance
Review Status:criteria provided, single submitter
Collection Method:clinical testing

- -

Jun 17, 2020
GeneDx
Significance:Likely benign
Review Status:criteria provided, single submitter
Collection Method:clinical testing

- -

Inborn genetic diseases Benign:1
Oct 05, 2016
Ambry Genetics
Significance:Likely benign
Review Status:criteria provided, single submitter
Collection Method:clinical testing

This alteration is classified as likely benign based on a combination of the following: seen in unaffected individuals, population frequency, intact protein function, lack of segregation with disease, co-occurrence, RNA analysis, in silico models, amino acid conservation, lack of disease association in case-control studies, and/or the mechanism of disease or impacted region is inconsistent with a known cause of pathogenicity. -

Developmental and epileptic encephalopathy Benign:1
Jan 22, 2025
Labcorp Genetics (formerly Invitae), Labcorp
Significance:Likely benign
Review Status:criteria provided, single submitter
Collection Method:clinical testing

- -

Computational scores

Source: dbNSFP v4.3

Name
Calibrated prediction
Score
Prediction
AlphaMissense
Benign
0.058
BayesDel_addAF
Benign
-0.13
T
BayesDel_noAF
Benign
-0.12
CADD
Benign
14
DANN
Benign
0.92
DEOGEN2
Benign
0.32
T;.;.;.;.
Eigen
Benign
-0.77
Eigen_PC
Benign
-0.65
FATHMM_MKL
Benign
0.13
N
LIST_S2
Benign
0.72
T;T;.;T;T
M_CAP
Benign
0.020
T
MetaRNN
Benign
0.098
T;T;T;T;T
MetaSVM
Benign
-0.38
T
MutationAssessor
Benign
0.69
N;.;.;.;N
PhyloP100
1.0
PrimateAI
Benign
0.37
T
PROVEAN
Benign
-1.1
N;N;.;.;.
REVEL
Uncertain
0.31
Sift
Benign
0.16
T;T;.;.;.
Sift4G
Benign
0.24
T;T;T;T;T
Polyphen
0.0
B;.;.;.;.
Vest4
0.11
MVP
0.77
MPC
1.4
ClinPred
0.94
D
GERP RS
1.4
Varity_R
0.17
gMVP
0.65
Mutation Taster
=94/6
polymorphism

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

Other links and lift over

dbSNP: rs368796221; hg19: chr12-52201031; API