NM_001165963.4:c.1703G>A

Variant summary

Our verdict is Uncertain significance. The variant received 2 ACMG points: 6P and 4B. PM1PP2PP3_ModeratePP5BS2

The NM_001165963.4(SCN1A):​c.1703G>A​(p.Arg568Gln) variant causes a missense change. The variant allele was found at a frequency of 0.00000743 in 1,614,136 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).

Frequency

Genomes: 𝑓 0.0000066 ( 0 hom., cov: 32)
Exomes 𝑓: 0.0000075 ( 0 hom. )

Consequence

SCN1A
NM_001165963.4 missense

Scores

11
5
3

Clinical Significance

Conflicting classifications of pathogenicity criteria provided, conflicting classifications P:1U:2

Conservation

PhyloP100: 4.88

Publications

3 publications found
Variant links:
Genes affected
SCN1A (HGNC:10585): (sodium voltage-gated channel alpha subunit 1) Voltage-dependent sodium channels are heteromeric complexes that regulate sodium exchange between intracellular and extracellular spaces and are essential for the generation and propagation of action potentials in muscle cells and neurons. Each sodium channel is composed of a large pore-forming, glycosylated alpha subunit and two smaller beta subunits. This gene encodes a sodium channel alpha subunit, which has four homologous domains, each of which contains six transmembrane regions. Allelic variants of this gene are associated with generalized epilepsy with febrile seizures and epileptic encephalopathy. Alternative splicing results in multiple transcript variants. The RefSeq Project has decided to create four representative RefSeq records. Three of the transcript variants are supported by experimental evidence and the fourth contains alternate 5' untranslated exons, the exact combination of which have not been experimentally confirmed for the full-length transcript. [provided by RefSeq, Oct 2015]
SCN1A-AS1 (HGNC:54069): (SCN1A and SCN9A antisense RNA 1)

Genome browser will be placed here

ACMG classification

Classification was made for transcript

Our verdict: Uncertain_significance. The variant received 2 ACMG points.

PM1
In a hotspot region, there are 2 aminoacids with missense pathogenic changes in the window of +-8 aminoacids around while only 0 benign, 15 uncertain in NM_001165963.4
PP2
Missense variant in the SCN1A gene, where missense mutations are typically associated with disease (based on misZ statistic). The gene has 848 curated pathogenic missense variants (we use a threshold of 10). The gene has 89 curated benign missense variants. Gene score misZ: 5.2206 (above the threshold of 3.09). Trascript score misZ: 7.6022 (above the threshold of 3.09). GenCC associations: The gene is linked to familial or sporadic hemiplegic migraine, myoclonic-astatic epilepsy, arthrogryposis, Dravet syndrome, malignant migrating partial seizures of infancy, generalized epilepsy with febrile seizures plus, type 2, migraine, familial hemiplegic, 3, developmental and epileptic encephalopathy, 6A, familial hemiplegic migraine, generalized epilepsy with febrile seizures plus, genetic developmental and epileptic encephalopathy, Lennox-Gastaut syndrome.
PP3
MetaRNN computational evidence supports a deleterious effect, 0.859
PP5
Variant 2-166044009-C-T is Pathogenic according to our data. Variant chr2-166044009-C-T is described in ClinVar as Conflicting_classifications_of_pathogenicity. ClinVar VariationId is 193841.
BS2
High AC in GnomAdExome4 at 11 AD,Unknown gene.

Transcripts

RefSeq

Gene Transcript HGVSc HGVSp Effect Exon rank MANE Protein UniProt
SCN1ANM_001165963.4 linkc.1703G>A p.Arg568Gln missense_variant Exon 14 of 29 ENST00000674923.1 NP_001159435.1

Ensembl

Gene Transcript HGVSc HGVSp Effect Exon rank TSL MANE Protein Appris UniProt
SCN1AENST00000674923.1 linkc.1703G>A p.Arg568Gln missense_variant Exon 14 of 29 NM_001165963.4 ENSP00000501589.1
SCN1AENST00000303395.9 linkc.1703G>A p.Arg568Gln missense_variant Exon 13 of 28 5 ENSP00000303540.4
SCN1AENST00000375405.7 linkc.1703G>A p.Arg568Gln missense_variant Exon 11 of 26 5 ENSP00000364554.3
SCN1AENST00000409050.2 linkc.1703G>A p.Arg568Gln missense_variant Exon 13 of 28 5 ENSP00000386312.1

Frequencies

GnomAD3 genomes
AF:
0.00000657
AC:
1
AN:
152144
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:
0.000193
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
GnomAD2 exomes
AF:
0.00000796
AC:
2
AN:
251104
AF XY:
0.00
show subpopulations
Gnomad AFR exome
AF:
0.00
Gnomad AMR exome
AF:
0.0000289
Gnomad ASJ exome
AF:
0.00
Gnomad EAS exome
AF:
0.00
Gnomad FIN exome
AF:
0.0000462
Gnomad NFE exome
AF:
0.00
Gnomad OTH exome
AF:
0.00
GnomAD4 exome
AF:
0.00000752
AC:
11
AN:
1461872
Hom.:
0
Cov.:
32
AF XY:
0.00000550
AC XY:
4
AN XY:
727236
show subpopulations
African (AFR)
AF:
0.0000299
AC:
1
AN:
33480
American (AMR)
AF:
0.0000447
AC:
2
AN:
44720
Ashkenazi Jewish (ASJ)
AF:
0.00
AC:
0
AN:
26136
East Asian (EAS)
AF:
0.0000252
AC:
1
AN:
39700
South Asian (SAS)
AF:
0.0000116
AC:
1
AN:
86256
European-Finnish (FIN)
AF:
0.0000187
AC:
1
AN:
53418
Middle Eastern (MID)
AF:
0.00
AC:
0
AN:
5768
European-Non Finnish (NFE)
AF:
0.00000450
AC:
5
AN:
1111998
Other (OTH)
AF:
0.00
AC:
0
AN:
60396
Allele Balance Distribution
Red line indicates average allele balance
Average allele balance: 0.493
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

Exome 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
GnomAD4 genome
AF:
0.00000657
AC:
1
AN:
152264
Hom.:
0
Cov.:
32
AF XY:
0.00
AC XY:
0
AN XY:
74448
show subpopulations
African (AFR)
AF:
0.00
AC:
0
AN:
41552
American (AMR)
AF:
0.00
AC:
0
AN:
15296
Ashkenazi Jewish (ASJ)
AF:
0.00
AC:
0
AN:
3470
East Asian (EAS)
AF:
0.000193
AC:
1
AN:
5180
South Asian (SAS)
AF:
0.00
AC:
0
AN:
4822
European-Finnish (FIN)
AF:
0.00
AC:
0
AN:
10608
Middle Eastern (MID)
AF:
0.00
AC:
0
AN:
294
European-Non Finnish (NFE)
AF:
0.00
AC:
0
AN:
68016
Other (OTH)
AF:
0.00
AC:
0
AN:
2114
Allele Balance Distribution
Red line indicates average allele balance
Average allele balance: 0.625
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:
0.00
Hom.:
0
Bravo
AF:
0.0000340

ClinVar

Significance: Conflicting classifications of pathogenicity
Submissions summary: Pathogenic:1Uncertain:2
Revision: criteria provided, conflicting classifications
LINK: link

Submissions by phenotype

not provided Uncertain:2
Nov 16, 2017
Eurofins Ntd Llc (ga)
Significance:Uncertain significance
Review Status:criteria provided, single submitter
Collection Method:clinical testing

- -

Apr 18, 2022
GeneDx
Significance:Uncertain significance
Review Status:criteria provided, single submitter
Collection Method:clinical testing

Reported in two unrelated patients with epilepsy in published literature (Arafat et al., 2017; Butler et al., 2017); In silico analysis supports that this missense variant has a deleterious effect on protein structure/function; Missense variants in this gene are often considered pathogenic (HGMD); This substitution is predicted to be in the cytoplasmic loop between the first and second homologous domains.; This variant is associated with the following publications: (PMID: 25348405, 18804930, 29056246, 28387369) -

Developmental and epileptic encephalopathy Pathogenic:1
Oct 24, 2024
Labcorp Genetics (formerly Invitae), Labcorp
Significance:Pathogenic
Review Status:criteria provided, single submitter
Collection Method:clinical testing

This sequence change replaces arginine, which is basic and polar, with glutamine, which is neutral and polar, at codon 568 of the SCN1A protein (p.Arg568Gln). This variant is present in population databases (rs794727025, gnomAD 0.004%). This missense change has been observed in individuals with clinical features of autosomal dominant SCN1A-related conditions and/or clinical features of SCN1A-related conditions (PMID: 28387369, 29056246; internal data). ClinVar contains an entry for this variant (Variation ID: 193841). Invitae Evidence Modeling of protein sequence and biophysical properties (such as structural, functional, and spatial information, amino acid conservation, physicochemical variation, residue mobility, and thermodynamic stability) indicates that this missense variant is expected to disrupt SCN1A protein function with a positive predictive value of 95%. For these reasons, this variant has been classified as Pathogenic. -

Computational scores

Source: dbNSFP v4.3

Name
Calibrated prediction
Score
Prediction
AlphaMissense
Benign
0.13
BayesDel_addAF
Pathogenic
0.30
D
BayesDel_noAF
Pathogenic
0.28
CADD
Pathogenic
27
DANN
Pathogenic
1.0
DEOGEN2
Uncertain
0.77
.;.;.;D;.;.;D;.;.;.
Eigen
Pathogenic
0.75
Eigen_PC
Pathogenic
0.68
FATHMM_MKL
Pathogenic
0.97
D
LIST_S2
Uncertain
0.95
D;D;D;D;.;D;.;.;D;D
M_CAP
Pathogenic
0.67
D
MetaRNN
Pathogenic
0.86
D;D;D;D;D;D;D;D;D;D
MetaSVM
Pathogenic
1.1
D
MutationAssessor
Uncertain
2.9
.;.;.;M;M;.;M;M;M;M
PhyloP100
4.9
PrimateAI
Pathogenic
0.81
D
PROVEAN
Uncertain
-2.9
.;.;.;D;.;.;D;.;D;D
REVEL
Pathogenic
0.86
Sift
Uncertain
0.0010
.;.;.;D;.;.;D;.;D;D
Sift4G
Benign
0.18
.;.;.;T;.;.;T;.;T;T
Polyphen
1.0, 1.0
.;.;.;D;D;.;D;D;D;.
Vest4
0.72, 0.66, 0.69, 0.62
MutPred
0.38
.;Loss of methylation at R568 (P = 0.0152);Loss of methylation at R568 (P = 0.0152);Loss of methylation at R568 (P = 0.0152);Loss of methylation at R568 (P = 0.0152);Loss of methylation at R568 (P = 0.0152);Loss of methylation at R568 (P = 0.0152);Loss of methylation at R568 (P = 0.0152);Loss of methylation at R568 (P = 0.0152);Loss of methylation at R568 (P = 0.0152);
MVP
0.97
MPC
1.8
ClinPred
0.99
D
GERP RS
4.7
RBP_binding_hub_radar
0.0
RBP_regulation_power_radar
1.7
Varity_R
0.52
gMVP
0.78
Mutation Taster
=0/100
disease causing

Splicing

Name
Calibrated prediction
Score
Prediction
SpliceAI score (max)
0.030
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: rs794727025; hg19: chr2-166900519; COSMIC: COSV57668384; API