2-166039453-T-G

Variant summary

Our verdict is Likely benign. The variant received -2 ACMG points: 3P and 5B. PM1PP2BP4BS2

The NM_001165963.4(SCN1A):​c.2559A>C​(p.Glu853Asp) variant causes a missense change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.0000298 in 1,612,596 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a benign outcome for this variant. Variant has been reported in ClinVar as Uncertain significance (★). Another variant affecting the same amino acid position, but resulting in a different missense (i.e. E853K) has been classified as Uncertain significance.

Frequency

Genomes: 𝑓 0.000026 ( 0 hom., cov: 31)
Exomes 𝑓: 0.000030 ( 0 hom. )

Consequence

SCN1A
NM_001165963.4 missense

Scores

1
8
10

Clinical Significance

Uncertain significance criteria provided, single submitter U:1

Conservation

PhyloP100: 0.727

Publications

2 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: Likely_benign. The variant received -2 ACMG points.

PM1
In a hotspot region, there are 7 aminoacids with missense pathogenic changes in the window of +-8 aminoacids around while only 1 benign, 9 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.
BP4
Computational evidence support a benign effect (MetaRNN=0.35054064).
BS2
High AC in GnomAdExome4 at 44 AD,Unknown gene.

Transcripts

RefSeq

Gene Transcript HGVSc HGVSp Effect Exon rank MANE Protein UniProt
SCN1ANM_001165963.4 linkc.2559A>C p.Glu853Asp missense_variant Exon 17 of 29 ENST00000674923.1 NP_001159435.1

Ensembl

Gene Transcript HGVSc HGVSp Effect Exon rank TSL MANE Protein Appris UniProt
SCN1AENST00000674923.1 linkc.2559A>C p.Glu853Asp missense_variant Exon 17 of 29 NM_001165963.4 ENSP00000501589.1
SCN1AENST00000303395.9 linkc.2559A>C p.Glu853Asp missense_variant Exon 16 of 28 5 ENSP00000303540.4
SCN1AENST00000375405.7 linkc.2526A>C p.Glu842Asp missense_variant Exon 14 of 26 5 ENSP00000364554.3
SCN1AENST00000409050.2 linkc.2475A>C p.Glu825Asp missense_variant Exon 16 of 28 5 ENSP00000386312.1

Frequencies

GnomAD3 genomes
AF:
0.0000264
AC:
4
AN:
151456
Hom.:
0
Cov.:
31
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:
0.0000589
Gnomad OTH
AF:
0.00
GnomAD2 exomes
AF:
0.0000119
AC:
3
AN:
251134
AF XY:
0.0000147
show subpopulations
Gnomad AFR exome
AF:
0.00
Gnomad AMR exome
AF:
0.00
Gnomad ASJ exome
AF:
0.00
Gnomad EAS exome
AF:
0.00
Gnomad FIN exome
AF:
0.00
Gnomad NFE exome
AF:
0.0000264
Gnomad OTH exome
AF:
0.00
GnomAD4 exome
AF:
0.0000301
AC:
44
AN:
1461140
Hom.:
0
Cov.:
36
AF XY:
0.0000303
AC XY:
22
AN XY:
726878
show subpopulations
African (AFR)
AF:
0.00
AC:
0
AN:
33460
American (AMR)
AF:
0.00
AC:
0
AN:
44710
Ashkenazi Jewish (ASJ)
AF:
0.00
AC:
0
AN:
26114
East Asian (EAS)
AF:
0.00
AC:
0
AN:
39658
South Asian (SAS)
AF:
0.00
AC:
0
AN:
86222
European-Finnish (FIN)
AF:
0.00
AC:
0
AN:
53400
Middle Eastern (MID)
AF:
0.00
AC:
0
AN:
5758
European-Non Finnish (NFE)
AF:
0.0000378
AC:
42
AN:
1111450
Other (OTH)
AF:
0.0000331
AC:
2
AN:
60368
Allele Balance Distribution
Red line indicates average allele balance
Average allele balance: 0.466
Heterozygous variant carriers
0
4
7
11
14
18
0.00
0.20
0.40
0.60
0.80
0.95
Allele balance

Age Distribution

Exome Het
Variant carriers
0
4
8
12
16
20
<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:
0.0000264
AC:
4
AN:
151456
Hom.:
0
Cov.:
31
AF XY:
0.0000135
AC XY:
1
AN XY:
73924
show subpopulations
African (AFR)
AF:
0.00
AC:
0
AN:
41204
American (AMR)
AF:
0.00
AC:
0
AN:
15192
Ashkenazi Jewish (ASJ)
AF:
0.00
AC:
0
AN:
3462
East Asian (EAS)
AF:
0.00
AC:
0
AN:
5156
South Asian (SAS)
AF:
0.00
AC:
0
AN:
4792
European-Finnish (FIN)
AF:
0.00
AC:
0
AN:
10422
Middle Eastern (MID)
AF:
0.00
AC:
0
AN:
316
European-Non Finnish (NFE)
AF:
0.0000589
AC:
4
AN:
67912
Other (OTH)
AF:
0.00
AC:
0
AN:
2088
Allele Balance Distribution
Red line indicates average allele balance
Average allele balance: 0.463
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:
0.0000282
Hom.:
0
Bravo
AF:
0.0000113

ClinVar

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

Submissions by phenotype

Developmental and epileptic encephalopathy Uncertain:1
Oct 31, 2024
Labcorp Genetics (formerly Invitae), Labcorp
Significance:Uncertain significance
Review Status:criteria provided, single submitter
Collection Method:clinical testing

This sequence change replaces glutamic acid, which is acidic and polar, with aspartic acid, which is acidic and polar, at codon 853 of the SCN1A protein (p.Glu853Asp). This variant is present in population databases (no rsID available, gnomAD 0.003%). This variant has not been reported in the literature in individuals affected with SCN1A-related conditions. ClinVar contains an entry for this variant (Variation ID: 566076). 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 not expected to disrupt SCN1A protein function with a negative predictive value of 95%. In summary, the available evidence is currently insufficient to determine the role of this variant in disease. Therefore, it has been classified as a Variant of Uncertain Significance. -

Computational scores

Source: dbNSFP v4.3

Name
Calibrated prediction
Score
Prediction
AlphaMissense
Uncertain
0.42
BayesDel_addAF
Uncertain
0.012
T
BayesDel_noAF
Benign
-0.16
CADD
Benign
23
DANN
Uncertain
0.99
DEOGEN2
Pathogenic
0.84
.;.;.;D;.;.;D;.;.;.
Eigen
Benign
-0.29
Eigen_PC
Benign
-0.14
FATHMM_MKL
Uncertain
0.91
D
LIST_S2
Benign
0.58
T;T;T;T;.;T;.;.;T;T
M_CAP
Uncertain
0.14
D
MetaRNN
Benign
0.35
T;T;T;T;T;T;T;T;T;T
MetaSVM
Uncertain
0.61
D
MutationAssessor
Benign
1.2
.;.;.;L;.;.;L;.;.;.
PhyloP100
0.73
PrimateAI
Uncertain
0.69
T
PROVEAN
Benign
-1.8
.;.;.;N;.;.;N;.;N;N
REVEL
Uncertain
0.36
Sift
Benign
0.041
.;.;.;D;.;.;D;.;D;D
Sift4G
Benign
0.33
.;.;.;T;.;.;T;.;T;T
Polyphen
0.0020, 0.0
.;.;.;B;B;.;B;B;B;.
Vest4
0.49, 0.56, 0.56, 0.52
MutPred
0.47
.;Gain of MoRF binding (P = 0.1262);.;Gain of MoRF binding (P = 0.1262);.;.;Gain of MoRF binding (P = 0.1262);.;.;.;
MVP
0.64
MPC
1.3
ClinPred
0.23
T
GERP RS
3.6
RBP_binding_hub_radar
0.0
RBP_regulation_power_radar
1.7
Varity_R
0.14
gMVP
0.92
Mutation Taster
=17/83
disease causing

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: rs764292628; hg19: chr2-166895963; API