2-165994215-G-T

Variant summary

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

The NM_001165963.4(SCN1A):​c.4783C>A​(p.Leu1595Ile) variant causes a missense change involving the alteration of a conserved nucleotide. The variant allele was found at a frequency of 0.0000062 in 1,612,628 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 0.000020 ( 0 hom., cov: 32)
Exomes 𝑓: 0.0000048 ( 0 hom. )

Consequence

SCN1A
NM_001165963.4 missense

Scores

11
3
4

Clinical Significance

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

Conservation

PhyloP100: 8.04

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: Uncertain_significance. The variant received 2 ACMG points.

PM1
In a hotspot region, there are 16 aminoacids with missense pathogenic changes in the window of +-8 aminoacids around while only 0 benign, 10 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, 0.875
PP5
Variant 2-165994215-G-T is Pathogenic according to our data. Variant chr2-165994215-G-T is described in ClinVar as Conflicting_classifications_of_pathogenicity. ClinVar VariationId is 569312.
BS2
High AC in GnomAdExome4 at 7 AD,Unknown gene.

Transcripts

RefSeq

Gene Transcript HGVSc HGVSp Effect Exon rank MANE Protein UniProt
SCN1ANM_001165963.4 linkc.4783C>A p.Leu1595Ile missense_variant Exon 28 of 29 ENST00000674923.1 NP_001159435.1

Ensembl

Gene Transcript HGVSc HGVSp Effect Exon rank TSL MANE Protein Appris UniProt
SCN1AENST00000674923.1 linkc.4783C>A p.Leu1595Ile missense_variant Exon 28 of 29 NM_001165963.4 ENSP00000501589.1
SCN1AENST00000303395.9 linkc.4783C>A p.Leu1595Ile missense_variant Exon 27 of 28 5 ENSP00000303540.4
SCN1AENST00000375405.7 linkc.4750C>A p.Leu1584Ile missense_variant Exon 25 of 26 5 ENSP00000364554.3
SCN1AENST00000409050.2 linkc.4699C>A p.Leu1567Ile missense_variant Exon 27 of 28 5 ENSP00000386312.1

Frequencies

GnomAD3 genomes
AF:
0.0000197
AC:
3
AN:
151942
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:
0.0000294
Gnomad OTH
AF:
0.00
GnomAD2 exomes
AF:
0.0000120
AC:
3
AN:
250288
AF XY:
0.00000739
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:
0.0000177
Gnomad OTH exome
AF:
0.000165
GnomAD4 exome
AF:
0.00000479
AC:
7
AN:
1460686
Hom.:
0
Cov.:
31
AF XY:
0.00000413
AC XY:
3
AN XY:
726656
show subpopulations
African (AFR)
AF:
0.00
AC:
0
AN:
33424
American (AMR)
AF:
0.00
AC:
0
AN:
44610
Ashkenazi Jewish (ASJ)
AF:
0.00
AC:
0
AN:
26110
East Asian (EAS)
AF:
0.00
AC:
0
AN:
39632
South Asian (SAS)
AF:
0.00
AC:
0
AN:
86204
European-Finnish (FIN)
AF:
0.00
AC:
0
AN:
53358
Middle Eastern (MID)
AF:
0.00
AC:
0
AN:
5758
European-Non Finnish (NFE)
AF:
0.00000540
AC:
6
AN:
1111282
Other (OTH)
AF:
0.0000166
AC:
1
AN:
60308
Allele Balance Distribution
Red line indicates average allele balance
Average allele balance: 0.511
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:
0.0000197
AC:
3
AN:
151942
Hom.:
0
Cov.:
32
AF XY:
0.00
AC XY:
0
AN XY:
74200
show subpopulations
African (AFR)
AF:
0.0000241
AC:
1
AN:
41410
American (AMR)
AF:
0.00
AC:
0
AN:
15226
Ashkenazi Jewish (ASJ)
AF:
0.00
AC:
0
AN:
3468
East Asian (EAS)
AF:
0.00
AC:
0
AN:
5156
South Asian (SAS)
AF:
0.00
AC:
0
AN:
4824
European-Finnish (FIN)
AF:
0.00
AC:
0
AN:
10606
Middle Eastern (MID)
AF:
0.00
AC:
0
AN:
316
European-Non Finnish (NFE)
AF:
0.0000294
AC:
2
AN:
67936
Other (OTH)
AF:
0.00
AC:
0
AN:
2088
Allele Balance Distribution
Red line indicates average allele balance
Average allele balance: 0.525
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:
0.0000264
ExAC
AF:
0.0000165
AC:
2
EpiCase
AF:
0.00
EpiControl
AF:
0.0000594

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
Jun 01, 2022
CeGaT Center for Human Genetics Tuebingen
Significance:Uncertain significance
Review Status:criteria provided, single submitter
Collection Method:clinical testing

SCN1A: PP2

Jan 11, 2023
GeneDx
Significance:Uncertain significance
Review Status:criteria provided, single submitter
Collection Method:clinical testing

Not observed at significant frequency in large population cohorts (gnomAD); Missense variants in this gene are often considered pathogenic (HGMD); In silico analysis supports that this missense variant does not alter protein structure/function; Has not been previously published as pathogenic or benign to our knowledge; This substitution is predicted to be within the intracellular loop between the S2 and S3 transmembrane segments of the fourth homologous domain

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

This sequence change replaces leucine, which is neutral and non-polar, with isoleucine, which is neutral and non-polar, at codon 1595 of the SCN1A protein (p.Leu1595Ile). This variant is present in population databases (rs756238700, gnomAD 0.002%). This missense change has been observed in individuals with clinical features of autosomal dominant SCN1A-related conditions (Invitae). ClinVar contains an entry for this variant (Variation ID: 569312). Advanced modeling of protein sequence and biophysical properties (such as structural, functional, and spatial information, amino acid conservation, physicochemical variation, residue mobility, and thermodynamic stability) performed at Invitae indicates that this missense variant is expected to disrupt SCN1A protein function with a positive predictive value of 95%. In summary, the currently available evidence indicates that the variant is pathogenic, but additional data are needed to prove that conclusively. Therefore, this variant has been classified as Likely Pathogenic.

Computational scores

Source: dbNSFP v4.3

Name
Calibrated prediction
Score
Prediction
AlphaMissense
Pathogenic
0.84
BayesDel_addAF
Pathogenic
0.36
D
BayesDel_noAF
Pathogenic
0.30
CADD
Uncertain
24
DANN
Uncertain
1.0
DEOGEN2
Benign
0.0
.;.;.;D;.;.;D;.;.;.
Eigen
Pathogenic
0.96
Eigen_PC
Pathogenic
0.91
FATHMM_MKL
Pathogenic
0.99
D
LIST_S2
Uncertain
0.94
D;D;D;D;.;D;.;.;D;D
M_CAP
Pathogenic
0.92
D
MetaRNN
Pathogenic
0.88
D;D;D;D;D;D;D;D;D;D
MetaSVM
Pathogenic
1.1
D
MutationAssessor
Benign
0.0
.;.;.;H;.;.;H;.;.;.
PhyloP100
8.0
PrimateAI
Uncertain
0.76
T
PROVEAN
Benign
0.0
.;.;.;N;.;.;N;.;N;N
REVEL
Benign
0.0
Sift
Pathogenic
0.0
.;.;.;D;.;.;D;.;D;D
Sift4G
Pathogenic
0.0
.;.;.;D;.;.;D;.;D;D
Vest4
0.0
ClinPred
0.99
D
GERP RS
5.9
Varity_R
0.46
gMVP
0.95
Mutation Taster
=0/100
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: rs756238700; hg19: chr2-166850725; COSMIC: COSV100319573; COSMIC: COSV100319573; API