rs121917907

Variant summary

Our verdict is Uncertain significance. The variant received 5 ACMG points: 5P and 0B. PM1PM2PP2

The NM_001165963.4(SCN1A):​c.187T>C​(p.Phe63Leu) variant causes a missense change. The variant allele was found at a frequency of 0.00000186 in 1,614,072 control chromosomes in the GnomAD database, with no homozygous occurrence. Variant has been reported in ClinVar as Uncertain significance (★).

Frequency

Genomes: 𝑓 0.0000066 ( 0 hom., cov: 31)
Exomes 𝑓: 0.0000014 ( 0 hom. )

Consequence

SCN1A
NM_001165963.4 missense

Scores

5
6
8

Clinical Significance

Uncertain significance criteria provided, single submitter U:1O:1

Conservation

PhyloP100: 5.43

Publications

8 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 5 ACMG points.

PM1
In a hotspot region, there are 3 aminoacids with missense pathogenic changes in the window of +-8 aminoacids around while only 0 benign, 5 uncertain in NM_001165963.4
PM2
Very rare variant in population databases, with high coverage;
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.

Transcripts

RefSeq

Gene Transcript HGVSc HGVSp Effect Exon rank MANE Protein UniProt
SCN1ANM_001165963.4 linkc.187T>C p.Phe63Leu missense_variant Exon 4 of 29 ENST00000674923.1 NP_001159435.1 P35498-1

Ensembl

Gene Transcript HGVSc HGVSp Effect Exon rank TSL MANE Protein Appris UniProt
SCN1AENST00000674923.1 linkc.187T>C p.Phe63Leu missense_variant Exon 4 of 29 NM_001165963.4 ENSP00000501589.1 P35498-1
SCN1AENST00000303395.9 linkc.187T>C p.Phe63Leu missense_variant Exon 3 of 28 5 ENSP00000303540.4 P35498-1
SCN1AENST00000375405.7 linkc.187T>C p.Phe63Leu missense_variant Exon 1 of 26 5 ENSP00000364554.3 P35498-2
SCN1AENST00000409050.2 linkc.187T>C p.Phe63Leu missense_variant Exon 3 of 28 5 ENSP00000386312.1 P35498-3

Frequencies

GnomAD3 genomes
AF:
0.00000657
AC:
1
AN:
152200
Hom.:
0
Cov.:
31
show subpopulations
Gnomad AFR
AF:
0.00
Gnomad AMI
AF:
0.00
Gnomad AMR
AF:
0.0000654
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:
0.00
Gnomad OTH
AF:
0.00
GnomAD4 exome
AF:
0.00000137
AC:
2
AN:
1461872
Hom.:
0
Cov.:
31
AF XY:
0.00000138
AC XY:
1
AN XY:
727236
show subpopulations
African (AFR)
AF:
0.00
AC:
0
AN:
33480
American (AMR)
AF:
0.00
AC:
0
AN:
44724
Ashkenazi Jewish (ASJ)
AF:
0.00
AC:
0
AN:
26134
East Asian (EAS)
AF:
0.00
AC:
0
AN:
39698
South Asian (SAS)
AF:
0.00
AC:
0
AN:
86258
European-Finnish (FIN)
AF:
0.00
AC:
0
AN:
53418
Middle Eastern (MID)
AF:
0.00
AC:
0
AN:
5766
European-Non Finnish (NFE)
AF:
0.00000180
AC:
2
AN:
1111998
Other (OTH)
AF:
0.00
AC:
0
AN:
60396
Allele Balance Distribution
Red line indicates average allele balance
Average allele balance: 0.525
Heterozygous variant carriers
0
1
1
2
2
3
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:
152200
Hom.:
0
Cov.:
31
AF XY:
0.00
AC XY:
0
AN XY:
74340
show subpopulations
African (AFR)
AF:
0.00
AC:
0
AN:
41452
American (AMR)
AF:
0.0000654
AC:
1
AN:
15282
Ashkenazi Jewish (ASJ)
AF:
0.00
AC:
0
AN:
3470
East Asian (EAS)
AF:
0.00
AC:
0
AN:
5200
South Asian (SAS)
AF:
0.00
AC:
0
AN:
4824
European-Finnish (FIN)
AF:
0.00
AC:
0
AN:
10620
Middle Eastern (MID)
AF:
0.00
AC:
0
AN:
316
European-Non Finnish (NFE)
AF:
0.00
AC:
0
AN:
68032
Other (OTH)
AF:
0.00
AC:
0
AN:
2092
Allele Balance Distribution
Red line indicates average allele balance
Average allele balance: 0.475
Heterozygous variant carriers
0
0
1
1
2
2
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:
0.00
Hom.:
0
Bravo
AF:
0.00000756

ClinVar

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

Submissions by phenotype

Developmental and epileptic encephalopathy Uncertain:1
Aug 07, 2024
Labcorp Genetics (formerly Invitae), Labcorp
Significance:Uncertain significance
Review Status:criteria provided, single submitter
Collection Method:clinical testing

This sequence change replaces phenylalanine, which is neutral and non-polar, with leucine, which is neutral and non-polar, at codon 63 of the SCN1A protein (p.Phe63Leu). This variant is not present in population databases (gnomAD no frequency). This missense change has been observed in individual(s) with severe myoclonic epilepsy of infancy (PMID: 20729507). ClinVar contains an entry for this variant (Variation ID: 68513). 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) has been performed at Invitae for this missense variant, however the output from this modeling did not meet the statistical confidence thresholds required to predict the impact of this variant on SCN1A protein function. 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. -

Severe myoclonic epilepsy in infancy Other:1
-
UniProtKB/Swiss-Prot
Significance:not provided
Review Status:no classification provided
Collection Method:literature only

- -

Computational scores

Source: dbNSFP v4.3

Name
Calibrated prediction
Score
Prediction
AlphaMissense
Pathogenic
0.91
BayesDel_addAF
Pathogenic
0.41
D
BayesDel_noAF
Pathogenic
0.35
CADD
Pathogenic
26
DANN
Benign
0.97
DEOGEN2
Pathogenic
0.81
.;.;.;D;.;.;D;.;.;.
Eigen
Benign
0.16
Eigen_PC
Uncertain
0.30
FATHMM_MKL
Uncertain
0.82
D
LIST_S2
Benign
0.62
T;T;T;T;.;T;.;.;T;T
M_CAP
Benign
0.072
D
MetaRNN
Uncertain
0.74
D;D;D;D;D;D;D;D;D;D
MetaSVM
Uncertain
0.59
D
MutationAssessor
Benign
1.9
.;.;.;L;L;.;L;L;L;L
PhyloP100
5.4
PrimateAI
Uncertain
0.69
T
PROVEAN
Uncertain
-4.1
.;.;.;D;.;.;D;.;D;D
REVEL
Pathogenic
0.72
Sift
Benign
0.10
.;.;.;T;.;.;T;.;T;T
Sift4G
Benign
0.63
.;.;.;T;.;.;T;.;T;T
Polyphen
0.10
.;.;.;.;B;.;.;B;B;.
Vest4
0.48, 0.76, 0.71, 0.61
MutPred
0.58
Gain of disorder (P = 0.1519);Gain of disorder (P = 0.1519);Gain of disorder (P = 0.1519);Gain of disorder (P = 0.1519);Gain of disorder (P = 0.1519);Gain of disorder (P = 0.1519);Gain of disorder (P = 0.1519);Gain of disorder (P = 0.1519);Gain of disorder (P = 0.1519);Gain of disorder (P = 0.1519);
MVP
0.99
MPC
1.0
ClinPred
0.89
D
GERP RS
5.5
PromoterAI
0.0081
Neutral
Varity_R
0.42
gMVP
0.86
Mutation Taster
=1/99
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: rs121917907; hg19: chr2-166929945; API