rs121917945

Variant summary

Our verdict is Pathogenic. The variant received 17 ACMG points: 17P and 0B. PM1PM2PM5PP2PP3_ModeratePP5_Very_Strong

The NM_001165963.4(SCN1A):​c.4352C>T​(p.Pro1451Leu) variant causes a missense change involving the alteration of a conserved nucleotide. The variant was absent in control chromosomes in GnomAD project. In-silico tool predicts a pathogenic outcome for this variant. Variant has been reported in ClinVar as Likely pathogenic (★★). Another variant affecting the same amino acid position, but resulting in a different missense (i.e. P1451T) has been classified as Pathogenic.

Frequency

Genomes: not found (cov: 32)
Exomes 𝑓: 0.0 ( 0 hom. )
Failed GnomAD Quality Control

Consequence

SCN1A
NM_001165963.4 missense

Scores

12
2
4

Clinical Significance

Pathogenic/Likely pathogenic criteria provided, multiple submitters, no conflicts P:3O:1

Conservation

PhyloP100: 9.87

Publications

10 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)

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ACMG classification

Classification was made for transcript

Our verdict: Pathogenic. The variant received 17 ACMG points.

PM1
In a hotspot region, there are 9 aminoacids with missense pathogenic changes in the window of +-8 aminoacids around while only 1 benign, 16 uncertain in NM_001165963.4
PM2
Very rare variant in population databases, with high coverage;
PM5
Other missense variant is known to change same aminoacid residue: Variant chr2-165998163-G-T is described in ClinVar as Pathogenic. ClinVar VariationId is 189843.Status of the report is criteria_provided_multiple_submitters_no_conflicts, 2 stars.
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, 0.922
PP5
Variant 2-165998162-G-A is Pathogenic according to our data. Variant chr2-165998162-G-A is described in ClinVar as Pathogenic/Likely_pathogenic. ClinVar VariationId is 68544.Status of the report is criteria_provided_multiple_submitters_no_conflicts, 2 stars.

Transcripts

RefSeq

Gene Transcript HGVSc HGVSp Effect Exon rank MANE Protein UniProt
SCN1ANM_001165963.4 linkc.4352C>T p.Pro1451Leu missense_variant Exon 26 of 29 ENST00000674923.1 NP_001159435.1

Ensembl

Gene Transcript HGVSc HGVSp Effect Exon rank TSL MANE Protein Appris UniProt
SCN1AENST00000674923.1 linkc.4352C>T p.Pro1451Leu missense_variant Exon 26 of 29 NM_001165963.4 ENSP00000501589.1
SCN1AENST00000303395.9 linkc.4352C>T p.Pro1451Leu missense_variant Exon 25 of 28 5 ENSP00000303540.4
SCN1AENST00000375405.7 linkc.4319C>T p.Pro1440Leu missense_variant Exon 23 of 26 5 ENSP00000364554.3
SCN1AENST00000409050.2 linkc.4268C>T p.Pro1423Leu missense_variant Exon 25 of 28 5 ENSP00000386312.1

Frequencies

GnomAD3 genomes
Cov.:
32
GnomAD4 exome
Data not reliable, filtered out with message: AC0
AF:
0.00
AC:
0
AN:
1453276
Hom.:
0
Cov.:
29
AF XY:
0.00
AC XY:
0
AN XY:
723084
African (AFR)
AF:
0.00
AC:
0
AN:
33118
American (AMR)
AF:
0.00
AC:
0
AN:
44412
Ashkenazi Jewish (ASJ)
AF:
0.00
AC:
0
AN:
25818
East Asian (EAS)
AF:
0.00
AC:
0
AN:
39388
South Asian (SAS)
AF:
0.00
AC:
0
AN:
85468
European-Finnish (FIN)
AF:
0.00
AC:
0
AN:
53220
Middle Eastern (MID)
AF:
0.00
AC:
0
AN:
5654
European-Non Finnish (NFE)
AF:
0.00
AC:
0
AN:
1106290
Other (OTH)
AF:
0.00
AC:
0
AN:
59908
GnomAD4 genome
Cov.:
32

ClinVar

Significance: Pathogenic/Likely pathogenic
Submissions summary: Pathogenic:3Other:1
Revision: criteria provided, multiple submitters, no conflicts
LINK: link

Submissions by phenotype

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

Jan 01, 2018
NeuroMeGen, Hospital Clinico Santiago de Compostela
Significance:Likely pathogenic
Review Status:criteria provided, single submitter
Collection Method:clinical testing

Developmental and epileptic encephalopathy Pathogenic:1
Nov 07, 2018
Labcorp Genetics (formerly Invitae), Labcorp
Significance:Pathogenic
Review Status:criteria provided, single submitter
Collection Method:clinical testing

For these reasons, this variant has been classified as Pathogenic. This variant disrupts the p.Pro1451 amino acid residue in SCN1A. Other variant(s) that disrupt this residue have been observed in affected individuals (PMID: 21248271, 26096185), suggesting that it is a clinically significant residue. As a result, variants that disrupt this residue are likely to be causative of disease. Algorithms developed to predict the effect of missense changes on protein structure and function (SIFT, PolyPhen-2, Align-GVGD) all suggest that this variant is likely to be disruptive, but these predictions have not been confirmed by published functional studies and their clinical significance is uncertain. This variant has been observed to be de novo in an individual affected with severe myoclonic epilepsy in infancy (SMEI) also known as Dravet syndrome (PMID: 17054684). ClinVar contains an entry for this variant (Variation ID: 68544). This variant is not present in population databases (ExAC no frequency). This sequence change replaces proline with leucine at codon 1451 of the SCN1A protein (p.Pro1451Leu). The proline residue is highly conserved and there is a moderate physicochemical difference between proline and leucine.

See cases Pathogenic:1
Oct 26, 2022
Génétique des Maladies du Développement, Hospices Civils de Lyon
Significance:Pathogenic
Review Status:criteria provided, single submitter
Collection Method:clinical testing

Computational scores

Source: dbNSFP v4.3

Name
Calibrated prediction
Score
Prediction
AlphaMissense
Pathogenic
0.99
BayesDel_addAF
Pathogenic
0.57
D
BayesDel_noAF
Pathogenic
0.58
CADD
Pathogenic
28
DANN
Uncertain
1.0
DEOGEN2
Benign
0.0
.;.;.;D;.;.;D;.;.;.
Eigen
Pathogenic
1.0
Eigen_PC
Pathogenic
0.92
FATHMM_MKL
Pathogenic
1.0
D
LIST_S2
Pathogenic
1.0
D;D;D;D;.;D;.;.;D;D
M_CAP
Pathogenic
0.94
D
MetaRNN
Pathogenic
0.92
D;D;D;D;D;D;D;D;D;D
MetaSVM
Pathogenic
1.0
D
MutationAssessor
Benign
0.0
.;.;.;H;.;.;H;.;.;.
PhyloP100
9.9
PrimateAI
Uncertain
0.73
T
PROVEAN
Benign
0.0
.;.;.;D;.;.;D;.;D;D
REVEL
Benign
0.0
Sift
Pathogenic
0.0
.;.;.;D;.;.;D;.;D;D
Sift4G
Pathogenic
0.0
.;.;.;D;.;.;D;.;D;D
Vest4
0.0
ClinPred
1.0
D
GERP RS
5.3
Varity_R
0.89
gMVP
1.0
Mutation Taster
=0/100
disease causing (ClinVar)

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: rs121917945; hg19: chr2-166854672; API