2-166039453-T-G

Position:

chr2-166039453-T-G

Variant summary

Our verdict is Likely benign. Variant got -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

Clinical Significance

Uncertain significance criteria provided, single submitter U:1

Conservation

PhyloP100: 0.727

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 links:

SCN1A-AS1 (HGNC:54069): (SCN1A and SCN9A antisense RNA 1)

SCN1A-AS1 links:

Genome browser will be placed here

ACMG classification

Classification made for transcript

Verdict is Likely_benign. Variant got -2 ACMG points.

PM1

In a hotspot region, there are 6 aminoacids with missense pathogenic changes in the window of +-8 aminoacids around while only 1 benign, 7 uncertain in NM_001165963.4

PP2

Missense variant in gene, where missense usually causes diseases (based on misZ statistic), SCN1A. . Gene score misZ 5.2206 (greater than the threshold 3.09). Trascript score misZ 7.6022 (greater than threshold 3.09). GenCC has associacion of gene with migraine, familial hemiplegic, 3, familial hemiplegic migraine, Dravet syndrome, malignant migrating partial seizures of infancy, generalized epilepsy with febrile seizures plus, myoclonic-astatic epilepsy, developmental and epileptic encephalopathy, developmental and epileptic encephalopathy, 6, familial or sporadic hemiplegic migraine, arthrogryposis, Lennox-Gastaut syndrome, generalized epilepsy with febrile seizures plus, type 2.

BP4

Computational evidence support a benign effect (MetaRNN=0.35054064).

BS2

High AC in GnomAdExome4 at 44 AD gene.

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	UniProt
SCN1A	NM_001165963.4 linkuse as main transcript	c.2559A>C	p.Glu853Asp	missense_variant	17/29	ENST00000674923.1

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Appris	UniProt
SCN1A	ENST00000674923.1 linkuse as main transcript	c.2559A>C	p.Glu853Asp	missense_variant	17/29		NM_001165963.4	P4	P35498-1
SCN1A-AS1	ENST00000651574.1 linkuse as main transcript	n.487+3323T>G		intron_variant, non_coding_transcript_variant

Frequencies

GnomAD3 genomes

AF:

0.0000264

AC:

AN:

151456

Hom.:

Cov.:

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

GnomAD3 exomes

AF:

0.0000119

AC:

AN:

251134

Hom.:

AF XY:

0.0000147

AC XY:

AN XY:

135720

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 SAS 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:

AN:

1461140

Hom.:

Cov.:

AF XY:

0.0000303

AC XY:

AN XY:

726878

show subpopulations

Gnomad4 AFR exome

AF:

0.00

Gnomad4 AMR exome

AF:

0.00

Gnomad4 ASJ exome

AF:

0.00

Gnomad4 EAS exome

AF:

0.00

Gnomad4 SAS exome

AF:

0.00

Gnomad4 FIN exome

AF:

0.00

Gnomad4 NFE exome

AF:

0.0000378

Gnomad4 OTH exome

AF:

0.0000331

GnomAD4 genome

AF:

0.0000264

AC:

AN:

151456

Hom.:

Cov.:

AF XY:

0.0000135

AC XY:

AN XY:

73924

show subpopulations

Gnomad4 AFR

AF:

0.00

Gnomad4 AMR

AF:

0.00

Gnomad4 ASJ

AF:

0.00

Gnomad4 EAS

AF:

0.00

Gnomad4 SAS

AF:

0.00

Gnomad4 FIN

AF:

0.00

Gnomad4 NFE

AF:

0.0000589

Gnomad4 OTH

AF:

0.00

Alfa

AF:

0.0000282

Hom.:

Bravo

AF:

0.0000113

ClinVar

Significance: Uncertain significance

Submissions summary: Uncertain:1

Revision: criteria provided, single submitter

LINK: link

Submissions by phenotype

Early infantile epileptic encephalopathy with suppression bursts

Uncertain:1

Uncertain significance, criteria provided, single submitter

clinical testing

Labcorp Genetics (formerly Invitae), Labcorp

Jan 20, 2023

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. 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 not expected to disrupt SCN1A protein function. ClinVar contains an entry for this variant (Variation ID: 566076). This variant has not been reported in the literature in individuals affected with SCN1A-related conditions. This variant is present in population databases (no rsID available, gnomAD 0.003%). 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). -

Computational scores

Source: dbNSFP v4.3

Name

Calibrated prediction

Score

Prediction

AlphaMissense

Uncertain

0.42

BayesDel_addAF

Uncertain

0.012

BayesDel_noAF

Benign

-0.16

CADD

Benign

DANN

Uncertain

0.99

DEOGEN2

Pathogenic

0.84

.;.;.;D;.;.;D;.;.;.

Eigen

Benign

-0.29

Eigen_PC

Benign

-0.14

FATHMM_MKL

Uncertain

0.91

LIST_S2

Benign

0.58

T;T;T;T;.;T;.;.;T;T

M_CAP

Uncertain

0.14

MetaRNN

Benign

0.35

T;T;T;T;T;T;T;T;T;T

MetaSVM

Uncertain

0.61

MutationAssessor

Benign

1.2

.;.;.;L;.;.;L;.;.;.

MutationTaster

Benign

0.94

D;D;D;D

PrimateAI

Uncertain

0.69

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

GERP RS

3.6

RBP_binding_hub_radar

0.0

RBP_regulation_power_radar

1.7

Varity_R

0.14

gMVP

0.92

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

LitVar

Below is the list of publications found by LitVar. It may be empty.

Variant summary

Frequency

Consequence

Scores

Clinical Significance

Conservation

ACMG classification

Transcripts

RefSeq

Ensembl

Frequencies

ClinVar

Submissions by phenotype

Computational scores

Splicing

Publications

LitVar

Other links and lift over