rs750516202

Positions:

chr2-166043860-G-A

Variant summary

Our verdict is Uncertain significance. Variant got 1 ACMG points: 5P and 4B. PM1PP2PP3_ModerateBS2

The NM_001165963.4(SCN1A):c.1852C>T(p.Arg618Cys) variant causes a missense change. The variant allele was found at a frequency of 0.0000112 in 1,614,044 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). Another variant affecting the same amino acid position, but resulting in a different missense (i.e. R618S) has been classified as Uncertain significance.

Frequency

Genomes: 𝑓 0.0000066 ( 0 hom., cov: 32)

Exomes 𝑓: 0.000012 ( 0 hom. )

Consequence

SCN1A
NM_001165963.4 missense

Scores

Clinical Significance

Conflicting classifications of pathogenicity criteria provided, conflicting classifications P:1U:3

Conservation

PhyloP100: 6.72

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 Uncertain_significance. Variant got 1 ACMG points.

PM1

In a hotspot region, there are 4 aminoacids with missense pathogenic changes in the window of +-8 aminoacids around while only 3 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.

PP3

MetaRNN computational evidence supports a deleterious effect, 0.893

BS2

High AC in GnomAdExome4 at 17 AD gene.

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	UniProt
SCN1A	NM_001165963.4 linkuse as main transcript	c.1852C>T	p.Arg618Cys	missense_variant	14/29	ENST00000674923.1

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Appris	UniProt
SCN1A	ENST00000674923.1 linkuse as main transcript	c.1852C>T	p.Arg618Cys	missense_variant	14/29		NM_001165963.4	P4	P35498-1
SCN1A-AS1	ENST00000651574.1 linkuse as main transcript	n.487+7730G>A		intron_variant, non_coding_transcript_variant

Frequencies

GnomAD3 genomes

AF:

0.00000657

AC:

AN:

152160

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:

0.0000147

Gnomad OTH

AF:

0.00

GnomAD3 exomes

AF:

0.00000398

AC:

AN:

251358

Hom.:

AF XY:

0.00000736

AC XY:

AN XY:

135842

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:

0.00000880

Gnomad OTH exome

AF:

0.00

GnomAD4 exome

AF:

0.0000116

AC:

AN:

1461884

Hom.:

Cov.:

AF XY:

0.0000138

AC XY:

AN XY:

727242

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:

0.0000153

Gnomad4 OTH exome

AF:

0.00

GnomAD4 genome

AF:

0.00000657

AC:

AN:

152160

Hom.:

Cov.:

AF XY:

0.0000135

AC XY:

AN XY:

74328

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:

0.0000147

Gnomad4 OTH

AF:

0.00

Bravo

AF:

0.00000756

ExAC

AF:

0.00000824

AC:

EpiCase

AF:

0.00

EpiControl

AF:

0.0000593

ClinVar

Significance: Conflicting classifications of pathogenicity

Submissions summary: Pathogenic:1Uncertain:3

Revision: criteria provided, conflicting classifications

LINK: link

Submissions by phenotype

not provided

Uncertain:2

Uncertain significance, criteria provided, single submitter	clinical testing	GeneDx	Jun 12, 2023	Observed in the homozygous state in siblings with febrile seizures and focal seizures, parents were unaffected (Brunklaus et al., 2015); Missense variants in this gene are often considered pathogenic (HGMD); In silico analysis supports that this missense variant has a deleterious effect on protein structure/function; Not observed at a significant frequency in large population cohorts (gnomAD); This variant is associated with the following publications: (PMID: 35813073, 35571373, 35074891, 25795284) -
Uncertain significance, criteria provided, single submitter	clinical testing	CeGaT Center for Human Genetics Tuebingen	Sep 01, 2022	SCN1A: PM2, PP2 -

Early infantile epileptic encephalopathy with suppression bursts

Pathogenic:1

Pathogenic, criteria provided, single submitter

clinical testing

Invitae

May 08, 2023

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. For these reasons, this variant has been classified as Pathogenic. ClinVar contains an entry for this variant (Variation ID: 220200). This missense change has been observed in individuals with generalized epilepsy with febrile seizures plus (PMID: 35571373; Invitae). This variant was reported in the homozygous state in two siblings affected with febrile seizures plus focal seizures and in the heterozygous state in the unaffected carrier parents (PMID: 25795284). Although SCN1A-related epilepsy is typically dominant, the authors propose that this variant may cause a recessive form of the disorder. This variant is present in population databases (rs750516202, gnomAD 0.0009%). This sequence change replaces arginine, which is basic and polar, with cysteine, which is neutral and slightly polar, at codon 618 of the SCN1A protein (p.Arg618Cys). -

Inborn genetic diseases

Uncertain:1

Uncertain significance, criteria provided, single submitter

clinical testing

Ambry Genetics

Feb 28, 2022

The c.1852C>T (p.R618C) alteration is located in exon 11 (coding exon 11) of the SCN1A gene. This alteration results from a C to T substitution at nucleotide position 1852, causing the arginine (R) at amino acid position 618 to be replaced by a cysteine (C). Based on insufficient or conflicting evidence, the clinical significance of this alteration remains unclear. -

Computational scores

Source: dbNSFP v4.3

Name

Calibrated prediction

Score

Prediction

AlphaMissense

Benign

0.19

BayesDel_addAF

Pathogenic

0.46

BayesDel_noAF

Pathogenic

0.43

CADD

Pathogenic

DANN

Pathogenic

1.0

DEOGEN2

Pathogenic

0.88

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

Eigen

Pathogenic

0.84

Eigen_PC

Pathogenic

0.77

FATHMM_MKL

Pathogenic

0.99

LIST_S2

Uncertain

0.95

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

M_CAP

Pathogenic

0.73

MetaRNN

Pathogenic

0.89

D;D;D;D;D;D;D;D;D;D

MetaSVM

Pathogenic

1.0

MutationAssessor

Pathogenic

3.3

.;.;.;M;M;.;M;M;M;M

MutationTaster

Benign

1.0

D;D;D;D

PrimateAI

Uncertain

0.65

PROVEAN

Pathogenic

-6.2

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

REVEL

Pathogenic

0.92

Sift

Pathogenic

0.0

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

Sift4G

Uncertain

0.013

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

Polyphen

1.0, 1.0

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

Vest4

0.75, 0.70, 0.78, 0.70

MutPred

0.34

.;Loss of methylation at R618 (P = 0.0274);Loss of methylation at R618 (P = 0.0274);Loss of methylation at R618 (P = 0.0274);Loss of methylation at R618 (P = 0.0274);Loss of methylation at R618 (P = 0.0274);Loss of methylation at R618 (P = 0.0274);Loss of methylation at R618 (P = 0.0274);Loss of methylation at R618 (P = 0.0274);Loss of methylation at R618 (P = 0.0274);

MVP

0.97

MPC

2.0

ClinPred

1.0

GERP RS

5.2

RBP_binding_hub_radar

0.0

RBP_regulation_power_radar

1.1

Varity_R

0.58

gMVP

0.74

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