rs121918771

Positions:

chr2-166051793-G-A

Variant summary

Our verdict is Likely benign. Variant got -2 ACMG points: 2P and 4B. PP2PP3BS2

The NM_001165963.4(SCN1A):c.890C>T(p.Thr297Ile) variant causes a missense change. The variant allele was found at a frequency of 0.0000143 in 1,610,272 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 0.000033 ( 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 U:4B:1O:1

Conservation

PhyloP100: 4.15

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.

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, 0.783

BS2

High AC in GnomAd4 at 5 AD gene.

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	Protein	UniProt
SCN1A	NM_001165963.4 linkuse as main transcript	c.890C>T	p.Thr297Ile	missense_variant	9/29	ENST00000674923.1	NP_001159435.1

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Protein	Appris	UniProt
SCN1A	ENST00000674923.1 linkuse as main transcript	c.890C>T	p.Thr297Ile	missense_variant	9/29		NM_001165963.4	ENSP00000501589	P4	P35498-1
SCN1A-AS1	ENST00000651574.1 linkuse as main transcript	n.487+15663G>A		intron_variant, non_coding_transcript_variant

Frequencies

GnomAD3 genomes

AF:

0.0000329

AC:

AN:

152052

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:

0.0000735

Gnomad OTH

AF:

0.00

GnomAD3 exomes

AF:

0.0000120

AC:

AN:

250174

Hom.:

AF XY:

0.00000740

AC XY:

AN XY:

135222

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:

0.0000266

Gnomad OTH exome

AF:

0.00

GnomAD4 exome

AF:

0.0000123

AC:

AN:

1458102

Hom.:

Cov.:

AF XY:

0.0000124

AC XY:

AN XY:

725536

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:

0.0000117

Gnomad4 OTH exome

AF:

0.0000664

GnomAD4 genome

AF:

0.0000329

AC:

AN:

152170

Hom.:

Cov.:

AF XY:

0.0000134

AC XY:

AN XY:

74398

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:

0.0000735

Gnomad4 OTH

AF:

0.00

Alfa

AF:

0.0000410

Hom.:

Bravo

AF:

0.0000227

ESP6500AA

AF:

0.00

AC:

ESP6500EA

AF:

0.000116

AC:

ExAC

AF:

0.0000165

AC:

EpiCase

AF:

0.0000546

EpiControl

AF:

0.0000593

ClinVar

Significance: Conflicting classifications of pathogenicity

Submissions summary: Uncertain:4Benign:1Other:1

Revision: criteria provided, conflicting classifications

LINK: link

Submissions by phenotype

not provided

Uncertain:2

Uncertain significance, criteria provided, single submitter	clinical testing	CeGaT Center for Human Genetics Tuebingen	Nov 01, 2017	- -
Uncertain significance, criteria provided, single submitter	clinical testing	GeneDx	May 23, 2024	Reported previously in several unrelated patients with severe myoclonic epilepsy in infancy (SMEI); in two families the variant was maternally inherited (PMID: 12821740, 15277629, 17054684); The T297I variant was identified in a patient with generalized epilepsy with febrile seizures plus (GEFS+) and idiopathic generalized epilepsy who had a second SCN1A variant in cis. Functional analysis of the T297I variant showed no significant difference compared to wildtype, suggesting T297I is not a pathogenic variant (PMID: 28951233); This substitution is predicted to be within the extracellular loop between the S5 and S6 transmembrane segments of the first homologous domain; In silico analysis supports that this missense variant has a deleterious effect on protein structure/function; This variant is associated with the following publications: (PMID: 23527921, 15277629, 17054684, 28951233, 28150151, 36336987, 12821740, 32897040) -

Migraine, familial hemiplegic, 3

Uncertain:1

Uncertain significance, criteria provided, single submitter

clinical testing

Illumina Laboratory Services, Illumina

Apr 27, 2017

This variant was observed as part of a predisposition screen in an ostensibly healthy population. A literature search was performed for the gene, cDNA change, and amino acid change (where applicable). No publications were found based on this search. Allele frequency data from public databases did not allow this variant to be ruled in or out of causing disease. Therefore, this variant is classified as a variant of unknown significance. -

Generalized epilepsy with febrile seizures plus, type 2

Uncertain:1

Uncertain significance, criteria provided, single submitter

clinical testing

Illumina Laboratory Services, Illumina

Apr 27, 2017

Early infantile epileptic encephalopathy with suppression bursts

Benign:1

Likely benign, criteria provided, single submitter

clinical testing

Labcorp Genetics (formerly Invitae), Labcorp

Dec 02, 2020

- -

Severe myoclonic epilepsy in infancy

Other:1

not provided, no classification provided

literature only

UniProtKB/Swiss-Prot

- -

Computational scores

Source: dbNSFP v4.3

Name

Calibrated prediction

Score

Prediction

AlphaMissense

Uncertain

0.52

BayesDel_addAF

Pathogenic

0.42

BayesDel_noAF

Pathogenic

0.44

CADD

Uncertain

DANN

Uncertain

1.0

DEOGEN2

Pathogenic

0.88

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

Eigen

Benign

0.13

Eigen_PC

Benign

0.13

FATHMM_MKL

Pathogenic

0.98

LIST_S2

Uncertain

0.89

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

M_CAP

Pathogenic

0.62

MetaRNN

Pathogenic

0.78

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

MetaSVM

Pathogenic

1.0

MutationAssessor

Uncertain

2.5

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

MutationTaster

Benign

0.67

N;N;N;N

PrimateAI

Uncertain

0.59

PROVEAN

Uncertain

-3.0

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

REVEL

Uncertain

0.64

Sift

Uncertain

0.0010

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

Sift4G

Uncertain

0.0040

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

Polyphen

0.74, 0.12

.;.;.;P;B;.;P;B;B;.

Vest4

0.74, 0.70, 0.69, 0.71

MVP

0.96

MPC

1.6

ClinPred

0.91

GERP RS

5.4

Varity_R

0.40

gMVP

0.91

Splicing

Name

Calibrated prediction

Score

Prediction

SpliceAI score (max)

0.010

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