rs121918738

Variant summary

Our verdict is Likely pathogenic. Variant got 8 ACMG points: 8P and 0B. PM1PM5PP2PP3_ModeratePP5

The NM_001165963.4(SCN1A):c.3629C>T(p.Thr1210Met) variant causes a missense change involving the alteration of a conserved nucleotide. The variant allele was found at a frequency of 0.0000062 in 1,612,136 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. T1210K) has been classified as Pathogenic.

Frequency

Genomes: 𝑓 0.000013 ( 0 hom., cov: 32)

Exomes 𝑓: 0.0000055 ( 0 hom. )

Consequence

SCN1A
NM_001165963.4 missense

Scores

Clinical Significance

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

Conservation

PhyloP100: 9.99

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:

LOC102724058 (HGNC:):

LOC102724058 links:

Genome browser will be placed here

ACMG classification

Classification made for transcript

Verdict is Likely_pathogenic. Variant got 8 ACMG points.

PM1

In a hotspot region, there are 7 aminoacids with missense pathogenic changes in the window of +-8 aminoacids around while only 1 benign, 9 uncertain in NM_001165963.4

PM5

Other missense variant is known to change same aminoacid residue: Variant chr2-166013820-G-T is described in ClinVar as [Pathogenic]. Clinvar id is 68617.Status of the report is criteria_provided_single_submitter, 1 stars.

PP2

Missense variant where missense usually causes diseases, SCN1A

PP3

MetaRNN computational evidence supports a deleterious effect, 0.937

PP5

Variant 2-166013820-G-A is Pathogenic according to our data. Variant chr2-166013820-G-A is described in ClinVar as [Conflicting_classifications_of_pathogenicity]. Clinvar id is 658067.We mark this variant Likely_pathogenic, oryginal submissions are: {Likely_pathogenic=1, Uncertain_significance=1}.

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	UniProt
SCN1A	NM_001165963.4 linkuse as main transcript	c.3629C>T	p.Thr1210Met	missense_variant	21/29	ENST00000674923.1
LOC102724058	NR_110598.1 linkuse as main transcript	n.176-1793G>A		intron_variant, non_coding_transcript_variant

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Appris	UniProt
SCN1A	ENST00000674923.1 linkuse as main transcript	c.3629C>T	p.Thr1210Met	missense_variant	21/29		NM_001165963.4	P4	P35498-1
SCN1A-AS1	ENST00000651574.1 linkuse as main transcript	n.193-1793G>A		intron_variant, non_coding_transcript_variant

Frequencies

GnomAD3 genomes

AF:

0.0000132

AC:

AN:

151610

Hom.:

Cov.:

show subpopulations

Gnomad AFR

AF:

0.0000483

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:

0.00

Gnomad OTH

AF:

0.00

GnomAD3 exomes

AF:

0.0000159

AC:

AN:

250842

Hom.:

AF XY:

0.0000148

AC XY:

AN XY:

135546

show subpopulations

Gnomad AFR exome

AF:

0.000123

Gnomad AMR exome

AF:

0.00

Gnomad ASJ exome

AF:

0.00

Gnomad EAS exome

AF:

0.0000544

Gnomad SAS exome

AF:

0.0000327

Gnomad FIN exome

AF:

0.00

Gnomad NFE exome

AF:

0.00

Gnomad OTH exome

AF:

0.00

GnomAD4 exome

AF:

0.00000548

AC:

AN:

1460526

Hom.:

Cov.:

AF XY:

0.00000551

AC XY:

AN XY:

726580

show subpopulations

Gnomad4 AFR exome

AF:

0.0000299

Gnomad4 AMR exome

AF:

0.00

Gnomad4 ASJ exome

AF:

0.00

Gnomad4 EAS exome

AF:

0.0000252

Gnomad4 SAS exome

AF:

0.0000232

Gnomad4 FIN exome

AF:

0.00

Gnomad4 NFE exome

AF:

0.00000360

Gnomad4 OTH exome

AF:

0.00

GnomAD4 genome

AF:

0.0000132

AC:

AN:

151610

Hom.:

Cov.:

AF XY:

0.00

AC XY:

AN XY:

74038

show subpopulations

Gnomad4 AFR

AF:

0.0000483

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:

0.00

Gnomad4 OTH

AF:

0.00

Alfa

AF:

0.0000283

Hom.:

Bravo

AF:

0.00000756

ESP6500AA

AF:

0.000227

AC:

ESP6500EA

AF:

0.00

AC:

ExAC

AF:

0.0000247

AC:

ClinVar

Significance: Conflicting classifications of pathogenicity

Submissions summary: Pathogenic:1Uncertain:1

Revision: criteria provided, conflicting classifications

LINK: link

Submissions by phenotype

Early infantile epileptic encephalopathy with suppression bursts

Pathogenic:1

Likely pathogenic, criteria provided, single submitter

clinical testing

Invitae

Aug 23, 2022

This missense change has been observed in individuals with clinical features of SCN1A-related conditions (PMID: 28202706; Invitae). This sequence change replaces threonine, which is neutral and polar, with methionine, which is neutral and non-polar, at codon 1210 of the SCN1A protein (p.Thr1210Met). This variant is present in population databases (rs121918738, gnomAD 0.01%). ClinVar contains an entry for this variant (Variation ID: 658067). 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. This variant disrupts the p.Thr1210 amino acid residue in SCN1A. Other variant(s) that disrupt this residue have been observed in individuals with SCN1A-related conditions (PMID: 19350499), which suggests that this may be a clinically significant amino acid residue. In summary, the currently available evidence indicates that the variant is pathogenic, but additional data are needed to prove that conclusively. Therefore, this variant has been classified as Likely Pathogenic. -

Inborn genetic diseases

Uncertain:1

Uncertain significance, criteria provided, single submitter

clinical testing

Ambry Genetics

Jun 23, 2020

The p.T1210M variant (also known as c.3629C>T), located in coding exon 18 of the SCN1A gene, results from a C to T substitution at nucleotide position 3629. The threonine at codon 1210 is replaced by methionine, an amino acid with similar properties. This alteration was detected in an individual with febrile seizures as well as in her unaffected father (Cetica V et al. Neurology, 2017 Mar;88:1037-1044). This amino acid position is highly conserved in available vertebrate species. In addition, this alteration is predicted to be deleterious by in silico analysis. Since supporting evidence is limited at this time, the clinical significance of this alteration remains unclear. -

Computational scores

Source: dbNSFP v4.3

Name

Calibrated prediction

Score

Prediction

AlphaMissense

Uncertain

0.36

BayesDel_addAF

Uncertain

0.14

BayesDel_noAF

Pathogenic

0.19

Cadd

Pathogenic

Dann

Uncertain

1.0

Eigen

Pathogenic

1.1

Eigen_PC

Pathogenic

0.98

FATHMM_MKL

Pathogenic

0.99

LIST_S2

Uncertain

0.90

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

M_CAP

Pathogenic

0.71

MetaRNN

Pathogenic

0.94

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

MetaSVM

Pathogenic

0.96

MutationTaster

Benign

1.0

D;D;D;D

PrimateAI

Pathogenic

0.81

Polyphen

1.0

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

Vest4

0.84, 0.85, 0.85, 0.85

MVP

0.98

MPC

1.8

ClinPred

1.0

GERP RS

5.4

Varity_R

0.88

gMVP

0.88

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