2-166046931-C-A

Variant names:

Variant summary

Our verdict is Pathogenic. Variant got 17 ACMG points: 17P and 0B. PM1PM2PM5PP2PP3_ModeratePP5_Very_Strong

The NM_001165963.4(SCN1A):c.1216G>T(p.Val406Phe) variant causes a missense change. 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 Pathogenic (★★). Another variant affecting the same amino acid position, but resulting in a different missense (i.e. V406A) has been classified as Likely pathogenic.

Frequency

Genomes: 𝑓 0.0 ( 0 hom., cov: 32)

Failed GnomAD Quality Control

Consequence

SCN1A
NM_001165963.4 missense

Scores

Clinical Significance

Conflicting classifications of pathogenicity criteria provided, conflicting classifications P:2U:1O:1

Conservation

PhyloP100: 6.17

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 Pathogenic. Variant got 17 ACMG points.

PM1

In a helix (size 38) in uniprot entity SCN1A_HUMAN there are 9 pathogenic changes around while only 0 benign (100%) 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 chr2-166046930-A-G is described in Lovd as [Likely_pathogenic].

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 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, 0.914

PP5

Variant 2-166046931-C-A is Pathogenic according to our data. Variant chr2-166046931-C-A is described in ClinVar as [Pathogenic]. Clinvar id is 68587.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
SCN1A	NM_001165963.4 link	c.1216G>T	p.Val406Phe	missense_variant	Exon 12 of 29	ENST00000674923.1	NP_001159435.1	P35498-1

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	TSL	MANE	Protein	UniProt
SCN1A	ENST00000674923.1 link	c.1216G>T	p.Val406Phe	missense_variant	Exon 12 of 29		NM_001165963.4	ENSP00000501589.1	P35498-1
SCN1A	ENST00000303395.9 link	c.1216G>T	p.Val406Phe	missense_variant	Exon 11 of 28	5		ENSP00000303540.4	P35498-1
SCN1A	ENST00000375405.7 link	c.1216G>T	p.Val406Phe	missense_variant	Exon 9 of 26	5		ENSP00000364554.3	P35498-2
SCN1A	ENST00000409050.1 link	c.1216G>T	p.Val406Phe	missense_variant	Exon 9 of 26	5		ENSP00000386312.1	P35498-3

Frequencies

GnomAD3 genomes

AF:

0.00

AC:

AN:

152106

Hom.:

Cov.:

FAILED QC

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:

0.00

Gnomad OTH

AF:

0.00

GnomAD4 exome

Cov.:

GnomAD4 genome

Data not reliable, filtered out with message: AC0;AS_VQSR

AF:

0.00

AC:

AN:

152106

Hom.:

Cov.:

AF XY:

0.00

AC XY:

AN XY:

74280

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:

0.00

Gnomad4 OTH

AF:

0.00

ClinVar

Significance: Conflicting classifications of pathogenicity

Submissions summary: Pathogenic:2Uncertain:1Other:1

Revision: criteria provided, conflicting classifications

LINK: link

Submissions by phenotype

Severe myoclonic epilepsy in infancy

Pathogenic:1Other:1

Apr 17, 2013

Athena Diagnostics

Significance: Pathogenic

Review Status: criteria provided, single submitter

Collection Method: clinical testing

- -

UniProtKB/Swiss-Prot

Significance: not provided

Review Status: no classification provided

Collection Method: literature only

- -

Early infantile epileptic encephalopathy with suppression bursts

Pathogenic:1

May 15, 2024

Labcorp Genetics (formerly Invitae), Labcorp

Significance: Pathogenic

Review Status: criteria provided, single submitter

Collection Method: clinical testing

This sequence change replaces valine, which is neutral and non-polar, with phenylalanine, which is neutral and non-polar, at codon 406 of the SCN1A protein (p.Val406Phe). This variant is not present in population databases (gnomAD no frequency). This missense change has been observed in individual(s) with SCN1A-related conditions (PMID: 19589774). In at least one individual the variant was observed to be de novo. ClinVar contains an entry for this variant (Variation ID: 68587). 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 with a positive predictive value of 95%. For these reasons, this variant has been classified as Pathogenic. -

not provided

Uncertain:1

Apr 30, 2015

Eurofins Ntd Llc (ga)

Significance: Uncertain significance

Review Status: criteria provided, single submitter

Collection Method: clinical testing

- -

Computational scores

Source: dbNSFP v4.3

Name

Calibrated prediction

Score

Prediction

AlphaMissense

Pathogenic

0.90

BayesDel_addAF

Pathogenic

0.50

BayesDel_noAF

Pathogenic

0.48

CADD

Uncertain

DANN

Uncertain

0.99

DEOGEN2

Pathogenic

0.97

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

Eigen

Pathogenic

0.74

Eigen_PC

Pathogenic

0.75

FATHMM_MKL

Pathogenic

0.98

LIST_S2

Uncertain

0.97

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

M_CAP

Pathogenic

0.90

MetaRNN

Pathogenic

0.91

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

MetaSVM

Pathogenic

1.1

MutationAssessor

Benign

1.0

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

PrimateAI

Pathogenic

0.83

PROVEAN

Pathogenic

-4.8

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

REVEL

Pathogenic

0.88

Sift

Pathogenic

0.0

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

Sift4G

Pathogenic

0.0

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

Polyphen

1.0, 1.0

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

Vest4

0.93, 0.95, 0.92, 0.91

MutPred

0.59

Loss of sheet (P = 0.0315);Loss of sheet (P = 0.0315);Loss of sheet (P = 0.0315);Loss of sheet (P = 0.0315);Loss of sheet (P = 0.0315);Loss of sheet (P = 0.0315);Loss of sheet (P = 0.0315);Loss of sheet (P = 0.0315);Loss of sheet (P = 0.0315);Loss of sheet (P = 0.0315);

MVP

0.97

MPC

2.0

ClinPred

1.0

GERP RS

5.5

Varity_R

0.90

gMVP

1.0

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