rs1060502186

Positions:

chr2-165991654-C-T

Variant summary

Our verdict is Likely pathogenic. Variant got 8 ACMG points: 8P and 0B. PM2PM5PP2PP3_ModeratePP5

The NM_001165963.4(SCN1A):c.5621G>A(p.Arg1874Gln) variant causes a missense change involving the alteration of a conserved nucleotide. The variant allele was found at a frequency of 0.00000124 in 1,613,758 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. R1874W) has been classified as Likely pathogenic.

Frequency

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

Exomes 𝑓: 6.8e-7 ( 0 hom. )

Consequence

SCN1A
NM_001165963.4 missense

Scores

Clinical Significance

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

Conservation

PhyloP100: 7.90

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.

PM2

Very rare variant in population databases, with high coverage;

PM5

Other missense variant is known to change same aminoacid residue: Variant chr2-165991655-G-A is described in Lovd as [Likely_pathogenic].

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, 0.872

PP5

Variant 2-165991654-C-T is Pathogenic according to our data. Variant chr2-165991654-C-T is described in ClinVar as [Conflicting_classifications_of_pathogenicity]. Clinvar id is 408927.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	Protein	UniProt
SCN1A	NM_001165963.4 linkuse as main transcript	c.5621G>A	p.Arg1874Gln	missense_variant	29/29	ENST00000674923.1	NP_001159435.1
LOC102724058	NR_110598.1 linkuse as main transcript	n.176-23959C>T		intron_variant, non_coding_transcript_variant

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Protein	Appris	UniProt
SCN1A	ENST00000674923.1 linkuse as main transcript	c.5621G>A	p.Arg1874Gln	missense_variant	29/29		NM_001165963.4	ENSP00000501589	P4	P35498-1
SCN1A-AS1	ENST00000651574.1 linkuse as main transcript	n.193-23959C>T		intron_variant, non_coding_transcript_variant

Frequencies

GnomAD3 genomes

AF:

0.00000658

AC:

AN:

152006

Hom.:

Cov.:

show subpopulations

Gnomad AFR

AF:

0.0000242

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

AF:

6.84e-7

AC:

AN:

1461752

Hom.:

Cov.:

AF XY:

0.00000138

AC XY:

AN XY:

727180

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:

8.99e-7

Gnomad4 OTH exome

AF:

0.00

GnomAD4 genome

AF:

0.00000658

AC:

AN:

152006

Hom.:

Cov.:

AF XY:

0.0000135

AC XY:

AN XY:

74226

show subpopulations

Gnomad4 AFR

AF:

0.0000242

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: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

Labcorp Genetics (formerly Invitae), Labcorp

Jul 18, 2022

ClinVar contains an entry for this variant (Variation ID: 408927). This missense change has been observed in individuals with clinical features of SCN1A-related conditions (PMID: 32276107; Invitae). This variant has been also described in reportedly unaffected individuals (Invitae). This variant is not present in population databases (gnomAD no frequency). This sequence change replaces arginine, which is basic and polar, with glutamine, which is neutral and polar, at codon 1874 of the SCN1A protein (p.Arg1874Gln). 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. 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. This variant disrupts the p.Arg1874 amino acid residue in SCN1A. Other variant(s) that disrupt this residue have been observed in individuals with SCN1A-related conditions (PMID: 31765958; Invitae), which suggests that this may be a clinically significant amino acid residue. Algorithms developed to predict the effect of sequence changes on RNA splicing suggest that this variant may create or strengthen a splice site. -

not provided

Uncertain:1

Uncertain significance, criteria provided, single submitter

clinical testing

GeneDx

Jul 28, 2023

Previously reported in an individual with febrile seizures, however evidence in support of pathogenicity for this variant was not provided in the report (Shibata et al., 2020); In silico analysis supports that this missense variant has a deleterious effect on protein structure/function; Not observed at significant frequency in large population cohorts (gnomAD); Missense variants in this gene are often considered pathogenic (HGMD); This substitution is predicted to be within the C-terminal cytoplasmic domain.; This variant is associated with the following publications: (PMID: 32276107) -

Computational scores

Source: dbNSFP v4.3

Name

Calibrated prediction

Score

Prediction

AlphaMissense

Uncertain

0.55

BayesDel_addAF

Pathogenic

0.51

BayesDel_noAF

Pathogenic

0.50

CADD

Pathogenic

DANN

Pathogenic

1.0

DEOGEN2

Pathogenic

0.84

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

Eigen

Pathogenic

0.95

Eigen_PC

Pathogenic

0.91

FATHMM_MKL

Pathogenic

0.99

LIST_S2

Uncertain

0.90

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

M_CAP

Pathogenic

0.85

MetaRNN

Pathogenic

0.87

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

MetaSVM

Pathogenic

1.1

MutationAssessor

Uncertain

2.8

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

MutationTaster

Benign

1.0

D;D;D;D

PrimateAI

Pathogenic

0.85

PROVEAN

Uncertain

-3.7

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

REVEL

Pathogenic

0.88

Sift

Pathogenic

0.0

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

Sift4G

Uncertain

0.012

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

Polyphen

1.0

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

Vest4

0.72, 0.77, 0.88

MutPred

0.45

.;.;.;Gain of methylation at K1873 (P = 0.1384);.;Gain of methylation at K1873 (P = 0.1384);.;.;.;

MVP

1.0

MPC

1.9

ClinPred

1.0

GERP RS

5.6

Varity_R

0.76

gMVP

0.86

Splicing

Name

Calibrated prediction

Score

Prediction

SpliceAI score (max)

0.020

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