Genetic Variant SCN1A:c.4284+1G>A (chr2-166002471-C-T) – ACMG Classification: Uncertain_significance (5 pts)

Variant summary

Our verdict is Uncertain significance. Variant got 5 ACMG points: 5P and 0B. PVS1_ModeratePM2PP5

The NM_001165963.4(SCN1A):c.4284+1G>A variant causes a splice donor, intron change involving the alteration of a conserved nucleotide. The variant was absent in control chromosomes in GnomAD project. In-silico tool predicts a pathogenic outcome for this variant. 3/3 splice prediction tools predicting alterations to normal splicing. Variant has been reported in ClinVar as Pathogenic (no stars).

Frequency

Genomes: 𝑓 0.0 ( 0 hom., cov: 31)

Failed GnomAD Quality Control

Consequence

SCN1A
NM_001165963.4 splice_donor, intron

Scores

Splicing: ADA: 1.000

Clinical Significance

Pathogenic no assertion criteria provided P: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 Uncertain_significance. Variant got 5 ACMG points.

PVS1

Splicing +-2 bp (donor or acceptor) variant, product NOT destroyed by NMD, known LOF gene, truncates exone, which is 0.04676617 fraction of the gene. No cryptic splice site detected. Exon removal is inframe change.

PM2

Very rare variant in population databases, with high coverage;

PP5

Variant 2-166002471-C-T is Pathogenic according to our data. Variant chr2-166002471-C-T is described in ClinVar as [Pathogenic]. Clinvar id is 1300202.Status of the report is no_assertion_criteria_provided, 0 stars.

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	MANE	Protein	UniProt
SCN1A	NM_001165963.4 link	c.4284+1G>A		splice_donor_variant, intron_variant	Intron 24 of 28	ENST00000674923.1	NP_001159435.1	P35498-1

Ensembl

Gene	Transcript	HGVSc	Effect	Exon rank	TSL	MANE	Protein	UniProt
SCN1A	ENST00000674923.1 link	c.4284+1G>A	splice_donor_variant, intron_variant	Intron 24 of 28		NM_001165963.4	ENSP00000501589.1	P35498-1
SCN1A	ENST00000303395.9 link	c.4284+1G>A	splice_donor_variant, intron_variant	Intron 23 of 27	5		ENSP00000303540.4	P35498-1
SCN1A	ENST00000375405.7 link	c.4251+1G>A	splice_donor_variant, intron_variant	Intron 21 of 25	5		ENSP00000364554.3	P35498-2
SCN1A	ENST00000409050.1 link	c.4200+1G>A	splice_donor_variant, intron_variant	Intron 21 of 25	5		ENSP00000386312.1	P35498-3

Frequencies

GnomAD3 genomes

AF:

0.00

AC:

AN:

151718

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

AF:

0.00

AC:

AN:

151718

Hom.:

Cov.:

AF XY:

0.00

AC XY:

AN XY:

74060

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: Pathogenic

Submissions summary: Pathogenic:1

Revision: no assertion criteria provided

LINK: link

Submissions by phenotype

Severe myoclonic epilepsy in infancy

Pathogenic:1

Oct 07, 2021

Unidad de Genómica Garrahan, Hospital de Pediatría Garrahan

Significance: Pathogenic

Review Status: no assertion criteria provided

Collection Method: clinical testing

- -

Computational scores

Source: dbNSFP v4.3

Name

Calibrated prediction

Score

Prediction

BayesDel_addAF

Pathogenic

0.63

BayesDel_noAF

Pathogenic

0.33

CADD

Pathogenic

DANN

Uncertain

0.99

Eigen

Pathogenic

1.2

Eigen_PC

Pathogenic

1.0

FATHMM_MKL

Pathogenic

0.99

GERP RS

5.2

Splicing

Name

Calibrated prediction

Score

Prediction

dbscSNV1_ADA

Pathogenic

1.0

dbscSNV1_RF

Pathogenic

0.92

SpliceAI score (max)

0.93

Details are displayed if max score is > 0.2

DS_DG_spliceai

0.23

Position offset: 49

DS_DL_spliceai

0.93

Position offset: 1

Find out detailed SpliceAI scores and Pangolin per-transcript scores at spliceailookup.broadinstitute.org

Publications

No publications associated with this variant yet.

Variant summary

Frequency

Consequence

Scores

Clinical Significance

Conservation

ACMG classification

Transcripts

RefSeq

Ensembl

Frequencies

ClinVar

Submissions by phenotype

Computational scores

Splicing

Publications

Other links and lift over