rs794726818

Positions:

• chr2-166046948-ATG-A

Variant summary

Our verdict is Pathogenic. Variant got 12 ACMG points: 12P and 0B. PVS1 PM2 PP5_Moderate

The NM_001165963.4(SCN1A):​c.1197_1198del​(p.Met400AspfsTer49) variant causes a frameshift change involving the alteration of a conserved nucleotide. The variant was absent in control chromosomes in GnomAD project. Variant has been reported in ClinVar as Pathogenic (★). Variant results in nonsense mediated mRNA decay.

• Frequency: Genomes: not found (cov: 33)
• Consequence: SCN1A NM_001165963.4 frameshift
• Clinical Significance: Pathogenic criteria provided, single submitter P:1
• Conservation: PhyloP100: 8.02

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-AS1 (HGNC:54069): (SCN1A and SCN9A antisense RNA 1)

ACMG classification

Verdict is Pathogenic. Variant got 12 ACMG points.

• PVS1: Loss of function variant, product undergoes nonsense mediated mRNA decay. LoF is a known mechanism of disease.
• PM2: Very rare variant in population databases, with high coverage
• PP5: Variant 2-166046948-ATG-A is Pathogenic according to our data. Variant chr2-166046948-ATG-A is described in ClinVar as [Pathogenic]. Clinvar id is 189987.Status of the report is criteria_provided_single_submitter, 1 stars.

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	Protein	UniProt
SCN1A	NM_001165963.4	c.1197_1198del	p.Met400AspfsTer49	frameshift_variant	12/29	ENST00000674923.1	NP_001159435.1

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Protein	Appris	UniProt
SCN1A	ENST00000674923.1	c.1197_1198del	p.Met400AspfsTer49	frameshift_variant	12/29		NM_001165963.4	ENSP00000501589	P4
SCN1A-AS1	ENST00000651574.1	n.487+10820_487+10821del		intron_variant, non_coding_transcript_variant

Frequencies

GnomAD3 genomes Cov.: 33

We have no GnomAD4 exomes data on this position. Probably position not covered by the project.

GnomAD4 genome Cov.: 33

ClinVar

Significance: Pathogenic

Submissions summary: Pathogenic:1

Revision: criteria provided, single submitter

Submissions by phenotype

Severe myoclonic epilepsy in infancy Pathogenic:1

Pathogenic, criteria provided, single submitter

research

Center for Bioinformatics, Peking University

Dec 20, 2014

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Computational scores

Source: dbNSFP v4.3

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

Other links and lift over

dbSNP: rs794726818; hg19: chr2-166903458;