chr2-165999719-T-G

Variant names:

• chr2-165999719-T-G
• rs794726734
• NM_001165963.4:c.4338+4A>C

Variant summary

Our verdict is Uncertain significance. The variant received 3 ACMG points: 4P and 1B. PM2 PP5_Moderate BP4

The NM_001165963.4(SCN1A):​c.4338+4A>C variant causes a splice region, intron change involving the alteration of a non-conserved nucleotide. The variant was absent in control chromosomes in GnomAD project. In-silico tool predicts a benign outcome for this variant. 3/3 splice prediction tools predict no significant impact on normal splicing. Variant has been reported in ClinVar as Pathogenic (★).

• Frequency: Genomes: not found (cov: 32)
• Consequence: SCN1A NM_001165963.4 splice_region, intron
• Scores: Splicing: ADA: 0.8908
• Clinical Significance: Pathogenic criteria provided, single submitter P:1
• Conservation: PhyloP100: 1.62
• Publications: 0 publications found

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)

LOC102724058 (HGNC:):

ACMG classification

Our verdict: Uncertain_significance. The variant received 3 ACMG points.

• PM2: Very rare variant in population databases, with high coverage
• PP5: Variant 2-165999719-T-G is Pathogenic according to our data. Variant chr2-165999719-T-G is described in ClinVar as Pathogenic. ClinVar VariationId is 189890.Status of the report is criteria_provided_single_submitter, 1 stars.
• BP4: Computational evidence support a benign effect (BayesDel_noAF=-0.3). . Strength limited to SUPPORTING due to the PP5.

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	MANE	Protein	UniProt
SCN1A	NM_001165963.4	c.4338+4A>C		splice_region_variant, intron_variant	Intron 25 of 28	ENST00000674923.1	NP_001159435.1

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	TSL	MANE	Protein	Appris	UniProt
SCN1A	ENST00000674923.1	c.4338+4A>C		splice_region_variant, intron_variant	Intron 25 of 28		NM_001165963.4	ENSP00000501589.1
SCN1A	ENST00000303395.9	c.4338+4A>C		splice_region_variant, intron_variant	Intron 24 of 27	5		ENSP00000303540.4
SCN1A	ENST00000375405.7	c.4305+4A>C		splice_region_variant, intron_variant	Intron 22 of 25	5		ENSP00000364554.3
SCN1A	ENST00000409050.2	c.4254+4A>C		splice_region_variant, intron_variant	Intron 24 of 27	5		ENSP00000386312.1

Frequencies

GnomAD3 genomes Cov.: 32

GnomAD4 exome Cov.: 27

GnomAD4 genome Cov.: 32

Alfa AF: 0.00 Hom.: 0

ClinVar

Significance: Pathogenic

Submissions summary: Pathogenic:1

Revision: criteria provided, single submitter

Submissions by phenotype

Severe myoclonic epilepsy in infancy Pathogenic:1

Dec 20, 2014

Center for Bioinformatics, Peking University

Significance: Pathogenic

Review Status: criteria provided, single submitter

Collection Method: research

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Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
BayesDel_noAF	Benign	-0.30
CADD	Uncertain	24
DANN	Benign	0.94
PhyloP100		1.6
Mutation Taster		=1/99	disease causing (ClinVar)

Splicing

Name	Calibrated prediction	Score	Prediction
dbscSNV1_ADA	Benign	0.89
dbscSNV1_RF	Benign	0.64
SpliceAI score (max)		0.010		Details are displayed if max score is > 0.2

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

Other links and lift over

dbSNP: rs794726734; hg19: chr2-166856229;