NM_001165963.4:c.2590C>T

Variant names:

• chr2-166038132-G-A
• rs140035595
• NM_001165963.4:c.2590C>T

Variant summary

Our verdict is Benign. The variant received -7 ACMG points: 0P and 7B. BP4_Moderate BP6 BS2

The NM_001165963.4(SCN1A):​c.2590C>T​(p.Leu864Leu) variant causes a splice region, synonymous change. The variant allele was found at a frequency of 0.00000499 in 1,603,700 control chromosomes in the GnomAD database, with no homozygous occurrence. 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 Conflicting classifications of pathogenicity (no stars).

• Frequency:
  • Genomes: 𝑓 0.000046 (0 hom., cov: 32)
  • Exomes 𝑓: 6.9e-7 (0 hom.)
• Consequence: SCN1A NM_001165963.4 splice_region, synonymous
• Scores: Splicing: ADA: 0.04951
• Clinical Significance: Conflicting classifications of pathogenicity criteria provided, conflicting classifications U:1 B:2
• Conservation: PhyloP100: 4.05
• Publications: 2 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)

ACMG classification

Our verdict: Benign. The variant received -7 ACMG points.

• BP4: Computational evidence support a benign effect (BayesDel_noAF=-0.39).
• BP6: Variant 2-166038132-G-A is Benign according to our data. Variant chr2-166038132-G-A is described in ClinVar as Conflicting_classifications_of_pathogenicity. ClinVar VariationId is 507584.
• BS2: High AC in GnomAd4 at 7 AD,Unknown gene.

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	MANE	Protein	UniProt
SCN1A	NM_001165963.4	c.2590C>T	p.Leu864Leu	splice_region_variant, synonymous_variant	Exon 18 of 29	ENST00000674923.1	NP_001159435.1

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	TSL	MANE	Protein	Appris	UniProt
SCN1A	ENST00000674923.1	c.2590C>T	p.Leu864Leu	splice_region_variant, synonymous_variant	Exon 18 of 29		NM_001165963.4	ENSP00000501589.1
SCN1A	ENST00000303395.9	c.2590C>T	p.Leu864Leu	splice_region_variant, synonymous_variant	Exon 17 of 28	5		ENSP00000303540.4
SCN1A	ENST00000375405.7	c.2557C>T	p.Leu853Leu	splice_region_variant, synonymous_variant	Exon 15 of 26	5		ENSP00000364554.3
SCN1A	ENST00000409050.2	c.2506C>T	p.Leu836Leu	splice_region_variant, synonymous_variant	Exon 17 of 28	5		ENSP00000386312.1

Frequencies

GnomAD3 genomes AF: 0.0000460 AC: 7 AN: 152130 Hom.: 0 Cov.: 32

Gnomad AFR AF: 0.000169

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

GnomAD2 exomes AF: 0.0000162 AC: 4 AN: 247134 AF XY: 0.0000149

Gnomad AFR exome AF: 0.000260

Gnomad AMR exome AF: 0.00

Gnomad ASJ exome AF: 0.00

Gnomad EAS exome AF: 0.00

Gnomad FIN exome AF: 0.00

Gnomad NFE exome AF: 0.00

Gnomad OTH exome AF: 0.00

GnomAD4 exome AF: 6.89e-7 AC: 1 AN: 1451570 Hom.: 0 Cov.: 29 AF XY: 0.00000138 AC XY: 1 AN XY: 722436

African (AFR) AF: 0.0000303 AC: 1 AN: 32970

American (AMR) AF: 0.00 AC: 0 AN: 44122

Ashkenazi Jewish (ASJ) AF: 0.00 AC: 0 AN: 25902

East Asian (EAS) AF: 0.00 AC: 0 AN: 39590

South Asian (SAS) AF: 0.00 AC: 0 AN: 85664

European-Finnish (FIN) AF: 0.00 AC: 0 AN: 53318

Middle Eastern (MID) AF: 0.00 AC: 0 AN: 5728

European-Non Finnish (NFE) AF: 0.00 AC: 0 AN: 1104324

Other (OTH) AF: 0.00 AC: 0 AN: 59952

GnomAD4 genome AF: 0.0000460 AC: 7 AN: 152130 Hom.: 0 Cov.: 32 AF XY: 0.0000673 AC XY: 5 AN XY: 74310

African (AFR) AF: 0.000169 AC: 7 AN: 41418

American (AMR) AF: 0.00 AC: 0 AN: 15270

Ashkenazi Jewish (ASJ) AF: 0.00 AC: 0 AN: 3466

East Asian (EAS) AF: 0.00 AC: 0 AN: 5192

South Asian (SAS) AF: 0.00 AC: 0 AN: 4824

European-Finnish (FIN) AF: 0.00 AC: 0 AN: 10612

Middle Eastern (MID) AF: 0.00 AC: 0 AN: 316

European-Non Finnish (NFE) AF: 0.00 AC: 0 AN: 68026

Other (OTH) AF: 0.00 AC: 0 AN: 2094

Alfa AF: 0.0000332 Hom.: 0

Bravo AF: 0.0000453

ClinVar

Significance: Conflicting classifications of pathogenicity

Submissions summary: Uncertain:1 Benign:2

Revision: criteria provided, conflicting classifications

Submissions by phenotype

Developmental and epileptic encephalopathy Uncertain:1

Oct 28, 2023

Labcorp Genetics (formerly Invitae), Labcorp

Significance: Uncertain significance

Review Status: criteria provided, single submitter

Collection Method: clinical testing

This sequence change affects codon 864 of the SCN1A mRNA. It is a 'silent' change, meaning that it does not change the encoded amino acid sequence of the SCN1A protein. It affects a nucleotide within the consensus splice site. This variant is present in population databases (rs140035595, gnomAD 0.02%). This variant has not been reported in the literature in individuals affected with SCN1A-related conditions. ClinVar contains an entry for this variant (Variation ID: 507584). Algorithms developed to predict the effect of sequence changes on RNA splicing suggest that this variant is not likely to affect RNA splicing. In summary, the available evidence is currently insufficient to determine the role of this variant in disease. Therefore, it has been classified as a Variant of Uncertain Significance. -

not specified Benign:1

Feb 27, 2017

GeneDx

Significance: Likely benign

Review Status: criteria provided, single submitter

Collection Method: clinical testing

This variant is considered likely benign or benign based on one or more of the following criteria: it is a conservative change, it occurs at a poorly conserved position in the protein, it is predicted to be benign by multiple in silico algorithms, and/or has population frequency not consistent with disease. -

Inborn genetic diseases Benign:1

Sep 12, 2017

Ambry Genetics

Significance: Likely benign

Review Status: criteria provided, single submitter

Collection Method: clinical testing

This alteration is classified as likely benign based on a combination of the following: seen in unaffected individuals, population frequency, intact protein function, lack of segregation with disease, co-occurrence, RNA analysis, in silico models, amino acid conservation, lack of disease association in case-control studies, and/or the mechanism of disease or impacted region is inconsistent with a known cause of pathogenicity. -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
BayesDel_noAF	Benign	-0.39
CADD	Benign	16
DANN	Benign	0.88
PhyloP100		4.1
Mutation Taster		=33/67	disease causing

Splicing

Name	Calibrated prediction	Score	Prediction
dbscSNV1_ADA	Benign	0.050
dbscSNV1_RF	Benign	0.24
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

Other links and lift over

dbSNP: rs140035595; hg19: chr2-166894642;