rs143980709

chr2-166012184-A-G

Variant summary

Our verdict is Benign. Variant got -17 ACMG points: 0P and 17B. BP4_Strong BP6_Very_Strong BP7 BS2

The NM_001165963.4(SCN1A):c.3804T>C(p.Leu1268=) variant causes a synonymous change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.000231 in 1,610,484 control chromosomes in the GnomAD database, including 1 homozygotes. In-silico tool predicts a benign outcome for this variant. Variant has been reported in ClinVar as Likely benign (★★).

• Frequency:
  • Genomes: 𝑓 0.0015 (0 hom., cov: 31)
  • Exomes 𝑓: 0.00010 (1 hom.)
• Consequence: SCN1A NM_001165963.4 synonymous
• Clinical Significance: Benign/Likely benign criteria provided, multiple submitters, no conflicts B:7
• Conservation: PhyloP100: 0.608

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

Verdict is Benign. Variant got -17 ACMG points.

• BP4: Computational evidence support a benign effect (BayesDel_noAF=-0.59).
• BP6: Variant 2-166012184-A-G is Benign according to our data. Variant chr2-166012184-A-G is described in ClinVar as [Likely_benign]. Clinvar id is 93646.Status of the report is criteria_provided_multiple_submitters_no_conflicts, 2 stars.
• BP7: Synonymous conserved (PhyloP=0.608 with no splicing effect.
• BS2: High AC in GnomAd at 226 AD gene.

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	UniProt
SCN1A	NM_001165963.4	c.3804T>C	p.Leu1268=	synonymous_variant	22/29	ENST00000674923.1
LOC102724058	NR_110598.1	n.176-3429A>G		intron_variant, non_coding_transcript_variant

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Appris	UniProt
SCN1A	ENST00000674923.1	c.3804T>C	p.Leu1268=	synonymous_variant	22/29		NM_001165963.4	P4
SCN1A-AS1	ENST00000651574.1	n.193-3429A>G		intron_variant, non_coding_transcript_variant

Frequencies

GnomAD3 genomes AF: 0.00149 AC: 226 AN: 151236 Hom.: 0 Cov.: 31

Gnomad AFR AF: 0.00520

Gnomad AMI AF: 0.00

Gnomad AMR AF: 0.000595

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: 0.000960

GnomAD3 exomes AF: 0.000340 AC: 85 AN: 250120 Hom.: 0 AF XY: 0.000266 AC XY: 36 AN XY: 135196

Gnomad AFR exome AF: 0.00506

Gnomad AMR exome AF: 0.0000872

Gnomad ASJ exome AF: 0.00

Gnomad EAS exome AF: 0.00

Gnomad SAS 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: 0.000101 AC: 148 AN: 1459130 Hom.: 1 Cov.: 31 AF XY: 0.0000827 AC XY: 60 AN XY: 725870

Gnomad4 AFR exome AF: 0.00393

Gnomad4 AMR exome AF: 0.000112

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: 0.00

Gnomad4 OTH exome AF: 0.000199

GnomAD4 genome AF: 0.00148 AC: 224 AN: 151354 Hom.: 0 Cov.: 31 AF XY: 0.00166 AC XY: 123 AN XY: 73940

Gnomad4 AFR AF: 0.00514

Gnomad4 AMR AF: 0.000594

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: 0.000950

Alfa AF: 0.00106 Hom.: 0

Bravo AF: 0.00130

ClinVar

Significance: Benign/Likely benign

Submissions summary: Benign:7

Revision: criteria provided, multiple submitters, no conflicts

Submissions by phenotype

not specified Benign:3

Benign, criteria provided, single submitter	clinical testing	GeneDx	Dec 09, 2013	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. -
Benign, criteria provided, single submitter	clinical testing	Eurofins Ntd Llc (ga)	May 28, 2015	- -
Benign, criteria provided, single submitter	clinical testing	Athena Diagnostics	Nov 29, 2016	- -

Migraine, familial hemiplegic, 3 Benign:1

Benign, criteria provided, single submitter

clinical testing

Illumina Laboratory Services, Illumina

Jan 12, 2018

This variant was observed in the ICSL laboratory as part of a predisposition screen in an ostensibly healthy population. It had not been previously curated by ICSL or reported in the Human Gene Mutation Database (HGMD: prior to June 1st, 2018), and was therefore a candidate for classification through an automated scoring system. Utilizing variant allele frequency, disease prevalence and penetrance estimates, and inheritance mode, an automated score was calculated to assess if this variant is too frequent to cause the disease. Based on the score and internal cut-off values, a variant classified as benign is not then subjected to further curation. The score for this variant resulted in a classification of benign for this disease. -

Inborn genetic diseases Benign:1

Likely benign, criteria provided, single submitter

clinical testing

Ambry Genetics

Dec 15, 2017

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. -

Early infantile epileptic encephalopathy with suppression bursts Benign:1

Benign, criteria provided, single submitter

clinical testing

Invitae

Nov 01, 2022

- -

Generalized epilepsy with febrile seizures plus, type 2 Benign:1

Likely benign, criteria provided, single submitter

clinical testing

Illumina Laboratory Services, Illumina

Jan 12, 2018

This variant was observed in the ICSL laboratory as part of a predisposition screen in an ostensibly healthy population. It had not been previously curated by ICSL or reported in the Human Gene Mutation Database (HGMD: prior to June 1st, 2018), and was therefore a candidate for classification through an automated scoring system. Utilizing variant allele frequency, disease prevalence and penetrance estimates, and inheritance mode, an automated score was calculated to assess if this variant is too frequent to cause the disease. Based on the score and internal cut-off values, a variant classified as likely benign is not then subjected to further curation. The score for this variant resulted in a classification of likely benign for this disease. -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
BayesDel_noAF	Benign	-0.59
Cadd	Benign	7.3
Dann	Benign	0.74

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: rs143980709; hg19: chr2-166868694;