2-166045270-G-T

Variant names:

• chr2-166045270-G-T
• rs1553545770
• NM_001165963.4:c.1435C>A

Variant summary

Our verdict is Likely benign. The variant received -1 ACMG points: 3P and 4B. PM2 PP2 BP4_Moderate BP6_Moderate

The NM_001165963.4(SCN1A):​c.1435C>A​(p.Leu479Ile) variant causes a missense change. The variant was absent in control chromosomes in GnomAD project. In-silico tool predicts a benign outcome for this variant. 13/22 in silico tools predict a benign outcome for this variant. Variant has been reported in ClinVar as Likely benign (★). Another variant affecting the same amino acid position, but resulting in a different missense (i.e. L479P) has been classified as Uncertain significance.

• Frequency: Genomes: not found (cov: 32)
• Consequence: SCN1A NM_001165963.4 missense
• Clinical Significance: Likely benign criteria provided, single submitter B:1
• Conservation: PhyloP100: 4.11
• 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)

ACMG classification

Our verdict: Likely_benign. The variant received -1 ACMG points.

• PM2: Very rare variant in population databases, with high coverage
• PP2: Missense variant in the SCN1A gene, where missense mutations are typically associated with disease (based on misZ statistic). The gene has 848 curated pathogenic missense variants (we use a threshold of 10). The gene has 89 curated benign missense variants. Gene score misZ: 5.2206 (above the threshold of 3.09). Trascript score misZ: 7.6022 (above the threshold of 3.09). GenCC associations: The gene is linked to familial or sporadic hemiplegic migraine, myoclonic-astatic epilepsy, arthrogryposis, Dravet syndrome, malignant migrating partial seizures of infancy, generalized epilepsy with febrile seizures plus, type 2, migraine, familial hemiplegic, 3, developmental and epileptic encephalopathy, 6A, familial hemiplegic migraine, generalized epilepsy with febrile seizures plus, genetic developmental and epileptic encephalopathy, Lennox-Gastaut syndrome.
• BP4: Computational evidence support a benign effect (MetaRNN=0.25319636).
• BP6: Variant 2-166045270-G-T is Benign according to our data. Variant chr2-166045270-G-T is described in ClinVar as Likely_benign. ClinVar VariationId is 530506.Status of the report is criteria_provided_single_submitter, 1 stars.

Variant Effect in Transcripts

ACMG analysis was done for transcript: NM_001165963.4. You can select a different transcript below to see updated ACMG assignments.

RefSeq Transcripts

Selected	Gene	Transcript	Tags	HGVSc	HGVSp	Effect	Exon Rank	Protein	UniProt
	SCN1A	NM_001165963.4	MANE Select	c.1435C>A	p.Leu479Ile	missense	Exon 13 of 29	NP_001159435.1
	SCN1A	NM_001202435.3		c.1435C>A	p.Leu479Ile	missense	Exon 12 of 28	NP_001189364.1
	SCN1A	NM_001353948.2		c.1435C>A	p.Leu479Ile	missense	Exon 11 of 27	NP_001340877.1

Ensembl Transcripts

Selected	Gene	Transcript	Tags	HGVSc	HGVSp	Effect	Exon Rank	Protein	UniProt
	SCN1A	ENST00000674923.1	MANE Select	c.1435C>A	p.Leu479Ile	missense	Exon 13 of 29	ENSP00000501589.1
	SCN1A	ENST00000303395.9	TSL:5	c.1435C>A	p.Leu479Ile	missense	Exon 12 of 28	ENSP00000303540.4
	SCN1A	ENST00000375405.7	TSL:5	c.1435C>A	p.Leu479Ile	missense	Exon 10 of 26	ENSP00000364554.3

Frequencies

GnomAD3 genomes Cov.: 32

GnomAD4 exome Cov.: 32

GnomAD4 genome Cov.: 32

Alfa AF: 0.0000936 Hom.: 0

Bravo AF: 0.00000756

ClinVar

Significance: Likely benign

Submissions summary: Benign:1

Revision: criteria provided, single submitter

Submissions by phenotype

Developmental and epileptic encephalopathy Benign:1

Dec 24, 2024

Labcorp Genetics (formerly Invitae), Labcorp

Significance: Likely benign

Review Status: criteria provided, single submitter

Collection Method: clinical testing

Computational scores

Source: dbNSFP v4.9

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Benign	0.084
BayesDel_addAF	Benign	-0.18	T
BayesDel_noAF	Benign	-0.49
CADD	Benign	22
DANN	Benign	0.96
DEOGEN2	Benign	0.40	T
Eigen	Uncertain	0.36
Eigen_PC	Uncertain	0.44
FATHMM_MKL	Pathogenic	0.97	D
LIST_S2	Benign	0.85	T
M_CAP	Benign	0.014	T
MetaRNN	Benign	0.25	T
MetaSVM	Benign	-0.88	T
MutationAssessor	Benign	0.32	N
PhyloP100		4.1
PrimateAI	Uncertain	0.55	T
PROVEAN	Benign	-0.81	N
REVEL	Benign	0.14
Sift	Benign	0.28	T
Sift4G	Benign	0.43	T
Polyphen		0.82	P
Vest4		0.32
MutPred		0.36		Gain of helix (P = 0.0143)
MVP		0.58
MPC		0.76
ClinPred		0.43	T
GERP RS		5.6
Varity_R		0.15
gMVP		0.49
Mutation Taster		=18/82	disease causing

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

Other links and lift over

dbSNP: rs1553545770; hg19: chr2-166901780;