rs121918777

Positions:

• chr2-165992194-T-A
• chr2-165992194-T-C

Variant summary

Our verdict is Likely pathogenic. Variant got 7 ACMG points: 7P and 0B. PM1 PM2 PP2 PP3_Moderate

The NM_001165963.4(SCN1A):​c.5081A>T​(p.Tyr1694Phe) variant causes a missense change involving the alteration of a conserved nucleotide. The variant allele was found at a frequency of 0.000000684 in 1,461,744 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a pathogenic outcome for this variant. No clinical diagnostic laboratories have submitted clinical-significance assessments for this variant to ClinVar.

• Frequency:
  • Genomes: not found (cov: 32)
  • Exomes 𝑓: 6.8e-7 (0 hom.)
• Consequence: SCN1A NM_001165963.4 missense
• Clinical Significance: Not reported in ClinVar
• Conservation: PhyloP100: 7.87

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 Likely_pathogenic. Variant got 7 ACMG points.

• PM1: In a repeat IV (size 298) in uniprot entity SCN1A_HUMAN there are 62 pathogenic changes around while only 3 benign (95%) in NM_001165963.4
• PM2: Very rare variant in population databases, with high coverage
• PP2: Missense variant in gene, where missense usually causes diseases (based on misZ statistic), SCN1A. . Gene score misZ 5.2206 (greater than the threshold 3.09). Trascript score misZ 7.6022 (greater than threshold 3.09). GenCC has associacion of gene with migraine, familial hemiplegic, 3, familial hemiplegic migraine, Dravet syndrome, malignant migrating partial seizures of infancy, generalized epilepsy with febrile seizures plus, myoclonic-astatic epilepsy, developmental and epileptic encephalopathy, developmental and epileptic encephalopathy, 6, familial or sporadic hemiplegic migraine, arthrogryposis, Lennox-Gastaut syndrome, generalized epilepsy with febrile seizures plus, type 2.
• PP3: MetaRNN computational evidence supports a deleterious effect, 0.888

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	Protein	UniProt
SCN1A	NM_001165963.4	c.5081A>T	p.Tyr1694Phe	missense_variant	29/29	ENST00000674923.1	NP_001159435.1
LOC102724058	NR_110598.1	n.176-23419T>A		intron_variant, non_coding_transcript_variant

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Protein	Appris	UniProt
SCN1A	ENST00000674923.1	c.5081A>T	p.Tyr1694Phe	missense_variant	29/29		NM_001165963.4	ENSP00000501589	P4
SCN1A-AS1	ENST00000651574.1	n.193-23419T>A		intron_variant, non_coding_transcript_variant

Frequencies

GnomAD3 genomes Cov.: 32

GnomAD3 exomes AF: 0.00000398 AC: 1 AN: 251314 Hom.: 0 AF XY: 0.00 AC XY: 0 AN XY: 135824

Gnomad AFR exome AF: 0.00

Gnomad AMR exome AF: 0.00

Gnomad ASJ exome AF: 0.00

Gnomad EAS exome AF: 0.0000544

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: 6.84e-7 AC: 1 AN: 1461744 Hom.: 0 Cov.: 31 AF XY: 0.00 AC XY: 0 AN XY: 727182

Gnomad4 AFR exome AF: 0.00

Gnomad4 AMR exome AF: 0.00

Gnomad4 ASJ exome AF: 0.00

Gnomad4 EAS exome AF: 0.0000252

Gnomad4 SAS exome AF: 0.00

Gnomad4 FIN exome AF: 0.00

Gnomad4 NFE exome AF: 0.00

Gnomad4 OTH exome AF: 0.00

GnomAD4 genome Cov.: 32

ClinVar

Not reported in ClinVar

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Benign	0.26
BayesDel_addAF	Pathogenic	0.20	D
BayesDel_noAF	Pathogenic	0.22
CADD	Uncertain	24
DANN	Uncertain	0.99
DEOGEN2	Pathogenic	0.96	.;.;.;D;.;D;.;.;.
Eigen	Pathogenic	0.88
Eigen_PC	Pathogenic	0.83
FATHMM_MKL	Pathogenic	0.99	D
LIST_S2	Uncertain	0.94	D;D;D;D;.;.;.;D;D
M_CAP	Pathogenic	0.88	D
MetaRNN	Pathogenic	0.89	D;D;D;D;D;D;D;D;D
MetaSVM	Pathogenic	1.1	D
MutationAssessor	Uncertain	2.6	.;.;.;M;.;M;.;.;.
MutationTaster	Benign	1.0	D;D;D;D
PrimateAI	Pathogenic	0.81	D
PROVEAN	Uncertain	-3.5	.;.;.;D;.;D;.;D;D
REVEL	Pathogenic	0.90
Sift	Pathogenic	0.0	.;.;.;D;.;D;.;D;D
Sift4G	Uncertain	0.042	.;.;.;D;.;D;.;D;D
Polyphen		1.0	.;.;.;.;D;.;D;D;.
Vest4		0.57, 0.58, 0.58, 0.63
MutPred		0.60		.;.;.;Loss of loop (P = 0.0986);.;Loss of loop (P = 0.0986);.;.;.;
MVP		0.93
MPC		1.7
ClinPred		0.99	D
GERP RS		5.5
Varity_R		0.80
gMVP		0.95

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: rs121918777; hg19: chr2-166848704;