rs1057519557

Variant names:

• chr12-51699783-A-G
• rs1057519557
• NM_001330260.2:c.920A>G
• SCN8A p.Asn307Ser

Variant summary

Our verdict is Likely benign. The variant received -1 ACMG points: 1P and 2B. PP2 BP4_Moderate

The NM_001330260.2(SCN8A):​c.920A>G​(p.Asn307Ser) variant causes a missense change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.00000411 in 1,460,008 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a benign outcome for this variant. 14/22 in silico tools predict a benign outcome for this variant. Variant has been reported in ClinVar as Uncertain significance (★★). The gene SCN8A is included in the ClinGen Criteria Specification Registry.

• Frequency:
  • Genomes: not found (cov: 31)
  • Exomes 𝑓: 0.0000041 (0 hom.)
• Consequence: SCN8A NM_001330260.2 missense
• Clinical Significance: Uncertain significance criteria provided, multiple submitters, no conflicts U:3
• Conservation: PhyloP100: 3.02
• Publications: 0 publications found

Genes affected

SCN8A (HGNC:10596): (sodium voltage-gated channel alpha subunit 8) This gene encodes a member of the sodium channel alpha subunit gene family. The encoded protein forms the ion pore region of the voltage-gated sodium channel. This protein is essential for the rapid membrane depolarization that occurs during the formation of the action potential in excitable neurons. Mutations in this gene are associated with cognitive disability, pancerebellar atrophy and ataxia. Alternate splicing results in multiple transcript variants.[provided by RefSeq, May 2010]

SCN8A Gene-Disease associations (from GenCC):

• complex neurodevelopmental disorder

  Inheritance: AD Classification: DEFINITIVE, STRONG Submitted by: ClinGen, PanelApp Australia
• developmental and epileptic encephalopathy, 13

  Inheritance: AR, AD Classification: DEFINITIVE, STRONG, LIMITED Submitted by: PanelApp Australia, Ambry Genetics, G2P, Labcorp Genetics (formerly Invitae)
• cognitive impairment with or without cerebellar ataxia

  Inheritance: AD Classification: STRONG Submitted by: Ambry Genetics, Labcorp Genetics (formerly Invitae)
• seizures, benign familial infantile, 5

  Inheritance: AD Classification: STRONG Submitted by: Labcorp Genetics (formerly Invitae)
• benign familial infantile epilepsy

  Inheritance: AD Classification: SUPPORTIVE Submitted by: Orphanet
• infantile convulsions and choreoathetosis

  Inheritance: AD Classification: SUPPORTIVE Submitted by: Orphanet
• undetermined early-onset epileptic encephalopathy

  Inheritance: AD Classification: SUPPORTIVE Submitted by: Orphanet
• myoclonus, familial, 2

  Inheritance: AD Classification: LIMITED Submitted by: Ambry Genetics

ACMG classification

Specifications for SCN8A are available in the ClinGen Criteria Specification Registry and recommended for reference when assigning criteria.

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

• PP2: Missense variant in the SCN8A gene, where missense mutations are typically associated with disease (based on misZ statistic). The gene has 213 curated pathogenic missense variants (we use a threshold of 10). The gene has 45 curated benign missense variants. Gene score misZ: 0.78755 (below the threshold of 3.09). Trascript score misZ: 10.436 (above the threshold of 3.09). GenCC associations: The gene is linked to seizures, benign familial infantile, 5, developmental and epileptic encephalopathy, 13, myoclonus, familial, 2, complex neurodevelopmental disorder, benign familial infantile epilepsy, cognitive impairment with or without cerebellar ataxia, undetermined early-onset epileptic encephalopathy, infantile convulsions and choreoathetosis.
• BP4: Computational evidence support a benign effect (MetaRNN=0.2387237).

Variant Effect in Transcripts

ACMG analysis was done for transcript: NM_001330260.2. You can select a different transcript below to see updated ACMG assignments.

RefSeq Transcripts

Sel.	Gene	Transcript	Tags	HGVSc	HGVSp	Effect	Exon Rank	Protein	UniProt
	SCN8A	NM_001330260.2	MANE Select	c.920A>G	p.Asn307Ser	missense	Exon 7 of 27	NP_001317189.1	Q9UQD0-2
	SCN8A	NM_014191.4	MANE Plus Clinical	c.920A>G	p.Asn307Ser	missense	Exon 7 of 27	NP_055006.1	Q9UQD0-1
	SCN8A	NM_001177984.3		c.920A>G	p.Asn307Ser	missense	Exon 7 of 26	NP_001171455.1	Q9UQD0-5

Ensembl Transcripts

Sel.	Gene	Transcript	Tags	HGVSc	HGVSp	Effect	Exon Rank	Protein	UniProt
	SCN8A	ENST00000354534.11	TSL:1 MANE Plus Clinical	c.920A>G	p.Asn307Ser	missense	Exon 7 of 27	ENSP00000346534.4	Q9UQD0-1
	SCN8A	ENST00000627620.5	TSL:5 MANE Select	c.920A>G	p.Asn307Ser	missense	Exon 7 of 27	ENSP00000487583.2	Q9UQD0-2
	SCN8A	ENST00000599343.5	TSL:5	c.920A>G	p.Asn307Ser	missense	Exon 6 of 26	ENSP00000476447.3	Q9UQD0-3

Frequencies

GnomAD3 genomes Cov.: 31

GnomAD4 exome AF: 0.00000411 AC: 6 AN: 1460008 Hom.: 0 Cov.: 30 AF XY: 0.00000551 AC XY: 4 AN XY: 726166

African (AFR) AF: 0.00 AC: 0 AN: 33448

American (AMR) AF: 0.00 AC: 0 AN: 44534

Ashkenazi Jewish (ASJ) AF: 0.00 AC: 0 AN: 26104

East Asian (EAS) AF: 0.00 AC: 0 AN: 39666

South Asian (SAS) AF: 0.00 AC: 0 AN: 85832

European-Finnish (FIN) AF: 0.00 AC: 0 AN: 53352

Middle Eastern (MID) AF: 0.00 AC: 0 AN: 5768

European-Non Finnish (NFE) AF: 0.00000540 AC: 6 AN: 1110972

Other (OTH) AF: 0.00 AC: 0 AN: 60332

GnomAD4 genome Cov.: 31

Alfa AF: 0.0000658 Hom.: 0

Bravo AF: 0.00000756

ClinVar

ClinVar submissions

Significance: Uncertain significance

Revision: criteria provided, multiple submitters, no conflicts

Pathogenic	VUS	Benign	Condition
-	1	-	Early-infantile DEE (1)
-	1	-	Epileptic encephalopathy (1)
-	1	-	not provided (1)

Computational scores

Source: dbNSFP v4.9

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Benign	0.073
BayesDel_addAF	Uncertain	0.057	T
BayesDel_noAF	Benign	-0.16
CADD	Uncertain	23
DANN	Benign	0.89
DEOGEN2	Uncertain	0.73	D
Eigen	Benign	-0.35
Eigen_PC	Benign	-0.14
FATHMM_MKL	Pathogenic	0.98	D
LIST_S2	Uncertain	0.93	D
M_CAP	Benign	0.050	D
MetaRNN	Benign	0.24	T
MetaSVM	Uncertain	-0.16	T
MutationAssessor	Benign	0.68	N
PhyloP100		3.0
PrimateAI	Uncertain	0.55	T
PROVEAN	Benign	-1.3	N
REVEL	Benign	0.26
Sift	Benign	0.26	T
Sift4G	Benign	0.86	T
Varity_R		0.054
gMVP		0.78
Mutation Taster		=77/23	polymorphism

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

MaxEntScan Visualizer can be used to analyze the impact of this mutation on the neighboring sequence.

Other links and lift over

dbSNP: rs1057519557;

hg19: chr12-52093567;