rs748136961

Variant names:

• chr12-51663012-G-A
• rs748136961
• NM_001330260.2:c.195G>A

Variant summary

Our verdict is Benign. The variant received -16 ACMG points: 0P and 16B. BP4_Strong BP6_Very_Strong BS1

The NM_001330260.2(SCN8A):​c.195G>A​(p.Leu65Leu) variant causes a synonymous change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.0000186 in 1,613,924 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 (★★). The gene SCN8A is included in the ClinGen Criteria Specification Registry.

• Frequency:
  • Genomes: 𝑓 0.000026 (1 hom., cov: 32)
  • Exomes 𝑓: 0.000018 (0 hom.)
• Consequence: SCN8A NM_001330260.2 synonymous
• Clinical Significance: Likely benign criteria provided, multiple submitters, no conflicts B:3
• Conservation: PhyloP100: 3.40
• 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: AD, AR Classification: DEFINITIVE, STRONG, LIMITED Submitted by: G2P, Ambry Genetics, Labcorp Genetics (formerly Invitae), PanelApp Australia
• 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: Benign. The variant received -16 ACMG points.

• BP4: Computational evidence support a benign effect (BayesDel_noAF=-0.47).
• BP6: Variant 12-51663012-G-A is Benign according to our data. Variant chr12-51663012-G-A is described in ClinVar as Likely_benign. ClinVar VariationId is 385247.Status of the report is criteria_provided_multiple_submitters_no_conflicts, 2 stars.
• BS1: Variant frequency is greater than expected in population amr. GnomAdExome4 allele frequency = 0.0000178 (26/1461710) while in subpopulation AMR AF = 0.000514 (23/44724). AF 95% confidence interval is 0.000351. There are 0 homozygotes in GnomAdExome4. There are 13 alleles in the male GnomAdExome4 subpopulation. Median coverage is 31. This position passed quality control check.

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.195G>A	p.Leu65Leu	synonymous	Exon 2 of 27	NP_001317189.1	Q9UQD0-2
	SCN8A	NM_014191.4	MANE Plus Clinical	c.195G>A	p.Leu65Leu	synonymous	Exon 2 of 27	NP_055006.1	Q9UQD0-1
	SCN8A	NM_001177984.3		c.195G>A	p.Leu65Leu	synonymous	Exon 2 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.195G>A	p.Leu65Leu	synonymous	Exon 2 of 27	ENSP00000346534.4	Q9UQD0-1
	SCN8A	ENST00000627620.5	TSL:5 MANE Select	c.195G>A	p.Leu65Leu	synonymous	Exon 2 of 27	ENSP00000487583.2	Q9UQD0-2
	SCN8A	ENST00000599343.5	TSL:5	c.195G>A	p.Leu65Leu	synonymous	Exon 1 of 26	ENSP00000476447.3	Q9UQD0-3

Frequencies

GnomAD3 genomes AF: 0.0000263 AC: 4 AN: 152214 Hom.: 1 Cov.: 32

Gnomad AFR AF: 0.00

Gnomad AMI AF: 0.00

Gnomad AMR AF: 0.000262

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: 0.0000923 AC: 23 AN: 249094 AF XY: 0.0000962

Gnomad AFR exome AF: 0.00

Gnomad AMR exome AF: 0.000637

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: 0.000165

GnomAD4 exome AF: 0.0000178 AC: 26 AN: 1461710 Hom.: 0 Cov.: 31 AF XY: 0.0000179 AC XY: 13 AN XY: 727136

African (AFR) AF: 0.0000299 AC: 1 AN: 33480

American (AMR) AF: 0.000514 AC: 23 AN: 44724

Ashkenazi Jewish (ASJ) AF: 0.00 AC: 0 AN: 26136

East Asian (EAS) AF: 0.00 AC: 0 AN: 39700

South Asian (SAS) AF: 0.00 AC: 0 AN: 86258

European-Finnish (FIN) AF: 0.00 AC: 0 AN: 53402

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

European-Non Finnish (NFE) AF: 0.00 AC: 0 AN: 1111868

Other (OTH) AF: 0.0000331 AC: 2 AN: 60374

GnomAD4 genome AF: 0.0000263 AC: 4 AN: 152214 Hom.: 1 Cov.: 32 AF XY: 0.0000134 AC XY: 1 AN XY: 74368

African (AFR) AF: 0.00 AC: 0 AN: 41452

American (AMR) AF: 0.000262 AC: 4 AN: 15286

Ashkenazi Jewish (ASJ) AF: 0.00 AC: 0 AN: 3472

East Asian (EAS) AF: 0.00 AC: 0 AN: 5198

South Asian (SAS) AF: 0.00 AC: 0 AN: 4834

European-Finnish (FIN) AF: 0.00 AC: 0 AN: 10622

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

European-Non Finnish (NFE) AF: 0.00 AC: 0 AN: 68030

Other (OTH) AF: 0.00 AC: 0 AN: 2092

Alfa AF: 0.0000712 Hom.: 0

Bravo AF: 0.0000453

ClinVar

ClinVar submissions

Significance: Likely benign

Revision: criteria provided, multiple submitters, no conflicts

Pathogenic	VUS	Benign	Condition
-	-	1	Developmental and epileptic encephalopathy (1)
-	-	1	not provided (1)
-	-	1	not specified (1)

Computational scores

Source: dbNSFP v4.9

Name	Calibrated prediction	Score	Prediction
BayesDel_noAF	Benign	-0.47
CADD	Benign	13
DANN	Benign	0.88
PhyloP100		3.4
PromoterAI		-0.094	Neutral

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: rs748136961; hg19: chr12-52056796;