rs371712630

chr12-51663087-G-Achr12-51663087-G-T

Variant summary

Our verdict is Benign. Variant got -11 ACMG points: 0P and 11B. BP4_Moderate BP6_Very_Strong BP7

The NM_014191.4(SCN8A):c.270G>A(p.Thr90=) variant causes a synonymous change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.000026 in 1,613,198 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a benign outcome for this variant. Variant has been reported in ClinVar as Likely benign (★★). Synonymous variant affecting the same amino acid position (i.e. T90T) has been classified as Likely benign.

• Frequency:
  • Genomes: 𝑓 0.0000066 (0 hom., cov: 32)
  • Exomes 𝑓: 0.000028 (0 hom.)
• Consequence: SCN8A NM_014191.4 synonymous
• Clinical Significance: Likely benign criteria provided, multiple submitters, no conflicts B:3
• Conservation: PhyloP100: 0.207

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]

ACMG classification

Verdict is Benign. Variant got -11 ACMG points.

• BP4: Computational evidence support a benign effect (BayesDel_noAF=-0.46).
• BP6: Variant 12-51663087-G-A is Benign according to our data. Variant chr12-51663087-G-A is described in ClinVar as [Likely_benign]. Clinvar id is 668464.Status of the report is criteria_provided_multiple_submitters_no_conflicts, 2 stars.
• BP7: Synonymous conserved (PhyloP=0.207 with no splicing effect.

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	UniProt
SCN8A	NM_001330260.2	c.270G>A	p.Thr90=	synonymous_variant	2/27	ENST00000627620.5
SCN8A	NM_014191.4	c.270G>A	p.Thr90=	synonymous_variant	2/27	ENST00000354534.11
SCN8A	NM_001177984.3	c.270G>A	p.Thr90=	synonymous_variant	2/26
SCN8A	NM_001369788.1	c.270G>A	p.Thr90=	synonymous_variant	2/26

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Appris	UniProt
SCN8A	ENST00000354534.11	c.270G>A	p.Thr90=	synonymous_variant	2/27	1	NM_014191.4	P4
SCN8A	ENST00000627620.5	c.270G>A	p.Thr90=	synonymous_variant	2/27	5	NM_001330260.2	A1

Frequencies

GnomAD3 genomes AF: 0.00000657 AC: 1 AN: 152216 Hom.: 0 Cov.: 32

Gnomad AFR AF: 0.00

Gnomad AMI AF: 0.00

Gnomad AMR AF: 0.00

Gnomad ASJ AF: 0.00

Gnomad EAS AF: 0.000192

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

GnomAD3 exomes AF: 0.0000161 AC: 4 AN: 248170 Hom.: 0 AF XY: 0.00000742 AC XY: 1 AN XY: 134728

Gnomad AFR exome AF: 0.0000646

Gnomad AMR exome AF: 0.00

Gnomad ASJ exome AF: 0.00

Gnomad EAS exome AF: 0.0000556

Gnomad SAS exome AF: 0.00

Gnomad FIN exome AF: 0.00

Gnomad NFE exome AF: 0.0000178

Gnomad OTH exome AF: 0.00

GnomAD4 exome AF: 0.0000281 AC: 41 AN: 1460982 Hom.: 0 Cov.: 31 AF XY: 0.0000179 AC XY: 13 AN XY: 726640

Gnomad4 AFR exome AF: 0.0000299

Gnomad4 AMR exome AF: 0.0000224

Gnomad4 ASJ exome AF: 0.00

Gnomad4 EAS exome AF: 0.000277

Gnomad4 SAS exome AF: 0.0000116

Gnomad4 FIN exome AF: 0.00

Gnomad4 NFE exome AF: 0.0000243

Gnomad4 OTH exome AF: 0.00

GnomAD4 genome AF: 0.00000657 AC: 1 AN: 152216 Hom.: 0 Cov.: 32 AF XY: 0.0000134 AC XY: 1 AN XY: 74374

Gnomad4 AFR AF: 0.00

Gnomad4 AMR AF: 0.00

Gnomad4 ASJ AF: 0.00

Gnomad4 EAS AF: 0.000192

Gnomad4 SAS AF: 0.00

Gnomad4 FIN AF: 0.00

Gnomad4 NFE AF: 0.00

Gnomad4 OTH AF: 0.00

Alfa AF: 0.0000565 Hom.: 0

Bravo AF: 0.0000264

ClinVar

Significance: Likely benign

Submissions summary: Benign:3

Revision: criteria provided, multiple submitters, no conflicts

Submissions by phenotype

not specified Benign:1

Likely benign, criteria provided, single submitter

clinical testing

Women's Health and Genetics/Laboratory Corporation of America, LabCorp

Aug 25, 2023

Variant summary: SCN8A c.270G>A alters a non-conserved nucleotide resulting in a synonymous change. Consensus agreement among computation tools predict no significant impact on normal splicing. However, these predictions have yet to be confirmed by functional studies. The variant allele was found at a frequency of 1.6e-05 in 248170 control chromosomes (gnomAD). The available data on variant occurrences in the general population are insufficient to allow any conclusion about variant significance. To our knowledge, no occurrence of c.270G>A in individuals affected with Early Infantile Epileptic Encephalopathy 13 and no experimental evidence demonstrating its impact on protein function have been reported. Two submitters have cited clinical-significance assessments for this variant to ClinVar after 2014. All submitters classified the variant as likely benign. Based on the evidence outlined above, the variant was classified as likely benign. -

Early infantile epileptic encephalopathy with suppression bursts Benign:1

Likely benign, criteria provided, single submitter

clinical testing

Invitae

Apr 18, 2023

- -

not provided Benign:1

Likely benign, criteria provided, single submitter

clinical testing

GeneDx

May 17, 2018

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. -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
BayesDel_noAF	Benign	-0.46
Cadd	Benign	13
Dann	Benign	0.78

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: rs371712630; hg19: chr12-52056871;