chr12-51663087-G-T

Position:

• chr12-51663087-G-T

Variant summary

Our verdict is Benign. Variant got -14 ACMG points: 0P and 14B. BP4_Strong BP6 BP7 BS1 BS2

The NM_014191.4(SCN8A):​c.270G>T​(p.Thr90=) variant causes a synonymous change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.0000273 in 1,613,316 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 Conflicting classifications of pathogenicity (no stars). Synonymous variant affecting the same amino acid position (i.e. T90T) has been classified as Likely benign.

• Frequency:
  • Genomes: 𝑓 0.000046 (0 hom., cov: 32)
  • Exomes 𝑓: 0.000025 (0 hom.)
• Consequence: SCN8A NM_014191.4 synonymous
• Clinical Significance: Conflicting classifications of pathogenicity criteria provided, conflicting classifications U:1 B:2
• 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 -14 ACMG points.

• BP4: Computational evidence support a benign effect (BayesDel_noAF=-0.54).
• BP6: Variant 12-51663087-G-T is Benign according to our data. Variant chr12-51663087-G-T is described in ClinVar as [Conflicting_classifications_of_pathogenicity]. Clinvar id is 195293.We mark this variant Likely_benign, oryginal submissions are: {Uncertain_significance=1, Benign=2}.
• BP7: Synonymous conserved (PhyloP=0.207 with no splicing effect.
• BS1: Variant frequency is greater than expected in population eas. gnomad4 allele frequency = 0.000046 (7/152334) while in subpopulation EAS AF= 0.000963 (5/5192). AF 95% confidence interval is 0.000379. There are 0 homozygotes in gnomad4. There are 3 alleles in male gnomad4 subpopulation. Median coverage is 32. This position pass quality control queck.
• BS2: High AC in GnomAd4 at 7 AD gene.

Transcripts

RefSeq

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

Ensembl

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

Frequencies

GnomAD3 genomes AF: 0.0000460 AC: 7 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: 0.000961

Gnomad SAS AF: 0.000207

Gnomad FIN AF: 0.00

Gnomad MID AF: 0.00

Gnomad NFE AF: 0.0000147

Gnomad OTH AF: 0.00

GnomAD3 exomes AF: 0.000105 AC: 26 AN: 248170 Hom.: 0 AF XY: 0.0000965 AC XY: 13 AN XY: 134728

Gnomad AFR exome AF: 0.00

Gnomad AMR exome AF: 0.00

Gnomad ASJ exome AF: 0.00

Gnomad EAS exome AF: 0.00128

Gnomad SAS exome AF: 0.0000327

Gnomad FIN exome AF: 0.00

Gnomad NFE exome AF: 0.00

Gnomad OTH exome AF: 0.000331

GnomAD4 exome AF: 0.0000253 AC: 37 AN: 1460982 Hom.: 0 Cov.: 31 AF XY: 0.0000261 AC XY: 19 AN XY: 726640

Gnomad4 AFR exome AF: 0.00

Gnomad4 AMR exome AF: 0.00

Gnomad4 ASJ exome AF: 0.00

Gnomad4 EAS exome AF: 0.000580

Gnomad4 SAS exome AF: 0.0000232

Gnomad4 FIN exome AF: 0.00

Gnomad4 NFE exome AF: 0.00

Gnomad4 OTH exome AF: 0.000199

GnomAD4 genome AF: 0.0000460 AC: 7 AN: 152334 Hom.: 0 Cov.: 32 AF XY: 0.0000403 AC XY: 3 AN XY: 74502

Gnomad4 AFR AF: 0.00

Gnomad4 AMR AF: 0.00

Gnomad4 ASJ AF: 0.00

Gnomad4 EAS AF: 0.000963

Gnomad4 SAS AF: 0.000207

Gnomad4 FIN AF: 0.00

Gnomad4 NFE AF: 0.0000147

Gnomad4 OTH AF: 0.00

Bravo AF: 0.00000378

Asia WGS AF: 0.00173 AC: 6 AN: 3478

ClinVar

Significance: Conflicting classifications of pathogenicity

Submissions summary: Uncertain:1 Benign:2

Revision: criteria provided, conflicting classifications

Submissions by phenotype

not provided Uncertain:1 Benign:1

Benign, criteria provided, single submitter	clinical testing	GeneDx	Aug 04, 2020	- -
Uncertain significance, criteria provided, single submitter	clinical testing	Eurofins Ntd Llc (ga)	Jan 20, 2015	- -

Early infantile epileptic encephalopathy with suppression bursts Benign:1

Benign, criteria provided, single submitter

clinical testing

Labcorp Genetics (formerly Invitae), Labcorp

Jan 22, 2024

- -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
BayesDel_noAF	Benign	-0.54
CADD	Benign	9.9
DANN	Benign	0.80

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;