dbSNP rs587776703: SCN8A:p.Pro1719ArgfsTer6 (chr12-51806641-CCT-C) – ACMG Classification: Likely_pathogenic (6 pts)

Variant summary

Our verdict is Likely pathogenic. Variant got 6 ACMG points: 6P and 0B. PVS1_StrongPM2

The NM_001330260.2(SCN8A):c.5156_5157delCT(p.Pro1719ArgfsTer6) variant causes a frameshift change involving the alteration of a conserved nucleotide. The variant allele was found at a frequency of 0.00000657 in 152,192 control chromosomes in the GnomAD database, with no homozygous occurrence. Variant has been reported in ClinVar as Uncertain significance (★).

Frequency

Genomes: 𝑓 0.0000066 ( 0 hom., cov: 32)

Consequence

SCN8A
NM_001330260.2 frameshift

Scores

Not classified

Clinical Significance

Uncertain significance criteria provided, single submitter P:1U:1

Conservation

PhyloP100: 7.91

Variant links:

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 links:

Genome browser will be placed here

ACMG classification

Classification made for transcript

Verdict is Likely_pathogenic. Variant got 6 ACMG points.

PVS1

Loss of function variant, product does not undergo nonsense mediated mRNA decay. Variant is located in the 3'-most exon, not predicted to undergo nonsense mediated mRNA decay. There are 6 pathogenic variants in the truncated region.

PM2

Very rare variant in population databases, with high coverage;

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	MANE	Protein	UniProt
SCN8A	NM_001330260.2 link	c.5156_5157delCT	p.Pro1719ArgfsTer6	frameshift_variant	Exon 27 of 27	ENST00000627620.5	NP_001317189.1	Q9UQD0-2Q6B4S4
SCN8A	NM_014191.4 link	c.5156_5157delCT	p.Pro1719ArgfsTer6	frameshift_variant	Exon 27 of 27	ENST00000354534.11	NP_055006.1	Q9UQD0-1
SCN8A	NM_001177984.3 link	c.5033_5034delCT	p.Pro1678ArgfsTer6	frameshift_variant	Exon 26 of 26		NP_001171455.1	Q9UQD0-5
SCN8A	NM_001369788.1 link	c.5033_5034delCT	p.Pro1678ArgfsTer6	frameshift_variant	Exon 26 of 26		NP_001356717.1

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	TSL	MANE	Protein	UniProt
SCN8A	ENST00000354534.11 link	c.5156_5157delCT	p.Pro1719ArgfsTer6	frameshift_variant	Exon 27 of 27	1	NM_014191.4	ENSP00000346534.4	Q9UQD0-1
SCN8A	ENST00000627620.5 link	c.5156_5157delCT	p.Pro1719ArgfsTer6	frameshift_variant	Exon 27 of 27	5	NM_001330260.2	ENSP00000487583.2	Q9UQD0-2
SCN8A	ENST00000599343.5 link	c.5189_5190delCT	p.Pro1730ArgfsTer6	frameshift_variant	Exon 26 of 26	5		ENSP00000476447.3	Q9UQD0-3
SCN8A	ENST00000355133.7 link	c.5033_5034delCT	p.Pro1678ArgfsTer6	frameshift_variant	Exon 25 of 25	1		ENSP00000347255.4	Q9UQD0-5

Frequencies

GnomAD3 genomes

AF:

0.00000657

AC:

AN:

152192

Hom.:

Cov.:

show subpopulations

Gnomad AFR

AF:

0.00

Gnomad AMI

AF:

0.00

Gnomad AMR

AF:

0.00

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:

0.0000147

Gnomad OTH

AF:

0.00

We have no GnomAD4 exomes data on this position. Probably position not covered by the project.

GnomAD4 genome

AF:

0.00000657

AC:

AN:

152192

Hom.:

Cov.:

AF XY:

0.00

AC XY:

AN XY:

74348

show subpopulations

Gnomad4 AFR

AF:

0.00

Gnomad4 AMR

AF:

0.00

Gnomad4 ASJ

AF:

0.00

Gnomad4 EAS

AF:

0.00

Gnomad4 SAS

AF:

0.00

Gnomad4 FIN

AF:

0.00

Gnomad4 NFE

AF:

0.0000147

Gnomad4 OTH

AF:

0.00

Bravo

AF:

0.00000378

ClinVar

Significance: Uncertain significance

Submissions summary: Pathogenic:1Uncertain:1

Revision: criteria provided, single submitter

LINK: link

Submissions by phenotype

Cognitive impairment with or without cerebellar ataxia

Pathogenic:1

Jun 01, 2006

OMIM

Significance: Pathogenic

Review Status: no assertion criteria provided

Collection Method: literature only

- -

not provided

Uncertain:1

Sep 14, 2023

GeneDx

Significance: Uncertain significance

Review Status: criteria provided, single submitter

Collection Method: clinical testing

Reported in the heterozygous state in a patient with marked delay of cognitive and motor development, ADHD, abnormal brain MRI, and cerebellar ataxia who inherited the variant from her mother with mild cognitive impairment (Trudeau et al., 2006); Frameshift variant predicted to result in protein truncation, as the last 262 amino acids are replaced with 5 different amino acids, and other loss-of-function variants have been reported downstream in HGMD; This variant is associated with the following publications: (PMID: 16236810) -

Computational scores

Source: dbNSFP v4.3

Name

Calibrated prediction

Score

Prediction

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

Below is the list of publications found by LitVar. It may be empty.

Variant summary

Frequency

Consequence

Scores

Clinical Significance

Conservation

ACMG classification

Transcripts

RefSeq

Ensembl

Frequencies

ClinVar

Submissions by phenotype

Computational scores

Splicing

Publications

LitVar

Other links and lift over