chr17-63948760-C-T

Position:

chr17-63948760-C-T

Variant summary

Our verdict is Likely benign. Variant got -5 ACMG points: 0P and 5B. BP6BS1

The NM_000334.4(SCN4A):c.2995G>A(p.Val999Met) variant causes a missense change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.0000935 in 1,604,894 control chromosomes in the GnomAD database, with no homozygous occurrence. Variant has been reported in ClinVar as Conflicting classifications of pathogenicity (no stars). Another variant affecting the same amino acid position, but resulting in a different missense (i.e. V999L) has been classified as Uncertain significance.

Frequency

Genomes: 𝑓 0.00024 ( 0 hom., cov: 33)

Exomes 𝑓: 0.000078 ( 0 hom. )

Consequence

SCN4A
NM_000334.4 missense

Scores

Clinical Significance

Conflicting classifications of pathogenicity criteria provided, conflicting classifications U:3B:5

Conservation

PhyloP100: 3.35

Variant links:

Genes affected

SCN4A (HGNC:10591): (sodium voltage-gated channel alpha subunit 4) Voltage-gated sodium channels are transmembrane glycoprotein complexes composed of a large alpha subunit with 24 transmembrane domains and one or more regulatory beta subunits. They are responsible for the generation and propagation of action potentials in neurons and muscle. This gene encodes one member of the sodium channel alpha subunit gene family. It is expressed in skeletal muscle, and mutations in this gene have been linked to several myotonia and periodic paralysis disorders. [provided by RefSeq, Jul 2008]

SCN4A links:

Genome browser will be placed here

ACMG classification

Classification made for transcript

Verdict is Likely_benign. Variant got -5 ACMG points.

BP6

Variant 17-63948760-C-T is Benign according to our data. Variant chr17-63948760-C-T is described in ClinVar as [Conflicting_classifications_of_pathogenicity]. Clinvar id is 324525.We mark this variant Likely_benign, oryginal submissions are: {Likely_benign=1, Uncertain_significance=3, Benign=4}.

BS1

Variant frequency is greater than expected in population afr. gnomad4_exome allele frequency = 0.0000778 (113/1452656) while in subpopulation AFR AF= 0.00138 (46/33338). AF 95% confidence interval is 0.00106. There are 0 homozygotes in gnomad4_exome. There are 46 alleles in male gnomad4_exome subpopulation. Median coverage is 31. This position pass quality control queck.

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	UniProt
SCN4A	NM_000334.4 linkuse as main transcript	c.2995G>A	p.Val999Met	missense_variant	16/24	ENST00000435607.3

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Appris	UniProt
SCN4A	ENST00000435607.3 linkuse as main transcript	c.2995G>A	p.Val999Met	missense_variant	16/24	1	NM_000334.4	P1
SCN4A	ENST00000584310.1 linkuse as main transcript	n.318G>A		non_coding_transcript_exon_variant	2/3	4

Frequencies

GnomAD3 genomes

AF:

0.000243

AC:

AN:

152238

Hom.:

Cov.:

show subpopulations

Gnomad AFR

AF:

0.000772

Gnomad AMI

AF:

0.00

Gnomad AMR

AF:

0.000131

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:

0.0000441

Gnomad OTH

AF:

0.00

GnomAD3 exomes

AF:

0.0000987

AC:

AN:

243126

Hom.:

AF XY:

0.0000757

AC XY:

AN XY:

132022

show subpopulations

Gnomad AFR exome

AF:

0.00112

Gnomad AMR exome

AF:

0.00

Gnomad ASJ exome

AF:

0.00

Gnomad EAS exome

AF:

0.0000558

Gnomad SAS exome

AF:

0.0000664

Gnomad FIN exome

AF:

0.00

Gnomad NFE exome

AF:

0.0000364

Gnomad OTH exome

AF:

0.00

GnomAD4 exome

AF:

0.0000778

AC:

113

AN:

1452656

Hom.:

Cov.:

AF XY:

0.0000638

AC XY:

AN XY:

721510

show subpopulations

Gnomad4 AFR exome

AF:

0.00138

Gnomad4 AMR exome

AF:

0.0000449

Gnomad4 ASJ exome

AF:

0.00

Gnomad4 EAS exome

AF:

0.0000253

Gnomad4 SAS exome

AF:

0.0000350

Gnomad4 FIN exome

AF:

0.00

Gnomad4 NFE exome

AF:

0.0000506

Gnomad4 OTH exome

AF:

0.0000834

GnomAD4 genome

AF:

0.000243

AC:

AN:

152238

Hom.:

Cov.:

AF XY:

0.000161

AC XY:

AN XY:

74366

show subpopulations

Gnomad4 AFR

AF:

0.000772

Gnomad4 AMR

AF:

0.000131

Gnomad4 ASJ

AF:

0.00

Gnomad4 EAS

AF:

0.00

Gnomad4 SAS

AF:

0.00

Gnomad4 FIN

AF:

0.00

Gnomad4 NFE

AF:

0.0000441

Gnomad4 OTH

AF:

0.00

Alfa

AF:

0.000134

Hom.:

Bravo

AF:

0.000370

ESP6500AA

AF:

0.000230

AC:

ESP6500EA

AF:

0.00

AC:

ExAC

AF:

0.0000660

AC:

ClinVar

Significance: Conflicting classifications of pathogenicity

Submissions summary: Uncertain:3Benign:5

Revision: criteria provided, conflicting classifications

LINK: link

Submissions by phenotype

Familial hyperkalemic periodic paralysis

Benign:2

Likely benign, criteria provided, single submitter	clinical testing	Labcorp Genetics (formerly Invitae), Labcorp	Dec 15, 2023	- -
Benign, criteria provided, single submitter	clinical testing	Illumina Laboratory Services, Illumina	Jan 12, 2018	This variant was observed in the ICSL laboratory as part of a predisposition screen in an ostensibly healthy population. It had not been previously curated by ICSL or reported in the Human Gene Mutation Database (HGMD: prior to June 1st, 2018), and was therefore a candidate for classification through an automated scoring system. Utilizing variant allele frequency, disease prevalence and penetrance estimates, and inheritance mode, an automated score was calculated to assess if this variant is too frequent to cause the disease. Based on the score and internal cut-off values, a variant classified as benign is not then subjected to further curation. The score for this variant resulted in a classification of benign for this disease. -

not provided

Uncertain:1

Uncertain significance, criteria provided, single submitter

clinical testing

GeneDx

Aug 17, 2022

In silico analysis supports that this missense variant does not alter protein structure/function; Has not been previously published as pathogenic or benign to our knowledge -

SCN4A-related disorder

Uncertain:1

Uncertain significance, criteria provided, single submitter

clinical testing

PreventionGenetics, part of Exact Sciences

May 25, 2023

The SCN4A c.2995G>A variant is predicted to result in the amino acid substitution p.Val999Met. To our knowledge, this variant has not been reported in the literature. This variant is reported in 0.10% of alleles in individuals of African descent in gnomAD (http://gnomad.broadinstitute.org/variant/17-62026120-C-T). Although we suspect that this variant may be benign, at this time, the clinical significance of this variant is uncertain due to the absence of conclusive functional and genetic evidence. -

Congenital myasthenic syndrome 16

Uncertain:1

Uncertain significance, criteria provided, single submitter

clinical testing

Illumina Laboratory Services, Illumina

Jan 12, 2018

This variant was observed in the ICSL laboratory as part of a predisposition screen in an ostensibly healthy population. It had not been previously curated by ICSL or reported in the Human Gene Mutation Database (HGMD: prior to June 1st, 2018), and was therefore a candidate for classification through an automated scoring system. Utilizing variant allele frequency, disease prevalence and penetrance estimates, and inheritance mode, an automated score was calculated to assess if this variant is too frequent to cause the disease. Based on the score, this variant could not be ruled out of causing disease and therefore its association with disease required further investigation. A literature search was performed for the gene, cDNA change, and amino acid change (if applicable). No publications were found based on this search. This variant was therefore classified as a variant of unknown significance for this disease. -

Hypokalemic periodic paralysis, type 2

Benign:1

Benign, criteria provided, single submitter

clinical testing

Illumina Laboratory Services, Illumina

Jan 12, 2018

This variant was observed in the ICSL laboratory as part of a predisposition screen in an ostensibly healthy population. It had not been previously curated by ICSL or reported in the Human Gene Mutation Database (HGMD: prior to June 1st, 2018), and was therefore a candidate for classification through an automated scoring system. Utilizing variant allele frequency, disease prevalence and penetrance estimates, and inheritance mode, an automated score was calculated to assess if this variant is too frequent to cause the disease. Based on the score and internal cut-off values, a variant classified as benign is not then subjected to further curation. The score for this variant resulted in a classification of benign for this disease. -

Paramyotonia congenita of Von Eulenburg

Benign:1

Benign, criteria provided, single submitter

clinical testing

Illumina Laboratory Services, Illumina

Jan 12, 2018

This variant was observed in the ICSL laboratory as part of a predisposition screen in an ostensibly healthy population. It had not been previously curated by ICSL or reported in the Human Gene Mutation Database (HGMD: prior to June 1st, 2018), and was therefore a candidate for classification through an automated scoring system. Utilizing variant allele frequency, disease prevalence and penetrance estimates, and inheritance mode, an automated score was calculated to assess if this variant is too frequent to cause the disease. Based on the score and internal cut-off values, a variant classified as benign is not then subjected to further curation. The score for this variant resulted in a classification of benign for this disease. -

Potassium-aggravated myotonia

Benign:1

Benign, criteria provided, single submitter

clinical testing

Illumina Laboratory Services, Illumina

Jan 12, 2018

This variant was observed in the ICSL laboratory as part of a predisposition screen in an ostensibly healthy population. It had not been previously curated by ICSL or reported in the Human Gene Mutation Database (HGMD: prior to June 1st, 2018), and was therefore a candidate for classification through an automated scoring system. Utilizing variant allele frequency, disease prevalence and penetrance estimates, and inheritance mode, an automated score was calculated to assess if this variant is too frequent to cause the disease. Based on the score and internal cut-off values, a variant classified as benign is not then subjected to further curation. The score for this variant resulted in a classification of benign for this disease. -

Computational scores

Source: dbNSFP v4.3

Name

Calibrated prediction

Score

Prediction

AlphaMissense

Uncertain

0.44

BayesDel_addAF

Benign

-0.19

BayesDel_noAF

Benign

-0.10

CADD

Uncertain

DANN

Uncertain

1.0

DEOGEN2

Uncertain

0.70

Eigen

Uncertain

0.45

Eigen_PC

Uncertain

0.38

FATHMM_MKL

Uncertain

0.94

LIST_S2

Uncertain

0.91

M_CAP

Uncertain

0.12

MetaRNN

Uncertain

0.61

MetaSVM

Uncertain

0.47

MutationAssessor

Uncertain

2.4

MutationTaster

Benign

1.0

D;D

PrimateAI

Uncertain

0.75

PROVEAN

Benign

-2.3

REVEL

Uncertain

0.60

Sift

Uncertain

0.024

Sift4G

Benign

0.13

Polyphen

1.0

Vest4

0.65

MVP

0.85

MPC

0.87

ClinPred

0.082

GERP RS

4.2

Varity_R

0.34

gMVP

0.59

Splicing

Name

Calibrated prediction

Score

Prediction

SpliceAI score (max)

0.050

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