NM_000334.4:c.952T>C

Variant names:

Variant summary

Our verdict is Likely benign. The variant received -2 ACMG points: 1P and 3B. PP2BP4_ModerateBP6

The NM_000334.4(SCN4A):c.952T>C(p.Trp318Arg) variant causes a missense change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.000739 in 1,613,832 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a benign outcome for this variant. 14/22 in silico tools predict a benign outcome for this variant. 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. W318C) has been classified as Uncertain significance.

Frequency

Genomes: 𝑓 0.00056 ( 0 hom., cov: 32)

Exomes 𝑓: 0.00076 ( 0 hom. )

Consequence

SCN4A
NM_000334.4 missense

Scores

Clinical Significance

Conflicting classifications of pathogenicity criteria provided, conflicting classifications U:4B:11

Conservation

PhyloP100: 0.371

Publications

2 publications found

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 Gene-Disease associations (from GenCC):

hyperkalemic periodic paralysis
Inheritance: AD Classification: DEFINITIVE, STRONG, SUPPORTIVE Submitted by: Labcorp Genetics (formerly Invitae), G2P, Genomics England PanelApp, Orphanet
paramyotonia congenita of Von Eulenburg
Inheritance: AD Classification: DEFINITIVE, STRONG, SUPPORTIVE Submitted by: Orphanet, G2P, Labcorp Genetics (formerly Invitae), Genomics England PanelApp, Laboratory for Molecular Medicine
SCN4A-related myopathy, autosomal recessive
Inheritance: AR Classification: DEFINITIVE, STRONG Submitted by: Illumina, ClinGen, PanelApp Australia
hypokalemic periodic paralysis, type 2
Inheritance: AD Classification: STRONG Submitted by: Labcorp Genetics (formerly Invitae), Genomics England PanelApp
potassium-aggravated myotonia
Inheritance: AD Classification: STRONG Submitted by: Labcorp Genetics (formerly Invitae)
congenital myasthenic syndrome 16
Inheritance: AR Classification: STRONG, LIMITED Submitted by: Genomics England PanelApp, Labcorp Genetics (formerly Invitae), Ambry Genetics
congenital myopathy
Inheritance: AR Classification: STRONG Submitted by: Genomics England PanelApp
congenital myopathy 22A, classic
Inheritance: AR Classification: STRONG Submitted by: Labcorp Genetics (formerly Invitae)
acetazolamide-responsive myotonia
Inheritance: AD Classification: SUPPORTIVE Submitted by: Orphanet
hypokalemic periodic paralysis
Inheritance: AD Classification: SUPPORTIVE Submitted by: Orphanet
myotonia fluctuans
Inheritance: AD Classification: SUPPORTIVE Submitted by: Orphanet
myotonia permanens
Inheritance: AD Classification: SUPPORTIVE Submitted by: Orphanet
postsynaptic congenital myasthenic syndrome
Inheritance: AR Classification: SUPPORTIVE Submitted by: Orphanet

SCN4A links:

Genome browser will be placed here

ACMG classification

Classification was made for transcript

Our verdict: Likely_benign. The variant received -2 ACMG points.

PP2

Missense variant in the gene, where a lot of missense mutations are associated with disease in ClinVar. The gene has 97 curated pathogenic missense variants (we use a threshold of 10). The gene has 19 curated benign missense variants. Gene score misZ: 1.5606 (below the threshold of 3.09). Trascript score misZ: 2.2224 (below the threshold of 3.09). GenCC associations: The gene is linked to congenital myasthenic syndrome 16, paramyotonia congenita of Von Eulenburg, hyperkalemic periodic paralysis, hypokalemic periodic paralysis, type 2, congenital myopathy, hypokalemic periodic paralysis, SCN4A-related myopathy, autosomal recessive, congenital myopathy 22A, classic, potassium-aggravated myotonia, postsynaptic congenital myasthenic syndrome, myotonia fluctuans, myotonia permanens, acetazolamide-responsive myotonia.

BP4

Computational evidence support a benign effect (MetaRNN=0.115801185).

BP6

Variant 17-63968107-A-G is Benign according to our data. Variant chr17-63968107-A-G is described in ClinVar as Conflicting_classifications_of_pathogenicity. ClinVar VariationId is 252477.

Variant Effect in Transcripts

ACMG analysis was done for transcript: NM_000334.4. 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
	SCN4A	NM_000334.4	MANE Select	c.952T>C	p.Trp318Arg	missense	Exon 6 of 24	NP_000325.4	P35499

Ensembl Transcripts

Sel.	Gene	Transcript	Tags	HGVSc	HGVSp	Effect	Exon Rank	Protein	UniProt
	SCN4A	ENST00000435607.3	TSL:1 MANE Select	c.952T>C	p.Trp318Arg	missense	Exon 6 of 24	ENSP00000396320.1	P35499

Frequencies

GnomAD3 genomes

AF:

0.000559

AC:

AN:

152024

Hom.:

Cov.:

show subpopulations

Gnomad AFR

AF:

0.000242

Gnomad AMI

AF:

0.00

Gnomad AMR

AF:

0.000393

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:

0.000985

Gnomad OTH

AF:

0.000961

GnomAD2 exomes

AF:

0.000618

AC:

154

AN:

249302

AF XY:

0.000710

show subpopulations

Gnomad AFR exome

AF:

0.0000645

Gnomad AMR exome

AF:

0.00

Gnomad ASJ exome

AF:

0.0000994

Gnomad EAS exome

AF:

0.00

Gnomad FIN exome

AF:

0.0000464

Gnomad NFE exome

AF:

0.00126

Gnomad OTH exome

AF:

0.000495

GnomAD4 exome

AF:

0.000757

AC:

1107

AN:

1461690

Hom.:

Cov.:

AF XY:

0.000773

AC XY:

562

AN XY:

727132

show subpopulations

African (AFR)

AF:

0.0000299

AC:

AN:

33480

American (AMR)

AF:

0.00

AC:

AN:

44724

Ashkenazi Jewish (ASJ)

AF:

0.0000383

AC:

AN:

26136

East Asian (EAS)

AF:

0.00

AC:

AN:

39700

South Asian (SAS)

AF:

0.000139

AC:

AN:

86254

European-Finnish (FIN)

AF:

0.0000375

AC:

AN:

53400

Middle Eastern (MID)

AF:

0.00

AC:

AN:

5768

European-Non Finnish (NFE)

AF:

0.000950

AC:

1056

AN:

1111856

Other (OTH)

AF:

0.000580

AC:

AN:

60372

Allele Balance Distribution

Red line indicates average allele balance

Average allele balance: 0.485

Heterozygous variant carriers

131

196

262

327

0.00

0.20

0.40

0.60

0.80

0.95

Allele balance

Age Distribution

Exome Het

Variant carriers

108

144

180

<30

30-35

35-40

40-45

45-50

50-55

55-60

60-65

65-70

70-75

75-80

>80

Age

GnomAD4 genome

AF:

0.000559

AC:

AN:

152142

Hom.:

Cov.:

AF XY:

0.000497

AC XY:

AN XY:

74388

show subpopulations

African (AFR)

AF:

0.000241

AC:

AN:

41474

American (AMR)

AF:

0.000392

AC:

AN:

15292

Ashkenazi Jewish (ASJ)

AF:

0.00

AC:

AN:

3468

East Asian (EAS)

AF:

0.00

AC:

AN:

5178

South Asian (SAS)

AF:

0.00

AC:

AN:

4812

European-Finnish (FIN)

AF:

0.00

AC:

AN:

10614

Middle Eastern (MID)

AF:

0.00

AC:

AN:

292

European-Non Finnish (NFE)

AF:

0.000985

AC:

AN:

67998

Other (OTH)

AF:

0.000951

AC:

AN:

2104

Allele Balance Distribution

Red line indicates average allele balance

Average allele balance: 0.507

Heterozygous variant carriers

0.00

0.20

0.40

0.60

0.80

0.95

Allele balance

Age Distribution

Genome Het

Variant carriers

<30

30-35

35-40

40-45

45-50

50-55

55-60

60-65

65-70

70-75

75-80

>80

Age

Alfa

AF:

0.000926

Hom.:

Bravo

AF:

0.000529

TwinsUK

AF:

0.00270

AC:

ALSPAC

AF:

0.00130

AC:

ESP6500AA

AF:

0.000460

AC:

ESP6500EA

AF:

0.00105

AC:

ExAC

AF:

0.000701

AC:

EpiCase

AF:

0.00120

EpiControl

AF:

0.00124

ClinVar

ClinVar submissions

Significance:Conflicting classifications of pathogenicity

Revision:criteria provided, conflicting classifications

View on ClinVar

Pathogenic

VUS

Benign

Condition

not provided (5)

not specified (3)

Hyperkalemic periodic paralysis (2)

Congenital myasthenic syndrome 16 (1)

Hypokalemic periodic paralysis, type 2 (1)

Inborn genetic diseases (1)

Paramyotonia congenita of Von Eulenburg (1)

Potassium-aggravated myotonia (1)

Computational scores

Source: dbNSFP v4.9

Name

Calibrated prediction

Score

Prediction

AlphaMissense

Benign

0.34

BayesDel_addAF

Benign

-0.24

BayesDel_noAF

Benign

-0.12

CADD

Benign

(source)

DANN

Benign

0.68

DEOGEN2

Uncertain

0.55

Eigen

Benign

-0.93

Eigen_PC

Benign

-1.0

FATHMM_MKL

Benign

0.69

LIST_S2

Benign

0.38

M_CAP

Uncertain

0.11

MetaRNN

Benign

0.12

MetaSVM

Uncertain

-0.21

MutationAssessor

Benign

-0.065

PhyloP100

0.37

PrimateAI

Benign

0.44

PROVEAN

Benign

-1.2

REVEL

Uncertain

0.38

Sift

Benign

0.24

Sift4G

Benign

0.25

Polyphen

0.16

Vest4

0.28

MutPred

0.79

Gain of disorder (P = 0.013)

MVP

0.59

MPC

0.56

ClinPred

0.016

GERP RS

0.79

Varity_R

0.12

gMVP

0.87

Mutation Taster

=96/4

polymorphism

(source)

Splicing

Name

Calibrated prediction

Score

Prediction

SpliceAI score (max)

0.010

Details are displayed if max score is > 0.2

Find out detailed SpliceAI scores and Pangolin per-transcript scores at spliceailookup.broadinstitute.org

Publications

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Variant summary

Frequency

Consequence

Scores

Clinical Significance

Conservation

Publications

ACMG classification

Variant Effect in Transcripts

RefSeq Transcripts

Ensembl Transcripts

Frequencies

Age Distribution

Age Distribution

ClinVar

Computational scores

Splicing

Publications

Other links and lift over