NM_000334.4:c.154C>T

Variant names:

Variant summary

Our verdict is Benign. The variant received -12 ACMG points: 1P and 13B. PP2BP4_StrongBP6BS1BS2

The NM_000334.4(SCN4A):c.154C>T(p.Arg52Trp) variant causes a missense change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.000474 in 1,613,644 control chromosomes in the GnomAD database, including 8 homozygotes. In-silico tool predicts a benign outcome for this variant. 12/21 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. R52Q) has been classified as Uncertain significance.

Frequency

Genomes: 𝑓 0.0024 ( 6 hom., cov: 32)

Exomes 𝑓: 0.00027 ( 2 hom. )

Consequence

SCN4A
NM_000334.4 missense

Scores

Clinical Significance

Conflicting classifications of pathogenicity criteria provided, conflicting classifications U:1B:3

Conservation

PhyloP100: 1.49

Publications

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

ENSG00000263489 (HGNC:):

ENSG00000263489 links:

Genome browser will be placed here

ACMG classification

Classification was made for transcript

Our verdict: Benign. The variant received -12 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=0.007462889).

BP6

Variant 17-63972688-G-A is Benign according to our data. Variant chr17-63972688-G-A is described in ClinVar as Conflicting_classifications_of_pathogenicity. ClinVar VariationId is 477399.

BS1

Variant frequency is greater than expected in population afr. GnomAd4 allele frequency = 0.00244 (371/152258) while in subpopulation AFR AF = 0.00814 (338/41546). AF 95% confidence interval is 0.00742. There are 6 homozygotes in GnomAd4. There are 175 alleles in the male GnomAd4 subpopulation. Median coverage is 32. This position passed quality control check.

BS2

High Homozygotes in GnomAd4 at 6 AR,AD gene

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	MANE	Protein	UniProt
SCN4A	NM_000334.4 link	c.154C>T	p.Arg52Trp	missense_variant	Exon 1 of 24	ENST00000435607.3	NP_000325.4	P35499

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	TSL	MANE	Protein	Appris	UniProt
SCN4A	ENST00000435607.3 link	c.154C>T	p.Arg52Trp	missense_variant	Exon 1 of 24	1	NM_000334.4	ENSP00000396320.1		P35499
ENSG00000263489	ENST00000577329.1 link	n.*232C>T		downstream_gene_variant		3

Frequencies

GnomAD3 genomes

AF:

0.00244

AC:

371

AN:

152140

Hom.:

Cov.:

show subpopulations

Gnomad AFR

AF:

0.00816

Gnomad AMI

AF:

0.00

Gnomad AMR

AF:

0.00111

Gnomad ASJ

AF:

0.00

Gnomad EAS

AF:

0.000193

Gnomad SAS

AF:

0.000207

Gnomad FIN

AF:

0.00

Gnomad MID

AF:

0.00633

Gnomad NFE

AF:

0.0000294

Gnomad OTH

AF:

0.00479

GnomAD2 exomes

AF:

0.000725

AC:

180

AN:

248422

AF XY:

0.000594

show subpopulations

Gnomad AFR exome

AF:

0.0101

Gnomad AMR exome

AF:

0.000610

Gnomad ASJ exome

AF:

0.00

Gnomad EAS exome

AF:

0.0000557

Gnomad FIN exome

AF:

0.00

Gnomad NFE exome

AF:

0.00000888

Gnomad OTH exome

AF:

0.000166

GnomAD4 exome

AF:

0.000270

AC:

394

AN:

1461386

Hom.:

Cov.:

AF XY:

0.000239

AC XY:

174

AN XY:

726942

show subpopulations

African (AFR)

AF:

0.00917

AC:

307

AN:

33474

American (AMR)

AF:

0.000604

AC:

AN:

44674

Ashkenazi Jewish (ASJ)

AF:

0.00

AC:

AN:

26132

East Asian (EAS)

AF:

0.00

AC:

AN:

39692

South Asian (SAS)

AF:

0.00

AC:

AN:

86182

European-Finnish (FIN)

AF:

0.00

AC:

AN:

53366

Middle Eastern (MID)

AF:

0.000173

AC:

AN:

5768

European-Non Finnish (NFE)

AF:

0.0000162

AC:

AN:

1111748

Other (OTH)

AF:

0.000679

AC:

AN:

60350

Allele Balance Distribution

Red line indicates average allele balance

Average allele balance: 0.478

Heterozygous variant carriers

105

131

0.00

0.20

0.40

0.60

0.80

0.95

Allele balance

Age Distribution

Exome Het

Exome Hom

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

GnomAD4 genome

AF:

0.00244

AC:

371

AN:

152258

Hom.:

Cov.:

AF XY:

0.00235

AC XY:

175

AN XY:

74436

show subpopulations

African (AFR)

AF:

0.00814

AC:

338

AN:

41546

American (AMR)

AF:

0.00111

AC:

AN:

15304

Ashkenazi Jewish (ASJ)

AF:

0.00

AC:

AN:

3468

East Asian (EAS)

AF:

0.000193

AC:

AN:

5182

South Asian (SAS)

AF:

0.000207

AC:

AN:

4830

European-Finnish (FIN)

AF:

0.00

AC:

AN:

10598

Middle Eastern (MID)

AF:

0.00680

AC:

AN:

294

European-Non Finnish (NFE)

AF:

0.0000294

AC:

AN:

68014

Other (OTH)

AF:

0.00474

AC:

AN:

2110

Allele Balance Distribution

Red line indicates average allele balance

Average allele balance: 0.497

Heterozygous variant carriers

103

0.00

0.20

0.40

0.60

0.80

0.95

Allele balance

Age Distribution

Genome Het

Genome Hom

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:

0.000907

Hom.:

Bravo

AF:

0.00290

ESP6500AA

AF:

0.00745

AC:

ESP6500EA

AF:

0.00

AC:

ExAC

AF:

0.000818

AC:

Asia WGS

AF:

0.000866

AC:

AN:

3478

EpiCase

AF:

0.00

EpiControl

AF:

0.0000594

ClinVar

Significance: Conflicting classifications of pathogenicity

Submissions summary: Uncertain:1Benign:3

Revision: criteria provided, conflicting classifications

LINK: link

Submissions by phenotype

Congenital myasthenic syndrome 16

Uncertain:1

Sep 01, 2017

Baylor Genetics

Significance:Uncertain significance

Review Status:criteria provided, single submitter

Collection Method:clinical testing

Possible pathogenicity based on finding it once in our laboratory in trans with another variant [p.R3T] in a 1-year-old female with congenital hypotonia, proximal weakness, mixed developmental disorder, congenital myasthenia gravis, GERD, failure to thrive. Variant has also been seen in others in combination with additional variants (phase unknown) but without features of this syndrome. -

not specified

Benign:1

May 22, 2017

GeneDx

Significance:Benign

Review Status:criteria provided, single submitter

Collection Method:clinical testing

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. -

not provided

Benign:1

Feb 01, 2018

Athena Diagnostics

Significance:Benign

Review Status:criteria provided, single submitter

Collection Method:clinical testing

- -

Familial hyperkalemic periodic paralysis

Benign:1

Jan 30, 2025

Labcorp Genetics (formerly Invitae), Labcorp

Significance:Benign

Review Status:criteria provided, single submitter

Collection Method:clinical testing

- -

Computational scores

Source: dbNSFP v4.3

Name

Calibrated prediction

Score

Prediction

AlphaMissense

Benign

0.11

BayesDel_addAF

Benign

-0.23

BayesDel_noAF

Benign

-0.10

CADD

Benign

(source)

DANN

Uncertain

1.0

DEOGEN2

Uncertain

0.47

Eigen

Benign

-0.26

Eigen_PC

Benign

-0.39

FATHMM_MKL

Benign

0.40

LIST_S2

Uncertain

0.91

MetaRNN

Benign

0.0075

MetaSVM

Uncertain

0.27

MutationAssessor

Uncertain

2.1

PhyloP100

1.5

PrimateAI

Benign

0.36

PROVEAN

Benign

-2.1

REVEL

Uncertain

0.34

Sift

Uncertain

0.0010

Sift4G

Uncertain

0.015

Polyphen

0.89

Vest4

0.30

MVP

0.85

MPC

0.31

ClinPred

0.042

GERP RS

-0.71

PromoterAI

-0.047

Neutral

(source)

Varity_R

0.10

gMVP

0.44

Mutation Taster

=99/1

polymorphism

(source)

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

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Variant summary

Frequency

Consequence

Scores

Clinical Significance

Conservation

Publications

ACMG classification

Transcripts

RefSeq

Ensembl

Frequencies

Age Distribution

Age Distribution

ClinVar

Submissions by phenotype

Computational scores

Splicing

Publications

Other links and lift over