NM_000334.4:c.403A>C

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.403A>C(p.Met135Leu) variant causes a missense change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.000472 in 1,613,484 control chromosomes in the GnomAD database, including 4 homozygotes. 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. M135T) has been classified as Benign.

Frequency

Genomes: 𝑓 0.00040 ( 0 hom., cov: 32)

Exomes 𝑓: 0.00048 ( 4 hom. )

Consequence

SCN4A
NM_000334.4 missense

Scores

Clinical Significance

Conflicting classifications of pathogenicity criteria provided, conflicting classifications U:2B:8

Conservation

PhyloP100: 1.53

Publications

5 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: 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=0.010896534).

BP6

Variant 17-63972215-T-G is Benign according to our data. Variant chr17-63972215-T-G is described in ClinVar as Conflicting_classifications_of_pathogenicity. ClinVar VariationId is 255852.

BS1

Variant frequency is greater than expected in population mid. GnomAdExome4 allele frequency = 0.000479 (700/1461248) while in subpopulation MID AF = 0.00191 (11/5768). AF 95% confidence interval is 0.00107. There are 4 homozygotes in GnomAdExome4. There are 342 alleles in the male GnomAdExome4 subpopulation. Median coverage is 31. This position passed quality control check.

BS2

High Homozygotes in GnomAdExome4 at 4 AR,AD gene

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.403A>C	p.Met135Leu	missense	Exon 3 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.403A>C	p.Met135Leu	missense	Exon 3 of 24	ENSP00000396320.1	P35499

Frequencies

GnomAD3 genomes

AF:

0.000401

AC:

AN:

152118

Hom.:

Cov.:

show subpopulations

Gnomad AFR

AF:

0.00

Gnomad AMI

AF:

0.00

Gnomad AMR

AF:

0.000327

Gnomad ASJ

AF:

0.00981

Gnomad EAS

AF:

0.00

Gnomad SAS

AF:

0.00

Gnomad FIN

AF:

0.00

Gnomad MID

AF:

0.00

Gnomad NFE

AF:

0.000294

Gnomad OTH

AF:

0.000959

GnomAD2 exomes

AF:

0.000786

AC:

195

AN:

248230

AF XY:

0.000795

show subpopulations

Gnomad AFR exome

AF:

0.00

Gnomad AMR exome

AF:

0.000378

Gnomad ASJ exome

AF:

0.0124

Gnomad EAS exome

AF:

0.00

Gnomad FIN exome

AF:

0.00

Gnomad NFE exome

AF:

0.000409

Gnomad OTH exome

AF:

0.00182

GnomAD4 exome

AF:

0.000479

AC:

700

AN:

1461248

Hom.:

Cov.:

AF XY:

0.000471

AC XY:

342

AN XY:

726874

show subpopulations

African (AFR)

AF:

0.00

AC:

AN:

33476

American (AMR)

AF:

0.000358

AC:

AN:

44632

Ashkenazi Jewish (ASJ)

AF:

0.0130

AC:

339

AN:

26124

East Asian (EAS)

AF:

0.00

AC:

AN:

39700

South Asian (SAS)

AF:

0.00

AC:

AN:

86134

European-Finnish (FIN)

AF:

0.0000187

AC:

AN:

53390

Middle Eastern (MID)

AF:

0.00191

AC:

AN:

5768

European-Non Finnish (NFE)

AF:

0.000245

AC:

272

AN:

1111664

Other (OTH)

AF:

0.00101

AC:

AN:

60360

Allele Balance Distribution

Red line indicates average allele balance

Average allele balance: 0.478

Heterozygous variant carriers

118

157

196

0.00

0.20

0.40

0.60

0.80

0.95

Allele balance

Age Distribution

Exome Het

Exome Hom

Variant carriers

100

<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:

0.000401

AC:

AN:

152236

Hom.:

Cov.:

AF XY:

0.000349

AC XY:

AN XY:

74424

show subpopulations

African (AFR)

AF:

0.00

AC:

AN:

41548

American (AMR)

AF:

0.000327

AC:

AN:

15300

Ashkenazi Jewish (ASJ)

AF:

0.00981

AC:

AN:

3466

East Asian (EAS)

AF:

0.00

AC:

AN:

5176

South Asian (SAS)

AF:

0.00

AC:

AN:

4812

European-Finnish (FIN)

AF:

0.00

AC:

AN:

10622

Middle Eastern (MID)

AF:

0.00

AC:

AN:

294

European-Non Finnish (NFE)

AF:

0.000294

AC:

AN:

67998

Other (OTH)

AF:

0.000949

AC:

AN:

2108

Allele Balance Distribution

Red line indicates average allele balance

Average allele balance: 0.511

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:

0.00103

Hom.:

Bravo

AF:

0.000472

TwinsUK

AF:

0.00

AC:

ALSPAC

AF:

0.000259

AC:

ESP6500AA

AF:

0.00

AC:

ESP6500EA

AF:

0.00141

AC:

ExAC

AF:

0.000759

AC:

EpiCase

AF:

0.000600

EpiControl

AF:

0.000773

ClinVar

ClinVar submissions

Significance:Conflicting classifications of pathogenicity

Revision:criteria provided, conflicting classifications

View on ClinVar

Pathogenic

VUS

Benign

Condition

Hyperkalemic periodic paralysis (2)

not provided (2)

Congenital myasthenic syndrome 16 (1)

Hypokalemic periodic paralysis, type 2 (1)

not specified (1)

Paramyotonia congenita of Von Eulenburg (1)

Potassium-aggravated myotonia (1)

SCN4A-related disorder (1)

Computational scores

Source: dbNSFP v4.9

Name

Calibrated prediction

Score

Prediction

AlphaMissense

Benign

0.11

BayesDel_addAF

Benign

-0.16

BayesDel_noAF

Benign

-0.15

CADD

Benign

(source)

DANN

Benign

0.86

DEOGEN2

Uncertain

0.73

Eigen

Benign

-0.59

Eigen_PC

Benign

-0.41

FATHMM_MKL

Uncertain

0.79

LIST_S2

Benign

0.72

M_CAP

Benign

0.037

MetaRNN

Benign

0.011

MetaSVM

Uncertain

-0.12

MutationAssessor

Benign

0.72

PhyloP100

1.5

PrimateAI

Uncertain

0.49

PROVEAN

Benign

-1.5

REVEL

Uncertain

0.38

Sift

Benign

0.20

Sift4G

Benign

0.96

Polyphen

0.0010

Vest4

0.30

MutPred

0.39

Loss of MoRF binding (P = 0.2129)

MVP

0.77

MPC

0.24

ClinPred

0.015

GERP RS

2.4

Varity_R

0.18

gMVP

0.57

Mutation Taster

=83/17

polymorphism

(source)

Splicing

Name

Calibrated prediction

Score

Prediction

SpliceAI score (max)

0.030

Details are displayed if max score is > 0.2

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

Publications

You must be logged in to view publications. This limit was set because tens of millions (!) of queries from AI bots are generated daily.

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