17-63972790-G-T

Variant summary

Our verdict is Likely benign. The variant received -3 ACMG points: 1P and 4B. PP2BS2

The NM_000334.4(SCN4A):​c.52C>A​(p.Arg18Ser) variant causes a missense change. The variant allele was found at a frequency of 0.000656 in 1,613,516 control chromosomes in the GnomAD database, including 2 homozygotes. 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. R18C) has been classified as Likely benign.

Frequency

Genomes: 𝑓 0.00051 ( 0 hom., cov: 32)
Exomes 𝑓: 0.00067 ( 2 hom. )

Consequence

SCN4A
NM_000334.4 missense

Scores

7
11

Clinical Significance

Conflicting classifications of pathogenicity criteria provided, conflicting classifications U:7B:1

Conservation

PhyloP100: 5.00

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

Genome browser will be placed here

ACMG classification

Classification was made for transcript

Our verdict: Likely_benign. The variant received -3 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.
BS2
High Homozygotes in GnomAdExome4 at 2 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.
GeneTranscriptTagsHGVScHGVSpEffectExon RankProteinUniProt
SCN4A
NM_000334.4
MANE Select
c.52C>Ap.Arg18Ser
missense
Exon 1 of 24NP_000325.4P35499

Ensembl Transcripts

Sel.
GeneTranscriptTagsHGVScHGVSpEffectExon RankProteinUniProt
SCN4A
ENST00000435607.3
TSL:1 MANE Select
c.52C>Ap.Arg18Ser
missense
Exon 1 of 24ENSP00000396320.1P35499
ENSG00000263489
ENST00000577329.1
TSL:3
n.*130C>A
downstream_gene
N/A

Frequencies

GnomAD3 genomes
AF:
0.000506
AC:
77
AN:
152190
Hom.:
0
Cov.:
32
show subpopulations
Gnomad AFR
AF:
0.000145
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:
0.000188
Gnomad MID
AF:
0.00316
Gnomad NFE
AF:
0.000941
Gnomad OTH
AF:
0.000957
GnomAD2 exomes
AF:
0.000384
AC:
95
AN:
247522
AF XY:
0.000446
show subpopulations
Gnomad AFR exome
AF:
0.000131
Gnomad AMR exome
AF:
0.000116
Gnomad ASJ exome
AF:
0.00
Gnomad EAS exome
AF:
0.00
Gnomad FIN exome
AF:
0.0000937
Gnomad NFE exome
AF:
0.000776
Gnomad OTH exome
AF:
0.00
GnomAD4 exome
AF:
0.000672
AC:
982
AN:
1461208
Hom.:
2
Cov.:
33
AF XY:
0.000644
AC XY:
468
AN XY:
726864
show subpopulations
African (AFR)
AF:
0.0000598
AC:
2
AN:
33472
American (AMR)
AF:
0.000134
AC:
6
AN:
44676
Ashkenazi Jewish (ASJ)
AF:
0.0000383
AC:
1
AN:
26118
East Asian (EAS)
AF:
0.0000252
AC:
1
AN:
39694
South Asian (SAS)
AF:
0.00
AC:
0
AN:
86194
European-Finnish (FIN)
AF:
0.000282
AC:
15
AN:
53204
Middle Eastern (MID)
AF:
0.000173
AC:
1
AN:
5766
European-Non Finnish (NFE)
AF:
0.000805
AC:
895
AN:
1111734
Other (OTH)
AF:
0.00101
AC:
61
AN:
60350
Allele Balance Distribution
Red line indicates average allele balance
Average allele balance: 0.472
Heterozygous variant carriers
0
60
120
180
240
300
0.00
0.20
0.40
0.60
0.80
0.95
Allele balance

Age Distribution

Exome Het
Variant carriers
0
34
68
102
136
170
<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:
0.000506
AC:
77
AN:
152308
Hom.:
0
Cov.:
32
AF XY:
0.000483
AC XY:
36
AN XY:
74472
show subpopulations
African (AFR)
AF:
0.000144
AC:
6
AN:
41576
American (AMR)
AF:
0.000131
AC:
2
AN:
15306
Ashkenazi Jewish (ASJ)
AF:
0.00
AC:
0
AN:
3472
East Asian (EAS)
AF:
0.00
AC:
0
AN:
5176
South Asian (SAS)
AF:
0.00
AC:
0
AN:
4826
European-Finnish (FIN)
AF:
0.000188
AC:
2
AN:
10622
Middle Eastern (MID)
AF:
0.00340
AC:
1
AN:
294
European-Non Finnish (NFE)
AF:
0.000941
AC:
64
AN:
68012
Other (OTH)
AF:
0.000947
AC:
2
AN:
2112
Allele Balance Distribution
Red line indicates average allele balance
Average allele balance: 0.489
Heterozygous variant carriers
0
3
7
10
14
17
0.00
0.20
0.40
0.60
0.80
0.95
Allele balance

Age Distribution

Genome Het
Variant carriers
0
2
4
6
8
10
<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:
0.000377
Hom.:
0
Bravo
AF:
0.000382
TwinsUK
AF:
0.00
AC:
0
ALSPAC
AF:
0.000259
AC:
1
ESP6500AA
AF:
0.000236
AC:
1
ESP6500EA
AF:
0.00118
AC:
10
ExAC
AF:
0.000446
AC:
54
EpiCase
AF:
0.000818
EpiControl
AF:
0.000712

ClinVar

ClinVar submissions
Significance:Conflicting classifications of pathogenicity
Revision:criteria provided, conflicting classifications
View on ClinVar
Pathogenic
VUS
Benign
Condition
-
3
1
not provided (4)
-
2
-
not specified (2)
-
1
-
Hyperkalemic periodic paralysis (1)
-
1
-
Paramyotonia congenita of Von Eulenburg;C0238357:Hyperkalemic periodic paralysis;C2750061:Hypokalemic periodic paralysis, type 2;C2931826:Potassium-aggravated myotonia;C3280112:Congenital myasthenic syndrome 16;C3714580:Hypokalemic periodic paralysis, type 1 (1)

Computational scores

Source: dbNSFP v4.9

Name
Calibrated prediction
Score
Prediction
AlphaMissense
Pathogenic
0.66
BayesDel_addAF
Uncertain
0.022
T
BayesDel_noAF
Pathogenic
0.18
CADD
Uncertain
25
DANN
Uncertain
0.99
DEOGEN2
Uncertain
0.74
D
Eigen
Uncertain
0.22
Eigen_PC
Uncertain
0.23
FATHMM_MKL
Pathogenic
0.98
D
LIST_S2
Uncertain
0.90
D
M_CAP
Pathogenic
0.41
D
MetaRNN
Uncertain
0.49
T
MetaSVM
Pathogenic
0.96
D
MutationAssessor
Pathogenic
2.9
M
PhyloP100
5.0
PrimateAI
Uncertain
0.54
T
PROVEAN
Uncertain
-3.7
D
REVEL
Pathogenic
0.67
Sift
Uncertain
0.018
D
Sift4G
Uncertain
0.018
D
Polyphen
0.51
P
Vest4
0.70
MVP
0.88
MPC
0.30
ClinPred
0.12
T
GERP RS
4.5
PromoterAI
-0.0041
Neutral
Varity_R
0.54
gMVP
0.82
Mutation Taster
=92/8
polymorphism

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

Other links and lift over

dbSNP: rs78592515; hg19: chr17-62050150; API