chr17-63948032-C-T

Variant summary

Our verdict is Likely benign. The variant received -1 ACMG points: 1P and 2B. PP2BP4_Moderate

The NM_000334.4(SCN4A):​c.3176G>A​(p.Arg1059Gln) variant causes a missense change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.0000211 in 1,611,386 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a benign outcome for this variant. 16/22 in silico tools predict a benign outcome for this variant. Variant has been reported in ClinVar as Uncertain significance (★★).

Frequency

Genomes: 𝑓 0.000026 ( 0 hom., cov: 33)
Exomes 𝑓: 0.000021 ( 0 hom. )

Consequence

SCN4A
NM_000334.4 missense

Scores

4
15

Clinical Significance

Uncertain significance criteria provided, multiple submitters, no conflicts U:3

Conservation

PhyloP100: 0.222

Publications

0 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

Genome browser will be placed here

ACMG classification

Classification was made for transcript

Our verdict: Likely_benign. The variant received -1 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=0.18422854).

Transcripts

RefSeq

Gene Transcript HGVSc HGVSp Effect Exon rank MANE Protein UniProt
SCN4ANM_000334.4 linkc.3176G>A p.Arg1059Gln missense_variant Exon 17 of 24 ENST00000435607.3 NP_000325.4 P35499

Ensembl

Gene Transcript HGVSc HGVSp Effect Exon rank TSL MANE Protein Appris UniProt
SCN4AENST00000435607.3 linkc.3176G>A p.Arg1059Gln missense_variant Exon 17 of 24 1 NM_000334.4 ENSP00000396320.1 P35499
SCN4AENST00000584310.1 linkn.499G>A non_coding_transcript_exon_variant Exon 3 of 3 4

Frequencies

GnomAD3 genomes
AF:
0.0000263
AC:
4
AN:
152212
Hom.:
0
Cov.:
33
show subpopulations
Gnomad AFR
AF:
0.0000241
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:
0.0000147
Gnomad OTH
AF:
0.00
GnomAD2 exomes
AF:
0.0000403
AC:
10
AN:
248266
AF XY:
0.0000371
show subpopulations
Gnomad AFR exome
AF:
0.00
Gnomad AMR exome
AF:
0.00
Gnomad ASJ exome
AF:
0.00
Gnomad EAS exome
AF:
0.00
Gnomad FIN exome
AF:
0.00
Gnomad NFE exome
AF:
0.0000889
Gnomad OTH exome
AF:
0.00
GnomAD4 exome
AF:
0.0000206
AC:
30
AN:
1459174
Hom.:
0
Cov.:
32
AF XY:
0.0000262
AC XY:
19
AN XY:
725490
show subpopulations
African (AFR)
AF:
0.0000299
AC:
1
AN:
33428
American (AMR)
AF:
0.00
AC:
0
AN:
44622
Ashkenazi Jewish (ASJ)
AF:
0.00
AC:
0
AN:
26066
East Asian (EAS)
AF:
0.00
AC:
0
AN:
39588
South Asian (SAS)
AF:
0.00
AC:
0
AN:
86096
European-Finnish (FIN)
AF:
0.0000375
AC:
2
AN:
53372
Middle Eastern (MID)
AF:
0.00
AC:
0
AN:
5754
European-Non Finnish (NFE)
AF:
0.0000216
AC:
24
AN:
1109996
Other (OTH)
AF:
0.0000498
AC:
3
AN:
60252
Allele Balance Distribution
Red line indicates average allele balance
Average allele balance: 0.512
Heterozygous variant carriers
0
2
4
5
7
9
0.00
0.20
0.40
0.60
0.80
0.95
Allele balance

Age Distribution

Exome 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
GnomAD4 genome
AF:
0.0000263
AC:
4
AN:
152212
Hom.:
0
Cov.:
33
AF XY:
0.0000269
AC XY:
2
AN XY:
74350
show subpopulations
⚠️ The allele balance in gnomAD version 4 Genomes is significantly skewed from the expected value of 0.5.
African (AFR)
AF:
0.0000241
AC:
1
AN:
41442
American (AMR)
AF:
0.000131
AC:
2
AN:
15288
Ashkenazi Jewish (ASJ)
AF:
0.00
AC:
0
AN:
3472
East Asian (EAS)
AF:
0.00
AC:
0
AN:
5204
South Asian (SAS)
AF:
0.00
AC:
0
AN:
4834
European-Finnish (FIN)
AF:
0.00
AC:
0
AN:
10620
Middle Eastern (MID)
AF:
0.00
AC:
0
AN:
316
European-Non Finnish (NFE)
AF:
0.0000147
AC:
1
AN:
68034
Other (OTH)
AF:
0.00
AC:
0
AN:
2090
⚠️ The allele balance in gnomAD version 4 Genomes is significantly skewed from the expected value of 0.5. (p-value = 0.000018), which strongly suggests a high chance of mosaicism in these individuals.
Allele Balance Distribution
Red line indicates average allele balance
Average allele balance: 0.388
Heterozygous variant carriers
0
1
1
2
2
3
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:
0.0000450
Hom.:
0
Bravo
AF:
0.0000340
ExAC
AF:
0.0000165
AC:
2
EpiCase
AF:
0.00
EpiControl
AF:
0.0000595

ClinVar

Significance: Uncertain significance
Submissions summary: Uncertain:3
Revision: criteria provided, multiple submitters, no conflicts
LINK: link

Submissions by phenotype

not provided Uncertain:2
Feb 28, 2024
Athena Diagnostics
Significance:Uncertain significance
Review Status:criteria provided, single submitter
Collection Method:clinical testing

Available data are insufficient to determine the clinical significance of the variant at this time. The frequency of this variant in the general population is higher than would generally be expected for pathogenic variants in this gene. (http://gnomad.broadinstitute.org) Computational tools predict that this variant is not damaging. -

Jul 28, 2020
Revvity Omics, Revvity
Significance:Uncertain significance
Review Status:criteria provided, single submitter
Collection Method:clinical testing

- -

Familial hyperkalemic periodic paralysis Uncertain:1
Feb 09, 2024
Labcorp Genetics (formerly Invitae), Labcorp
Significance:Uncertain significance
Review Status:criteria provided, single submitter
Collection Method:clinical testing

This sequence change replaces arginine, which is basic and polar, with glutamine, which is neutral and polar, at codon 1059 of the SCN4A protein (p.Arg1059Gln). This variant is present in population databases (rs749433088, gnomAD 0.008%). This variant has not been reported in the literature in individuals affected with SCN4A-related conditions. ClinVar contains an entry for this variant (Variation ID: 477413). Advanced modeling of protein sequence and biophysical properties (such as structural, functional, and spatial information, amino acid conservation, physicochemical variation, residue mobility, and thermodynamic stability) performed at Invitae indicates that this missense variant is not expected to disrupt SCN4A protein function with a negative predictive value of 95%. In summary, the available evidence is currently insufficient to determine the role of this variant in disease. Therefore, it has been classified as a Variant of Uncertain Significance. -

Computational scores

Source: dbNSFP v4.3

Name
Calibrated prediction
Score
Prediction
AlphaMissense
Benign
0.079
BayesDel_addAF
Benign
-0.11
T
BayesDel_noAF
Benign
-0.20
CADD
Benign
18
DANN
Uncertain
1.0
DEOGEN2
Uncertain
0.78
D
Eigen
Benign
-0.89
Eigen_PC
Benign
-0.89
FATHMM_MKL
Benign
0.042
N
LIST_S2
Uncertain
0.91
D
M_CAP
Benign
0.074
D
MetaRNN
Benign
0.18
T
MetaSVM
Uncertain
-0.010
T
MutationAssessor
Benign
0.89
L
PhyloP100
0.22
PrimateAI
Benign
0.41
T
PROVEAN
Benign
-1.9
N
REVEL
Benign
0.18
Sift
Benign
0.045
D
Sift4G
Benign
0.14
T
Polyphen
0.0050
B
Vest4
0.42
MutPred
0.39
Gain of helix (P = 0.0696);
MVP
0.56
MPC
0.30
ClinPred
0.052
T
GERP RS
-1.1
Varity_R
0.31
gMVP
0.37
Mutation Taster
=93/7
polymorphism

Splicing

Name
Calibrated prediction
Score
Prediction
SpliceAI score (max)
0.040
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: rs749433088; hg19: chr17-62025392; API