rs748828476

Variant summary

Our verdict is Likely benign. The variant received -5 ACMG points: 0P and 5B. BP4_StrongBP6

The NM_000334.4(SCN4A):​c.703+6G>A variant causes a splice region, intron change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.00000516 in 1,550,352 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a benign outcome for this variant. 3/3 splice prediction tools predict no significant impact on normal splicing. Variant has been reported in ClinVar as Conflicting classifications of pathogenicity (no stars).

Frequency

Genomes: 𝑓 0.0000066 ( 0 hom., cov: 31)
Exomes 𝑓: 0.0000050 ( 0 hom. )

Consequence

SCN4A
NM_000334.4 splice_region, intron

Scores

2
Splicing: ADA: 0.001209
2

Clinical Significance

Conflicting classifications of pathogenicity criteria provided, conflicting classifications U:1B:2

Conservation

PhyloP100: -0.0930

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 -5 ACMG points.

BP4
Computational evidence support a benign effect (BayesDel_noAF=-0.62).
BP6
Variant 17-63971156-C-T is Benign according to our data. Variant chr17-63971156-C-T is described in ClinVar as Conflicting_classifications_of_pathogenicity. ClinVar VariationId is 255861.

Transcripts

RefSeq

Gene Transcript HGVSc HGVSp Effect Exon rank MANE Protein UniProt
SCN4ANM_000334.4 linkc.703+6G>A splice_region_variant, intron_variant Intron 5 of 23 ENST00000435607.3 NP_000325.4 P35499

Ensembl

Gene Transcript HGVSc HGVSp Effect Exon rank TSL MANE Protein Appris UniProt
SCN4AENST00000435607.3 linkc.703+6G>A splice_region_variant, intron_variant Intron 5 of 23 1 NM_000334.4 ENSP00000396320.1 P35499

Frequencies

GnomAD3 genomes
AF:
0.00000657
AC:
1
AN:
152240
Hom.:
0
Cov.:
31
show subpopulations
Gnomad AFR
AF:
0.00
Gnomad AMI
AF:
0.00
Gnomad AMR
AF:
0.00
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:
0.0000185
AC:
3
AN:
162240
AF XY:
0.00
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:
0.0000466
Gnomad OTH exome
AF:
0.00
GnomAD4 exome
AF:
0.00000501
AC:
7
AN:
1398112
Hom.:
0
Cov.:
32
AF XY:
0.00000290
AC XY:
2
AN XY:
690362
show subpopulations
African (AFR)
AF:
0.00
AC:
0
AN:
31792
American (AMR)
AF:
0.00
AC:
0
AN:
36196
Ashkenazi Jewish (ASJ)
AF:
0.00
AC:
0
AN:
25180
East Asian (EAS)
AF:
0.00
AC:
0
AN:
36124
South Asian (SAS)
AF:
0.00
AC:
0
AN:
79356
European-Finnish (FIN)
AF:
0.00
AC:
0
AN:
49488
Middle Eastern (MID)
AF:
0.000176
AC:
1
AN:
5690
European-Non Finnish (NFE)
AF:
0.00000465
AC:
5
AN:
1076260
Other (OTH)
AF:
0.0000172
AC:
1
AN:
58026
Allele Balance Distribution
Red line indicates average allele balance
Average allele balance: 0.496
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

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:
0.00000657
AC:
1
AN:
152240
Hom.:
0
Cov.:
31
AF XY:
0.00
AC XY:
0
AN XY:
74364
show subpopulations
⚠️ The allele balance in gnomAD version 4 Genomes is significantly skewed from the expected value of 0.5.
African (AFR)
AF:
0.00
AC:
0
AN:
41464
American (AMR)
AF:
0.00
AC:
0
AN:
15292
Ashkenazi Jewish (ASJ)
AF:
0.00
AC:
0
AN:
3472
East Asian (EAS)
AF:
0.00
AC:
0
AN:
5190
South Asian (SAS)
AF:
0.00
AC:
0
AN:
4834
European-Finnish (FIN)
AF:
0.00
AC:
0
AN:
10622
Middle Eastern (MID)
AF:
0.00
AC:
0
AN:
316
European-Non Finnish (NFE)
AF:
0.0000147
AC:
1
AN:
68044
Other (OTH)
AF:
0.00
AC:
0
AN:
2094
⚠️ The allele balance in gnomAD version 4 Genomes is significantly skewed from the expected value of 0.5. (p-value = 0), which strongly suggests a high chance of mosaicism in these individuals.
Allele Balance Distribution
Red line indicates average allele balance
Average allele balance: 0.375
Heterozygous variant carriers
0
0
1
1
2
2
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:
0.0000312
Hom.:
0
Bravo
AF:
0.0000151

ClinVar

Significance: Conflicting classifications of pathogenicity
Submissions summary: Uncertain:1Benign:2
Revision: criteria provided, conflicting classifications
LINK: link

Submissions by phenotype

Familial hyperkalemic periodic paralysis Uncertain:1
Jan 04, 2024
Labcorp Genetics (formerly Invitae), Labcorp
Significance:Uncertain significance
Review Status:criteria provided, single submitter
Collection Method:clinical testing

This sequence change falls in intron 5 of the SCN4A gene. It does not directly change the encoded amino acid sequence of the SCN4A protein. It affects a nucleotide within the consensus splice site. The frequency data for this variant in the population databases is considered unreliable, as metrics indicate poor data quality at this position in the gnomAD database. 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: 255861). Variants that disrupt the consensus splice site are a relatively common cause of aberrant splicing (PMID: 17576681, 9536098). Algorithms developed to predict the effect of sequence changes on RNA splicing suggest that this variant is not likely to affect RNA splicing. 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. -

not specified Benign:1
-
PreventionGenetics, part of Exact Sciences
Significance:Likely benign
Review Status:criteria provided, single submitter
Collection Method:clinical testing

- -

not provided Benign:1
-
Breakthrough Genomics, Breakthrough Genomics
Significance:Likely benign
Review Status:criteria provided, single submitter
Collection Method:not provided

- -

Computational scores

Source: dbNSFP v4.3

Name
Calibrated prediction
Score
Prediction
BayesDel_noAF
Benign
-0.62
CADD
Benign
14
DANN
Benign
0.81
PhyloP100
-0.093

Splicing

Name
Calibrated prediction
Score
Prediction
dbscSNV1_ADA
Benign
0.0012
dbscSNV1_RF
Benign
0.022
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: rs748828476; hg19: chr17-62048516; COSMIC: COSV104713786; COSMIC: COSV104713786; API