NM_000334.4:c.2015G>A
Variant summary
Our verdict is Pathogenic. The variant received 19 ACMG points: 19P and 0B. PM1PM2PM5PP2PP3_StrongPP5_Very_Strong
The NM_000334.4(SCN4A):c.2015G>A(p.Arg672His) variant causes a missense change. The variant allele was found at a frequency of 0.00000343 in 1,458,254 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a pathogenic outcome for this variant. Variant has been reported in ClinVar as Pathogenic (★★). Another variant affecting the same amino acid position, but resulting in a different missense (i.e. R672C) has been classified as Pathogenic.
Frequency
Consequence
NM_000334.4 missense
Scores
Clinical Significance
Conservation
Publications
- hyperkalemic periodic paralysisInheritance: AD Classification: DEFINITIVE, STRONG, SUPPORTIVE Submitted by: Genomics England PanelApp, Labcorp Genetics (formerly Invitae), G2P, Orphanet
- paramyotonia congenita of Von EulenburgInheritance: AD Classification: DEFINITIVE, STRONG, SUPPORTIVE Submitted by: Laboratory for Molecular Medicine, Genomics England PanelApp, Labcorp Genetics (formerly Invitae), G2P, Orphanet
- SCN4A-related myopathy, autosomal recessiveInheritance: AR Classification: DEFINITIVE Submitted by: Illumina, ClinGen
- hypokalemic periodic paralysis, type 2Inheritance: AD Classification: STRONG Submitted by: Genomics England PanelApp, Labcorp Genetics (formerly Invitae)
- potassium-aggravated myotoniaInheritance: AD Classification: STRONG Submitted by: Labcorp Genetics (formerly Invitae)
- congenital myasthenic syndrome 16Inheritance: AR Classification: STRONG, LIMITED Submitted by: PanelApp Australia, Ambry Genetics, Genomics England PanelApp, Labcorp Genetics (formerly Invitae)
- congenital myopathyInheritance: AR Classification: STRONG Submitted by: Genomics England PanelApp
- congenital myopathy 22A, classicInheritance: AR Classification: STRONG Submitted by: Labcorp Genetics (formerly Invitae)
- acetazolamide-responsive myotoniaInheritance: AD Classification: SUPPORTIVE Submitted by: Orphanet
- hypokalemic periodic paralysisInheritance: AD Classification: SUPPORTIVE Submitted by: Orphanet
- myotonia fluctuansInheritance: AD Classification: SUPPORTIVE Submitted by: Orphanet
- myotonia permanensInheritance: AD Classification: SUPPORTIVE Submitted by: Orphanet
- postsynaptic congenital myasthenic syndromeInheritance: AR Classification: SUPPORTIVE Submitted by: Orphanet
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ACMG classification
Our verdict: Pathogenic. The variant received 19 ACMG points.
Transcripts
RefSeq
| Gene | Transcript | HGVSc | HGVSp | Effect | Exon rank | MANE | Protein | UniProt |
|---|---|---|---|---|---|---|---|---|
| SCN4A | NM_000334.4 | c.2015G>A | p.Arg672His | missense_variant | Exon 12 of 24 | ENST00000435607.3 | NP_000325.4 |
Ensembl
Frequencies
GnomAD3 genomes Cov.: 32
GnomAD2 exomes AF: 0.0000121 AC: 3AN: 247856 AF XY: 0.00000744 show subpopulations
GnomAD4 exome AF: 0.00000343 AC: 5AN: 1458254Hom.: 0 Cov.: 32 AF XY: 0.00000414 AC XY: 3AN XY: 724910 show subpopulations
Age Distribution
GnomAD4 genome Cov.: 32
ClinVar
Submissions by phenotype
Familial hyperkalemic periodic paralysis Pathogenic:3Other:1
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This sequence change replaces arginine, which is basic and polar, with histidine, which is basic and polar, at codon 672 of the SCN4A protein (p.Arg672His). This variant is present in population databases (rs80338788, gnomAD 0.005%). This missense change has been observed in individual(s) with hypokalemic periodic paralysis (PMID: 10944223, 14504341, 15596759, 19225109, 22253645, 23019082, 25213595). It has also been observed to segregate with disease in related individuals. ClinVar contains an entry for this variant (Variation ID: 5912). Invitae Evidence Modeling of protein sequence and biophysical properties (such as structural, functional, and spatial information, amino acid conservation, physicochemical variation, residue mobility, and thermodynamic stability) indicates that this missense variant is expected to disrupt SCN4A protein function with a positive predictive value of 95%. Experimental studies have shown that this missense change affects SCN4A function (PMID: 10944223, 11912116, 18824591). This variant disrupts the p.Arg672 amino acid residue in SCN4A. Other variant(s) that disrupt this residue have been determined to be pathogenic (PMID: 10944223, 11558801, 11912116, 15482957, 17330043, 18824591, 19225109, 20660662, 25024265, 26252573). This suggests that this residue is clinically significant, and that variants that disrupt this residue are likely to be disease-causing. For these reasons, this variant has been classified as Pathogenic. -
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not provided Pathogenic:3
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SCN4A: PM1, PM2, PM5, PS4:Moderate, PP3, PS3:Supporting -
Published functional studies show that this variant alters channel inactivation and decreases current density, thus reducing the number of excitable channels during membrane depolarization (PMID: 20660662, 10944223); In silico analysis supports that this missense variant has a deleterious effect on protein structure/function; Not observed at significant frequency in large population cohorts (gnomAD); This variant is associated with the following publications: (PMID: 18824591, 26252573, 20301669, 32619119, 23019082, 19225109, 10944223, 20301512, 25024265, 33144682, 33389921, 36796140, 36779057, 20660662, 34608571, 25213595, 38609989) -
Hypokalemic periodic paralysis, type 2 Pathogenic:1Other:1
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Paramyotonia congenita of Von Eulenburg Pathogenic:1
PS4,PS3,PM2,PP3 -
Acetazolamide-responsive myotonia Pathogenic:1
Variant summary: SCN4A c.2015G>A (p.Arg672His) results in a non-conservative amino acid change located in the Ion transport domain (IPR005821) of the encoded protein sequence. Four of five in-silico tools predict a damaging effect of the variant on protein function. The variant allele was found at a frequency of 1.2e-05 in 247856 control chromosomes (gnomAD). c.2015G>A has been reported in the literature in multiple individuals affected with Hypokalaemic periodic paralysis (Jurkat-Rott_2000, Horga_2013). These data indicate that the variant is very likely to be associated with disease. Functional studies reported this variant affects SCN4A protein function (Jurkat-Rott_2000, Struyk_2008, Sokolov_2010). The following publications have been ascertained in the context of this evaluation (PMID: 23516313, 10944223, 20660662, 17591984). Six submitters have cited clinical-significance assessments for this variant to ClinVar after 2014. All submitters classified the variant as pathogenic. Based on the evidence outlined above, the variant was classified as pathogenic. -
Paramyotonia congenita of Von Eulenburg;C0238357:Familial hyperkalemic periodic paralysis;C2750061:Hypokalemic periodic paralysis, type 2;C2931826:Potassium-aggravated myotonia;C3280112:Congenital myasthenic syndrome 16;C3714580:Hypokalemic periodic paralysis, type 1 Pathogenic:1
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Computational scores
Source:
Splicing
Find out detailed SpliceAI scores and Pangolin per-transcript scores at