rs781412058
Variant summary
Our verdict is Likely pathogenic. The variant received 6 ACMG points: 7P and 1B. PM1PP2PP3_StrongBS1_Supporting
The NM_000334.4(SCN4A):c.1926G>T(p.Trp642Cys) variant causes a missense change involving the alteration of a conserved nucleotide. The variant allele was found at a frequency of 0.0000397 in 1,613,860 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a pathogenic outcome for this variant. 13/22 in silico tools predict a damaging outcome for this variant. Variant has been reported in ClinVar as Uncertain significance (★★).
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: Likely_pathogenic. The variant received 6 ACMG points.
Transcripts
RefSeq
Ensembl
Frequencies
GnomAD3 genomes AF: 0.000263 AC: 40AN: 152192Hom.: 0 Cov.: 32 show subpopulations
GnomAD2 exomes AF: 0.0000602 AC: 15AN: 249176 AF XY: 0.0000518 show subpopulations
GnomAD4 exome AF: 0.0000164 AC: 24AN: 1461668Hom.: 0 Cov.: 32 AF XY: 0.0000151 AC XY: 11AN XY: 727116 show subpopulations
Age Distribution
GnomAD4 genome AF: 0.000263 AC: 40AN: 152192Hom.: 0 Cov.: 32 AF XY: 0.000417 AC XY: 31AN XY: 74358 show subpopulations
Age Distribution
ClinVar
Submissions by phenotype
not provided Uncertain:2
In silico analysis supports that this missense variant has a deleterious effect on protein structure/function; Has not been previously published as pathogenic or benign to our knowledge -
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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;C5830453:Congenital myopathy 22A, classic;C5830501:Congenital myopathy 22B, severe fetal Uncertain:1
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Familial hyperkalemic periodic paralysis Uncertain:1
This sequence change replaces tryptophan, which is neutral and slightly polar, with cysteine, which is neutral and slightly polar, at codon 642 of the SCN4A protein (p.Trp642Cys). This variant is present in population databases (rs781412058, gnomAD 0.04%). 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: 575671). 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 expected to disrupt SCN4A protein function with a positive 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:
Splicing
Find out detailed SpliceAI scores and Pangolin per-transcript scores at