rs766365683
Variant summary
Our verdict is Uncertain significance. The variant received 3 ACMG points: 3P and 0B. PM1PP2
The NM_000334.4(SCN4A):c.5126A>G(p.Asn1709Ser) variant causes a missense change involving the alteration of a conserved nucleotide. The variant allele was found at a frequency of 0.0000186 in 1,613,460 control chromosomes in the GnomAD database, with no homozygous occurrence. Variant has been reported in ClinVar as Uncertain significance (★★). Another variant affecting the same amino acid position, but resulting in a different missense (i.e. N1709K) has been classified 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: Uncertain_significance. The variant received 3 ACMG points.
Transcripts
RefSeq
Ensembl
Frequencies
GnomAD3 genomes AF: 0.0000395 AC: 6AN: 151766Hom.: 0 Cov.: 32 show subpopulations
GnomAD2 exomes AF: 0.0000642 AC: 16AN: 249186 AF XY: 0.0000296 show subpopulations
GnomAD4 exome AF: 0.0000164 AC: 24AN: 1461694Hom.: 0 Cov.: 30 AF XY: 0.00000963 AC XY: 7AN XY: 727132 show subpopulations
Age Distribution
GnomAD4 genome AF: 0.0000395 AC: 6AN: 151766Hom.: 0 Cov.: 32 AF XY: 0.0000675 AC XY: 5AN XY: 74118 show subpopulations
Age Distribution
ClinVar
Submissions by phenotype
not provided Uncertain:4
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In silico analysis supports that this missense variant has a deleterious effect on protein structure/function; This variant is associated with the following publications: (PMID: 32670189) -
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). This variant is statistically more frequent in the patient population than in the general population, which is weak evidence this variant may be disease causing. This variant has been identified in at least one individual with clinical features of myotonia. Computational tools disagree on the variant's effect on normal protein function. -
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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 asparagine, which is neutral and polar, with serine, which is neutral and polar, at codon 1709 of the SCN4A protein (p.Asn1709Ser). This variant is present in population databases (rs766365683, gnomAD 0.05%). This missense change has been observed in individual(s) with myotonia (PMID: 32670189). ClinVar contains an entry for this variant (Variation ID: 448286). 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 80%. 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