SCN4A (Nav1.4) variants and mutations

SCN4A (also known as Nav1.4) is a human protein-coding gene encoding a sodium channel protein type 4 subunit alpha protein. Its rapid sodium current initiates and propagates skeletal-muscle action potentials. Gain- and loss-of-function variants cause disorders of muscle excitability including sodium-channel myotonia, paramyotonia congenita, periodic paralysis, and some congenital myopathies. This analysis covers 3,238 SCN4A variants and mutations. Of these, 73% have computational variant effect predictions. Disease context includes paramyotonia congenita of Von Eulenburg, hyperkalemic periodic paralysis, and potassium-aggravated myotonia. Example SCN4A variants include M1?, A2P, and A2T.

Variant analysis overview

Variant and mutation evidence

Clinical, disease, and population context

Protein structure and variant hotspots

Data sources

Evidence in this analysis draws on EBI Proteins Variation, UniProt, gnomAD v4, EuropePMC, 3D Hotspot Analysis, Interaction Network Analysis, Protein Data Bank, AlphaFold DB, gnomAD constraint, Open Targets, MaveDB, LitVar.

Notable SCN4A variants

Examples include M1?, A2P, A2T, A2V, R3*, R3T, P4S, P4T. Listed records include available protein-change notation, database identifiers, clinical classifications, computational predictions, population evidence, experimental measurements, and disease context.