Mutations of skeletal muscle sodium channel a subunit (SCN4A) gene are associated with a group of allelic diseases, including periodic paralysis, paramyotonia congenital, sodium channel myotonia, and congenital myasthenic syndrome. Periodic paralysis is characterized by episodic attacks of flaccid weakness with the fluctuation of serum potassium, which are usually limited to skeletal muscles ow...

Overwhelming evidence now supports Simpson's concept, originally proposed in 1960, that acquired myasthenia gravis (MG) is an autoimmune disease in which antibodies are directed against the nicotine postsynaptic acetylcholine receptor (AChR).1 An autoimmune pathogenesis of acquired MG implies that those myasthenic syndromes which occur in a congenital and familial setting may have a different, ...