SCN4A and congenital myasthenic syndrome: In a 20yo normokalemic female, SCN4A-related CMS manifested as sudden attacks of respiratory and bulbar paralysis since birth, lasting 3–30 min and recurring one to three times per month, delayed motor development, easy fatigability, ptosis, ophthalmoparesis, and later as persisting facial, truncal, or limb weakness [96].