label: Normokalemic Periodic Paralysis
label_lc: normokalemic periodic paralysis
description: "An autosomal dominant inherited non-dystrophic myotonia caused by mutations of the SCN4A gene, resulting in sodium muscle channelopathy. Currently, it is considered a variant of hyperkalemic periodic paralysis.  Patients with normokalemic periodic paralysis do not have any change in their potassium levels during weakness, but become weak when they ingest potassium."