Hyperkalemic Periodic Paralysis

**Semantic type:** Disease or Syndrome

**Definition:** A rare, autosomal dominant inherited disorder caused by mutations in the SCN4A gene. It is characterized by occasional episodes of muscle weakness or paralysis which are usually accompanied by increased levels of potassium in the blood. In some cases, the episodes of paralysis are associated with normal blood potassium levels. Ingestion of potassium can trigger attacks in affected individuals.