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Normokalemic periodic paralysis

Other Names for this Disease
  • Normokalemic PP
  • NormoKPP
  • Periodic paralysis type 3
  • Potassium-sensitive normokalemic periodic paralysis
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Normokalemic periodic paralysis (NormoKPP) is an inherited muscle disorder characterized by episodic attacks of muscle weakness.[1][2] It was initially considered a distinct condition, but most physicians now consider it to be a variant form of hyperkalemic periodic paralysis. People with hyperkalemic periodic paralysis have increased potassium levels during an attack; people with the normokalemic form do not experience any change in their potassium levels during weakness, but most grow weak when given potassium.[3] Studies have shown that both forms of the condition are caused by mutations in the SCN4A gene and it is inherited in an autosomal dominant manner.[2] The goals of treatment are to relieve acute symptoms and prevent further attacks.[3]
Last updated: 9/12/2012


  1. Young-Wha Song et al. Normokalemic periodic paralysis is not a distinct disease. Muscle and Nerve. August 2012; epub:
  2. S. Vicart et al. New mutations of SCN4A cause a potassium-sensitive normokalemic periodic paralysis. Neurology. December 2004; 63(11):2120-2127.
  3. What is periodic paralysis?. Periodic Paralysis International. June 21, 2011; Accessed 9/11/2012.
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