Elsevier

Kidney International

Volume 57, Issue 3, March 2000, Pages 772-779
Kidney International

Forefronts in Nephrology: Ion Channelopathies
Spectrum of sodium channel disturbances in the nondystrophic myotonias and periodic paralyses

https://doi.org/10.1046/j.1523-1755.2000.00914.xGet rights and content
Under an Elsevier user license
open archive

Spectrum of sodium channel disturbances in the nondystrophic myotonias and periodic paralyses. Several heritable forms of myotonia and periodic paralysis are caused by missense mutations in the voltage-gated sodium channel of skeletal muscle. Mutations produce gain-of-function defects, either disrupted inactivation or enhanced activation. Both defects result in too much inward Na current which may either initiate pathologic bursts of action potentials (myotonia) or cause flaccid paralysis by depolarizing fibers to a refractory inexcitable state. Myotonic stiffness and periodic paralysis occur as paroxysmal attacks often triggered by environmental factors such as serum K+, cold, or exercise. Many gaps remain in our understanding of the interactions between genetic predisposition and these environmental influences. Targeted gene manipulation in animals may provide the tools to fill in these gaps.

Keywords

skeletal muscle
human
electrophysiology
hereditary disease
genetic disorder

Cited by (0)