potassium-aggravated myotonia

Potassium-Aggravated Myotonia (MIM.608390) is subdivided into myotonia fluctuans, myotonia permanens, and acetazolamide-responsive myotonia.

The typical presentation is that of a painful myotonia that fluctuates and is aggravated by exercise or rest after exercise, potassium loads, and exposure to depolarizing neuromuscular blocking agents. These patients do not experience episodic weakness or progressive myopathy.

This disease is caused by mutations of the sodium channel SCN4A gene on chromosome 17q.

See also

 channelopathies