Myotonia congenita is a hereditary chloride channel disorder characterized by delayed relaxation of skeletal muscle (myotonia). It is caused by mutations in the skeletal muscle chloride channel gene CLCN1 on chromosome 7. The phenotypic spectrum of myotonia congenita ranges from mild myotonia disclosed only by clinical examination to severe and disabling myotonia with transient weakness and myo...

Non-dystrophic myotonia (NDM) is a group of rare mono-genetic muscle disorders caused by skeletal sodium or chloride channelopathies. These are characterized high tone and the inability muscles to relax spontaneously after voluntary contraction. Myotonia congenita refers form NDM that typically manifests during later stages childhood. It occurs as result genetic mutations affecting channels fou...

Several cloned ClC-type Cl- channels open and close in a voltage-dependent manner. The Torpedo electric organ Cl- channel, ClC-0, is the best studied member of this gene family. ClC-0 is gated by a fast and a slow gating mechanism of opposite voltage direction. Fast gating is dependent on voltage and on the external and internal Cl- concentration, and it has been proposed that the permeant anio...