Sodium channel defects in myotonia and periodic paralysis.
Myotonias and periodic paralyses constitute a diverse group of inherited disorders of muscle in which the primary defect is an alteration in the electrical excitability of the muscle fiber. The ion channel defects underlying these excitability derangements have recently been elucidated at the molecular and functional levels. This review focuses on sodium channel mutations that disrupt inactivation and thereby cause both the enhanced excitability of myotonia (muscle stiffness due to repetitive discharges) and the inexcitability resulting from depolarization during attacks of paralysis.
Cannon
S C
SC
Department of Neurobiology, Harvard Medical School, Massachusetts General Hospital, Boston, Massachusetts 02114, USA.
D000818:Animals; D015220:Calcium Channels / Q000235:genetics; D020746:Calcium Channels, L-Type; D018118:Chloride Channels / Q000235:genetics; D006801:Humans; D018482:Muscle, Skeletal / Q000503:physiopathology; D009222:Myotonia / Q000145:classification / Q000235:genetics / Q000503:physiopathology*; D065636:Myotonin-Protein Kinase; D010245:Paralyses, Familial Periodic / Q000145:classification / Q000235:genetics / Q000503:physiopathology*; D017354:Point Mutation; D011494:Protein Kinases / Q000235:genetics; D017346:Protein Serine-Threonine Kinases; D017433:Protein Structure, Secondary; D015222:Sodium Channels / Q000737:chemistry / Q000235:genetics* / Q000502:physiology; D018911:Trinucleotide Repeats
D015220:Calcium Channels; D020746:Calcium Channels, L-Type; D018118:Chloride Channels; C585517:DMPK protein, human; D015222:Sodium Channels; D011494:Protein Kinases; D065636:Myotonin-Protein Kinase; D017346:Protein Serine-Threonine Kinases