title: Myotonia congenita.
abstract: Myotonia is a symptom of many different acquired and genetic muscular conditions that impair the relaxation phase of muscular contraction. Myotonia congenita is a specific inherited disorder of muscle membrane hyperexcitability caused by reduced sarcolemmal chloride conductance due to mutations in CLCN1, the gene coding for the main skeletal muscle chloride channel ClC-1. The disorder may be transmitted as either an autosomal-dominant or recessive trait with close to 130 currently known mutations. Although this is a rare disorder, elucidation of the pathophysiology underlying myotonia congenita established the importance of sarcolemmal chloride conductance in the control of muscle excitability and demonstrated the first example of human disease associated with the ClC family of chloride transporting proteins.
authors.affiliation: Department of Neurology, UC Davis School of Medicine, Sacramento, California 95817.
authors.forename: Christoph
authors.initials: C
authors.lastname: Lossin
authors.affiliation: Departments of Medicine and Pharmacology, Vanderbilt University School of Medicine, Nashville, Tennessee 37232.
authors.forename: Alfred L
authors.initials: AL
authors.lastname: George
mesh_terms: D000818:Animals; D018118:Chloride Channels / Q000235:genetics; D004195:Disease Models, Animal; D006801:Humans; D009154:Mutation / Q000235:genetics; D009224:Myotonia Congenita / Q000235:genetics* / Q000473:pathology / Q000503:physiopathology / Q000628:therapy
chemical_list: D018118:Chloride Channels