Myotonia congenita (MC) is a genetic disease that displays impaired relaxation of skeletal muscle and muscle hypertrophy. This disease is mainly caused by mutations of CLCN1 that encodes human skeletal muscle chloride channel (CLC-1). CLC-1 is a voltage gated chloride channel that activates upon depolarizing potentials and play a major role in stabilization of resting membrane potentials in ske...

OBJECTIVES A mild, slowly progressive course of proximal myotonic myopathy, also known as myotonic dystrophy type 2, over years allowing the patient to continue with extreme sport activity, has been only rarely reported. METHODS Case report. RESULTS The patient is a 54-year-old female sport teacher who developed myotonia of the distal upper limbs at the age of 32 years. Over the following 2...

Julius thomsen first published his account of myotonia (an unusual muscle stiffness disorder) in himself and his family in 1876. By november 1971, Peter Becker was already famous for his eponymous Becker muscular dystrophy when he came to the second international congress on Muscle Diseases, in Perth. there, he presented an extensive study of myotonia, recognising a recessively inherited diseas...

The group of dominant non-dystrophic myotonias, comprising disorders characterized by clinically similar forms of myogenic muscle stiffness, is genetically inhomogeneous. Dominant myotonia congenita (Thomsen's disease) is linked to CLCN1, the gene encoding the major muscle chloride channel, localized on chromosome 7q35. In contrast, dominant myotonias sensitive to potassium are caused by point ...

The phenomenon of myotonia comprises a lingering relaxation of muscle after contraction, and a slow tonic response to stimuli of an electrical or mechanical nature. The condition may be ameliorated or even extinguished by repeated effort. Although well known and the commonest form of hereditary muscular disorder seen in young adults, it is, nevertheless, a rare condition. Three distinct forms o...

Although the sodium channel blocker mexiletine is considered the first-line drug in myotonia, some patients experiment adverse effects, while others do not gain any benefit. Other antimyotonic drugs are thus needed to offer mexiletine alternatives. In the present study, we used a previously-validated rat model of myotonia congenita to compare six marketed sodium channel blockers to mexiletine. ...

Nearly 20 years ago Evans (1944) suggested that the cardiac abnormalities that are associated with myotonia atrophica might in some cases be an important aid to the early diagnosis of this disease. This report concerns a patient who was first thought to be a case of non-specific myocarditis, but who later proved to be one of cardiomyopathy due to myotonia atrophica after a family history of thi...