Non-dystrophic myotonias (NDM) are rare muscle disorders caused by mutations in skeletal voltage-gated channels leading to delayed relaxation after voluntary contraction. They subdivided into sodium channelopathies, when the mutation is SCN4A gene, and chloride CLCN1 gene. Symptoms, which may differ according subtype, exacerbating factors, over disease course, can include stiffness, pain, fatig...

Electrical membrane properties of skeletal muscle fibers have been thoroughly studied over the last five to six decades. This has shown that muscle fibers from a wide range of species, including fish, amphibians, reptiles, birds, and mammals, are all characterized by high resting membrane permeability for Cl(-) ions. Thus, in resting human muscle, ClC-1 Cl(-) ion channels account for ∼80% of th...

Claudins ( approximately 23 kDa) with four transmembrane domains are major cell adhesion molecules working at tight junctions in vertebrates, where the intercellular space is tightly sealed (reviewed in ). We examined here the possible occurrence of claudin-like proteins in invertebrates, which do not bear typical tight junctions. Close blast searching of the C. elegans genome database identifi...