A working hypothesis on the mechanism of the dominant-negative effect of disease-causing CLCN1 mutations is that the inheritance pattern of a mutation is decided by its functional effect on ClC-1 channel gating; mutations that impinge on the common-gating result in dominant myotonia, whereas those only changing the gating of individual protopores lead to a recessive inheritance pattern (30, 38, 95). This evidence concerns the gene CLCN1 and Myotonia.