>>11522454Myotonia congenita is caused by an inherited disorder of a chloride channel in the muscles of the skeleton (skeletal muscle chloride channel 1, CLCN1).[13] Congenital myotonia can be inherited as an autosomal dominant trait (with incomplete penetrance) or a recessive trait, resulting in the varying severity of the condition.[14][15] In affected goats, the CLCN1 gene contains a missense mutation; the amino acid alanine is replaced with a proline residue.[15] This small change causes the chloride channel in the muscle fibres to have a reduced conductance of chloride ions.[16] This missense mutation occurs in a sequence of seven amino acids that are included in a group of closely related channels including that of humans and rats.[14] This causes a delay in the relaxation of the muscles after the goat has made an involuntary movement.
