Additionally, Mbnl1 overexpression reverses myotonia in transgenic HSALR mice, which express a CUGexp RNA in skeletal muscle, and transgenic MBNL1 overexpression mice are viable with normal muscle structure and function (Chamberlain & Ranum, 2012; Kanadia et al, 2006). This evidence concerns the gene MBNL1 and Myotonia.