CACNA1S and Myotonia: Because aberrant expression of the CaV1.1e splice variant correlates with the degree of muscle weakness in DM1 patients, and forced missplicing of CaV1.1 exon 29 caused centrally localized nuclei in a myotonia mouse model, it has been suggested that increased calcium influx through the developmental CaV1.1e splice variant may contribute to the myopathy (Santoro et al., 2014; Tang et al., 2012).