CLCN1 and Myotonia: Mis‐splicing of Clcn1 has been suggested to cause myotonia.[13] Treatment of the HSALR mice with i.p. JM642 (10 and 20 mg kg−1) rescued the mis‐splicing in the Clcn1 gene, leading to an exclusion rate of 61±2.3 % (P=0.03) and 70±2.3 % (P=0.01), respectively, although an improvement of phenotypic myotonia was not apparent due to the partial rescue of splicing.