Expression of miR‐1 is lost in the myocardium of myotonic dystrophy patients, concomitant with up regulation of its targets Connexin 43 (Cx43) and calcium voltage‐gated channel subunit alpha1C (CAV1.2) may at least partly account for the arrhythmia, which is observed in these patients 128. This evidence concerns the gene GJA1 and myotonic dystrophy.