To address the potential effects of ASOs in aggravating some DM1 symptoms by further reducing DMPK protein expression, cardiac and muscle functions were evaluated in heterozygous Dmpk mice in which the expression of Dmpk mRNAs in these tissues was reduced by 90% by the injection of the ASO IONIS 486178 [97]. This evidence concerns the gene DMPK and myotonic dystrophy type 1.