We tested splicing patterns of six genes that are known to be regulated by MBNL1 and contribute to DM1 pathogenesis [troponin T2 – TNNT2, insulin receptor – INSR, sarcoplasmic/endoplasmic reticulum calcium ATPase 1 – ATP2A1 or SERCA1, dystonin – DST, and Muscleblind 1/2 – MBNL 1/2 (Savkur et al., 2001; Kuyumcu-Martinez and Cooper, 2006; Hino et al., 2007; Childs-Disney et al., 2013; Santoro et al., 2013; Arandel et al., 2017; Batra et al., 2017; Renna et al., 2017, 2019)]. This evidence concerns the gene ATP2A1 and myotonic dystrophy type 1.