For example, neuron-iPSCs were generated from patients affected by myotonic dystrophy 1 (DM1) (Du et al., 2013; Xia et al., 2013; Ueki et al., 2017), caused by an expansion of the CTG trinucleotide repeats in the 3′ untranslated region of the dystrophia myotonica protein kinase (DMPK) gene (Brook et al., 1992). Here, DMPK is linked to myotonic dystrophy type 1.