In other diseases, the repeat is located in noncoding regions: in the muscle disease myotonic dystrophy type 1 (DM1) [1,5] the CTG repeat is located in the 3′ untranslated region (UTR) of the gene DMPK, and in Friedreich ataxia [1,5,6] (FRDA) a GAA repeat is located within the first intron of the gene FRDA. This evidence concerns the gene FXN and myotonic dystrophy type 1.