PPP2R2B and Friedreich ataxia: In the second category, the expansion of different repeats, including CGG, GAA, CTG, and CAG, occur within the non-coding or untranslated regions (UTR), leading to fragile X syndrome (FRAX), Friedreich's ataxia (FRDA), myotonic dystrophy type 1 (DM1), SCA8, and SCA12 [1], [2], [3], [4], [5].