FXN and Friedreich ataxia: The FXN targeting gRNA produced a level of methylation in the FRDA-DMR that was approximately two-thirds of the level seen in PBMCs from a heterogeneous group of FRDA patients (Fig. 7C; FRDA PBMC data are depicted as a composite of the 32 patients in Fig. 3A), and it was mostly located within the FRDA-DMR.