GPAA1 and Friedreich ataxia: In this FRDA cohort, the average lengths of the GAA tracts are 454 and 898 repeats for FXN alleles 1 and 2 (GAA1 and GAA2), respectively (Table S1), whereas the number of GAA triplets did not exceed 40 repeats in any of the CTRL fibroblast lines (Li et al., 2015b).