FXN and Friedreich ataxia: We tested the possibility that the CT genotype confers improved clinical outcomes in individuals with FRDA by positively affecting the expression of FXN. We measured FXN mRNA levels in blood samples collected from the 138 subjects of our exploratory analysis as well as the larger cohort of 536 subjects and found no correlation between SNP status and FXN mRNA levels in multivariable regression models with GAA1, a known predictor of frataxin levels (data not shown).