FXN and Friedreich ataxia: One such repeat tract, a stretch of GAA trinucleotide repeats in intron 1 of the frataxin (FXN) gene, was identified almost 3 decades ago as the cause of Friedreich ataxia (FRDA).1 FRDA is an autosomal recessive neurodegenerative disorder caused by the biallelic expansion of these repeats, leading to transcriptional silencing of the mutated gene and reduced frataxin levels.