Friedreich's ataxia, the most frequent progressive autosomal recessive disorder involving the central and peripheral nervous systems, is mostly associated with unstable expansion of GAA trinucleotide repeats in the first intron of the FXN gene, which encodes the mitochondrial frataxin protein. Since FXN was shown to be involved in Friedreich's ataxia in the late 1990s, the consequence of fratax...
