FMR1 and fragile X-associated tremor/ataxia syndrome: RAN translation is also initiated by hexanucleotide GGGGCC repeat expansion in intron 1 of the C9FTD/ALS gene C9ORF72 [19,21,22], and by CGG repeat expansion in the 5’ UTR of FMR1, causing fragile X-associated tremor ataxia syndrome (FXTAS) [20].