Review Article

Mechanism of Repeat-Associated MicroRNAs in Fragile X Syndrome

Table 1

Triplet repeat expansion diseases (TREDs) that have been identified in humans.

TRED disordersSite of pathogenExpansionRepeat no.

Dentatorubral-pallidoluysian atrophy (DRPLA)Atrophin-1, exonsCAG49–88
Fragile X syndrome (FXS)FMR1, 5′-UTRCGG>200
Fragile X-associated tremor ataxia syndrome (FXTAS)FMR1, 5′-UTRCGG55–200
Fragile X syndrome E (FRAXE)FMR2, 5′-UTRCCG200–900
Friedreich ataxia (FRDA)Frataxin, intronGAA200–1,700
Myotonic dystrophy type 1 (DM1)DMPK, 3′-UTRCTG50–1,000
Myotonic dystrophy type 2 (DM2)ZNF9, intron 1 CCTG75–11,000
Huntington’s disease (HD)Huntingtin, exon 1CAG40–121
Huntington’s disease-like 2 (HDL2)JPH3, intron, exon, or 3′-UTRCTG66–78
Spinobulbar muscular atrophy (SBMA)Androgen receptor, intronCAG38–62
Spinal cerebellar ataxia (SCA) types 1–3, 7Ataxin 1–3, 7, exonsCAG37–300
SCA type 8 (SCA8)(ncRNA)*UDCTG>74
SCA type 17 (SCA17)TBP, exonCAG47–63

*UD: undefined.