Base Editing Offers New Hope for Treating CAG and GAA Repeat Expansion Disorders

This study investigates the potential of cytosine base editors (CBEs) and adenine base editors (ABEs) to treat repeat expansion disorders such as Huntington's disease (HD) and Friedreich's ataxia (FRDA). Researchers designed editors targeting CAG and GAA repeats and demonstrated their effectiveness in in vitro and in vivo experiments. CBEs significantly reduced CAG repeat expansion, even promoting contraction, in a mouse model of HD. ABEs stabilized GAA repeats and increased FXN gene expression in a mouse model of FRDA. While off-target effects exist, the findings highlight the significant potential of these base editors for treating repeat expansion disorders.