successful targeting of causative loci for Huntington’s disease ( HTT ; CAG repeat), Fragile X syndrome ( FMR1 ; CGG repeat), amyotrophic lateral sclerosis (ALS) and frontotemporal dementia ( C9orf72 ; GGGGCC repeat), and spinocerebellar ataxia type 10 (SCA10) ( ATXN10 ; variable ATTCT ...