However, the expansion of CGG repeats (CGGexp) to intermediate size, called premutations (PMs, 55–200 CGG repeats), can cause different fragile X-PM-associated conditions (FXPACs)1, including fragile X-associated tremor/ataxia syndrome (FXTAS), fragile X-associated primary ovarian insufficiency (FXPOI), and fragile X-associated neuropsychiatric disorders (FXANDs). This evidence concerns the gene PSMB5 and fragile X-associated tremor/ataxia syndrome.