Second, it will be important to include movement disorder comparison groups in future studies of aging premutation carriers to determine the specificity of our sensorimotor markers to FMR1 premutation carriers, though we propose that the next critical step is to determine the specificity of key sensorimotor issues to symptomatic compared to asymptomatic FMR1 premutation carriers so that disease presence can be reliably identified in aging individuals who test positive for premutation alleles. The gene discussed is FMR1; the disease is movement disorder.