Fragile X–Associated Tremor/Ataxia Syndrome in a Man in His 30s

Fragile X–associated tremor/ataxia syndrome (FXTAS) is a neurodegenerative disorder that usually begins in the early 60s1,2 and affects carriers of premutation expansion (55–200 CGG repeats) of the fragile × mental retardation 1 (FMR1) gene. It is caused by elevated levels of FMR1 messenger RNA, leading to toxicity. Clinical features include progressive cerebellar ataxia and intention tremor. Associated symptoms include autonomic dysfunction, peripheral neuropathy, and cognitive impairment2.