Fragile X-associated tremor/ataxia syndrome presenting in a woman after chemotherapy

Abstract

Fragile X, the most common inherited cause of mental retardation, is an X-linked disease with expansion of triplet repeats (>200 CGG repeats) of the fragile X mental retardation-1 gene (FMR1). This encodes for a protein (FMRP) highly expressed in neurons, whose normal role has been linked to G-quartets and regulation of microtubule associated protein 1B mRNA translation.1 Alleles exist in an unmethylated active state, including those in the premutation range (55 to 200 CGG repeats). A new syndrome, the fragile X-associated tremor/ataxia syndrome2 (FXTAS), seen in male carriers of the premutation, is characterized by tremor, gait ataxia, cognitive deficits, and in some patients, by parkinsonian signs. The onset of FXTAS is from the fifth decade and half of those affected have high signal intensity abnormalities on T2W MRI in the middle cerebellar peduncles. Few women have been described with this disorder. We report a woman carrier of the FMR1 gene in the premutation range, who …