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Review
. 2009 Dec;57(8):830-6.
doi: 10.2310/JIM.0b013e3181af59c4.

Fragile X-associated tremor/ataxia syndrome: clinical phenotype, diagnosis, and treatment

Affiliations
Review

Fragile X-associated tremor/ataxia syndrome: clinical phenotype, diagnosis, and treatment

Maureen A Leehey. J Investig Med. 2009 Dec.

Abstract

Fragile X-associated tremor/ataxia syndrome (FXTAS) is a neurodegenerative disorder caused by a CGG repeat expansion in the premutation range (55-200) in the fragile X mental retardation 1 gene. Onset is typically in the early seventh decade, and men are principally affected. The major signs are cerebellar gait ataxia, intention tremor, frontal executive dysfunction, and global brain atrophy. Other frequent findings are parkinsonism (mild), peripheral neuropathy, psychiatric symptoms (depression, anxiety, and agitation), and autonomic dysfunction. The clinical presentation is heterogeneous, with individuals presenting with varied dominating signs, such as tremor, dementia, or neuropathy. Magnetic resonance imaging shows atrophy and patchy white matter lesions in the cerebral hemispheres and middle cerebellar peduncles. The latter has been designated the middle cerebellar peduncle sign, which occurs in about 60% of affected men, and is relatively specific for FXTAS. Affected females generally have less severe disease, less cognitive decline, and some symptoms different from that of men, for example, muscle pain. Management of FXTAS is complex and includes assessment of the patient's neurological and medical deficits, treatment of symptoms, and provision of relevant referrals, especially genetic counseling. Treatment is empirical, based on anecdotal experience and on knowledge of what works for symptoms of other disorders that also exist in FXTAS. Presently, the disorder is underrecognized because the first published report was only in 2001 and because the presentation is variable and mainly consists of a combination of signs common in the elderly. However, accurate diagnosis is critical for the patient and for the family because they need education regarding their genetic and health risks.

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Figures

Figure 1
Figure 1
Fragile X Syndrome (FXS) vs. Fragile X-associated Tremor/Ataxia Syndrome (FXTAS). This figure demonstrates that FXS and FXTAS are very different disorders, and that each results from a different length of the repeat expansion that occurs in the same gene, fragile X mental retardation 1 (FMR1). Two males are shown, because males are more affected than females since the gene mutation is on the X chromosome.

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References

    1. Hagerman RJ, Leehey M, Heinrichs W, et al. Intention tremor, parkinsonism, and generalized brain atrophy in male carriers of fragile X. Neurology. 2001;57:127–130. - PubMed
    1. Tassone F, Hagerman RJ, Taylor AK, Gane LW, Godfrey TE, Hagerman PJ. Elevated levels of FMR1 mRNA in carrier males: a new mechanism of involvement in the fragile-X syndrome. American Journal of Human Genetics. 2000;66:6–15. - PMC - PubMed
    1. Tassone F, Hagerman RJ, Garcia-Arocena D, Khandjian EW, Greco CM, Hagerman PJ. Intranuclear inclusions in neural cells with premutation alleles in fragile X associated tremor/ataxia syndrome. J Med Genet. 2004;41:e43. - PMC - PubMed
    1. Brussino A, Gellera C, Saluto A, et al. FMR1 gene premutation is a frequent genetic cause of late-onset sporadic cerebellar ataxia. Neurology. 2005;64:145–147. - PubMed
    1. Van Esch H, Dom R, Bex D, et al. Screening for FMR-1 premutations in 122 older Flemish males presenting with ataxia. Eur J Hum Genet. 2005;13:121–123. - PubMed

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