Fragile X-associated tremor/ataxia syndrome: Intrafamilial variability and the size of the FMR1 premutation CGG repeat

Authors

  • Leonardo P. Capelli MSc,

    1. Department of Genetics and Evolutionary Biology, Institute of Biosciences, University of São Paulo, São Paulo, Brazil
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  • Márcia R. R. Gonçalves MD,

    1. Department of Neurology, School of Medicine, University of São Paulo, São Paulo, Brazil
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  • Fernando Kok MD,

    1. Department of Genetics and Evolutionary Biology, Institute of Biosciences, University of São Paulo, São Paulo, Brazil
    2. Department of Neurology, School of Medicine, University of São Paulo, São Paulo, Brazil
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  • Cláudia C. Leite MD,

    1. Department of Radiology, School of Medicine, University of São Paulo, São Paulo, Brazil
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  • Ricardo Nitrini MD,

    1. Department of Neurology, School of Medicine, University of São Paulo, São Paulo, Brazil
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  • Egberto R. Barbosa MD,

    1. Department of Neurology, School of Medicine, University of São Paulo, São Paulo, Brazil
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  • Angela M. Vianna-Morgante PhD

    Corresponding author
    1. Department of Genetics and Evolutionary Biology, Institute of Biosciences, University of São Paulo, São Paulo, Brazil
    • Departamento de Genética e Biologia Evolutiva, Instituto de Biociências, Universidade de São Paulo, CP 11461, 05422-970 São Paulo, Brazil
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Abstract

Fragile X-associated tremor/ataxia syndrome (FXTAS) is a neurological progressive disorder associated with the FMR1 gene premutation. We report on variable presentation of findings associated with FXTAS in 3 brothers aged 68, 74, and 73 years, carrying premutation alleles of (CGG)123, (CGG)109, and (CGG)91 triplets, respectively. Based on previously proposed diagnostic criteria for the syndrome, clinical and radiological data allowed establishing a “definite” diagnosis of FXTAS in the two carriers of the longest (CGG)n. The carrier of the (CGG)91 allele, although presenting a major radiological sign of the syndrome (symmetrical white-matter lesions in the middle cerebellar peduncles), did not have any significant neurological manifestation at 73 years of age. © 2007 Movement Disorder Society

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