Grigsby Jim, Brega Angela G, Jacquemont Sébastien, Loesch Danuta Z, Leehey Maureen A, Goodrich Glenn K, Hagerman Randi J, Epstein Jennifer, Wilson Rebecca, Cogswell Jennifer B, Jardini Tristan, Tassone Flora, Hagerman Paul J
Department of Medicine, University of Colorado Health Sciences Center, Aurora, CO 80045, USA.
J Neurol Sci. 2006 Oct 25;248(1-2):227-33. doi: 10.1016/j.jns.2006.05.016. Epub 2006 Jun 15.
Disorders associated with fragile X syndrome involve a trinucleotide (CGG) repeat expansion in the FMR1 gene. Recently, a progressive movement disorder (fragile X-associated tremor/ataxia syndrome [FXTAS]) has been identified in premutation carriers, persons with 55 to 200 CGG repeats. In addition to ataxia, action tremor, and Parkinsonism, early case reports suggested that FXTAS involves impaired cognition, but the precise nature of the impairment has not been elucidated. In this first, preliminary study of the subject, circumscribed aspects of cognitive functioning were examined in 25 men with FXTAS. Subjects' performance on the cognitive tests was compared with normative data. Scores on two measures of executive cognitive functioning showed a high prevalence of substantial impairment. Capacity for inhibition was severely affected in one-quarter of this highly educated sample; information processing speed was profoundly impaired in most subjects. Although mean verbal and performance IQ scores were not significantly different from the general population, they were quite low given the sample's educational level. Cognitive and functional impairment was greater for men with more CGG repeats, although number of repeats was not associated with age of onset of either tremor or ataxia. The results provide evidence that FXTAS involves marked impairment of executive cognitive abilities.
与脆性X综合征相关的疾病涉及FMR1基因中的三核苷酸（CGG）重复序列扩增。最近，在携带前突变的个体（即具有55至200个CGG重复序列的人）中发现了一种进行性运动障碍（脆性X相关震颤/共济失调综合征 [FXTAS]）。除了共济失调、动作性震颤和帕金森综合征外，早期病例报告表明FXTAS涉及认知功能受损，但这种损害的确切性质尚未阐明。在对该主题的首次初步研究中，对25名患有FXTAS的男性的认知功能的特定方面进行了检查。将受试者在认知测试中的表现与标准数据进行了比较。两项执行认知功能测量指标的得分显示，存在严重损害的比例很高。在这个受过高等教育的样本中，四分之一的人抑制能力受到严重影响；大多数受试者的信息处理速度受到严重损害。尽管言语和操作智商的平均得分与一般人群没有显著差异，但鉴于样本的教育水平，这些得分相当低。CGG重复序列较多的男性认知和功能损害更大，尽管重复序列的数量与震颤或共济失调的发病年龄无关。结果提供了证据表明FXTAS涉及执行认知能力的明显损害。
