Kasuga Kensaku, Ikeuchi Takeshi, Arakawa Keiko, Yajima Ryuji, Tokutake Takayoshi, Nishizawa Masatoyo
Department of Neurology, Brain Research Institute, Niigata University, Niigata, Japan.
Case Rep Neurol. 2011 May;3(2):118-23. doi: 10.1159/000328838. Epub 2011 May 24.
Fragile X-associated tremor/ataxia syndrome (FXTAS) is a late-onset neurodegenerative disorder that primarily affects males who are carriers of a premutation of a CGG expansion in the FMR1 gene. In Asian populations, FXTAS has rarely been reported. Here, we report the case of a Japanese FXTAS patient who showed predominant executive cognitive deficits as the main feature of his disease. In contrast, the patient exhibited only very mild symptoms of intention tremor and ataxia, which did not interfere with daily activities. A gene analysis revealed that the patient carried a premutation of a CGG expansion (111 CGG repeats) in the FMR1 gene. The mRNA expression level of FMR1 in the patient was 1.5-fold higher than in controls. On brain MRI scans, fluid-attenuated inversion recovery images showed high-intensity lesions in the middle cerebellar peduncles and the cerebral white matter, with a frontal predominance. The present case extends previous notions regarding the cognitive impairment in FXTAS patients. Recognizing FXTAS patients with predominant cognitive impairment from various ethnic backgrounds would contribute to our understanding of the phenotypic variation of this disease.
脆性X相关震颤/共济失调综合征（FXTAS）是一种迟发性神经退行性疾病，主要影响携带FMR1基因CGG重复序列前突变的男性。在亚洲人群中，FXTAS鲜有报道。在此，我们报告一例日本FXTAS患者，其以显著的执行认知缺陷为主要疾病特征。相比之下，该患者仅表现出非常轻微的意向性震颤和共济失调症状，并未干扰日常活动。基因分析显示，该患者携带FMR1基因CGG重复序列前突变（111个CGG重复）。患者FMR1的mRNA表达水平比对照组高1.5倍。在脑部MRI扫描中，液体衰减反转恢复图像显示小脑中间脚和脑白质有高强度病变，以额叶为主。本病例扩展了以往关于FXTAS患者认知障碍的认识。识别来自不同种族背景、以认知障碍为主的FXTAS患者将有助于我们理解该疾病的表型变异。
