摘要： 多聚谷氨酰胺病是一类中枢神经系统退行性疾病，由致病基因外显子内胞嘧啶-腺嘌呤-鸟嘌呤（CAG）三核苷酸重复序列拷贝数异常扩增导致其编码的多聚谷氨酰胺链异常延长，引起多聚谷氨酰胺扩展突变型蛋白积聚而致病。迄今为止，共发现9 种因多聚谷氨酰胺扩展突变型蛋白积聚引起的遗传性神经退行性疾病。CAG 重复序列在代间传递过程中发生动态突变（拷贝数不断扩增），进而导致发病年龄提前和疾病严重程度增加。

关键词: 神经变性疾病, 谷氨酰胺, 三核苷酸重复, 动态突变, 综述

Abstract: Polyglutamine (polyQ) disease is a group of neurodegenerative disorders caused by abnormal expansion of CAG repeats within coding regions of certain causative genes, which are translated into a series of abnormally expanded polyQ tracts causing cytotoxicity. So far, nine diseases caused by expanded polyQ tracts have been demonstrated including Huntington's disease (HD), spinobulbar muscular atrophy (SBMA), dentatorubral-pallidoluysian atrophy (DRPLA) and several spinocerebellar ataxias subtypes (SCA). In human, long CAG repeats tend to expand during transmissions from parent to offspring, named as dynamic mutation, leading to an earlier age of disease onset and more severe symptoms in subsequent generations. The review presents some novel mechanisms based on dynamic mutation.

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