Fragile X-associated tremor/ataxia syndrome (FXTAS) is an inherited neurodegenerative disorder caused by an expansion of 55-200 CGG repeats at 5UTR of FMR1 gene, known as premutation. The main clinical and neuropathological features of FXTAS include progressive intention tremor, gait ataxia, neuronal cell loss and presence of ubiquitin-positive intranuclear inclusions in neurons and astrocytes. Various mitochondrial dysfunctions are reported in in vitro/vivo models of FXTAS; however, the molecular mechanisms underlying such mitochondrial dysfunctions are unclear. CGG expansions are pathogenic through distinct mechanisms involving RNA gain of function, impaired DNA damage repair and FMRpolyG toxicity. Here, we have systematically reviewed the reports of mitochondrial dysfunctions under premutation condition. We have also focused on potential emerging mechanisms to understand mitochondrial associated pathology in FXTAS. This review highlights the important role of mitochondria in FXTAS and other related disorders; and suggests focus of future studies on mitochondrial dysfunction along with other prevailing mechanisms to alleviate neurodegeneration.

脆弱的X相关震颤/共济失调综合征（FXTAS）是一种遗传性神经退行性疾病，由FMR1基因5UTR处55-200个CGG重复序列的扩增引起，称为前突变。FXTAS的主要临床和神经病理学特征包括进行性意图震颤，步态共济失调，神经元细胞丢失以及神经元和星形胶质细胞中泛素阳性核内包涵体的存在。体外/体内报道了各种线粒体功能障碍FXTAS的模型；然而，这种线粒体功能障碍的分子机制尚不清楚。CGG扩展通过涉及RNA功能获得，DNA损伤修复受损和FMRpolyG毒性的独特机制而致病。在这里，我们系统地审查了在突变前线粒体功能障碍的报道。我们还专注于潜在的新兴机制，以了解FXTAS中的线粒体相关病理。这篇综述强调了线粒体在FXTAS和其他相关疾病中的重要作用；并建议将研究重点放在线粒体功能障碍以及其他减轻神经变性的流行机制上。