Department of Neuroscience, Mayo Clinic Jacksonville, 4500 San Pablo Road, Jacksonville, FL 32224, USA.
Parkinsonism Relat Disord. 2013 Feb;19(2):198-201. doi: 10.1016/j.parkreldis.2012.09.013. Epub 2012 Oct 18.
The hexanucleotide expanded repeat (GGGGCC) in intron 1 of the C9orf72 gene is recognized as the most common genetic form of amyotrophic lateral sclerosis (ALS) and frontotemporal dementia (FTD). However, as part of the clinical phenotype, some patients present with parkinsonism. The present study investigated the potential expansion or association of the C9orf72 repeat length with susceptibility to Parkinson's disease and related disorders, essential tremor and restless legs syndrome. One restless legs syndrome patient was shown to harbor a repeat expansion, however on clinical follow-up this patient was observed to have developed frontotemporal dementia. There was no evidence of association of repeat length on disease risk or age-at-onset for any of the three disorders. Therefore the C9orf72 hexanucleotide repeat expansion appears to be specific to TDP-43 driven amyotrophic lateral sclerosis and dementia.
六核苷酸扩展重复（GGGGCC）在 C9orf72 基因的内含子 1 中被认为是肌萎缩侧索硬化症（ALS）和额颞叶痴呆（FTD）最常见的遗传形式。然而，作为临床表型的一部分，一些患者出现帕金森病。本研究调查了 C9orf72 重复长度与帕金森病及相关疾病、特发性震颤和不宁腿综合征易感性的潜在关联。一名不宁腿综合征患者携带重复扩展，但在临床随访中，该患者被观察到发展为额颞叶痴呆。在这三种疾病中，没有证据表明重复长度与疾病风险或发病年龄有关。因此，C9orf72 六核苷酸重复扩展似乎是 TDP-43 驱动的肌萎缩侧索硬化症和痴呆的特异性。
