Biomaterial Database

The Natural History of Spinocerebellar Ataxia Type 3 in Mainland China: A 2-Year Cohort Study. 2022

Yun Peng, and Linliu Peng, and Zhao Chen, and Huirong Peng, and Puzhi Wang, and Youming Zhang, and Yangping Li, and Chunrong Wang, and Yuting Shi, and Xuan Hou, and Zhe Long, and Hongyu Yuan, and Na Wan, and Linlin Wan, and Keqin Xu, and Lijing Lei, and Shang Wang, and Lang He, and Yue Xie, and Yiqing Gong, and Qi Deng, and Guangdong Zou, and Zhichao Tang, and Lu Shen, and Kun Xia, and Rong Qiu, and Thomas Klockgether, and Beisha Tang, and Hong Jiang

Department of Neurology, Xiangya Hospital, Central South University, Changsha, China.

The natural history of spinocerebellar ataxia type 3 (SCA3) has been reported in several populations and shows heterogeneity in progression rate and affecting factors. However, it remains unexplored in the population of Mainland China. This study aimed to identify the disease progression rate and its potential affecting factors in patients with SCA3 in Mainland China. We enrolled patients with genetically confirmed SCA3 in Mainland China. Patients were seen at three visits, i.e., baseline, 1 year, and 2 years. The primary outcome was the Scale for the Assessment and Rating of Ataxia (SARA), and the secondary outcomes were the Inventory of Non-Ataxia Signs (INAS) as well as the SCA Functional Index (SCAFI). Between 1 October 2015, and 30 September 2016, we enrolled 263 patients with SCA3. We analyzed 247 patients with at least one follow-up visit. The annual progression rate of SARA was 1.49 points per year (SE 0.08, 95% confidence interval [CI] 1.33-1.65, p < 0.0001). The annual progression rates of INAS and SCAFI were 0.56 points per year (SE 0.05, 95% CI 0.47-0.66, p < 0.001) and -0.30 points per year (SE 0.01, 95% CI -0.33∼-0.28, p < 0.001), respectively. Faster progression in SARA was associated with longer length of the expanded allele of ATXN3 (p < 0.0001); faster progression in INAS was associated with lower INAS at baseline (p < 0.0001); faster decline in SCAFI was associated with shorter length of the normal allele of ATXN3 (p = 0.036) and higher SCAFI at baseline (p < 0.0001). Our results provide quantitative data on the disease progression of patients with SCA3 in Mainland China and its corresponding affecting factors, which could facilitate the sample size calculation and patient stratification in future clinical trials. This study was registered with Chictr.org on 15 September 2015, number ChiCTR-OOC-15007124.