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Parkinson’s Disease
Volume 2016, Article ID 5731734, 8 pages
Research Article

The Association between C9orf72 Repeats and Risk of Alzheimer’s Disease and Amyotrophic Lateral Sclerosis: A Meta-Analysis

Xiangya Hospital, Central South University, Hunan, China

Received 27 January 2016; Accepted 4 April 2016

Academic Editor: Jan Aasly

Copyright © 2016 Li Shu et al. This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.


C9orf72 is the most common genetic cause of amyotrophic lateral sclerosis (ALS) and frontotemporal dementia (FTD) in Caucasian populations. However, the relationship between C9orf72 repeats and Alzheimer’s disease (AD) was not clear. Additionally, there were few articles assessing C9orf72 in other ethnicities with ALS. In this meta-analysis, we aimed to investigate the relationship between C9orf72 repeat expansions (≥30 repeats) and intermediate repeat copies (20–29 repeats) and AD or ALS. The results suggested positive correlations between C9orf72 repeat expansions and the risk of Alzheimer’s disease (OR = 6.36, 95% CI = 3.13–12.92, and ), while intermediate repeat copies of C9orf72 gene were not associated with the risk of the disease. C9orf72 repeat expansions were positively correlated with the risk of familial and sporadic ALS (OR = 293.25, 95% CI = 148.17–580.38, and ; OR = 35.57, 95% CI = 19.61–64.51, and ). There was a positive correlation between the gene variations and ALS risk among Caucasians and Asians (OR = 57.56, 95% CI = 36.73–90.22, and ; OR = 6.35, 95% CI = 1.39–29.02, and ).