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Parkinson’s Disease
Volume 2017, Article ID 4318416, 11 pages
https://doi.org/10.1155/2017/4318416
Review Article

Genetic Variants in SNCA and the Risk of Sporadic Parkinson’s Disease and Clinical Outcomes: A Review

1Memory Studies Laboratory, Department of Physiology, Universidade Federal do Rio Grande do Norte, Natal, RN, Brazil
2Behavioral Neuroscience Laboratory, Department of Pharmacology, Universidade Federal de São Paulo, São Paulo, SP, Brazil

Correspondence should be addressed to Regina Helena Silva; moc.liamg@avlishaniger

Received 13 January 2017; Revised 17 April 2017; Accepted 24 May 2017; Published 11 July 2017

Academic Editor: Hao Deng

Copyright © 2017 Clarissa Loureiro das Chagas Campêlo and Regina Helena Silva. 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.

Abstract

There is increasing evidence of the contribution of genetic susceptibility to the etiology of Parkinson’s disease (PD). Genetic variations in the SNCA gene are well established by linkage and genome-wide association studies. Positive associations of single nucleotide polymorphisms (SNPs) in SNCA and increased risk for PD were found. However, the role of SNCA variants in individual traits or phenotypes of PD is unknown. Here, we reviewed the current literature and identified 57 studies, performed in fourteen different countries, that investigated SNCA variants and susceptibility to PD. We discussed the findings based on environmental factors, history of PD, clinical outcomes, and ethnicity. In conclusion, SNPs within the SNCA gene can modify the susceptibility to PD, leading to increased or decreased risk. The risk associations of some SNPs varied among samples. Of notice, no studies in South American or African populations were found. There is little information about the effects of these variants on particular clinical aspects of PD, such as motor and nonmotor symptoms. Similarly, evidence of possible interactions between SNCA SNPs and environmental factors or disease progression is scarce. There is a need to expand the clinical applicability of these data as well as to investigate the role of SNCA SNPs in populations with different ethnic backgrounds.