SNCA rs356182 variant increases risk of sporadic Parkinson's disease in ethnic Chinese

Abstract

Purpose: A genome-wide association study (GWAS) has recently identified a novel single nucleotide polymorphism (SNP) rs356182 at SNCA that can modulate the risk of Parkinson's disease (PD) in Caucasian ancestry. The present study was designed to clarify the strength of the association in ethnic Chinese population.

Methods: Using a case-control methodology, we genotyped the SNP rs356182 to investigate the association with risk of PD. A total of 2205 ethnic Han Chinese study subjects comprising 1053 sporadic PD patients (581 males, 472 females) and 1152 controls (604 males, 548 females) were recruited from Mainland China. Additionally, the SHEsis software platform was applied for linkage disequilibrium (LD) analysis between rs356182 and another PD-associated synuclein SNP rs356219 we previously reported.

Results: The frequency of SNCA rs356182-G allele was significantly higher in PD group than that in controls (odds ratio (OR)=1.470, 95% confidence interval (CI): 1.284-1.683, P=2.306E-8). Subjects carrying GG/AG genotype had an increased risk compared with the AA carriers (OR=1.162, 95% CI: 1.143-2.274, P=0.006). Among all the genotypes of rs356182, GG genotype showed the strongest association with risk of PD (GG vs. AG/AA, OR=1.620, 95% CI: 1.368-1.919, P=2.001E-8). However, the gender, onset age, disease duration, Hoehn-Yahr stage, UPDRS scores and other clinical features were similar between GG genotype carriers and non-carriers. No LD between rs356182 and rs356219 was found in our population (r(2)=0.016 and D'=0.163).

Conclusion: Our study firstly demonstrates that SNCA rs356182 variant has an increased risk of susceptibility to PD in Han Chinese population. Further functional analysis is required to determine the role of this SNP in development of PD.

Keywords: Alpha-synuclein; Parkinson's disease; Single nucleotide polymorphism.