LRRK2 Gly2385Arg variant is a risk factor of Parkinson's disease among Han-Chinese from mainland China

Mutations in the gene encoding Leucine-rich repeat kinase 2 (LRRK2) have been recently linked with autosomal-dominant parkinsonism, and polymorphisms have been commonly associated with sporadic Parkinson's disease (PD). A p.2385G > R variant has been reported as a risk factor for PD in Taiwan, Singapore and Japan. Herein, we have assessed the frequency of this polymorphism among the ethnic Han-Chinese population in a case-control study. A total of 600 patients with PD and 334 unrelated healthy controls were genotyped using PCR-restriction fragment length polymorphism analysis. Hardy-Weinberg equilibrium of each group was calculated, and differences in genotype frequencies between groups were assessed by the Chi-square test. In the PD cohort, 70 patients (11.7%) were heterozygous and 1 (0.2%) was homozygous for the p.2385G > R variant. This was significantly more frequent than in the controls [3.3%, Odds ratio = 3.9, 95% confidence interval (CI) = 2.1-7.5, P < 0.01]. Clinically, the age of PD onset of the p.2385G > R carriers was lower than the non-carriers (P = 0.01). Our study indicates that this LRRK2 p.2385G > R substitution contributes to the development of PD in ethnic Han-Chinese population, which may play important implications for future study on molecular genetics and pathogenesis of PD.