Essential tremor and the common LRRK2 G2385R variant

Abstract

Co-existence of Parkinson's disease (PD) and essential tremor (ET) suggests a possible overlapping pathophysiology between these two conditions. PD patients with leucine-rich repeat kinase-2 (LRRK2) mutations have been reported to present initially with ET. A common LRRK2 Gly2385Arg variant has been widely shown to be associated with a two fold increased risk of PD in various Asian populations. We analyzed the Gly2385Arg variant in a cohort of ET and controls. A total of 419 subjects comprising of 172 ET and 247 controls were included. The mean age, age at onset of ET, and age of controls were 52.1,19.6, 41.8, 21.6, and 62.2,11.6 years, comprising of 53.0% and 54.3% men, respectively. The Gly2385Arg variant was demonstrated in 5/172 (2.9%) ET patients compared to 10/247 (4.0%) of controls (odds ratio = 0.72, 95% CI 0.24, 2.1, p = 0.6). All the Gly2385Arg carriers were heterozygotes. The LRRK2 Gly2385Arg variant is not a significant risk factor for ET in our population. 2008 Elsevier Ltd. All rights reserved.