A study of LRRK2 mutations and Parkinson's disease in Brazil.

Mutations in the Leucine-rich repeat kinase 2 (LRRK2) gene are known as a common cause of Parkinson's disease (PD) among patients from different geographic origins. In this study, we evaluated the prevalence of LRRK2 mutations in exons 31 and 41 in a cohort of 154 consecutive, unrelated Brazilian patients with familial or sporadic PD, including early and late onset patients. The LRRK2 p.G2019S mutation was present in heterozygous state in three index cases (approximately 2%), and in three additional relatives. No carriers of this mutation were found among 250 control chromosomes. Clinically, all mutation-positive patients presented a typical PD phenotype and a good response to levodopa. Mutation segregation analysis in a large sibling showed incomplete penetrance of the p.G2019S. Our findings suggest that the LRRK2 p.G2019S mutation has a substantial contribution to PD susceptibility among Brazilian population and add new clues to current research of this disease.