Genetic Analysis ofPARK2andPINK1Genes in Brazilian Patients with Early-Onset Parkinson's Disease

Parkinson's disease is the second most frequent neurodegenerative disorder in the world, affecting 1-2% of individuals over the age of 65. The etiology of Parkinson's disease is complex, with the involvement of gene-environment interactions. Although it is considered a disease of late manifestation, early-onset forms of parkinsonism contribute to 5–10% of all cases. In the present study, we screened mutations in coding regions ofPARK2andPINK1genes in 136 unrelated Brazilian patients with early-onset Parkinson's disease through automatic sequencing. We identified six missense variants inPARK2gene: one known pathogenic mutation, two variants of uncertain role, and three nonpathogenic changes. No pathogenic mutation was identified inPINK1gene, only benign polymorphisms. All putative pathogenic variants found in this study were in heterozygous state. Our data show thatPARK2point mutations are more common in Brazilian early-onset Parkinson's disease patients (2.9%) thanPINK1missense variants (0%), corroborating other studies worldwide.