Meta-analysis of Parkinson's disease: identification of a novel locus, RIT2.

Objective: Genome-wide association (GWAS) methods have identified genes contributing to Parkinson's disease (PD); we sought to identify additional genes associated with PD susceptibility.

Methods: A 2-stage design was used. First, individual level genotypic data from 5 recent PD GWAS (Discovery Sample: 4,238 PD cases and 4,239 controls) were combined.

Predictors of time to requiring dopaminergic treatment in 2 Parkinson's disease cohorts.

The rate of progression of Parkinson's disease (PD) is highly variable. Knowledge of factors associated with disease milestones and commonly used research outcome measures helps with patient counseling and guides the design and interpretation of clinical studies. The objective of the study was to identify prognostic factors for time to acquiring disability requiring dopaminergic therapy that are reproducible within 2 large prospectively followed cohorts.

A longitudinal program for biomarker development in Parkinson's disease: a feasibility study.

Long-term follow up is necessary to understand the natural history of treated Parkinson's disease (PD). The Longitudinal and Biomarker Study in PD (LABS-PD) is an observational study designed to prospectively measure the evolution of motor and non-motor features of PD and sample promising biomarkers from early to late stage illness. LABS-PD is organized on the premise that cohorts from completed clinical trials can be re-recruited for long-term follow up.