Epidemiological studies have estimated a cumulative prevalence of PD of greater than 1 per thousand. When prevalence is 
 limited to senior populations, this proportion increases nearly 10-fold. The estimated genetic risk ratio for PD is 
 approximately 1.7 (70% increased risk for PD if a sibling has PD) for all ages, and increases over 7-fold for those under 
 age 66 years. The role for genes contributing to the risk of PD is therefore significant.
 This study utilized the well characterized <a href="./study.cgi?id=phs000003">collection of North American Caucasians 
 with Parkinson's disease</a>, and <a href="./study.cgi?id=phs000004">neurologically normal controls</a> from the sample 
 population which are banked in the National Institute of Neurological Disorders and Stroke (NINDS Repository) collection 
 for a first stage whole genome analysis. Genome-wide, single nucleotide polymorphism (SNP) genotyping of these publicly 
 available samples was originally done in 267 Parkinson's disease patients and 270 controls, and this has been extended 
 to include genome wide genotyping in 939 Parkinson's disease cases and 802 controls.
 The NINDS repository was established in 10-2001 towards the goal of developing standardized, broadly useful diagnostic 
 and other clinical data and a collection of DNA and cell line samples to further advances in gene discovery of neurological 
 disorders. All samples, phenotypic, and genotypic data are available to the research community including to academics and 
 industry scientists. In addition, well characterized neurologically normal control subjects are a part of the collection. 
 This collection formed the basis of this first stage study by Fung et al., and the expanded study by Simon-Sanchez et al. 
 The genotyping data was generated and provided by the laboratory of Dr. Andrew Singleton NIA, and Dr. John Hardy 
 NIA (NIH Intramural, funding from NIA and NINDS).
 Important links to apply for individual-level data
 <ol>
 <li><a href="http://dbgap.ncbi.nlm.nih.gov/aa/wga.cgi?view_pdf&#x26;stacc=phs000089.v3.p2">Data Use Certification Requirements (DUC)</a></li>
 <li><a href="http://view.ncbi.nlm.nih.gov/dbgap-controlled">Apply here for controlled access to individual level data</a></li>
 <li><a href="GetPdf.cgi?id=phd000577">Participant Protection Policy FAQ</a></li>
 </ol>

NINDS- Genome-Wide Genotyping in Parkinson's Disease

Parkinson Disease study on dbGaP (1,741 participants)