Parkinson's Diseases Susceptibility Genes and Pesticides

The recruitment status of this study is unknown because the information has not been verified recently.
Verified September 2002 by National Institute of Environmental Health Sciences (NIEHS).
Recruitment status was  Recruiting
Sponsor:
Information provided by:
National Institute of Environmental Health Sciences (NIEHS)
ClinicalTrials.gov Identifier:
NCT00044590
First received: September 3, 2002
Last updated: June 23, 2005
Last verified: September 2002
  Purpose

Parkinson's disease (PD) occurrence is higher in rural than in urban populations of industrialized countries. Epidemiologic and human tissue studies suggest that pesticides may be responsible for causing dopaminergic cell death at increased rates. While many pathophysiologic pathways may be involved in the neurodegeneration responsible for PD, genetic factors are likely to determine a general susceptibility to neurodegeneration.


Condition
Parkinson's Disease

Study Type: Observational
Study Design: Observational Model: Case Control
Time Perspective: Cross-Sectional

Resource links provided by NLM:


Further study details as provided by National Institute of Environmental Health Sciences (NIEHS):

Estimated Enrollment: 1200
Study Start Date: September 2000
Estimated Study Completion Date: September 2005
Detailed Description:

While many pathophysiologic pathways may be involved in the neurodegeneration responsible for PD, genetic factors are likely to determine a general susceptibility to neurodegeneration. There are a number of genetic polymorphisms of genes such as those coding for the cytochrome p450 super-family of genes referred to as 'susceptibility genes'. However, they are generally not sufficient to cause disease unless a person encounters exposure to an environmental toxin: the disease is caused by a gene-environment interaction. Thus, it is imperative to assess genetic susceptibility in individuals exposed to a toxin. We will test the gene-environment interaction hypothesis by conducting an epidemiologic population-based case-control study of newly diagnosed PD patients from three rural California counties: Kern, Fresno, and Tulare. Over a four year period, we expect to collect 400 cases referred to us by local neurologists, farm worker clinics, and Parkinson's foundations. For each case, one population control will be selected at random from residential parcel maps and Medicare databases and, in addition, one unaffected sibling control and - when possible - affected siblings to avoid potential biases and inefficiencies inherent in the use of each type of control. For each study subject, an environmental and occupational pesticide exposure estimate will be derived using California pesticide-use reporting (PUR) data and information about pesticide application on crops in combination with crop patterns shown in satellite images and aerial photographs; in addition, extensive exposure interviews will be conducted with all study subjects. In a three-tiered approach to examine the effects of gene-environment interactions we will: 1) test for association (and linkage) of PD to selected loci associated with PD in earlier studies using multiallelic repeat markers and genotyping; 2) test for association using intragenic single nucleotide polymorphisms (SNPs) of 50 candidate genes arrayed to create "the PD array"; and 3) use future technical possibilities to screen for genome wide associations using array technology to scan 5,000-10,000 SNPs throughout the genome. Data analysis will employ hierarchical modeling procedures to take into account multiple comparison issues and to incorporate prior knowledge such as increased neurotoxicity due to the interaction of gene products and chemicals.

  Eligibility

Ages Eligible for Study:   18 Years and older
Genders Eligible for Study:   Both
Accepts Healthy Volunteers:   Yes
Criteria

Newly diagnosed patients with idiopathic PD (first PD diagnosis after January 1998 who are currently living in one of the three target counties (Kern, Tulare, Fresno) and have lived in California for at least 5 years are eligible for participation. For each patient, one or more unaffected sibling controls and one population control will be recruited. The population control are being selected randomly from Medicare records (95% of all controls) and residential parcel listings (for those patients younger than 65 years of age only; the same inclusion criteria will be applied as to the cases. The controls are being marginally matched to cases according to 5-year age categories (e.g. 50-54, 55-59, 60-64, etc.), race (white, African-American, Asian, Hispanic, other), and sex.

All study cases by definition will be patients who elicited care from health care providers.

We are aiming to enroll every newly diagnosed PD patient into our study and expect patient population participating in our study that is as diverse as the rural population.

  Contacts and Locations
Choosing to participate in a study is an important personal decision. Talk with your doctor and family members or friends about deciding to join a study. To learn more about this study, you or your doctor may contact the study research staff using the Contacts provided below. For general information, see Learn About Clinical Studies.

Please refer to this study by its ClinicalTrials.gov identifier: NCT00044590

Locations
United States, California
Beate Ritz, UCLA Department of Epidemiology Recruiting
Los Angeles, California, United States, 90095-1772
Contact: Beate R Ritz, MD, Ph.D.    310-206-7458    britz@ucla.edu   
Principal Investigator: Beate R Ritz, M.D., Ph.D.         
Sponsors and Collaborators
  More Information

No publications provided

ClinicalTrials.gov Identifier: NCT00044590     History of Changes
Other Study ID Numbers: 10544-CP-001
Study First Received: September 3, 2002
Last Updated: June 23, 2005
Health Authority: United States: Federal Government

Keywords provided by National Institute of Environmental Health Sciences (NIEHS):
Parkinson's disease
Pesticides
Genetic susceptibility
Polymorphisms

Additional relevant MeSH terms:
Disease Susceptibility
Parkinson Disease
Disease Attributes
Pathologic Processes
Parkinsonian Disorders
Basal Ganglia Diseases
Brain Diseases
Central Nervous System Diseases
Nervous System Diseases
Movement Disorders
Neurodegenerative Diseases

ClinicalTrials.gov processed this record on August 28, 2014