UCLA Parkinson’s Disease Environment and Genes Study (PEG)
The ultimate goal of our study is to enroll at least 400 rural
newly diagnosed cases of Parkinson’s disease (PD), 400 population-based
controls, and 200-300 sibling controls over a period of 4 years
(between 2001-2005). We started screening and enrollment of patients
in April 2001. Since then, recruitment letters were mailed to
approximately 3000 individual patients and 3000 population controls.
We screened 800 patients who contacted us and 240 were eligible
meaning that they were incident cases and we were able to examine
them within 3 years after diagnosis. To date, we collected data
from 220 patients. We also collected data from 120 eligible age-gender
matched population controls randomly sampled from the residents
in the three counties and from 70 sibling controls.
Samples and data we are collecting
We are successful in collecting blood for genotyping and in a
smaller subgroup of patients we are, in addition, collecting platelets
for assessment of mitochondrial Co-enzyme I function.
PD patients and controls undergo a neurologic evaluation by one
of our UCLA study neurologists. Risk factor interviews are mostly
conducted by phone to allow blinding of the interviewer to case
Environmental and occupational exposure measures for each study
subject are created from interview data providing us with residential
and occupational histories and behavioral risk factor profiles
in conjunction with California data on historical land-use and
Our recruitment of study subjects will continue for 2 more years
until the end of 2005 and we will continue to attempt to ascertain
all newly diagnosed PD patients in Kern, Fresno and Tulare counties.
Ritz B, Yu F. Parkinson's disease mortality and pesticide exposure
in California 1984-1994. Int J Epidemiol. 2000 Apr;29(2):323-9.
Rull R., Ritz B. Historical Pesticide Exposure Using Pesticide-Use
and Land-Use Survey Data: An Assessment of Misclassification Error
and Bias. Environ Health Perspect. 2003 Oct;111(13):1582-9.
Kang G.A., Bronstein J.M., Masterman D.L., Redelings M., Crum
J.A., Ritz B. Clinical Characteristics in Early Parkinson's
Disease in a Central Californian Population-based Study. Neurology.
Submitted for review 2004