Environmental Factors in Parkinson's Disease

A Twin Study of Environmental Factors in Parkinson's Disease

The primary purpose is to assess the importance of environmental factors for Parkinson's Disease (PD) in a population-based sample of Swedish twins.

Project description

In PD discordant twin pairs, what are the environmental factors that contribute to the disease in the affected twin and or protect the unaffected twin? Second, we want to investigate whether the earlier reports of low heritability for elderly male twins can be confirmed for female pairs.

All twins 55 years of age and older in the Swedish Twin Registry have been screened for most complex diseases. 626 twins have screened positive for PD and most pairs are discordant. To establish diagnosis, a physician will examine all potential cases and their co-twins and their medical records will be reviewed. Environmental factors will be studied through the use of discordant pairs, where genetic susceptibility to the disease can be controlled.

Environmental exposures are being secured with telephone interviews and from a questionnaire collected 30 years ago. Recent results indicate that genetic factors play a very small role. A better understanding of the etiology of PD is important for the possibility of delaying onset or even preventing the disease, as well as for providing guidance for molecular biology studies.

Project leader

Professor

Nancy Pedersen

Phone: +46-(0)8-524 874 18
Organizational unit: Department of Medical Epidemiology and Biostatistics (MEB), C8
E-mail: Nancy.Pedersen@ki.se

Financing: NIH (NIEHS)

Partners

Margaret Gatz, University of Southern California, Los Angeles, USA

Karin Wirdefeldt, PhD

References

No evidence for heritability of Parkinson disease in Swedish twins.
Wirdefeldt K, Gatz M, Schalling M, Pedersen N
Neurology 2004 Jul;63(2):305-11
Risk and protective factors for Parkinson's disease: a study in Swedish twins.
Wirdefeldt K, Gatz M, Pawitan Y, Pedersen N
Ann. Neurol. 2005 Jan;57(1):27-33
Risk and protective factors for Parkinson's disease: a study in Swedish twins.
Wirdefeldt K, Gatz M, Pawitan Y, Pedersen N
Ann. Neurol. 2005 Jan;57(1):27-33
No evidence for heritability of Parkinson disease in Swedish twins.
Wirdefeldt K, Gatz M, Schalling M, Pedersen N
Neurology 2004 Jul;63(2):305-11

Neurodegenerative diseasesTwin research