Parkinson’s disease exposome-wide association study in Egyptians

Project Title: Parkinson’s disease exposome-wide association study in Egyptians

Funding: Bartlett Fund for Critical Challenges; The American University in Cairo

Principal Investigator(s): Mohamed Salama (AUC; Egypt)

Co-PIs: Mie Rizig (UCL; UK)/ Noah Scovronick (Emory, USA)/ Donghai Liang (Emory USA)/ Hassan El-Fawal (AUC; Egypt)

Study Rationale: 

The causes of Parkinson’s Disease (PD) are not fully known, but it likely results from a complex interaction between genetic and environmental factors. Possible environmental contributors include air and water pollution and chemicals found in pesticides. One challenge in understanding the causes of PD is that it often occurs late in life, meaning that the people who get it have been exposed to many types of environmental factors; it is therefore difficult to know which factors – or combinations of factors – contributed to the disease. Fortunately, new scientific methods allow us to identify many of the environmental risks that people have been exposed to throughout their lives. These new methods can help us figure out what causes PD in different populations.


We believe that PD develops in response to a cluster of interacting genetic and environmental factors. These factors may differ according to geography, population and lifestyle factors. In Egypt, putative environmental risk factors may include exposure to air pollution, chemicals in pesticides and/or contaminants in drinking water.

 Study Design:

We will use several existing, high-quality datasets to conduct new investigations into the effects on PD development of multiple environmental exposures individually, and jointly. Data sources include: (1) questionnaire data that provides information on occupational and lifestyle factors, (2) an air quality model that can reconstruct historical exposure to air pollution, (3) data from hair samples and silicone wristbands that collect data on exposure to persistent chemicals, and (4) blood samples that include genetic and metabolic data. We will investigate which of these factors – alone or together – may lead to PD.

Impact on Diagnosis/Treatment of Parkinson’s disease:         

We expect that our findings will help provide future targets for therapeutic intervention and also inform the design of environmental policies capable of reducing people’s exposure to dangerous pollutants.

 Next Steps for Development:

 Our findings should be validated in future studies using cohorts from other locations and with more patients. Our methods and models can also be expanded to include other potentially relevant environmental risk factors and can be modified to assess other PD-related outcomes such as hospitalizations.