Environmental and genetic risk factors for Parkinson's disease

Abstract Parkinson's disease is the second most common neurodegenerative disease. Diagnosis is made clinically upon the presence of a number of symptoms. Symptoms include motor disturbances and nonmotor manifestations, which may precede diagnosis by many years. Current treatment options fail to stop disease progression. The cause of the disease remains an enigma, but it is thought to be an interplay of genetic and environmental factors. Many risk factors have been examined for association with Parkinson's disease, and an umbrella review of meta-analyses indicated that physical activity, constipation, smoking, anxiety or depression, beta-blockers, serum uric acid, and traumatic brain injury are associated with risk for Parkinson's disease. Also, genome-wide association studies have identified 44 genetic polymorphisms associated with increased risk for Parkinson's disease. In the present chapter, we discuss recent advances from large-scale research efforts in the field of environmental and genetic epidemiology of Parkinson's disease along with several challenges encountered in epidemiological research for Parkinson's disease.