500,000 Americans are afflicted with Parkinson's disease (Cummings, 1999) . It is most common in the elderly population, usually detected in those over 50 years of age (Beyer et. al., 1999) . It seems to be more common in men than in women (McGeer, 1997) . Also, there continues to be controversy about whether the disease is caused by genetic or environmental factors.Genetic Factors
The genetic claim is that there is a mutation on the alpha-synuclein protein which may play a role in the disease. The mutation seems to be on chromosome 4. PD has only been reported to be associated with genetic factors when the onset of the disease is early.
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Exposure to 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP) and its relation to PD have been studied. It has been found that it can cause a syndrome with features similar to those of PD. The idea is that exposure to environmental toxins may be the key player. There is a chemical resemblance of MPTP to pesticides and herbicides. It is suggested that those who live in a rural environment, consume well water, or live in close proximity to industrial plants may be at a greater risk for starting the lethal cascade of PD.
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