The cause of Parkinson's disease is unknown, but a few factors seem to act as a role. These factors include. 1) Genes. Researchers have identified specific genetic mutations that can cause Parkinson's disease, but these are uncommon except in rare cases with many family members affected by Parkinson's disease. However, certain gene variations appear to increase the risk of Parkinson's disease but with a relatively small risk of Parkinson's disease for each of these genetic markers. 2) Environment. Exposure to certain toxins or environmental factors may increase the risk of later Parkinson's disease, but the risk is relatively small. 3) The presence of Lewy bodies. Clumps of specific substances within brain cells are microscopic markers of Parkinson's disease.

These are called Lewy bodies, and researchers believe these Lewy bodies hold an important clue to the cause of Parkinson's disease. 4) A-synuclein is found within Lewy bodies. Although many substances are found within Lewy bodies, scientists believe the most important of these is the natural and widespread protein called alpha-synuclein. It's found in all Lewy bodies in a clumped form that cells can't break down.