Parkinson's Disease - Introduction

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• Defective genes that regulate the molecules alpha synuclein and parkin, which are important in the PD disease process, may be responsible for a number of early-onset cases. For example, genetic abnormalities the alpha synuclein protein have been detected in some early-onset Parkinson's patients of European descent.
• The parkin gene may be the cause of many cases of early-onset Parkinson's in young adults. (Parkinson's cases associated with this mutation tend to progress slowly and respond well to treatment, even after years of symptoms. Dementia is also rare with this form.)

Late Onset PD. Two landmark studies published in the Journal of the American Medical Association provided the first evidence of a genetic link to late-onset Parkinson’s disease. In these 2001 studies, researchers found that regions on chromosomes 5, 6, 8, 9, and 17 were implicated with Parkinson’s. The parkin gene (located on chromosome 6) and the tau gene (located on chromosome 17) were both found in families that had late onset Parkinson’s. Parkin was previously thought to be responsible only for early-onset Parkinson’s, but this research identified it in families that had both early- and late-onset disease forms. These studies also bolstered the theory that Parkinson’s does have a genetic component and is not caused solely by environmental factors. A 2005 study found that a G2019S mutation in the LRRK gene, located on the PARK8 region of chromosome 12, was definitively associated with late-onset Parkinson’s disease in North American and European families.

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Environmental Assaults and Oxygen-Free Radicals

Environmental toxins, infections, and other triggers can provoke excessive production in the body of oxygen free-radicals, damaging particles that may play a major role in the deterioration of nerve cells that lead to Parkinson's.

Infectious Organisms. Some research has identified immune factors that suggest a viral presence in the Lewy bodies and swollen nerve pathways of Parkinson's brains. Influenza and other potent viruses have long been known to be a cause of parkinsonism. In one well-known example, a major flu epidemic causing encephalitis in the early twentieth century left many of its victims with parkinsonism.