The Pope and Michael J. Fox have it, but you may one day be able to avoid it.
Duke researchers recently discovered genetic risk factors for Parkinson's disease and have finally come one step closer in unraveling this crippling neurodegenerative disease.
The researchers were the first to link specific genetic risk factors to the prevalence of Parkinson's disease in patients--something many experts have speculated about, but never been able to prove.
"Research for Parkinson's disease has been going on for quite a while, but it wasn't until the last five or six years, that the genetic component was added," said Dr. Jeffery Vance, primary investigator of the study, professor of neurology and associate professor of genetics. "Nowadays, genetics is changing in terms of what we can study."
Previous studies had suggested a correlation between genetic defects in mitochondria and the frequency of Parkinson's disease, vaguely pointing to the fact that mitochondria are the energy providers for cells and that patients with Parkinson's disease have trouble with movement-intensive activities such as walking.
"Mitochondria have been implicated in having some involvement in Parkinson's disease for years," Vance said. "For example, it's been well known that when you take a mitochondria from a cell with Parkinson's, and put it into another cell, the functioning problems associated with Parkinson's occur."
Mitochondrial DNA from 609 Parkinson's disease patients and 340 control patients with no indication of Parkinson's, was examined. The study identified genetic variations in mitochondrial DNA within the complex I protein, which is involved in the first step along the energy transfer pathway. The genetic variations the researchers studied also happened to differ according to ethnic groups and sex.
Vance said two variations in particular--labeled the "J" and "K" groups--were under-represented in Parkinson's disease patients and over-represented in the control group. Specifically, a change in the 10,398th base pair in the J variant was discovered to assume a protective effect. This base pair mutation was also observed more frequently in females than males and has been known to be more prevalent in Hispanics and blacks.
Such observations suggest patients with Parkinson's disease should fit the opposite profile of those people with the J variant mutation--male and Caucasian, which in fact is the case.
"It fits the epidemiology of the disease and the known findings of Parkinson's disease well," Vance said.
Currently afflicting millions of people in their 50s and early 60s, such advances in Parkinson's research are particularly significant as baby boomers begin to age. The long-term goal of such genetically-oriented research is to emphasize the prospect of preventing patients who are most susceptible to the disease from getting it in the first place.
"The idea is if you could determine beforehand, what you may be going to get sick from later, physicians could then offer preventive strategies, in order to prevent the disease," Vance said. "The way we're going to get there is through genetics and human genome research."
Other experts, however, took a less optimistic outlook.
"I don't have a crystal ball. People many years ago said that they would have a cure for Parkinson's in five years," said Paul Maestrone, director of scientific and medical affairs at the American Parkinson's Disease Association. "Five years later, those same people said it would take five more years. Right now, I'm afraid it'll take much more than that."
Researchers still have yet to understand what the mitochondrial mutation does and why it helps prevent Parkinson's disease, Vance cautioned. "You're working on things today for the successes of tomorrow. And sometimes tomorrow can be a long way away," he said.
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