An international study suggests that a genetic mutation puts
carriers at higher risk for developing Parkinson's disease, a
neurodegenerative disorder that affects an estimated 100,000 people
in Canada alone.
Parkinson's disease occurs when nerve cells degenerate in the part
of the brain that controls muscle movement, causing symptoms that
include tremors in the hands, arms or legs, poor balance and co-
ordination and a stiff walk.

Although it affects more than one per cent of people over age 65,
little is known about its causes.

However, a report in Wednesday's issue of the Journal of the
American Medical Association suggests that people with longer
lengths of a DNA segment that promotes activity of a gene known as
alpha-synuclein had a 1½ times greater risk of developing the
disease.

"This is an important step forward because the contribution of
common genetic risk factors to the development of Parkinson's has
long been suspected, but the high quality of data needed to make
such discoveries has been missing," said Dr. Demetrius Maraganore, a
neurologist at the Mayo Clinic in Rochester, Minn., and the lead
investigator for the study.

Potential therapies to reduce how much alpha-synuclein protein is
produced may help prevent or delay the onset of Parkinson's or halt
or slow its progression, Maraganore said.

Earlier studies had linked rare mutations in the alpha-synuclein
gene to Parkinson's in a few families, but the results were
inconsistent.

In the latest study, researchers from 11 countries analyzed clinical
and genetic data from two groups made up of about the same
proportions of ages and genders: 2,692 patients with Parkinson's
disease and 2,652 healthy people.

The new findings suggest that the alpha-synuclein gene plays a role
in Parkinson's in several populations worldwide.

The researchers estimate the genetic link may explain about three
per cent of the risk for Parkinson's in the general population.

08 Aug 2006 (CBC News)