New York, Jul 26 (IANS): Scientists have found that a gene, previously linked only to three-four per cent of people with Parkinson's disease, could play an important role in most people with the neurodegenerative disease.

The gene, called LLRK2, was previously thought to only cause disease when mutated, but researchers have found that it may be just as significant in the non-hereditary form of the disease.

"This discovery is extremely consequential for Parkinson's disease because it suggests that therapies currently being developed for a small group of patients may benefit everybody with the disease," said J. Timothy Greenamyre, Professor at the University of Pittsburgh in Pennsylvania, US.

Parkinson's affects as many as 10 million people worldwide and has no known cause, but is thought to involve both genetic and environmental factors.

In 2004, researchers discovered that mutations in the LRRK2 gene (commonly pronounced as "Lark2"), overactivated the protein and caused Parkinson's in a small group of people, often in a hereditary fashion.

The team engineered a molecular "beacon" that attached to LRRK2 and glowed red under a microscope only if the protein was active.

Tests of postmortem brain tissue, with no mutations in LRRK2, and healthy individuals of approximately the same age, indicated that in "dopamine neurons" -- the brain cells most commonly affected in Parkinson's -- LRRK2 was highly active in individuals affected by the disease, but not in the healthy individuals.

This suggests that LRRK2 overactivity may be important in all people with Parkinson's, not just those who have a mutation in the gene, the researchers said in the paper published in the journal Science Translational Medicine.

"LRRK2 ties together both genetic and environmental causes of Parkinson's, as we were able to show that external factors like oxidative stress or toxins can activate LRRK2, which can in turn cause Lewy bodies to form in the brain," said Roberto Di Maio, Assistant Professor at the varsity.