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Abnormal gene implicated in Parkinson's

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TBO.com
The Suncoast News
Published: July 11, 2012

An international team based in Canada that included Florida researchers has reported the discovery of an abnormal gene that leads to the onset of Parkinson's disease.

The report, presented last month at the 16th International Congress of Parkinson's Disease and Movement Disorders, in Dublin, Ireland, was the result of nearly three decades of studies involving Mennonite families in Canada.

The discovery will help shed light on Parkinson's disease and related neurological disorders, and lead to earlier diagnosis and treatment.

The study was led by Matthew Farrer, a professor of medical genetics at the University of British Columbia. Farrer specializes in the study of the genetic basis of Parkinson's and other brain disorders.

Farrer gave the keynote address at the Parkinson's disease conference in Ireland.

Ali Rajput and his son Alex, both neurologists at the University of Saskatchewan, took part in the study. The Rajputs have amassed a collection of more than 500 brains and 2,200 blood samples from people with Parkinson's. In addition, Ali Rajput has been working with the main Mennonite family involved in the study since 1983.

The other members of the research team came from the Mayo Clinic in Florida in Jacksonville; McGill University in Montreal; and St. Olav's Hospital in Trondheim, Norway.

The researchers say they have identified a mutated form of a gene known as DNAJC13 as the culprit in Parkinson's disease. They discovered the genetic abnormality while sifting through a huge volume of genetic samples from Parkinson's patients and healthy subjects using a technique called massively parallel DNA sequencing.

"This discovery paves the way for further research to determine the nature of brain abnormalities which this gene defect produces," Ali Rajput said.

"It also promises to help us find ways to detect Parkinson's disease early and to develop drugs which will one day halt the progression of the disease."

Thirteen of 57 members of the extended Saskatchewan family in the study had been previously diagnosed with Parkinson's disease. Three other single cases from Saskatchewan and one family from British Columbia were found to have the same mutation. All were of Mennonite Christian background and of Dutch-German-Russian ancestry.

In Parkinson's disease, cells in the mid-region of the brain known as the substantia nigra die off. The substantia nigra is known to play a role in the regulation of movement.

People with Parkinson's disease experience progressively worsening symptoms such as tremors, slowness of movement, stiffness and mental impairment. About 4 million people around the world, including 1 million in North America, have Parkinson's, according to the U.S. National Institutes of Health.

This makes Parkinson's disease the second most common chronic neurodegenerative disorder, behind only Alzheimer's disease.