Print

Print


Registry Could Nail Causes Of Parkinson's
Helen Pearson

Published online: 05 November 2004

Californian database may help track down roots of brain disease.

An immense database of Parkinson's disease patients is being launched
in California. Medical researchers say the database will be essential
for tracking down the causes of the disease.

Once established, the state-wide registry will be the biggest for the
disease in the world. It gained formal approval in late September
when Governor Arnold Schwarzenegger signed a bill requiring doctors
to register every new patient diagnosed with the movement disorder in
a central database.

Researchers say the new registry will be crucial for pinning down
which environmental factors, such as pesticides or diet, are
important in triggering the disease. This has become a priority with
the growing realisation that genes alone cannot explain people's
risk.

Nailing the culprits

Parkinson's is caused when dopamine-producing cells in the brain die
or are damaged, causing symptoms such as tremors, stiff or slow
movement and problems with balance.

Although the disease is thought to affect as many as 2% of people,
researchers have struggled to build up an accurate picture of the
types of people it strikes. Unlike cancer, for example, the disease
is rarely recorded as a cause of death because patients succumb to
other conditions.

Genes alone are thought to explain only a tiny fraction of cases. At
the same time, numerous studies have suggested that there may be a
wide range of environmental triggers, from polluting metals and
solvents to diet and head trauma, but no clear-cut cause has been
found. "We have a lot of hints but no smoking gun," says William
Langston, director of the Parkinson's Institute in Sunnyvale,
California, who joined other neurologists and patient advocacy groups
in campaigning for the registry.

Researchers now believe that people with the right combination of
genes and environmental triggers develop the disease. For example,
pesticides may have a greater impact on the brain cells of people
genetically susceptible to their effects. If at-risk groups can be
identified, individuals might be able to change their lifestyle to
ward off the disease.

Armed with the new database, researchers will be able to identify
patients they are keen to study and approach them for further
information about their medical history and exposure to environmental
triggers. They are particularly keen to test the idea that the
disease is brought on by contact with pesticides or other toxic
chemicals. California has been logging the use of these chemicals for
the past 25 years.

Strength in diversity

At present, scientists tend to collect and study groups of
Parkinson's patients within a certain region or clinic. But these
groups are often small and do not accurately represent the full range
of patients in the wider population.

Some efforts have been made to build up larger studies. Nebraska
already runs a registry, for example, and information on Parkinson's
patients is also collected nationally in Denmark.

But the 35-million population of California means that the new
registry could enrol as many as 5000 patients each year, and the
state's diversity means it will span a range of socio-economic groups
and ethnicities, as well as rural and urban areas.

"This could be the final step towards finding the environmental
triggers for the disease," says Langston.

A two-year pilot project, funded by $0.5 million from the US National
Institute of Environmental Health Sciences and the Michael J. Fox
Foundation for Parkinson's Research, will determine how best to
create and run the registry. After this, it is unclear how the
registry will pay its way, although the organisers say they are
confident they will secure financing.

"It has the potential to be a powerful tool," says epidemiologist
Carl Counsell, who studies Parkinson's disease at the University of
Aberdeen, UK. But he warns that the new registry may still miss some
patients, because many go undiagnosed.

SOURCE: Nature.com, UK
http://tinyurl.com/67634

* * *

----------------------------------------------------------------------
To sign-off Parkinsn send a message to: mailto:[log in to unmask]
In the body of the message put: signoff parkinsn