Not Just A Family Affair

PARKINSON'S DISEASE

As baby boomers age, the number of those worried about getting
Parkinson's If Disease (PD)--with its shuffling gait, frozen facial
features and risk of depression--is on the rise. But people concerned
about their own welfare because an older family member had PD can likely
lay their fears to rest.

New research indicates that genes are not the determining factor in
typical PD--the type that hits after age 50. The study, launched from The
Parkinson's Institute in Sunnyvale, California, reviewed the medical
records of more than 15,000 World War II veterans, of which 193 were
twins.

"When we compared fraternal and genetic twins over the age of 50,"
says Caroline Tanner, M.D., Ph.D., who led the study, "we found both just
as likely to develop the disease. There was no way we could stand the
data on its head to reveal any hint of a genetic basis for the disease in
the older group."

The opposite was true for men younger than 50, Tanner observes.
Though fewer men in this group got PD--it's uncommon before middle
age--identical twins were more likely to both have the disease than were
fraternal twins. This points to a genetic factor in those who get the
disease before age 50, says Tanner.

Still, "even with the younger men," Tanner notes, "you need to
remember not every case of PD is automatically inherited." She expects
that further research will help identify more precisely the non-genetic
causes of the disease.