Scientists have identified a new gene variant that seems to
strongly raise the risk for Alzheimer's disease, giving a fresh
target for research into treatments for the mind-robbing
disorder. About 35 million people worldwide have dementia, and
Alzheimer's is the most common type. In the U.S., about 5
million have Alzheimer's. Medicines such as Aricept and Namenda
just temporarily ease symptoms. There is no known cure. Until
now, only one gene — ApoE — has been found to have a big impact
on Alzheimer's risk. About 17 percent of the population has at
least one copy of the problem version of this gene but nearly
half of all people with Alzheimer's do. Other genes that have
been tied to the disease raise risk only a little, or cause the
less common type of Alzheimer's that develops earlier in life,
before age 60. The new gene, TREM2, already has been tied to a
couple other forms of dementia. Researchers led by deCODE
Genetics Inc. of Iceland honed in on a version of it they
identified through mapping the entire g