A mutation found in about one in 200 elderly Icelanders raised
the risk of developing Alzheimer's disease threefold, a new
study found. The mutation, in an immunoregulatory gene known as
TREM2, was more common in Alzheimer's disease patients than in
the general 85-and-older population in Iceland, according to Dr.
Kari Stefansson of deCode Genetics in Reykjavik, Iceland, and
colleagues. Because of the gene's function within the central
nervous system, the mutation "may lead to an increased
predisposition to Alzheimer's disease through impaired
containment of inflammatory processes," the researchers wrote
online in the New England Journal of Medicine. Read this story
on www.medpagetoday.com. Such processes have been implicated in
Alzheimer's disease previously, they noted. In fact, the so-
called amyloid theory of the disease holds that brain
inflammation is the "downstream effect" of the accumulation of
beta-amyloid protein plaques, Stefansson and colleagues wrote.
On the other hand, the TREM2 mutation's rarity