New genetic mutation tied to Alzheimer's disease

NEW YORK (Reuters Health) - Scientists have found evidence that a mutation in a gene called CALHM1 that results in abnormal calcium signaling influences the risk of Alzheimer's disease, a devastating neurodegenerative disease that affects early 18 million people in the world.

"CALHM1 is an attractive new drug target," Dr. Fabien Campagne from Weill Medical College of Cornell University, New York, told Reuters Health. "The design of drugs that activate CALHM1 could have a beneficial effect in patients who do not have the polymorphism (mutation), as well as in patients who carry the polymorphism."

The CALHM1 mutation is associated with the late-onset form of Alzheimer's disease. This form of the disease affects people age 65 and older and represents about 90 percent of Alzheimer's cases. The rarer early-onset inherited form of the disease affects people from about age 30 to 65.

According to the scientists, the CALHM1 mutation seems to disrupt a previously uncharacterized brain calcium channel and fuels the subsequent accumulation of amyloid beta protein -- an important component of the senile plaques that clog up the brains of patients with Alzheimer's disease.

Campagne and colleagues propose that "variants in the CALHM genes may constitute robust risk factors for late-onset Alzheimer's disease."

SOURCE: Cell, June 27, 2008.