A leading geneticist said current research is laying the groundwork for the reliable prediction of Alzheimer's disease, and predicted that new ways of dealing with Alzheimer's may be as little as five years away.

Rudolph E. Tanzi, who directs genetics and aging research at the Massachusetts General Hospital, said the number of people diagnosed with Alzheimer's in the United States would grow from the current four to six million to more than 14 million people by 2040.

However, Tanzi told the American Association for the Advancement of Science (AAAS) annual meeting in Denver that current research lays the groundwork to identify genes that will allow for the reliable prediction of the disease and provide new clues about the biological causes of disease so that it may one day be prevented.

Currently, Alzheimer's is diagnosed after eliminating other possible causes for symptoms such as short-term memory loss. However, an autopsy provides the only sure diagnosis of the condition.

Tanzi said genetic findings indicate that inheritance and genetics plays at least some role in virtually every case of Alzheimer's. He and other researchers have already identified four different genes that play a role in Alzheimer's disease.

Three of these genes have been shown to cause the disease known as early-onset Alzheimer's, which accounts for 5 to 10 percent of all cases. The fourth gene, involved in cholesterol metabolism, places people at risk, but does not directly cause Alzheimer's.

Tanzi said the treatment of Alzheimer's could begin to change as early as five years from now, given a strong link between high cholesterol and risk and recent research regarding preventive factors such as vitamin E to combat antioxidants and folic acid to lower the amount of the amino acid homocysteine in the blood.

Other sources: American Association for the Advancement of Science