Five Newly-Discovered Genes Linked To Alzheimer's Risk

Scientists may be a step closer to unraveling the mysteries of Alzheimer's disease and finding a cure for the dreaded affliction that robs the aging of their memory.

Researchers say they have identified four more genes that may serve as triggers for the onset of the disease. With this information, they say, they may be able to devise a drug, or therapeutic lifestyle, that can prevent more than have the cases.

Four of the new genes are linked to late-onset Alzheimer's disease. Each of these genes adds to the risk of developing this most common form of the disease, and together they offer a portal into the causes of Alzheimer's.

New pathways

"A significant aspect of our research is that these genes clarify three new pathways," said Richard Mayeux, one of the lead scientists in the study and Chairman of the Department of Neurology of Columbia University Medical Center.

The genes are related to the accumulation of amyloid in the brain. These new genes are involved in inflammatory processes, lipid metabolism, and the movement of molecules within cells.

"Therefore, we may now have four pathways that are critically related to the disease and that could really make a difference in how we study and potentially prevent and treat it," ssaid Mayeux.

Intriguing results

The study also revealed other intriguing results.  Dr. Michael Boehnke, a professor at the University of Michigan and an outside advisor to the study, says researchers found that injuries that cause an inflammation of the brain --  such as strokes and head injuries  -- increases the risk of Alzheimer's.

He also says that the study found that some of the newly discovered genes appear to be affected by cholesterol, leading researchers to conclude that people with high levels of cholesterol are more at risk for Alzheimer's disease.

The study is one of the largest of its kind. It was led by the University of Pennsylvania School of Medicine, the University of Miami, Boston University School of Medicine and Columbia University. It analyzed more than 11,000 people with Alzheimer's and a nearly equal number of elderly people with no symptoms of dementia. In all, it studied about 54,000 individuals.

"This is the culmination of years of work on Alzheimer's disease by a large number of scientists, yet it is just the beginning in defining how genes influence memory and intellectual function as we age. We're all tremendously excited by our progress so far, but much remains to be done, both in understanding the genetics and in defining how these genes influence the disease process," said Gerald D. Schellenberg, a University of Pennsylvania researcher.

Objectives

The research had two main objectives. First, identification of new Alzheimer's disease genes will provide major clues as to its underlying cause. Scientists say the knowledge gained from this study will lead to development of more effective drugs.

Second, the gene discovery will help physicians predict who is at greatest risk of developing Alzheimer's disease. This, researchers say, will be important as preventive measures become available. Identification of these risk genes will also help researchers to determine the disease-initiating steps that begin in the brain long before any symptoms of memory loss or intellectual decline are apparent.

Eventually, it is hoped that researchers will be able to describe the events that lead to the destruction of large parts of the brain and, ultimately, complete loss of cognitive abilities.