UM Researchers Help Identify New Gene Associated With Alzheimer's Disease in African Americans

Date: Apr-17-2013Researchers at the University of Miami Miller School of Medicine collaborated with an international team to identify a new gene associated with Alzheimer's disease in African Americans. Published April 10 in the prestigious Journal of the American Medical Association, their study, "Variants in the ATP-binding cassette transporter, ABCA7, and the apolipoprotein E ε4 allele substantially and equally influence risk of late-onset Alzheimer's disease in African Americans," provides new directions for biological, genetic and therapeutic studies of Alzheimer's disease.

Margaret A. Pericak-Vance, Ph.D., director of the John P. Hussman Institute for Human Genomics and one of the senior authors, leads the analysis group for the Alzheimer's Disease Genetics Consortium, which is responsible for the paper.

The research is believed to be the largest genome-wide association study conducted on late-onset Alzheimer's disease in African Americans, and includes 1,968 cases and 3,928 controls collected at multiple sites between 1989 and 2011.

"It is critical to identify and assess genetic contributions to Alzheimer's disease in all populations," said Pericak-Vance, who has researched the genetics of Alzheimer's for decades. "Health disparities have had an especially profound effect on the overall health of African Americans in the United States and, although Alzheimer's occurs as frequently in African Americans as other populations, there have been significantly fewer studies that include this population. This research will enable African Americans to take full advantage of the benefits of genomic medicine when it is translated into clinical practice."

Pericak-Vance's 1993 Science paper was the first to identify a form of the apolipoprotein E gene (APOE ε4), a gene involved in lipid metabolism, as a risk variant in Alzheimer's disease. It accounts for more than 40 percent of all cases of Alzheimer's, and remains the largest overall predictor for the disease. The paper continues to be one of the most-cited in all biomedical research.

While the latest paper confirms that APOE ε4 is the strongest risk factor for Alzheimer's in African Americans, it also found that ABCA7, a gene likewise involved in lipid metabolism, is the second highest contributing risk factor in late-onset Alzheimer's disease in African Americans. ABCA7 had previously been found to contribute to Alzheimer's disease risk in non-Hispanic whites, but with a small effect. The paper showed that ABCA7 is associated almost as strongly in African Americans as APOE ε4 is in non-Hispanic whites.

These findings suggest that lipid metabolism is an important pathway of late-onset Alzheimer's disease in African Americans. Understanding the etiology of Alzheimer's disease will have a significant impact on future disease management.

Courtesy: Medical News Today Note: Any medical information available in this news section is not intended as a substitute for informed medical advice and you should not take any action before consulting with a health care professional.