African Americans are more likely to develop Alzheimer's disease, according to a study released Tuesday. Researchers discovered a gene mutation known as ABCA7 that may double the risk of Alzheimer's disease in African Americans. Previous studies found genes that were linked to Alzheimer's, but few have focused specifically on the genes related to this most common form of dementia.
Findings of the study were published in the Journal of the American Medical Association. Researchers gathered and combined data from 18 Alzheimer's Disease Centers funded by the U.S. National Institutes of Health (NIH). The data was collected from African American men and women between 1989 and 2011.
For the study, the researchers examined the data of 6,000 African American participants. Late-onset Alzheimer's, the most common form among the elderly, was found in 2,000 of the participants.
The team of researchers looked for the known genes related to Alzheimer's. One strong link is a specific gene that is a well known risk factor for Alzheimer's, called apolipoprotein E or APOE for short. This gene carries the instructions responsible for producing a protein in the body that carries cholesterol.
As in whites, a variant of this gene called APOE-e4 doubles the risk of Alzheimer's disease in African Americans. Another gene that contributes to the production of cholesterol and fats was found, called ABCA7. This specific gene has a stronger effect on African Americans than it does whites and is a major genetic risk factor.
"This is a major finding because it shows that blacks have an additional risk factor compared to whites. It's a highly significant risk that doesn't exist in other populations. In order to find interventions, we need to explore all the various risks," Director of Neuroscience at the National Institute on Aging, a branch of the National Institutes of Health, Neil Buckholtz, said.
In the U.S., one-third of people diagnosed with late-onset Alzheimer's disease are 80 and older. According the NIH, as many as 5 million Americans have Alzheimer's disease and that number may triple by 2050.