African-Americans with a certain gene variant have nearly double the risk of developing late-onset Alzheimer's disease than those without it, a new study out Tuesday found.

But the gene doesn't seem to be affiliated with higher incidence of Alzheimer's among white populations, the scientists said in the report in the Journal of the American Medical Association.

"These findings suggest that the genetic underpinnings of Alzheimer's disease may vary among different populations -- and so should not be treated homogeneously," said first author Christiane Reitz of Columbia University Medical Center.

African-Americans have much higher rates of late-onset Alzheimer's -- by far the most common form of the disease -- than whites. But "until now, data on the genetics of Alzheimer's in this patient population have been extremely limited," said senior author Richard Mayeux, also of Columbia.

The new study analyzed genetic data from nearly 6,000 African-American participants, the largest genome-wide search for Alzheimer's genes among the population group.

The study helped scientists confirm that the ABCA7 gene variant is linked to a higher incidence of late-onset Alzheimer's among African Americans. The gene is involved in the production of cholesterol and lipids.

Imbalances in these two molecules can lead to vascular disease and strokes -- and, thanks to this new research, may be related to the development of dementia.

This suggests that treatments that fight high cholesterol and vascular disease may also prove effective at warding off Alzheimer's disease among African-Americans.

The research also confirmed that a second gene variant, long known to be a risk factor for Alzheimer's among whites, is also affiliated with higher risk among African-Americans.

"Both genes raise the risk of Alzheimer's in this population twofold," said Reitz, who noted that previous results from smaller studies had been inconsistent.

Read more:
New gene linked with double Alzheimer's risk for blacks

Comments are closed.