Study Says Gene in African-Americans Double Alzheimer's Risk

A new gene mutation has been identified that could make African-Americans with it twice as likely to develop Alzheimer's disease in old age as those without it

Researchers identified the same gene variants in older African-Americans that they had found in older people of European ancestry. according to a new study published in the Journal of the American Medical Association, researchers found that African-Americans with Alzheimer's disease were slightly more likely to have one gene, ABCA7, that is thought to confer risk for the disease.

This finding is a result of the largest database search for Alzheimer's genes among 6,000 African-Americans.

"The first thing this tells us is there are probably many different ways to get Alzheimer's,'' says the study's senior author, Richard Mayeux, chair of the department of neurology at Columbia University Medical Center, New York. "It might be like some forms of cancer where the type of cancer you have dictates the type of treatment you receive."

Since the ABCA7 gene is involved with the production of cholesterol in the body, it suggests that Alzheimer's in African-Americans may be more affected by cholesterol levels than whites. It is also associated with the production of amyloid, a protein that makes up most of the plaques found in the brains of those with Alzheimer's.

However, the experts caution that widespread genetic testing for Alzheimer's is still a long way to come. "We are not yet at the point where we can take what we know about Alzheimer's genes and come up with an accurate risk assessment," Mayeux said.

John Hardy, an Alzheimer's researcher at University College London and a discoverer of the first gene mutation found to cause Alzheimer's, said the data confirmed what was already known among those of European descent, "I don't think they tell us much new."