Researchers at the Mayo Clinic in Florida participated in a nationwide study that found minor differences between genes that contribute to late-onset Alzheimer's disease in African-Americans and in Caucasians. The study, published in an open-access article in the April 10 issue The Journal of the American Medical Association (JAMA), was the first to look at the genetics of a large number of African-Americans diagnosed with this common form of Alzheimer's disease (1,968 patients) compared to 3,928 normal elderly African-American control participants. The Alzheimer's Disease Genetics Consortium conducted the study, which included Mayo Clinic in Florida investigators Neill R. Graff-Radford, M.D., and Nilufer Ertekin-Taner, M.D., Ph.D. They provided genetic samples and data from their Alzheimer's disease databank. The study found that the most common risk factor in these African-American patients was the APOE gene, which is also true for Caucasians with the disorder. In addition, another gene, ABCA7, which was discovered to be a risk locus for Caucasians, was also a significant risk factor in African-American patients. The study concluded that association with variants at the ABCA7 gene increased the risk for late-onset Alzheimer's disease approximately 1.8-fold in these African-American patients compared to 1.1-fold to 1.2-fold in individuals of European ancestry, although the biologic implications of this difference remains to be established. Still, these differences may not fully explain the genetic basis for development of Alzheimer's disease, the researchers say. The disorder is believed to arise from a number of different genes along with environmental influences.Login Or Register To Read Full Story