SNP Spots Late Alzheimer's Risk in African-Americans

TUESDAY, April 9 (HealthDay News) -- A novel variant in the ATP-Binding Cassette Transporter (ABCA7) has been identified, which is associated with late-onset Alzheimer's disease in African-Americans, according to a study published April 10 in the Journal of the American Medical Association.

Christiane Reitz, M.D., Ph.D., from Columbia University in New York City, and colleagues examined genetic loci associated with late-onset Alzheimer's disease in a cohort of 5,896 African-Americans (1,968 case participants and 3,928 controls), aged 60 years or older.

In models adjusted for sex, age, APOE genotype, and population stratification, the researchers identified genome-wide significance for a single nucleotide polymorphism in ABCA7 (rs115550680, allele = G; odds ratio [OR], 1.79), with an effect size similar to that of the APOE ε4-determinining SNP (OR, 2.31). The SNP in ABCA7 was in linkage disequilibrium with SNPs that have been associated with Alzheimer's disease in Europeans. In gene-based analyses accounting for linkage disequilibrium between markers, several loci previously associated with Alzheimer's disease, which did not reach genome-wide significance, were replicated.

"In this meta-analysis of data from African-American participants, Alzheimer's disease was significantly associated with variants in ABCA7 and with other genes that have been associated with Alzheimer's disease in individuals of European ancestry," the authors write.

Several authors disclosed financial ties to the pharmaceutical and biotechnology industries. GlaxoSmithKline partially funded the study.

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