In summary, we presented a genomewide linkage scan of AD in an AA population, based on a dense SNP map. We identified one linkage peak empirically established as genomewide-significant, the first such finding in an AA population. This finding, if replicated or otherwise confirmed (by identification of a risk locus that maps within the linkage peak), will provide useful information in the search for genetic loci influencing AD risk specifically in the AA population – either through direct query of the linked region, or by providing a signal that can be used to rank SNPs in a genome wide association analysis, as a way to address the severe multiple testing issues inevitably countered in the course of genome wide association designs (43). Regardless of whether such a risk locus would affect outcome exclusively in AAs or generalizes to other populations, it may be expected to point to mechanisms of action for risk that apply globally.
